feat: move delete provider button to header area (#412)

- Button now shows 'Test' by default instead of persisting 'Verified' state
- Verified status is still shown via green badge in provider header
- Updated OpenAI suggested models list with latest GPT-5.x series

.github/workflows/ci.yml

@@ -0,0 +1,44 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+jobs:
+  ci:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+          cache: 'npm'
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Type check
+        run: npx tsc --noEmit
+
+      - name: Lint check
+        run: npm run check
+
+      - name: Build
+        run: npm run build
+
+      - name: Security audit
+        run: npm audit --audit-level=high --omit=dev

.github/workflows/docker-build.yml

@@ -63,6 +63,8 @@ jobs:
           cache-from: type=gha
           cache-to: type=gha,mode=max
           platforms: linux/amd64,linux/arm64
+          build-args: |
+            NEXT_PUBLIC_SHOW_ABOUT_AND_NOTICE=true
 
       # Push to AWS ECR for App Runner auto-deploy
       - name: Configure AWS credentials

.github/workflows/electron-release.yml

@@ -0,0 +1,46 @@
+name: Electron Release
+
+on:
+  push:
+    tags:
+      - "v*"
+  workflow_dispatch:
+    inputs:
+      version:
+        description: "Version tag (e.g., v0.4.5)"
+        required: false
+
+jobs:
+  build:
+    permissions:
+      contents: write
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - os: macos-latest
+            platform: mac
+          - os: windows-latest
+            platform: win
+          - os: ubuntu-latest
+            platform: linux
+
+    runs-on: ${{ matrix.os }}
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: "npm"
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Build and publish Electron app
+        run: npm run dist:${{ matrix.platform }}
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.gitignore

@@ -50,3 +50,16 @@ push-via-ec2.sh
 .wrangler/
 .env*.local
 
+# Electron
+/dist-electron/
+/release/
+/electron-standalone/
+*.dmg
+*.exe
+*.AppImage
+*.deb
+*.rpm
+*.snap
+
+CLAUDE.md
+.spec-workflow

Dockerfile

@@ -26,6 +26,10 @@ ENV NEXT_TELEMETRY_DISABLED=1
 ARG NEXT_PUBLIC_DRAWIO_BASE_URL=https://embed.diagrams.net
 ENV NEXT_PUBLIC_DRAWIO_BASE_URL=${NEXT_PUBLIC_DRAWIO_BASE_URL}
 
+# Build-time argument to show About link and Notice icon
+ARG NEXT_PUBLIC_SHOW_ABOUT_AND_NOTICE=false
+ENV NEXT_PUBLIC_SHOW_ABOUT_AND_NOTICE=${NEXT_PUBLIC_SHOW_ABOUT_AND_NOTICE}
+
 # Build Next.js application (standalone mode)
 RUN npm run build
 

README.md

@@ -33,6 +33,7 @@ https://github.com/user-attachments/assets/9d60a3e8-4a1c-4b5e-acbb-26af2d3eabd1
   - [MCP Server (Preview)](#mcp-server-preview)
   - [Getting Started](#getting-started)
     - [Try it Online](#try-it-online)
+    - [Desktop Application](#desktop-application)
     - [Run with Docker (Recommended)](#run-with-docker-recommended)
     - [Installation](#installation)
   - [Deployment](#deployment)
@@ -135,6 +136,28 @@ No installation needed! Try the app directly on our demo site:
 
 > **Bring Your Own API Key**: You can use your own API key to bypass usage limits on the demo site. Click the Settings icon in the chat panel to configure your provider and API key. Your key is stored locally in your browser and is never stored on the server.
 
+### Desktop Application
+
+Download the native desktop app for your platform from the [Releases page](https://github.com/DayuanJiang/next-ai-draw-io/releases):
+
+| Platform | Download |
+|----------|----------|
+| macOS | `.dmg` (Intel & Apple Silicon) |
+| Windows | `.exe` installer (x64 & ARM64) |
+| Linux | `.AppImage` or `.deb` (x64 & ARM64) |
+
+**Features:**
+- **Secure API key storage**: Credentials encrypted using OS keychain
+- **Configuration presets**: Save and switch between AI providers via menu
+- **Native file dialogs**: Open/save `.drawio` files directly
+- **Offline capable**: Works without internet after first launch
+
+**Quick Setup:**
+1. Download and install for your platform
+2. Open the app → **Menu → Configuration → Manage Presets**
+3. Add your AI provider credentials
+4. Start creating diagrams!
+
 ### Run with Docker (Recommended)
 
 If you just want to run it locally, the best way is to use Docker.

app/[lang]/about/cn/page.tsx

@@ -117,9 +117,9 @@ export default function AboutCN() {
                                     (TPS/TPM)。一旦超限，系统就会暂停，导致请求失败。
                                 </p>
                                 <p>
-                                    由于使用量过高，我已将模型从 Claude 更换为{" "}
+                                    由于使用量过高，我已将模型从 Opus 4.5 更换为{" "}
                                     <span className="font-semibold text-amber-700">
-                                        minimax-m2
+                                        Haiku 4.5
                                     </span>
                                     ，以降低成本。
                                 </p>

app/[lang]/about/ja/page.tsx

@@ -126,9 +126,9 @@ export default function AboutJA() {
                                 </p>
                                 <p>
                                     利用量の増加に伴い、コスト削減のためモデルを
-                                    Claude から{" "}
+                                    Opus 4.5 から{" "}
                                     <span className="font-semibold text-amber-700">
-                                        minimax-m2
+                                        Haiku 4.5
                                     </span>{" "}
                                     に変更しました。
                                 </p>

app/[lang]/about/page.tsx

@@ -129,9 +129,9 @@ export default function About() {
                                 </p>
                                 <p>
                                     Due to the high usage, I have changed the
-                                    model from Claude to{" "}
+                                    model from Opus 4.5 to{" "}
                                     <span className="font-semibold text-amber-700">
-                                        minimax-m2
+                                        Haiku 4.5
                                     </span>
                                     , which is more cost-effective.
                                 </p>

app/api/chat/route.ts

@@ -14,6 +14,11 @@ import path from "path"
 import { z } from "zod"
 import { getAIModel, supportsPromptCaching } from "@/lib/ai-providers"
 import { findCachedResponse } from "@/lib/cached-responses"
+import {
+    checkAndIncrementRequest,
+    isQuotaEnabled,
+    recordTokenUsage,
+} from "@/lib/dynamo-quota-manager"
 import {
     getTelemetryConfig,
     setTraceInput,
@@ -21,6 +26,7 @@ import {
     wrapWithObserve,
 } from "@/lib/langfuse"
 import { getSystemPrompt } from "@/lib/system-prompts"
+import { getUserIdFromRequest } from "@/lib/user-id"
 
 export const maxDuration = 120
 
@@ -162,9 +168,8 @@ async function handleChatRequest(req: Request): Promise<Response> {
 
     const { messages, xml, previousXml, sessionId } = await req.json()
 
-    // Get user IP for Langfuse tracking
-    const forwardedFor = req.headers.get("x-forwarded-for")
-    const userId = forwardedFor?.split(",")[0]?.trim() || "anonymous"
+    // Get user ID for Langfuse tracking and quota
+    const userId = getUserIdFromRequest(req)
 
     // Validate sessionId for Langfuse (must be string, max 200 chars)
     const validSessionId =
@@ -173,9 +178,12 @@ async function handleChatRequest(req: Request): Promise<Response> {
             : undefined
 
     // Extract user input text for Langfuse trace
-    const lastMessage = messages[messages.length - 1]
+    // Find the last USER message, not just the last message (which could be assistant in multi-step tool flows)
+    const lastUserMessage = [...messages]
+        .reverse()
+        .find((m: any) => m.role === "user")
     const userInputText =
-        lastMessage?.parts?.find((p: any) => p.type === "text")?.text || ""
+        lastUserMessage?.parts?.find((p: any) => p.type === "text")?.text || ""
 
     // Update Langfuse trace with input, session, and user
     setTraceInput({
@@ -184,6 +192,33 @@ async function handleChatRequest(req: Request): Promise<Response> {
         userId: userId,
     })
 
+    // === SERVER-SIDE QUOTA CHECK START ===
+    // Quota is opt-in: only enabled when DYNAMODB_QUOTA_TABLE env var is set
+    const hasOwnApiKey = !!(
+        req.headers.get("x-ai-provider") && req.headers.get("x-ai-api-key")
+    )
+
+    // Skip quota check if: quota disabled, user has own API key, or is anonymous
+    if (isQuotaEnabled() && !hasOwnApiKey && userId !== "anonymous") {
+        const quotaCheck = await checkAndIncrementRequest(userId, {
+            requests: Number(process.env.DAILY_REQUEST_LIMIT) || 10,
+            tokens: Number(process.env.DAILY_TOKEN_LIMIT) || 200000,
+            tpm: Number(process.env.TPM_LIMIT) || 20000,
+        })
+        if (!quotaCheck.allowed) {
+            return Response.json(
+                {
+                    error: quotaCheck.error,
+                    type: quotaCheck.type,
+                    used: quotaCheck.used,
+                    limit: quotaCheck.limit,
+                },
+                { status: 429 },
+            )
+        }
+    }
+    // === SERVER-SIDE QUOTA CHECK END ===
+
     // === FILE VALIDATION START ===
     const fileValidation = validateFileParts(messages)
     if (!fileValidation.valid) {
@@ -214,6 +249,11 @@ async function handleChatRequest(req: Request): Promise<Response> {
         baseUrl: req.headers.get("x-ai-base-url"),
         apiKey: req.headers.get("x-ai-api-key"),
         modelId: req.headers.get("x-ai-model"),
+        // AWS Bedrock credentials
+        awsAccessKeyId: req.headers.get("x-aws-access-key-id"),
+        awsSecretAccessKey: req.headers.get("x-aws-secret-access-key"),
+        awsRegion: req.headers.get("x-aws-region"),
+        awsSessionToken: req.headers.get("x-aws-session-token"),
     }
 
     // Read minimal style preference from header
@@ -232,9 +272,10 @@ async function handleChatRequest(req: Request): Promise<Response> {
     // Get the appropriate system prompt based on model (extended for Opus/Haiku 4.5)
     const systemMessage = getSystemPrompt(modelId, minimalStyle)
 
-    // Extract file parts (images) from the last message
+    // Extract file parts (images) from the last user message
     const fileParts =
-        lastMessage.parts?.filter((part: any) => part.type === "file") || []
+        lastUserMessage?.parts?.filter((part: any) => part.type === "file") ||
+        []
 
     // User input only - XML is now in a separate cached system message
     const formattedUserInput = `User input:
@@ -243,7 +284,7 @@ ${userInputText}
 """`
 
     // Convert UIMessages to ModelMessages and add system message
-    const modelMessages = convertToModelMessages(messages)
+    const modelMessages = await convertToModelMessages(messages)
 
     // DEBUG: Log incoming messages structure
     console.log("[route.ts] Incoming messages count:", messages.length)
@@ -497,12 +538,26 @@ ${userInputText}
                 userId,
             }),
         }),
-        onFinish: ({ text, usage }) => {
-            // Pass usage to Langfuse (Bedrock streaming doesn't auto-report tokens to telemetry)
-            setTraceOutput(text, {
-                promptTokens: usage?.inputTokens,
-                completionTokens: usage?.outputTokens,
-            })
+        onFinish: ({ text, totalUsage }) => {
+            // AI SDK 6 telemetry auto-reports token usage on its spans
+            setTraceOutput(text)
+
+            // Record token usage for server-side quota tracking (if enabled)
+            // Use totalUsage (cumulative across all steps) instead of usage (final step only)
+            // Include all 4 token types: input, output, cache read, cache write
+            if (
+                isQuotaEnabled() &&
+                !hasOwnApiKey &&
+                userId !== "anonymous" &&
+                totalUsage
+            ) {
+                const totalTokens =
+                    (totalUsage.inputTokens || 0) +
+                    (totalUsage.outputTokens || 0) +
+                    (totalUsage.cachedInputTokens || 0) +
+                    (totalUsage.inputTokenDetails?.cacheWriteTokens || 0)
+                recordTokenUsage(userId, totalTokens)
+            }
         },
         tools: {
             // Client-side tool that will be executed on the client
@@ -554,14 +609,22 @@ Operations:
 
 For update/add, new_xml must be a complete mxCell element including mxGeometry.
 
-⚠️ JSON ESCAPING: Every " inside new_xml MUST be escaped as \\". Example: id=\\"5\\" value=\\"Label\\"`,
+⚠️ JSON ESCAPING: Every " inside new_xml MUST be escaped as \\". Example: id=\\"5\\" value=\\"Label\\"
+
+Example - Add a rectangle:
+{"operations": [{"operation": "add", "cell_id": "rect-1", "new_xml": "<mxCell id=\\"rect-1\\" value=\\"Hello\\" style=\\"rounded=0;\\" vertex=\\"1\\" parent=\\"1\\"><mxGeometry x=\\"100\\" y=\\"100\\" width=\\"120\\" height=\\"60\\" as=\\"geometry\\"/></mxCell>"}]}
+
+Example - Delete a cell:
+{"operations": [{"operation": "delete", "cell_id": "rect-1"}]}`,
                 inputSchema: z.object({
                     operations: z
                         .array(
                             z.object({
-                                type: z
+                                operation: z
                                     .enum(["update", "add", "delete"])
-                                    .describe("Operation type"),
+                                    .describe(
+                                        "Operation to perform: add, update, or delete",
+                                    ),
                                 cell_id: z
                                     .string()
                                     .describe(
@@ -672,19 +735,9 @@ Call this tool to get shape names and usage syntax for a specific library.`,
         messageMetadata: ({ part }) => {
             if (part.type === "finish") {
                 const usage = (part as any).totalUsage
-                if (!usage) {
-                    console.warn(
-                        "[messageMetadata] No usage data in finish part",
-                    )
-                    return undefined
-                }
-                // Total input = non-cached + cached (these are separate counts)
-                // Note: cacheWriteInputTokens is not available on finish part
-                const totalInputTokens =
-                    (usage.inputTokens ?? 0) + (usage.cachedInputTokens ?? 0)
+                // AI SDK 6 provides totalTokens directly
                 return {
-                    inputTokens: totalInputTokens,
-                    outputTokens: usage.outputTokens ?? 0,
+                    totalTokens: usage?.totalTokens ?? 0,
                     finishReason: (part as any).finishReason,
                 }
             }

app/api/log-feedback/route.ts

@@ -1,6 +1,7 @@
 import { randomUUID } from "crypto"
 import { z } from "zod"
 import { getLangfuseClient } from "@/lib/langfuse"
+import { getUserIdFromRequest } from "@/lib/user-id"
 
 const feedbackSchema = z.object({
     messageId: z.string().min(1).max(200),
@@ -27,9 +28,13 @@ export async function POST(req: Request) {
 
     const { messageId, feedback, sessionId } = data
 
-    // Get user IP for tracking
-    const forwardedFor = req.headers.get("x-forwarded-for")
-    const userId = forwardedFor?.split(",")[0]?.trim() || "anonymous"
+    // Skip logging if no sessionId - prevents attaching to wrong user's trace
+    if (!sessionId) {
+        return Response.json({ success: true, logged: false })
+    }
+
+    // Get user ID for tracking
+    const userId = getUserIdFromRequest(req)
 
     try {
         // Find the most recent chat trace for this session to attach the score to

app/api/log-save/route.ts

@@ -27,6 +27,11 @@ export async function POST(req: Request) {
 
     const { filename, format, sessionId } = data
 
+    // Skip logging if no sessionId - prevents attaching to wrong user's trace
+    if (!sessionId) {
+        return Response.json({ success: true, logged: false })
+    }
+
     try {
         const timestamp = new Date().toISOString()
 

app/api/validate-model/route.ts

@@ -0,0 +1,281 @@
+import { createAmazonBedrock } from "@ai-sdk/amazon-bedrock"
+import { createAnthropic } from "@ai-sdk/anthropic"
+import { createDeepSeek, deepseek } from "@ai-sdk/deepseek"
+import { createGateway } from "@ai-sdk/gateway"
+import { createGoogleGenerativeAI } from "@ai-sdk/google"
+import { createOpenAI } from "@ai-sdk/openai"
+import { createOpenRouter } from "@openrouter/ai-sdk-provider"
+import { generateText } from "ai"
+import { NextResponse } from "next/server"
+import { createOllama } from "ollama-ai-provider-v2"
+
+export const runtime = "nodejs"
+
+/**
+ * SECURITY: Check if URL points to private/internal network (SSRF protection)
+ * Blocks: localhost, private IPs, link-local, AWS metadata service
+ */
+function isPrivateUrl(urlString: string): boolean {
+    try {
+        const url = new URL(urlString)
+        const hostname = url.hostname.toLowerCase()
+
+        // Block localhost
+        if (
+            hostname === "localhost" ||
+            hostname === "127.0.0.1" ||
+            hostname === "::1"
+        ) {
+            return true
+        }
+
+        // Block AWS/cloud metadata endpoints
+        if (
+            hostname === "169.254.169.254" ||
+            hostname === "metadata.google.internal"
+        ) {
+            return true
+        }
+
+        // Check for private IPv4 ranges
+        const ipv4Match = hostname.match(
+            /^(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})$/,
+        )
+        if (ipv4Match) {
+            const [, a, b] = ipv4Match.map(Number)
+            // 10.0.0.0/8
+            if (a === 10) return true
+            // 172.16.0.0/12
+            if (a === 172 && b >= 16 && b <= 31) return true
+            // 192.168.0.0/16
+            if (a === 192 && b === 168) return true
+            // 169.254.0.0/16 (link-local)
+            if (a === 169 && b === 254) return true
+            // 127.0.0.0/8 (loopback)
+            if (a === 127) return true
+        }
+
+        // Block common internal hostnames
+        if (
+            hostname.endsWith(".local") ||
+            hostname.endsWith(".internal") ||
+            hostname.endsWith(".localhost")
+        ) {
+            return true
+        }
+
+        return false
+    } catch {
+        // Invalid URL - block it
+        return true
+    }
+}
+
+interface ValidateRequest {
+    provider: string
+    apiKey: string
+    baseUrl?: string
+    modelId: string
+    // AWS Bedrock specific
+    awsAccessKeyId?: string
+    awsSecretAccessKey?: string
+    awsRegion?: string
+}
+
+export async function POST(req: Request) {
+    try {
+        const body: ValidateRequest = await req.json()
+        const {
+            provider,
+            apiKey,
+            baseUrl,
+            modelId,
+            awsAccessKeyId,
+            awsSecretAccessKey,
+            awsRegion,
+        } = body
+
+        if (!provider || !modelId) {
+            return NextResponse.json(
+                { valid: false, error: "Provider and model ID are required" },
+                { status: 400 },
+            )
+        }
+
+        // SECURITY: Block SSRF attacks via custom baseUrl
+        if (baseUrl && isPrivateUrl(baseUrl)) {
+            return NextResponse.json(
+                { valid: false, error: "Invalid base URL" },
+                { status: 400 },
+            )
+        }
+
+        // Validate credentials based on provider
+        if (provider === "bedrock") {
+            if (!awsAccessKeyId || !awsSecretAccessKey || !awsRegion) {
+                return NextResponse.json(
+                    {
+                        valid: false,
+                        error: "AWS credentials (Access Key ID, Secret Access Key, Region) are required",
+                    },
+                    { status: 400 },
+                )
+            }
+        } else if (provider !== "ollama" && !apiKey) {
+            return NextResponse.json(
+                { valid: false, error: "API key is required" },
+                { status: 400 },
+            )
+        }
+
+        let model: any
+
+        switch (provider) {
+            case "openai": {
+                const openai = createOpenAI({
+                    apiKey,
+                    ...(baseUrl && { baseURL: baseUrl }),
+                })
+                model = openai.chat(modelId)
+                break
+            }
+
+            case "anthropic": {
+                const anthropic = createAnthropic({
+                    apiKey,
+                    baseURL: baseUrl || "https://api.anthropic.com/v1",
+                })
+                model = anthropic(modelId)
+                break
+            }
+
+            case "google": {
+                const google = createGoogleGenerativeAI({
+                    apiKey,
+                    ...(baseUrl && { baseURL: baseUrl }),
+                })
+                model = google(modelId)
+                break
+            }
+
+            case "azure": {
+                const azure = createOpenAI({
+                    apiKey,
+                    baseURL: baseUrl,
+                })
+                model = azure.chat(modelId)
+                break
+            }
+
+            case "bedrock": {
+                const bedrock = createAmazonBedrock({
+                    accessKeyId: awsAccessKeyId,
+                    secretAccessKey: awsSecretAccessKey,
+                    region: awsRegion,
+                })
+                model = bedrock(modelId)
+                break
+            }
+
+            case "openrouter": {
+                const openrouter = createOpenRouter({
+                    apiKey,
+                    ...(baseUrl && { baseURL: baseUrl }),
+                })
+                model = openrouter(modelId)
+                break
+            }
+
+            case "deepseek": {
+                if (baseUrl || apiKey) {
+                    const ds = createDeepSeek({
+                        apiKey,
+                        ...(baseUrl && { baseURL: baseUrl }),
+                    })
+                    model = ds(modelId)
+                } else {
+                    model = deepseek(modelId)
+                }
+                break
+            }
+
+            case "siliconflow": {
+                const sf = createOpenAI({
+                    apiKey,
+                    baseURL: baseUrl || "https://api.siliconflow.com/v1",
+                })
+                model = sf.chat(modelId)
+                break
+            }
+
+            case "ollama": {
+                const ollama = createOllama({
+                    baseURL: baseUrl || "http://localhost:11434",
+                })
+                model = ollama(modelId)
+                break
+            }
+
+            case "gateway": {
+                const gw = createGateway({
+                    apiKey,
+                    ...(baseUrl && { baseURL: baseUrl }),
+                })
+                model = gw(modelId)
+                break
+            }
+
+            default:
+                return NextResponse.json(
+                    { valid: false, error: `Unknown provider: ${provider}` },
+                    { status: 400 },
+                )
+        }
+
+        // Make a minimal test request
+        const startTime = Date.now()
+        await generateText({
+            model,
+            prompt: "Say 'OK'",
+            maxOutputTokens: 20,
+        })
+        const responseTime = Date.now() - startTime
+
+        return NextResponse.json({
+            valid: true,
+            responseTime,
+        })
+    } catch (error) {
+        console.error("[validate-model] Error:", error)
+
+        let errorMessage = "Validation failed"
+        if (error instanceof Error) {
+            // Extract meaningful error message
+            if (
+                error.message.includes("401") ||
+                error.message.includes("Unauthorized")
+            ) {
+                errorMessage = "Invalid API key"
+            } else if (
+                error.message.includes("404") ||
+                error.message.includes("not found")
+            ) {
+                errorMessage = "Model not found"
+            } else if (
+                error.message.includes("429") ||
+                error.message.includes("rate limit")
+            ) {
+                errorMessage = "Rate limited - try again later"
+            } else if (error.message.includes("ECONNREFUSED")) {
+                errorMessage = "Cannot connect to server"
+            } else {
+                errorMessage = error.message.slice(0, 100)
+            }
+        }
+
+        return NextResponse.json(
+            { valid: false, error: errorMessage },
+            { status: 200 }, // Return 200 so client can read error message
+        )
+    }
+}

app/globals.css

@@ -144,6 +144,68 @@
     --sidebar-ring: oklch(0.7 0.16 265);
 }
 
+/* ============================================
+   REFINED MINIMAL DESIGN SYSTEM
+   ============================================ */
+
+:root {
+    /* Surface layers for depth */
+    --surface-0: oklch(1 0 0);
+    --surface-1: oklch(0.985 0.002 240);
+    --surface-2: oklch(0.97 0.004 240);
+    --surface-elevated: oklch(1 0 0);
+
+    /* Subtle borders */
+    --border-subtle: oklch(0.94 0.008 260);
+    --border-default: oklch(0.91 0.012 260);
+
+    /* Interactive states */
+    --interactive-hover: oklch(0.96 0.015 260);
+    --interactive-active: oklch(0.93 0.02 265);
+
+    /* Success state */
+    --success: oklch(0.65 0.18 145);
+    --success-muted: oklch(0.95 0.03 145);
+
+    /* Animation timing */
+    --duration-fast: 120ms;
+    --duration-normal: 200ms;
+    --duration-slow: 300ms;
+    --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
+    --ease-in-out: cubic-bezier(0.4, 0, 0.2, 1);
+    --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
+}
+
+.dark {
+    --surface-0: oklch(0.15 0.015 260);
+    --surface-1: oklch(0.18 0.015 260);
+    --surface-2: oklch(0.22 0.015 260);
+    --surface-elevated: oklch(0.25 0.015 260);
+
+    --border-subtle: oklch(0.25 0.012 260);
+    --border-default: oklch(0.3 0.015 260);
+
+    --interactive-hover: oklch(0.25 0.02 265);
+    --interactive-active: oklch(0.3 0.025 270);
+
+    --success: oklch(0.7 0.16 145);
+    --success-muted: oklch(0.25 0.04 145);
+}
+
+/* Expose surface colors to Tailwind */
+@theme inline {
+    --color-surface-0: var(--surface-0);
+    --color-surface-1: var(--surface-1);
+    --color-surface-2: var(--surface-2);
+    --color-surface-elevated: var(--surface-elevated);
+    --color-border-subtle: var(--border-subtle);
+    --color-border-default: var(--border-default);
+    --color-interactive-hover: var(--interactive-hover);
+    --color-interactive-active: var(--interactive-active);
+    --color-success: var(--success);
+    --color-success-muted: var(--success-muted);
+}
+
 @layer base {
     * {
         @apply border-border outline-ring/50;
@@ -257,3 +319,83 @@
     -webkit-text-fill-color: transparent;
     background-clip: text;
 }
+
+/* ============================================
+   REFINED DIALOG STYLES
+   ============================================ */
+
+/* Refined dialog shadow - multi-layer soft shadow */
+.shadow-dialog {
+    box-shadow:
+        0 0 0 1px oklch(0 0 0 / 0.03),
+        0 2px 4px oklch(0 0 0 / 0.02),
+        0 12px 24px oklch(0 0 0 / 0.06),
+        0 24px 48px oklch(0 0 0 / 0.04);
+}
+
+.dark .shadow-dialog {
+    box-shadow:
+        0 0 0 1px oklch(1 0 0 / 0.05),
+        0 2px 4px oklch(0 0 0 / 0.2),
+        0 12px 24px oklch(0 0 0 / 0.3),
+        0 24px 48px oklch(0 0 0 / 0.2);
+}
+
+/* Dialog animations */
+@keyframes dialog-in {
+    from {
+        opacity: 0;
+        transform: translate(-50%, -48%) scale(0.96);
+    }
+    to {
+        opacity: 1;
+        transform: translate(-50%, -50%) scale(1);
+    }
+}
+
+@keyframes dialog-out {
+    from {
+        opacity: 1;
+        transform: translate(-50%, -50%) scale(1);
+    }
+    to {
+        opacity: 0;
+        transform: translate(-50%, -48%) scale(0.96);
+    }
+}
+
+.animate-dialog-in {
+    animation: dialog-in var(--duration-normal) var(--ease-out) forwards;
+}
+
+.animate-dialog-out {
+    animation: dialog-out 150ms var(--ease-out) forwards;
+}
+
+/* Check pop animation for validation success */
+@keyframes check-pop {
+    0% {
+        transform: scale(0.8);
+        opacity: 0;
+    }
+    50% {
+        transform: scale(1.1);
+    }
+    100% {
+        transform: scale(1);
+        opacity: 1;
+    }
+}
+
+.animate-check-pop {
+    animation: check-pop 0.25s var(--ease-spring) forwards;
+}
+
+/* Reduced motion support */
+@media (prefers-reduced-motion: reduce) {
+    .animate-dialog-in,
+    .animate-dialog-out,
+    .animate-check-pop {
+        animation: none;
+    }
+}

app/manifest.ts

@@ -1,24 +1,24 @@
 import type { MetadataRoute } from "next"
-
+import { getAssetUrl } from "@/lib/base-path"
 export default function manifest(): MetadataRoute.Manifest {
     return {
         name: "Next AI Draw.io",
         short_name: "AIDraw.io",
         description:
             "Create AWS architecture diagrams, flowcharts, and technical diagrams using AI. Free online tool integrating draw.io with AI assistance for professional diagram creation.",
-        start_url: "/",
+        start_url: getAssetUrl("/"),
         display: "standalone",
         background_color: "#f9fafb",
         theme_color: "#171d26",
         icons: [
             {
-                src: "/favicon-192x192.png",
+                src: getAssetUrl("/favicon-192x192.png"),
                 sizes: "192x192",
                 type: "image/png",
                 purpose: "any",
             },
             {
-                src: "/favicon-512x512.png",
+                src: getAssetUrl("/favicon-512x512.png"),
                 sizes: "512x512",
                 type: "image/png",
                 purpose: "any",

components/ai-elements/model-selector.tsx

@@ -0,0 +1,170 @@
+import { Cloud } from "lucide-react"
+import type { ComponentProps, ReactNode } from "react"
+import {
+    Command,
+    CommandDialog,
+    CommandEmpty,
+    CommandGroup,
+    CommandInput,
+    CommandItem,
+    CommandList,
+    CommandSeparator,
+    CommandShortcut,
+} from "@/components/ui/command"
+import {
+    Dialog,
+    DialogContent,
+    DialogTitle,
+    DialogTrigger,
+} from "@/components/ui/dialog"
+import { cn } from "@/lib/utils"
+
+export type ModelSelectorProps = ComponentProps<typeof Dialog>
+
+export const ModelSelector = (props: ModelSelectorProps) => (
+    <Dialog {...props} />
+)
+
+export type ModelSelectorTriggerProps = ComponentProps<typeof DialogTrigger>
+
+export const ModelSelectorTrigger = (props: ModelSelectorTriggerProps) => (
+    <DialogTrigger {...props} />
+)
+
+export type ModelSelectorContentProps = ComponentProps<typeof DialogContent> & {
+    title?: ReactNode
+}
+
+export const ModelSelectorContent = ({
+    className,
+    children,
+    title = "Model Selector",
+    ...props
+}: ModelSelectorContentProps) => (
+    <DialogContent className={cn("p-0", className)} {...props}>
+        <DialogTitle className="sr-only">{title}</DialogTitle>
+        <Command className="**:data-[slot=command-input-wrapper]:h-auto">
+            {children}
+        </Command>
+    </DialogContent>
+)
+
+export type ModelSelectorDialogProps = ComponentProps<typeof CommandDialog>
+
+export const ModelSelectorDialog = (props: ModelSelectorDialogProps) => (
+    <CommandDialog {...props} />
+)
+
+export type ModelSelectorInputProps = ComponentProps<typeof CommandInput>
+
+export const ModelSelectorInput = ({
+    className,
+    ...props
+}: ModelSelectorInputProps) => (
+    <CommandInput className={cn("h-auto py-3.5", className)} {...props} />
+)
+
+export type ModelSelectorListProps = ComponentProps<typeof CommandList>
+
+export const ModelSelectorList = ({
+    className,
+    ...props
+}: ModelSelectorListProps) => (
+    <div className="relative">
+        <CommandList
+            className={cn(
+                // Hide scrollbar on all platforms
+                "[&::-webkit-scrollbar]:hidden [-ms-overflow-style:none] [scrollbar-width:none]",
+                className,
+            )}
+            {...props}
+        />
+        {/* Bottom shadow indicator for scrollable content */}
+        <div className="pointer-events-none absolute bottom-0 left-0 right-0 h-12 bg-gradient-to-t from-muted/80 via-muted/40 to-transparent" />
+    </div>
+)
+
+export type ModelSelectorEmptyProps = ComponentProps<typeof CommandEmpty>
+
+export const ModelSelectorEmpty = (props: ModelSelectorEmptyProps) => (
+    <CommandEmpty {...props} />
+)
+
+export type ModelSelectorGroupProps = ComponentProps<typeof CommandGroup>
+
+export const ModelSelectorGroup = (props: ModelSelectorGroupProps) => (
+    <CommandGroup {...props} />
+)
+
+export type ModelSelectorItemProps = ComponentProps<typeof CommandItem>
+
+export const ModelSelectorItem = (props: ModelSelectorItemProps) => (
+    <CommandItem {...props} />
+)
+
+export type ModelSelectorShortcutProps = ComponentProps<typeof CommandShortcut>
+
+export const ModelSelectorShortcut = (props: ModelSelectorShortcutProps) => (
+    <CommandShortcut {...props} />
+)
+
+export type ModelSelectorSeparatorProps = ComponentProps<
+    typeof CommandSeparator
+>
+
+export const ModelSelectorSeparator = (props: ModelSelectorSeparatorProps) => (
+    <CommandSeparator {...props} />
+)
+
+export type ModelSelectorLogoProps = Omit<
+    ComponentProps<"img">,
+    "src" | "alt"
+> & {
+    provider: string
+}
+
+export const ModelSelectorLogo = ({
+    provider,
+    className,
+    ...props
+}: ModelSelectorLogoProps) => {
+    // Use Lucide icon for bedrock since models.dev doesn't have a good AWS icon
+    if (provider === "amazon-bedrock") {
+        return <Cloud className={cn("size-4", className)} />
+    }
+
+    return (
+        <img
+            {...props}
+            alt={`${provider} logo`}
+            className={cn("size-4 dark:invert", className)}
+            height={16}
+            src={`https://models.dev/logos/${provider}.svg`}
+            width={16}
+        />
+    )
+}
+
+export type ModelSelectorLogoGroupProps = ComponentProps<"div">
+
+export const ModelSelectorLogoGroup = ({
+    className,
+    ...props
+}: ModelSelectorLogoGroupProps) => (
+    <div
+        className={cn(
+            "-space-x-1 flex shrink-0 items-center [&>img]:rounded-full [&>img]:bg-background [&>img]:p-px [&>img]:ring-1 dark:[&>img]:bg-foreground",
+            className,
+        )}
+        {...props}
+    />
+)
+
+export type ModelSelectorNameProps = ComponentProps<"span">
+
+export const ModelSelectorName = ({
+    className,
+    ...props
+}: ModelSelectorNameProps) => (
+    <span className={cn("flex-1 truncate text-left", className)} {...props} />
+)

components/chat-example-panel.tsx

@@ -9,6 +9,7 @@ import {
     Zap,
 } from "lucide-react"
 import { useDictionary } from "@/hooks/use-dictionary"
+import { getAssetUrl } from "@/lib/base-path"
 
 interface ExampleCardProps {
     icon: React.ReactNode
@@ -79,7 +80,7 @@ export default function ExamplePanel({
         setInput("Replicate this flowchart.")
 
         try {
-            const response = await fetch("/example.png")
+            const response = await fetch(getAssetUrl("/example.png"))
             const blob = await response.blob()
             const file = new File([blob], "example.png", { type: "image/png" })
             setFiles([file])
@@ -92,7 +93,7 @@ export default function ExamplePanel({
         setInput("Replicate this in aws style")
 
         try {
-            const response = await fetch("/architecture.png")
+            const response = await fetch(getAssetUrl("/architecture.png"))
             const blob = await response.blob()
             const file = new File([blob], "architecture.png", {
                 type: "image/png",
@@ -107,7 +108,7 @@ export default function ExamplePanel({
         setInput("Summarize this paper as a diagram")
 
         try {
-            const response = await fetch("/chain-of-thought.txt")
+            const response = await fetch(getAssetUrl("/chain-of-thought.txt"))
             const blob = await response.blob()
             const file = new File([blob], "chain-of-thought.txt", {
                 type: "text/plain",

components/chat-input.tsx

@@ -14,6 +14,7 @@ import { toast } from "sonner"
 import { ButtonWithTooltip } from "@/components/button-with-tooltip"
 import { ErrorToast } from "@/components/error-toast"
 import { HistoryDialog } from "@/components/history-dialog"
+import { ModelSelector } from "@/components/model-selector"
 import { ResetWarningModal } from "@/components/reset-warning-modal"
 import { SaveDialog } from "@/components/save-dialog"
 import { Button } from "@/components/ui/button"
@@ -28,6 +29,7 @@ import { useDiagram } from "@/contexts/diagram-context"
 import { useDictionary } from "@/hooks/use-dictionary"
 import { formatMessage } from "@/lib/i18n/utils"
 import { isPdfFile, isTextFile } from "@/lib/pdf-utils"
+import type { FlattenedModel } from "@/lib/types/model-config"
 import { FilePreviewList } from "./file-preview-list"
 
 const MAX_IMAGE_SIZE = 2 * 1024 * 1024 // 2MB
@@ -156,6 +158,11 @@ interface ChatInputProps {
     error?: Error | null
     minimalStyle?: boolean
     onMinimalStyleChange?: (value: boolean) => void
+    // Model selector props
+    models?: FlattenedModel[]
+    selectedModelId?: string
+    onModelSelect?: (modelId: string | undefined) => void
+    onConfigureModels?: () => void
 }
 
 export function ChatInput({
@@ -173,6 +180,10 @@ export function ChatInput({
     error = null,
     minimalStyle = false,
     onMinimalStyleChange = () => {},
+    models = [],
+    selectedModelId,
+    onModelSelect = () => {},
+    onConfigureModels = () => {},
 }: ChatInputProps) {
     const dict = useDictionary()
     const {
@@ -465,6 +476,14 @@ export function ChatInput({
                             disabled={isDisabled}
                         />
 
+                        <ModelSelector
+                            models={models}
+                            selectedModelId={selectedModelId}
+                            onSelect={onModelSelect}
+                            onConfigure={onConfigureModels}
+                            disabled={isDisabled}
+                        />
+
                         <div className="w-px h-5 bg-border mx-1" />
 
                         <Button

components/chat-message-display.tsx

@@ -27,9 +27,11 @@ import {
     ReasoningTrigger,
 } from "@/components/ai-elements/reasoning"
 import { ScrollArea } from "@/components/ui/scroll-area"
+import { getApiEndpoint } from "@/lib/base-path"
 import {
     applyDiagramOperations,
     convertToLegalXml,
+    extractCompleteMxCells,
     isMxCellXmlComplete,
     replaceNodes,
     validateAndFixXml,
@@ -38,7 +40,7 @@ import ExamplePanel from "./chat-example-panel"
 import { CodeBlock } from "./code-block"
 
 interface DiagramOperation {
-    type: "update" | "add" | "delete"
+    operation: "update" | "add" | "delete"
     cell_id: string
     new_xml?: string
 }
@@ -51,12 +53,12 @@ function getCompleteOperations(
     return operations.filter(
         (op) =>
             op &&
-            typeof op.type === "string" &&
-            ["update", "add", "delete"].includes(op.type) &&
+            typeof op.operation === "string" &&
+            ["update", "add", "delete"].includes(op.operation) &&
             typeof op.cell_id === "string" &&
             op.cell_id.length > 0 &&
             // delete doesn't need new_xml, update/add do
-            (op.type === "delete" || typeof op.new_xml === "string"),
+            (op.operation === "delete" || typeof op.new_xml === "string"),
     )
 }
 
@@ -77,20 +79,20 @@ function OperationsDisplay({ operations }: { operations: DiagramOperation[] }) {
         <div className="space-y-3">
             {operations.map((op, index) => (
                 <div
-                    key={`${op.type}-${op.cell_id}-${index}`}
+                    key={`${op.operation}-${op.cell_id}-${index}`}
                     className="rounded-lg border border-border/50 overflow-hidden bg-background/50"
                 >
                     <div className="px-3 py-1.5 bg-muted/40 border-b border-border/30 flex items-center gap-2">
                         <span
                             className={`text-[10px] font-medium uppercase tracking-wide ${
-                                op.type === "delete"
+                                op.operation === "delete"
                                     ? "text-red-600"
-                                    : op.type === "add"
+                                    : op.operation === "add"
                                       ? "text-green-600"
                                       : "text-blue-600"
                             }`}
                         >
-                            {op.type}
+                            {op.operation}
                         </span>
                         <span className="text-xs text-muted-foreground">
                             cell_id: {op.cell_id}
@@ -291,7 +293,7 @@ export function ChatMessageDisplay({
         setFeedback((prev) => ({ ...prev, [messageId]: value }))
 
         try {
-            await fetch("/api/log-feedback", {
+            await fetch(getApiEndpoint("/api/log-feedback"), {
                 method: "POST",
                 headers: { "Content-Type": "application/json" },
                 body: JSON.stringify({
@@ -314,12 +316,28 @@ export function ChatMessageDisplay({
 
     const handleDisplayChart = useCallback(
         (xml: string, showToast = false) => {
-            const currentXml = xml || ""
+            let currentXml = xml || ""
+            const startTime = performance.now()
+
+            // During streaming (showToast=false), extract only complete mxCell elements
+            // This allows progressive rendering even with partial/incomplete trailing XML
+            if (!showToast) {
+                const completeCells = extractCompleteMxCells(currentXml)
+                if (!completeCells) {
+                    return
+                }
+                currentXml = completeCells
+            }
+
             const convertedXml = convertToLegalXml(currentXml)
             if (convertedXml !== previousXML.current) {
                 // Parse and validate XML BEFORE calling replaceNodes
                 const parser = new DOMParser()
-                const testDoc = parser.parseFromString(convertedXml, "text/xml")
+                // Wrap in root element for parsing multiple mxCell elements
+                const testDoc = parser.parseFromString(
+                    `<root>${convertedXml}</root>`,
+                    "text/xml",
+                )
                 const parseError = testDoc.querySelector("parsererror")
 
                 if (parseError) {
@@ -346,7 +364,22 @@ export function ChatMessageDisplay({
                         `<mxfile><diagram name="Page-1" id="page-1"><mxGraphModel><root><mxCell id="0"/><mxCell id="1" parent="0"/></root></mxGraphModel></diagram></mxfile>`
                     const replacedXML = replaceNodes(baseXML, convertedXml)
 
-                    // Validate and auto-fix the XML
+                    const xmlProcessTime = performance.now() - startTime
+
+                    // During streaming (showToast=false), skip heavy validation for lower latency
+                    // The quick DOM parse check above catches malformed XML
+                    // Full validation runs on final output (showToast=true)
+                    if (!showToast) {
+                        previousXML.current = convertedXml
+                        const loadStartTime = performance.now()
+                        onDisplayChart(replacedXML, true)
+                        console.log(
+                            `[Streaming] XML processing: ${xmlProcessTime.toFixed(1)}ms, drawio load: ${(performance.now() - loadStartTime).toFixed(1)}ms`,
+                        )
+                        return
+                    }
+
+                    // Final output: run full validation and auto-fix
                     const validation = validateAndFixXml(replacedXML)
                     if (validation.valid) {
                         previousXML.current = convertedXml
@@ -359,18 +392,19 @@ export function ChatMessageDisplay({
                             )
                         }
                         // Skip validation in loadDiagram since we already validated above
+                        const loadStartTime = performance.now()
                         onDisplayChart(xmlToLoad, true)
+                        console.log(
+                            `[Final] XML processing: ${xmlProcessTime.toFixed(1)}ms, validation+load: ${(performance.now() - loadStartTime).toFixed(1)}ms`,
+                        )
                     } else {
                         console.error(
                             "[ChatMessageDisplay] XML validation failed:",
                             validation.error,
                         )
-                        // Only show toast if this is the final XML (not during streaming)
-                        if (showToast) {
-                            toast.error(
-                                "Diagram validation failed. Please try regenerating.",
-                            )
-                        }
+                        toast.error(
+                            "Diagram validation failed. Please try regenerating.",
+                        )
                     }
                 } catch (error) {
                     console.error(
@@ -602,17 +636,10 @@ export function ChatMessageDisplay({
             }
         })
 
-        // Cleanup: clear any pending debounce timeout on unmount
-        return () => {
-            if (debounceTimeoutRef.current) {
-                clearTimeout(debounceTimeoutRef.current)
-                debounceTimeoutRef.current = null
-            }
-            if (editDebounceTimeoutRef.current) {
-                clearTimeout(editDebounceTimeoutRef.current)
-                editDebounceTimeoutRef.current = null
-            }
-        }
+        // NOTE: Don't cleanup debounce timeouts here!
+        // The cleanup runs on every re-render (when messages changes),
+        // which would cancel the timeout before it fires.
+        // Let the timeouts complete naturally - they're harmless if component unmounts.
     }, [messages, handleDisplayChart, chartXML])
 
     const renderToolPart = (part: ToolPartLike) => {

components/chat-panel.tsx

@@ -18,18 +18,26 @@ import { FaGithub } from "react-icons/fa"
 import { Toaster, toast } from "sonner"
 import { ButtonWithTooltip } from "@/components/button-with-tooltip"
 import { ChatInput } from "@/components/chat-input"
+import { ModelConfigDialog } from "@/components/model-config-dialog"
 import { ResetWarningModal } from "@/components/reset-warning-modal"
 import { SettingsDialog } from "@/components/settings-dialog"
+import {
+    Tooltip,
+    TooltipContent,
+    TooltipTrigger,
+} from "@/components/ui/tooltip"
 import { useDiagram } from "@/contexts/diagram-context"
+import { useDiagramToolHandlers } from "@/hooks/use-diagram-tool-handlers"
 import { useDictionary } from "@/hooks/use-dictionary"
-import { getAIConfig } from "@/lib/ai-config"
+import { getSelectedAIConfig, useModelConfig } from "@/hooks/use-model-config"
+import { getApiEndpoint } from "@/lib/base-path"
 import { findCachedResponse } from "@/lib/cached-responses"
 import { isPdfFile, isTextFile } from "@/lib/pdf-utils"
 import { type FileData, useFileProcessor } from "@/lib/use-file-processor"
 import { useQuotaManager } from "@/lib/use-quota-manager"
-import { formatXML, isMxCellXmlComplete, wrapWithMxFile } from "@/lib/utils"
+import { formatXML } from "@/lib/utils"
 import { ChatMessageDisplay } from "./chat-message-display"
-import LanguageToggle from "./language-toggle"
+import { DevXmlSimulator } from "./dev-xml-simulator"
 
 // localStorage keys for persistence
 const STORAGE_MESSAGES_KEY = "next-ai-draw-io-messages"
@@ -71,6 +79,8 @@ const TOOL_ERROR_STATE = "output-error" as const
 const DEBUG = process.env.NODE_ENV === "development"
 const MAX_AUTO_RETRY_COUNT = 1
 
+const MAX_CONTINUATION_RETRY_COUNT = 2 // Limit for truncation continuation retries
+
 /**
  * Check if auto-resubmit should happen based on tool errors.
  * Only checks the LAST tool part (most recent tool call), not all tool parts.
@@ -146,7 +156,10 @@ export default function ChatPanel({
 
     const [showHistory, setShowHistory] = useState(false)
     const [showSettingsDialog, setShowSettingsDialog] = useState(false)
-    const [, setAccessCodeRequired] = useState(false)
+    const [showModelConfigDialog, setShowModelConfigDialog] = useState(false)
+
+    // Model configuration hook
+    const modelConfig = useModelConfig()
     const [input, setInput] = useState("")
     const [dailyRequestLimit, setDailyRequestLimit] = useState(0)
     const [dailyTokenLimit, setDailyTokenLimit] = useState(0)
@@ -164,15 +177,14 @@ export default function ChatPanel({
 
     // Check config on mount
     useEffect(() => {
-        fetch("/api/config")
+        fetch(getApiEndpoint("/api/config"))
             .then((res) => res.json())
             .then((data) => {
-                setAccessCodeRequired(data.accessCodeRequired)
                 setDailyRequestLimit(data.dailyRequestLimit || 0)
                 setDailyTokenLimit(data.dailyTokenLimit || 0)
                 setTpmLimit(data.tpmLimit || 0)
             })
-            .catch(() => setAccessCodeRequired(false))
+            .catch(() => {})
     }, [])
 
     // Quota management using extracted hook
@@ -203,11 +215,10 @@ export default function ChatPanel({
         chartXMLRef.current = chartXML
     }, [chartXML])
 
-    // Ref to hold stop function for use in onToolCall (avoids stale closure)
-    const stopRef = useRef<(() => void) | null>(null)
-
     // Ref to track consecutive auto-retry count (reset on user action)
     const autoRetryCountRef = useRef(0)
+    // Ref to track continuation retry count (for truncation handling)
+    const continuationRetryCountRef = useRef(0)
 
     // Ref to accumulate partial XML when output is truncated due to maxOutputTokens
     // When partialXmlRef.current.length > 0, we're in continuation mode
@@ -226,6 +237,16 @@ export default function ChatPanel({
     > | null>(null)
     const LOCAL_STORAGE_DEBOUNCE_MS = 1000 // Save at most once per second
 
+    // Diagram tool handlers (display_diagram, edit_diagram, append_diagram)
+    const { handleToolCall } = useDiagramToolHandlers({
+        partialXmlRef,
+        editDiagramOriginalXmlRef,
+        chartXMLRef,
+        onDisplayChart,
+        onFetchChart,
+        onExport,
+    })
+
     const {
         messages,
         sendMessage,
@@ -236,315 +257,49 @@ export default function ChatPanel({
         setMessages,
     } = useChat({
         transport: new DefaultChatTransport({
-            api: "/api/chat",
+            api: getApiEndpoint("/api/chat"),
         }),
-        async onToolCall({ toolCall }) {
-            if (DEBUG) {
-                console.log(
-                    `[onToolCall] Tool: ${toolCall.toolName}, CallId: ${toolCall.toolCallId}`,
-                )
-            }
-
-            if (toolCall.toolName === "display_diagram") {
-                const { xml } = toolCall.input as { xml: string }
-
-                // DEBUG: Log raw input to diagnose false truncation detection
-                console.log(
-                    "[display_diagram] XML ending (last 100 chars):",
-                    xml.slice(-100),
-                )
-                console.log("[display_diagram] XML length:", xml.length)
-
-                // Check if XML is truncated (incomplete mxCell indicates truncated output)
-                const isTruncated = !isMxCellXmlComplete(xml)
-                console.log("[display_diagram] isTruncated:", isTruncated)
-
-                if (isTruncated) {
-                    // Store the partial XML for continuation via append_diagram
-                    partialXmlRef.current = xml
-
-                    // Tell LLM to use append_diagram to continue
-                    const partialEnding = partialXmlRef.current.slice(-500)
-                    addToolOutput({
-                        tool: "display_diagram",
-                        toolCallId: toolCall.toolCallId,
-                        state: "output-error",
-                        errorText: `Output was truncated due to length limits. Use the append_diagram tool to continue.
-
-Your output ended with:
-\`\`\`
-${partialEnding}
-\`\`\`
-
-NEXT STEP: Call append_diagram with the continuation XML.
-- Do NOT include wrapper tags or root cells (id="0", id="1")
-- Start from EXACTLY where you stopped
-- Complete all remaining mxCell elements`,
-                    })
-                    return
-                }
-
-                // Complete XML received - use it directly
-                // (continuation is now handled via append_diagram tool)
-                const finalXml = xml
-                partialXmlRef.current = "" // Reset any partial from previous truncation
-
-                // Wrap raw XML with full mxfile structure for draw.io
-                const fullXml = wrapWithMxFile(finalXml)
-
-                // loadDiagram validates and returns error if invalid
-                const validationError = onDisplayChart(fullXml)
-
-                if (validationError) {
-                    console.warn(
-                        "[display_diagram] Validation error:",
-                        validationError,
-                    )
-                    // Return error to model - sendAutomaticallyWhen will trigger retry
-                    if (DEBUG) {
-                        console.log(
-                            "[display_diagram] Adding tool output with state: output-error",
-                        )
-                    }
-                    addToolOutput({
-                        tool: "display_diagram",
-                        toolCallId: toolCall.toolCallId,
-                        state: "output-error",
-                        errorText: `${validationError}
-
-Please fix the XML issues and call display_diagram again with corrected XML.
-
-Your failed XML:
-\`\`\`xml
-${finalXml}
-\`\`\``,
-                    })
-                } else {
-                    // Success - diagram will be rendered by chat-message-display
-                    if (DEBUG) {
-                        console.log(
-                            "[display_diagram] Success! Adding tool output with state: output-available",
-                        )
-                    }
-                    addToolOutput({
-                        tool: "display_diagram",
-                        toolCallId: toolCall.toolCallId,
-                        output: "Successfully displayed the diagram.",
-                    })
-                    if (DEBUG) {
-                        console.log(
-                            "[display_diagram] Tool output added. Diagram should be visible now.",
-                        )
-                    }
-                }
-            } else if (toolCall.toolName === "edit_diagram") {
-                const { operations } = toolCall.input as {
-                    operations: Array<{
-                        type: "update" | "add" | "delete"
-                        cell_id: string
-                        new_xml?: string
-                    }>
-                }
-
-                let currentXml = ""
-                try {
-                    // Use the original XML captured during streaming (shared with chat-message-display)
-                    // This ensures we apply operations to the same base XML that streaming used
-                    const originalXml = editDiagramOriginalXmlRef.current.get(
-                        toolCall.toolCallId,
-                    )
-                    if (originalXml) {
-                        currentXml = originalXml
-                    } else {
-                        // Fallback: use chartXML from ref if streaming didn't capture original
-                        const cachedXML = chartXMLRef.current
-                        if (cachedXML) {
-                            currentXml = cachedXML
-                        } else {
-                            // Last resort: export from iframe
-                            currentXml = await onFetchChart(false)
-                        }
-                    }
-
-                    const { applyDiagramOperations } = await import(
-                        "@/lib/utils"
-                    )
-                    const { result: editedXml, errors } =
-                        applyDiagramOperations(currentXml, operations)
-
-                    // Check for operation errors
-                    if (errors.length > 0) {
-                        const errorMessages = errors
-                            .map(
-                                (e) =>
-                                    `- ${e.type} on cell_id="${e.cellId}": ${e.message}`,
-                            )
-                            .join("\n")
-
-                        addToolOutput({
-                            tool: "edit_diagram",
-                            toolCallId: toolCall.toolCallId,
-                            state: "output-error",
-                            errorText: `Some operations failed:\n${errorMessages}
-
-Current diagram XML:
-\`\`\`xml
-${currentXml}
-\`\`\`
-
-Please check the cell IDs and retry.`,
-                        })
-                        // Clean up the shared original XML ref
-                        editDiagramOriginalXmlRef.current.delete(
-                            toolCall.toolCallId,
-                        )
-                        return
-                    }
-
-                    // loadDiagram validates and returns error if invalid
-                    const validationError = onDisplayChart(editedXml)
-                    if (validationError) {
-                        console.warn(
-                            "[edit_diagram] Validation error:",
-                            validationError,
-                        )
-                        addToolOutput({
-                            tool: "edit_diagram",
-                            toolCallId: toolCall.toolCallId,
-                            state: "output-error",
-                            errorText: `Edit produced invalid XML: ${validationError}
-
-Current diagram XML:
-\`\`\`xml
-${currentXml}
-\`\`\`
-
-Please fix the operations to avoid structural issues.`,
-                        })
-                        // Clean up the shared original XML ref
-                        editDiagramOriginalXmlRef.current.delete(
-                            toolCall.toolCallId,
-                        )
-                        return
-                    }
-                    onExport()
-                    addToolOutput({
-                        tool: "edit_diagram",
-                        toolCallId: toolCall.toolCallId,
-                        output: `Successfully applied ${operations.length} operation(s) to the diagram.`,
-                    })
-                    // Clean up the shared original XML ref
-                    editDiagramOriginalXmlRef.current.delete(
-                        toolCall.toolCallId,
-                    )
-                } catch (error) {
-                    console.error("[edit_diagram] Failed:", error)
-
-                    const errorMessage =
-                        error instanceof Error ? error.message : String(error)
-
-                    addToolOutput({
-                        tool: "edit_diagram",
-                        toolCallId: toolCall.toolCallId,
-                        state: "output-error",
-                        errorText: `Edit failed: ${errorMessage}
-
-Current diagram XML:
-\`\`\`xml
-${currentXml || "No XML available"}
-\`\`\`
-
-Please check cell IDs and retry, or use display_diagram to regenerate.`,
-                    })
-                    // Clean up the shared original XML ref even on error
-                    editDiagramOriginalXmlRef.current.delete(
-                        toolCall.toolCallId,
-                    )
-                }
-            } else if (toolCall.toolName === "append_diagram") {
-                const { xml } = toolCall.input as { xml: string }
-
-                // Detect if LLM incorrectly started fresh instead of continuing
-                // LLM should only output bare mxCells now, so wrapper tags indicate error
-                const trimmed = xml.trim()
-                const isFreshStart =
-                    trimmed.startsWith("<mxGraphModel") ||
-                    trimmed.startsWith("<root") ||
-                    trimmed.startsWith("<mxfile") ||
-                    trimmed.startsWith('<mxCell id="0"') ||
-                    trimmed.startsWith('<mxCell id="1"')
-
-                if (isFreshStart) {
-                    addToolOutput({
-                        tool: "append_diagram",
-                        toolCallId: toolCall.toolCallId,
-                        state: "output-error",
-                        errorText: `ERROR: You started fresh with wrapper tags. Do NOT include wrapper tags or root cells (id="0", id="1").
-
-Continue from EXACTLY where the partial ended:
-\`\`\`
-${partialXmlRef.current.slice(-500)}
-\`\`\`
-
-Start your continuation with the NEXT character after where it stopped.`,
-                    })
-                    return
-                }
-
-                // Append to accumulated XML
-                partialXmlRef.current += xml
-
-                // Check if XML is now complete (last mxCell is complete)
-                const isComplete = isMxCellXmlComplete(partialXmlRef.current)
-
-                if (isComplete) {
-                    // Wrap and display the complete diagram
-                    const finalXml = partialXmlRef.current
-                    partialXmlRef.current = "" // Reset
-
-                    const fullXml = wrapWithMxFile(finalXml)
-                    const validationError = onDisplayChart(fullXml)
-
-                    if (validationError) {
-                        addToolOutput({
-                            tool: "append_diagram",
-                            toolCallId: toolCall.toolCallId,
-                            state: "output-error",
-                            errorText: `Validation error after assembly: ${validationError}
-
-Assembled XML:
-\`\`\`xml
-${finalXml.substring(0, 2000)}...
-\`\`\`
-
-Please use display_diagram with corrected XML.`,
-                        })
-                    } else {
-                        addToolOutput({
-                            tool: "append_diagram",
-                            toolCallId: toolCall.toolCallId,
-                            output: "Diagram assembly complete and displayed successfully.",
-                        })
-                    }
-                } else {
-                    // Still incomplete - signal to continue
-                    addToolOutput({
-                        tool: "append_diagram",
-                        toolCallId: toolCall.toolCallId,
-                        state: "output-error",
-                        errorText: `XML still incomplete (mxCell not closed). Call append_diagram again to continue.
-
-Current ending:
-\`\`\`
-${partialXmlRef.current.slice(-500)}
-\`\`\`
-
-Continue from EXACTLY where you stopped.`,
-                    })
-                }
-            }
+        onToolCall: async ({ toolCall }) => {
+            await handleToolCall({ toolCall }, addToolOutput)
         },
         onError: (error) => {
+            // Handle server-side quota limit (429 response)
+            // AI SDK puts the full response body in error.message for non-OK responses
+            try {
+                const data = JSON.parse(error.message)
+                if (data.type === "request") {
+                    quotaManager.showQuotaLimitToast(data.used, data.limit)
+                    return
+                }
+                if (data.type === "token") {
+                    quotaManager.showTokenLimitToast(data.used, data.limit)
+                    return
+                }
+                if (data.type === "tpm") {
+                    quotaManager.showTPMLimitToast(data.limit)
+                    return
+                }
+            } catch {
+                // Not JSON, fall through to string matching for backwards compatibility
+            }
+
+            // Fallback to string matching
+            if (error.message.includes("Daily request limit")) {
+                quotaManager.showQuotaLimitToast()
+                return
+            }
+            if (error.message.includes("Daily token limit")) {
+                quotaManager.showTokenLimitToast()
+                return
+            }
+            if (
+                error.message.includes("Rate limit exceeded") ||
+                error.message.includes("tokens per minute")
+            ) {
+                quotaManager.showTPMLimitToast()
+                return
+            }
+
             // Silence access code error in console since it's handled by UI
             if (!error.message.includes("Invalid or missing access code")) {
                 console.error("Chat error:", error)
@@ -609,8 +364,7 @@ Continue from EXACTLY where you stopped.`,
             })
 
             if (error.message.includes("Invalid or missing access code")) {
-                // Show settings button and open dialog to help user fix it
-                setAccessCodeRequired(true)
+                // Show settings dialog to help user fix it
                 setShowSettingsDialog(true)
             }
         },
@@ -622,22 +376,6 @@ Continue from EXACTLY where you stopped.`,
 
             // DEBUG: Log finish reason to diagnose truncation
             console.log("[onFinish] finishReason:", metadata?.finishReason)
-            console.log("[onFinish] metadata:", metadata)
-
-            if (metadata) {
-                // Use Number.isFinite to guard against NaN (typeof NaN === 'number' is true)
-                const inputTokens = Number.isFinite(metadata.inputTokens)
-                    ? (metadata.inputTokens as number)
-                    : 0
-                const outputTokens = Number.isFinite(metadata.outputTokens)
-                    ? (metadata.outputTokens as number)
-                    : 0
-                const actualTokens = inputTokens + outputTokens
-                if (actualTokens > 0) {
-                    quotaManager.incrementTokenCount(actualTokens)
-                    quotaManager.incrementTPMCount(actualTokens)
-                }
-            }
         },
         sendAutomaticallyWhen: ({ messages }) => {
             const isInContinuationMode = partialXmlRef.current.length > 0
@@ -649,15 +387,25 @@ Continue from EXACTLY where you stopped.`,
             if (!shouldRetry) {
                 // No error, reset retry count and clear state
                 autoRetryCountRef.current = 0
+                continuationRetryCountRef.current = 0
                 partialXmlRef.current = ""
                 return false
             }
 
-            // Continuation mode: unlimited retries (truncation continuation, not real errors)
-            // Server limits to 5 steps via stepCountIs(5)
+            // Continuation mode: limited retries for truncation handling
             if (isInContinuationMode) {
-                // Don't count against retry limit for continuation
-                // Quota checks still apply below
+                if (
+                    continuationRetryCountRef.current >=
+                    MAX_CONTINUATION_RETRY_COUNT
+                ) {
+                    toast.error(
+                        `Continuation retry limit reached (${MAX_CONTINUATION_RETRY_COUNT}). The diagram may be too complex.`,
+                    )
+                    continuationRetryCountRef.current = 0
+                    partialXmlRef.current = ""
+                    return false
+                }
+                continuationRetryCountRef.current++
             } else {
                 // Regular error: check retry count limit
                 if (autoRetryCountRef.current >= MAX_AUTO_RETRY_COUNT) {
@@ -672,30 +420,10 @@ Continue from EXACTLY where you stopped.`,
                 autoRetryCountRef.current++
             }
 
-            // Check quota limits before auto-retry
-            const tokenLimitCheck = quotaManager.checkTokenLimit()
-            if (!tokenLimitCheck.allowed) {
-                quotaManager.showTokenLimitToast(tokenLimitCheck.used)
-                autoRetryCountRef.current = 0
-                partialXmlRef.current = ""
-                return false
-            }
-
-            const tpmCheck = quotaManager.checkTPMLimit()
-            if (!tpmCheck.allowed) {
-                quotaManager.showTPMLimitToast()
-                autoRetryCountRef.current = 0
-                partialXmlRef.current = ""
-                return false
-            }
-
             return true
         },
     })
 
-    // Update stopRef so onToolCall can access it
-    stopRef.current = stop
-
     // Ref to track latest messages for unload persistence
     const messagesRef = useRef(messages)
     useEffect(() => {
@@ -905,9 +633,6 @@ Continue from EXACTLY where you stopped.`,
                 xmlSnapshotsRef.current.set(messageIndex, chartXml)
                 saveXmlSnapshots()
 
-                // Check all quota limits
-                if (!checkAllQuotaLimits()) return
-
                 sendChatMessage(parts, chartXml, previousXml, sessionId)
 
                 // Token count is tracked in onFinish with actual server usage
@@ -985,30 +710,7 @@ Continue from EXACTLY where you stopped.`,
         saveXmlSnapshots()
     }
 
-    // Check all quota limits (daily requests, tokens, TPM)
-    const checkAllQuotaLimits = (): boolean => {
-        const limitCheck = quotaManager.checkDailyLimit()
-        if (!limitCheck.allowed) {
-            quotaManager.showQuotaLimitToast()
-            return false
-        }
-
-        const tokenLimitCheck = quotaManager.checkTokenLimit()
-        if (!tokenLimitCheck.allowed) {
-            quotaManager.showTokenLimitToast(tokenLimitCheck.used)
-            return false
-        }
-
-        const tpmCheck = quotaManager.checkTPMLimit()
-        if (!tpmCheck.allowed) {
-            quotaManager.showTPMLimitToast()
-            return false
-        }
-
-        return true
-    }
-
-    // Send chat message with headers and increment quota
+    // Send chat message with headers
     const sendChatMessage = (
         parts: any,
         xml: string,
@@ -1017,9 +719,10 @@ Continue from EXACTLY where you stopped.`,
     ) => {
         // Reset all retry/continuation state on user-initiated message
         autoRetryCountRef.current = 0
+        continuationRetryCountRef.current = 0
         partialXmlRef.current = ""
 
-        const config = getAIConfig()
+        const config = getSelectedAIConfig()
 
         sendMessage(
             { parts },
@@ -1036,6 +739,20 @@ Continue from EXACTLY where you stopped.`,
                             "x-ai-api-key": config.aiApiKey,
                         }),
                         ...(config.aiModel && { "x-ai-model": config.aiModel }),
+                        // AWS Bedrock credentials
+                        ...(config.awsAccessKeyId && {
+                            "x-aws-access-key-id": config.awsAccessKeyId,
+                        }),
+                        ...(config.awsSecretAccessKey && {
+                            "x-aws-secret-access-key":
+                                config.awsSecretAccessKey,
+                        }),
+                        ...(config.awsRegion && {
+                            "x-aws-region": config.awsRegion,
+                        }),
+                        ...(config.awsSessionToken && {
+                            "x-aws-session-token": config.awsSessionToken,
+                        }),
                     }),
                     ...(minimalStyle && {
                         "x-minimal-style": "true",
@@ -1043,7 +760,6 @@ Continue from EXACTLY where you stopped.`,
                 },
             },
         )
-        quotaManager.incrementRequestCount()
     }
 
     // Process files and append content to user text (handles PDF, text, and optionally images)
@@ -1131,13 +847,8 @@ Continue from EXACTLY where you stopped.`,
             setMessages(newMessages)
         })
 
-        // Check all quota limits
-        if (!checkAllQuotaLimits()) return
-
         // Now send the message after state is guaranteed to be updated
         sendChatMessage(userParts, savedXml, previousXml, sessionId)
-
-        // Token count is tracked in onFinish with actual server usage
     }
 
     const handleEditMessage = async (messageIndex: number, newText: string) => {
@@ -1179,12 +890,8 @@ Continue from EXACTLY where you stopped.`,
             setMessages(newMessages)
         })
 
-        // Check all quota limits
-        if (!checkAllQuotaLimits()) return
-
         // Now send the edited message after state is guaranteed to be updated
         sendChatMessage(newParts, savedXml, previousXml, sessionId)
-        // Token count is tracked in onFinish with actual server usage
     }
 
     // Collapsed view (desktop only)
@@ -1248,32 +955,18 @@ Continue from EXACTLY where you stopped.`,
                                 Next AI Drawio
                             </h1>
                         </div>
-                        {!isMobile && (
-                            <Link
-                                href="/about"
-                                target="_blank"
-                                rel="noopener noreferrer"
-                                className="text-sm text-muted-foreground hover:text-foreground transition-colors ml-2"
-                            >
-                                About
-                            </Link>
-                        )}
-                        {!isMobile && (
-                            <Link
-                                href="/about"
-                                target="_blank"
-                                rel="noopener noreferrer"
-                            >
-                                <ButtonWithTooltip
-                                    tooltipContent="Due to high usage, I have changed the model to minimax-m2 and added some usage limits. See About page for details."
-                                    variant="ghost"
-                                    size="icon"
-                                    className="h-6 w-6 text-amber-500 hover:text-amber-600"
+                        {!isMobile &&
+                            process.env.NEXT_PUBLIC_SHOW_ABOUT_AND_NOTICE ===
+                                "true" && (
+                                <Link
+                                    href="/about"
+                                    target="_blank"
+                                    rel="noopener noreferrer"
+                                    className="text-sm text-muted-foreground hover:text-foreground transition-colors ml-2"
                                 >
-                                    <AlertTriangle className="h-4 w-4" />
-                                </ButtonWithTooltip>
-                            </Link>
-                        )}
+                                    About
+                                </Link>
+                            )}
                     </div>
                     <div className="flex items-center gap-1 justify-end overflow-visible">
                         <ButtonWithTooltip
@@ -1288,16 +981,23 @@ Continue from EXACTLY where you stopped.`,
                             />
                         </ButtonWithTooltip>
                         <div className="w-px h-5 bg-border mx-1" />
-                        <a
-                            href="https://github.com/DayuanJiang/next-ai-draw-io"
-                            target="_blank"
-                            rel="noopener noreferrer"
-                            className="p-2 rounded-lg text-muted-foreground hover:text-foreground hover:bg-accent transition-colors"
-                        >
-                            <FaGithub
-                                className={`${isMobile ? "w-4 h-4" : "w-5 h-5"}`}
-                            />
-                        </a>
+
+                        <Tooltip>
+                            <TooltipTrigger asChild>
+                                <a
+                                    href="https://github.com/DayuanJiang/next-ai-draw-io"
+                                    target="_blank"
+                                    rel="noopener noreferrer"
+                                    className="inline-flex items-center justify-center h-9 w-9 rounded-md text-muted-foreground hover:text-foreground hover:bg-accent transition-colors"
+                                >
+                                    <FaGithub
+                                        className={`${isMobile ? "w-4 h-4" : "w-5 h-5"}`}
+                                    />
+                                </a>
+                            </TooltipTrigger>
+                            <TooltipContent>{dict.nav.github}</TooltipContent>
+                        </Tooltip>
+
                         <ButtonWithTooltip
                             tooltipContent={dict.nav.settings}
                             variant="ghost"
@@ -1310,7 +1010,6 @@ Continue from EXACTLY where you stopped.`,
                             />
                         </ButtonWithTooltip>
                         <div className="hidden sm:flex items-center gap-2">
-                            <LanguageToggle />
                             {!isMobile && (
                                 <ButtonWithTooltip
                                     tooltipContent={dict.nav.hidePanel}
@@ -1342,6 +1041,14 @@ Continue from EXACTLY where you stopped.`,
                 />
             </main>
 
+            {/* Dev XML Streaming Simulator - only in development */}
+            {DEBUG && (
+                <DevXmlSimulator
+                    setMessages={setMessages}
+                    onDisplayChart={onDisplayChart}
+                />
+            )}
+
             {/* Input */}
             <footer
                 className={`${isMobile ? "p-2" : "p-4"} border-t border-border/50 bg-card/50`}
@@ -1361,6 +1068,10 @@ Continue from EXACTLY where you stopped.`,
                     error={error}
                     minimalStyle={minimalStyle}
                     onMinimalStyleChange={setMinimalStyle}
+                    models={modelConfig.models}
+                    selectedModelId={modelConfig.selectedModelId}
+                    onModelSelect={modelConfig.setSelectedModelId}
+                    onConfigureModels={() => setShowModelConfigDialog(true)}
                 />
             </footer>
 
@@ -1374,6 +1085,12 @@ Continue from EXACTLY where you stopped.`,
                 onToggleDarkMode={onToggleDarkMode}
             />
 
+            <ModelConfigDialog
+                open={showModelConfigDialog}
+                onOpenChange={setShowModelConfigDialog}
+                modelConfig={modelConfig}
+            />
+
             <ResetWarningModal
                 open={showNewChatDialog}
                 onOpenChange={setShowNewChatDialog}

components/dev-xml-simulator.tsx

@@ -0,0 +1,350 @@
+"use client"
+
+import { useEffect, useRef, useState } from "react"
+import { wrapWithMxFile } from "@/lib/utils"
+
+// Dev XML presets for streaming simulator
+const DEV_XML_PRESETS: Record<string, string> = {
+    "Simple Box": `<mxCell id="2" value="Hello World" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#dae8fc;strokeColor=#6c8ebf;" vertex="1" parent="1">
+  <mxGeometry x="120" y="100" width="120" height="60" as="geometry"/>
+</mxCell>`,
+    "Two Boxes with Arrow": `<mxCell id="2" value="Start" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#d5e8d4;strokeColor=#82b366;" vertex="1" parent="1">
+  <mxGeometry x="100" y="100" width="100" height="50" as="geometry"/>
+</mxCell>
+<mxCell id="3" value="End" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#f8cecc;strokeColor=#b85450;" vertex="1" parent="1">
+  <mxGeometry x="300" y="100" width="100" height="50" as="geometry"/>
+</mxCell>
+<mxCell id="4" value="" style="endArrow=classic;html=1;" edge="1" parent="1" source="2" target="3">
+  <mxGeometry relative="1" as="geometry"/>
+</mxCell>`,
+    Flowchart: `<mxCell id="2" value="Start" style="ellipse;whiteSpace=wrap;html=1;fillColor=#d5e8d4;strokeColor=#82b366;" vertex="1" parent="1">
+  <mxGeometry x="160" y="40" width="80" height="40" as="geometry"/>
+</mxCell>
+<mxCell id="3" value="Process A" style="rounded=0;whiteSpace=wrap;html=1;fillColor=#dae8fc;strokeColor=#6c8ebf;" vertex="1" parent="1">
+  <mxGeometry x="140" y="120" width="120" height="60" as="geometry"/>
+</mxCell>
+<mxCell id="4" value="Decision" style="rhombus;whiteSpace=wrap;html=1;fillColor=#fff2cc;strokeColor=#d6b656;" vertex="1" parent="1">
+  <mxGeometry x="150" y="220" width="100" height="80" as="geometry"/>
+</mxCell>
+<mxCell id="5" value="Process B" style="rounded=0;whiteSpace=wrap;html=1;fillColor=#dae8fc;strokeColor=#6c8ebf;" vertex="1" parent="1">
+  <mxGeometry x="300" y="230" width="120" height="60" as="geometry"/>
+</mxCell>
+<mxCell id="6" value="End" style="ellipse;whiteSpace=wrap;html=1;fillColor=#f8cecc;strokeColor=#b85450;" vertex="1" parent="1">
+  <mxGeometry x="160" y="340" width="80" height="40" as="geometry"/>
+</mxCell>
+<mxCell id="7" style="endArrow=classic;html=1;" edge="1" parent="1" source="2" target="3">
+  <mxGeometry relative="1" as="geometry"/>
+</mxCell>
+<mxCell id="8" style="endArrow=classic;html=1;" edge="1" parent="1" source="3" target="4">
+  <mxGeometry relative="1" as="geometry"/>
+</mxCell>
+<mxCell id="9" value="Yes" style="endArrow=classic;html=1;" edge="1" parent="1" source="4" target="6">
+  <mxGeometry relative="1" as="geometry"/>
+</mxCell>
+<mxCell id="10" value="No" style="endArrow=classic;html=1;exitX=1;exitY=0.5;exitDx=0;exitDy=0;" edge="1" parent="1" source="4" target="5">
+  <mxGeometry relative="1" as="geometry"/>
+</mxCell>`,
+    "Truncated (Error Test)": `<mxCell id="2" value="This cell is truncated" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#dae8fc;strokeColor=#6c8ebf;" vertex="1" parent="1">
+  <mxGeometry x="120" y="100" width="120" height="60" as="geometry"/>
+</mxCell>
+<mxCell id="3" value="Incomplete" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#f8cecc;strokeColor`,
+    "HTML Escape + Cell Truncate": `<mxCell id="2" value="<b>Chain-of-Thought Prompting</b><br/><font size='12'>Eliciting Reasoning in Large Language Models</font>" style="rounded=0;whiteSpace=wrap;html=1;fillColor=#dae8fc;strokeColor=#6c8ebf;fontSize=16;fontStyle=1;" vertex="1" parent="1">
+  <mxGeometry x="40" y="40" width="720" height="60" as="geometry"/>
+</mxCell>
+<mxCell id="3" value="<b>Problem: LLM Reasoning Limitations</b><br/>• Scaling parameters alone insufficient for logical tasks<br/>• Arithmetic, commonsense, symbolic reasoning challenges<br/>• Standard prompting fails on multi-step problems" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#ffe6cc;strokeColor=#d79b00;" vertex="1" parent="1">
+  <mxGeometry x="40" y="120" width="340" height="120" as="geometry"/>
+</mxCell>
+<mxCell id="4" value="<b>Traditional Approaches</b><br/>1. <b>Finetuning:</b> Expensive, task-specific<br/>2. <b>Standard Few-Shot:</b> Input→Output pairs<br/>   (No explanation of reasoning)" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#fff2cc;strokeColor=#d6b656;" vertex="1" parent="1">
+  <mxGeometry x="420" y="120" width="340" height="120" as="geometry"/>
+</mxCell>
+<mxCell id="5" value="<b>CoT Methodology</b><br/>• Add reasoning steps to few-shot examples<br/>• Natural language intermediate steps<br/>• No parameter updates needed<br/>• Model learns to generate own thought process" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#d5e8d4;strokeColor=#82b366;" vertex="1" parent="1">
+  <mxGeometry x="40" y="260" width="340" height="100" as="geometry"/>
+</mxCell>
+<mxCell id="6" value="<b>Example Comparison</b><br/><b>Standard:</b><br/>Q: Roger has 5 balls. He buys 2 cans of 3 balls. How many?<br/>A: 11.<br/><br/><b>CoT:</b><br/>Q: Roger has 5 balls. He buys 2 cans of 3 balls. How many?<br/>A: Roger started with 5 balls. 2 cans of 3 tennis balls each is 6 tennis balls. 5 + 6 = 11. The answer is 11." style="rounded=1;whiteSpace=wrap;html=1;fillColor=#e1d5e7;strokeColor=#9673a6;" vertex="1" parent="1">
+  <mxGeometry x="420" y="260" width="340" height="140" as="geometry"/>
+</mxCell>
+<mxCell id="7" value="<b>Experimental Models</b><br/>• GPT-3 (175B)<br/>• LaMDA (137B)<br/>• PaLM (540B)<br/>• UL2 (20B)<br/>• Codex" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#f8cecc;strokeColor=#b85450;" vertex="1" parent="1">
+  <mxGeometry x="40" y="380" width="340" height="100" as="geometry"/>
+</mxCell>
+<mxCell id="8" value="<b>Reasoning Domains Tested</b><br/>1. <b>Arithmetic:</b> GSM8K, SVAMP, ASDiv, AQuA, MAWPS<br/>2. <b>Commonsense:</b> CSQA, StrategyQA, Date Understanding, Sports Understanding<br/>3. <b>Symbolic:</b> Last Letter Concatenation, Coin Flip" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#f5f5f5;strokeColor=#666666;" vertex="1" parent="1">
+  <mxGeometry x="420" y="420" width="340" height="100" as="geometry"/>
+</mxCell>
+<mxCell id="9" value="<b>Key Results: Arithmetic</b><br/>• PaLM 540B + CoT: <b>56.9%</b> on GSM8K<br/>   (vs 17.9% standard)<br/>• Surpassed finetuned GPT-3 (55%)<br/>• With calculator: <b>58.6%</b>" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#d5e8d4;strokeColor=#82b366;" vertex="1" parent="1">
+  <mxGeometry x="40" y="500" width="220" height="100" as="geometry"/>
+</mxCell>
+<mxCell id="10" value="<b>Key Results: Commonsense</b><br/>• StrategyQA: <b>75.6%</b><br/>   (vs 69.4% SOTA)<br/>• Sports Understanding: <b>95.4%</b><br/>   (vs 84% human)" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#d5e8d4;strokeColor=#82b366;" vertex="1" parent="1">
+  <mxGeometry x="280" y="500" width="220" height="100" as="geometry"/>
+</mxCell>
+<mxCell id="11" value="<b>Key Results: Symbolic</b><br/>• OOD Generalization<br/>• Coin Flip: Trained on 2 flips<br/>   Works on 3-4 flips with CoT<br/>• Standard prompting fails" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#d5e8d4;strokeColor=#82b366;" vertex="1" parent="1">
+  <mxGeometry x="540" y="500" width="220" height="100" as="geometry"/>
+</mxCell>
+<mxCell id="12" value="<b>Emergent Ability of Scale</b><br/>• Small models (&lt;10B): No benefit, often harmful<br/>• Large models (100B+): Reasoning emerges<br/>• CoT gains increase dramatically with scale" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#ffe6cc;strokeColor=#d79b00;" vertex="1" parent="1">
+  <mxGeometry x="40" y="620" width="340" height="80" as="geometry"/>
+</mxCell>
+<mxCell id="13" value="<b>Ablation Studies</b><br/>1. Equation only: Worse than CoT<br/>2. Variable compute (...): No improvement<br/>3. Answer first, then reasoning: Same as baseline<br/>→ Content matters, not just extra tokens" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#fff2cc;strokeColor=#d6b656;" vertex="1" parent="1">
+  <mxGeometry x="420" y="620" width="340" height="80" as="geometry"/>
+</mxCell>
+<mxCell id="14" value="<b>Error Analysis</b><br/>• Semantic understanding errors<br/>• One-step missing errors<br/>• Calculation errors<br/>• Larger models reduce semantic/missing-step errors" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#f8cecc;strokeColor=#b85450;" vertex="1" parent="1">
+  <mxGeometry x="40" y="720" width="340" height="80" as="geometry"/>
+</mxCell>
+<mxCell id="15" value="<b>Conclusion</b><br/>• CoT unlocks reasoning potential<br/>• Simple paradigm: &quot;show your work&quot;<br/>• Emergent capability of large models<br/>• No specialized architecture needed" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#dae8fc;strokeColor=#6c8ebf;" vertex="1" parent="1">
+  <mxGeometry x="420" y="720" width="340" height="80" as="geometry"/>
+</mxCell>
+<mxCell id="16" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;exitX=0.5;exitY=1;entryX=0.5;entryY=0;" edge="1" parent="1" source="3" target="5">
+  <mxGeometry relative="1" as="geometry"/>
+</mxCell>
+<mxCell id="17" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;exitX=0.5;exitY=1;entryX=0.5;entryY=0;" edge="1" parent="1" source="4" target="6">
+  <mxGeometry relative="1" as="geometry"/>
+</mxCell>
+<mxCell id="18" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;exitX=0.5;exitY=1;entryX=0.5;entryY=0;" edge="1" parent="1" source="5" target="7">
+  <mxGeometry relative="1" as="geometry"/>
+</mxCell>
+<mxCell id="19" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;exitX=0.5;exitY=1;entryX=0.5;entryY=0;" edge="1" parent="1" source="6" target="8">
+  <mxGeometry relative="1" as="geometry"/>
+</mxCell>
+<mxCell id="20" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;exitX=0.5;exitY=1;entryX=0.25;entryY=0;" edge="1" parent="1" source="7" target="9">
+  <mxGeometry relative="1" as="geometry"/>
+</mxCell>
+<mxCell id="21" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;exitX=0.5;exitY=1;entryX=0.5;entryY=0;" edge="1" parent="1" source="7" target="10">
+  <mxGeometry relative="1" as="geometry"/>
+</mxCell>
+<mxCell id="22" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;exitX=0.5;exitY=1;entryX=0.75;entryY=0;" edge="1" parent="1" source="7" target="11">
+  <mxGeometry relative="1" as="geometry"/>
+</mxCell>
+<mxCell id="23" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;exitX=0.5;exitY=1;entryX=0.5;entryY=0;" edge="1" parent="1" source="9" target="12">
+  <mxGeometry relative="1" as="geometry"/>
+</mxCell>
+<mxCell id="24" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;exitX=0.5;exitY=1;entryX=0.5;entryY=0;" edge="1" parent="1" source="10" target="13">
+  <mxGeometry relative="1" as="geometry"/>
+</mxCell>
+<mxCell id="25" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;exitX=0.5;exitY=1;entryX=0.5;entryY=0;" edge="1" parent="1" source="11" target="14">
+  <mxGeometry relative="1" as="geometry"/>
+</mxCell>
+<mxCell id="26" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;exitX=0.5;exitY=1;entryX=0.5;entryY=0;" edge="1" parent="1" source="12" target="15">
+  <mxGeometry relative="1" as="geometry"/>
+</mxCell>
+<mxCell id="27" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;exitX=0.5;exitY=1;entryX=0.5;entryY=0;" edge="1" parent="1" source="13" target="15">
+  <mxGeometry relative="1" as="geometry"/>
+</mxCell>
+<mxCell id="28" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;exitX=0.5;exitY=1;entryX=0.5;entryY=0;" edge="1" parent="1" source="14" target="15">
+  <mxGeometry relative="1" as="geometry"/>
+</mxCell>`,
+}
+
+interface DevXmlSimulatorProps {
+    setMessages: React.Dispatch<React.SetStateAction<any[]>>
+    onDisplayChart: (xml: string) => void
+}
+
+export function DevXmlSimulator({
+    setMessages,
+    onDisplayChart,
+}: DevXmlSimulatorProps) {
+    const [devXml, setDevXml] = useState("")
+    const [isSimulating, setIsSimulating] = useState(false)
+    const [devIntervalMs, setDevIntervalMs] = useState(1)
+    const [devChunkSize, setDevChunkSize] = useState(10)
+    const devStopRef = useRef(false)
+    const devXmlInitializedRef = useRef(false)
+
+    // Restore dev XML from localStorage on mount (after hydration)
+    useEffect(() => {
+        const saved = localStorage.getItem("dev-xml-simulator")
+        if (saved) setDevXml(saved)
+        devXmlInitializedRef.current = true
+    }, [])
+
+    // Save dev XML to localStorage (only after initial load)
+    useEffect(() => {
+        if (devXmlInitializedRef.current) {
+            localStorage.setItem("dev-xml-simulator", devXml)
+        }
+    }, [devXml])
+
+    const handleDevSimulate = async () => {
+        if (!devXml.trim() || isSimulating) return
+
+        setIsSimulating(true)
+        devStopRef.current = false
+        const toolCallId = `dev-sim-${Date.now()}`
+        const xml = devXml.trim()
+
+        // Add user message and initial assistant message with empty XML
+        const userMsg = {
+            id: `user-${Date.now()}`,
+            role: "user" as const,
+            parts: [
+                {
+                    type: "text" as const,
+                    text: "[Dev] Simulating XML streaming",
+                },
+            ],
+        }
+        const assistantMsg = {
+            id: `assistant-${Date.now()}`,
+            role: "assistant" as const,
+            parts: [
+                {
+                    type: "tool-display_diagram" as const,
+                    toolCallId,
+                    state: "input-streaming" as const,
+                    input: { xml: "" },
+                },
+            ],
+        }
+        setMessages((prev) => [...prev, userMsg, assistantMsg] as any)
+
+        // Stream characters progressively
+        for (let i = 0; i < xml.length; i += devChunkSize) {
+            if (devStopRef.current) {
+                setIsSimulating(false)
+                return
+            }
+
+            const chunk = xml.slice(0, i + devChunkSize)
+
+            setMessages((prev) => {
+                const updated = [...prev]
+                const lastMsg = updated[updated.length - 1] as any
+                if (lastMsg?.role === "assistant" && lastMsg.parts?.[0]) {
+                    lastMsg.parts[0].input = { xml: chunk }
+                }
+                return updated
+            })
+
+            await new Promise((r) => setTimeout(r, devIntervalMs))
+        }
+
+        if (devStopRef.current) {
+            setIsSimulating(false)
+            return
+        }
+
+        // Finalize: set state to output-available
+        setMessages((prev) => {
+            const updated = [...prev]
+            const lastMsg = updated[updated.length - 1] as any
+            if (lastMsg?.role === "assistant" && lastMsg.parts?.[0]) {
+                lastMsg.parts[0].state = "output-available"
+                lastMsg.parts[0].output = "Successfully displayed the diagram."
+                lastMsg.parts[0].input = { xml }
+            }
+            return updated
+        })
+
+        // Display the final diagram
+        const fullXml = wrapWithMxFile(xml)
+        onDisplayChart(fullXml)
+
+        setIsSimulating(false)
+    }
+
+    return (
+        <div className="border-t border-dashed border-orange-500/50 px-4 py-2 bg-orange-50/50 dark:bg-orange-950/30">
+            <details>
+                <summary className="text-xs text-orange-600 dark:text-orange-400 cursor-pointer font-medium">
+                    Dev: XML Streaming Simulator
+                </summary>
+                <div className="mt-2 space-y-2">
+                    <div className="flex items-center gap-2">
+                        <label className="text-xs text-muted-foreground whitespace-nowrap">
+                            Preset:
+                        </label>
+                        <select
+                            onChange={(e) => {
+                                if (e.target.value) {
+                                    setDevXml(DEV_XML_PRESETS[e.target.value])
+                                }
+                            }}
+                            className="flex-1 text-xs p-1 border rounded bg-background"
+                            defaultValue=""
+                        >
+                            <option value="" disabled>
+                                Select a preset...
+                            </option>
+                            {Object.keys(DEV_XML_PRESETS).map((name) => (
+                                <option key={name} value={name}>
+                                    {name}
+                                </option>
+                            ))}
+                        </select>
+                        <button
+                            type="button"
+                            onClick={() => setDevXml("")}
+                            className="px-2 py-1 text-xs text-muted-foreground hover:text-foreground border rounded"
+                        >
+                            Clear
+                        </button>
+                    </div>
+                    <textarea
+                        value={devXml}
+                        onChange={(e) => setDevXml(e.target.value)}
+                        placeholder="Paste mxCell XML here or select a preset..."
+                        className="w-full h-24 text-xs font-mono p-2 border rounded bg-background"
+                    />
+                    <div className="flex items-center gap-4">
+                        <div className="flex items-center gap-2 flex-1">
+                            <label className="text-xs text-muted-foreground whitespace-nowrap">
+                                Interval:
+                            </label>
+                            <input
+                                type="range"
+                                min="1"
+                                max="200"
+                                step="1"
+                                value={devIntervalMs}
+                                onChange={(e) =>
+                                    setDevIntervalMs(Number(e.target.value))
+                                }
+                                className="flex-1 h-1 accent-orange-500"
+                            />
+                            <span className="text-xs text-muted-foreground w-12">
+                                {devIntervalMs}ms
+                            </span>
+                        </div>
+                        <div className="flex items-center gap-2">
+                            <label className="text-xs text-muted-foreground whitespace-nowrap">
+                                Chars:
+                            </label>
+                            <input
+                                type="number"
+                                min="1"
+                                max="100"
+                                value={devChunkSize}
+                                onChange={(e) =>
+                                    setDevChunkSize(
+                                        Math.max(1, Number(e.target.value)),
+                                    )
+                                }
+                                className="w-14 text-xs p-1 border rounded bg-background"
+                            />
+                        </div>
+                    </div>
+                    <div className="flex gap-2">
+                        <button
+                            type="button"
+                            onClick={handleDevSimulate}
+                            disabled={isSimulating || !devXml.trim()}
+                            className="px-3 py-1 text-xs bg-orange-500 text-white rounded hover:bg-orange-600 disabled:opacity-50 disabled:cursor-not-allowed"
+                        >
+                            {isSimulating
+                                ? "Streaming..."
+                                : `Simulate (${devChunkSize} chars/${devIntervalMs}ms)`}
+                        </button>
+                        {isSimulating && (
+                            <button
+                                type="button"
+                                onClick={() => {
+                                    devStopRef.current = true
+                                }}
+                                className="px-3 py-1 text-xs bg-red-500 text-white rounded hover:bg-red-600"
+                            >
+                                Stop
+                            </button>
+                        )}
+                    </div>
+                </div>
+            </details>
+        </div>
+    )
+}

components/language-toggle.tsx

@@ -1,108 +0,0 @@
-"use client"
-
-import { Globe } from "lucide-react"
-import { usePathname, useRouter, useSearchParams } from "next/navigation"
-import { Suspense, useEffect, useRef, useState } from "react"
-import { i18n, type Locale } from "@/lib/i18n/config"
-
-const LABELS: Record<string, string> = {
-    en: "EN",
-    zh: "中文",
-    ja: "日本語",
-}
-
-function LanguageToggleInner({ className = "" }: { className?: string }) {
-    const router = useRouter()
-    const pathname = usePathname() || "/"
-    const search = useSearchParams()
-    const [open, setOpen] = useState(false)
-    const [value, setValue] = useState<Locale>(i18n.defaultLocale)
-    const ref = useRef<HTMLDivElement | null>(null)
-
-    useEffect(() => {
-        const seg = pathname.split("/").filter(Boolean)
-        const first = seg[0]
-        if (first && i18n.locales.includes(first as Locale))
-            setValue(first as Locale)
-        else setValue(i18n.defaultLocale)
-    }, [pathname])
-
-    useEffect(() => {
-        function onDoc(e: MouseEvent) {
-            if (!ref.current) return
-            if (!ref.current.contains(e.target as Node)) setOpen(false)
-        }
-        if (open) document.addEventListener("mousedown", onDoc)
-        return () => document.removeEventListener("mousedown", onDoc)
-    }, [open])
-
-    const changeLocale = (lang: string) => {
-        const parts = pathname.split("/")
-        if (parts.length > 1 && i18n.locales.includes(parts[1] as Locale)) {
-            parts[1] = lang
-        } else {
-            parts.splice(1, 0, lang)
-        }
-        const newPath = parts.join("/") || "/"
-        const searchStr = search?.toString() ? `?${search.toString()}` : ""
-        setOpen(false)
-        router.push(newPath + searchStr)
-    }
-
-    return (
-        <div className={`relative inline-flex ${className}`} ref={ref}>
-            <button
-                aria-haspopup="menu"
-                aria-expanded={open}
-                onClick={() => setOpen((s) => !s)}
-                className="p-2 rounded-full hover:bg-accent/20 transition-colors text-muted-foreground"
-                aria-label="Change language"
-            >
-                <Globe className="w-5 h-5" />
-            </button>
-            {open && (
-                <div className="absolute right-0 top-full mt-2 w-40 bg-popover dark:bg-popover text-popover-foreground rounded-xl shadow-md border border-border/30 overflow-hidden z-50">
-                    <div className="grid gap-0 divide-y divide-border/30">
-                        {i18n.locales.map((loc) => (
-                            <button
-                                key={loc}
-                                onClick={() => changeLocale(loc)}
-                                className={`flex items-center gap-2 px-4 py-2 text-sm w-full text-left hover:bg-accent/10 transition-colors ${value === loc ? "bg-accent/10 font-semibold" : ""}`}
-                            >
-                                <span className="flex-1">
-                                    {LABELS[loc] ?? loc}
-                                </span>
-                                {value === loc && (
-                                    <span className="text-xs opacity-70">
-                                        ✓
-                                    </span>
-                                )}
-                            </button>
-                        ))}
-                    </div>
-                </div>
-            )}
-        </div>
-    )
-}
-
-export default function LanguageToggle({
-    className = "",
-}: {
-    className?: string
-}) {
-    return (
-        <Suspense
-            fallback={
-                <button
-                    className="p-2 rounded-full text-muted-foreground opacity-50"
-                    disabled
-                >
-                    <Globe className="w-5 h-5" />
-                </button>
-            }
-        >
-            <LanguageToggleInner className={className} />
-        </Suspense>
-    )
-}

components/model-selector.tsx

@@ -0,0 +1,222 @@
+"use client"
+
+import { Bot, Check, ChevronDown, Server, Settings2 } from "lucide-react"
+import { useMemo, useState } from "react"
+import {
+    ModelSelectorContent,
+    ModelSelectorEmpty,
+    ModelSelectorGroup,
+    ModelSelectorInput,
+    ModelSelectorItem,
+    ModelSelectorList,
+    ModelSelectorLogo,
+    ModelSelectorName,
+    ModelSelector as ModelSelectorRoot,
+    ModelSelectorSeparator,
+    ModelSelectorTrigger,
+} from "@/components/ai-elements/model-selector"
+import { ButtonWithTooltip } from "@/components/button-with-tooltip"
+import { useDictionary } from "@/hooks/use-dictionary"
+import type { FlattenedModel } from "@/lib/types/model-config"
+import { cn } from "@/lib/utils"
+
+interface ModelSelectorProps {
+    models: FlattenedModel[]
+    selectedModelId: string | undefined
+    onSelect: (modelId: string | undefined) => void
+    onConfigure: () => void
+    disabled?: boolean
+}
+
+// Map our provider names to models.dev logo names
+const PROVIDER_LOGO_MAP: Record<string, string> = {
+    openai: "openai",
+    anthropic: "anthropic",
+    google: "google",
+    azure: "azure",
+    bedrock: "amazon-bedrock",
+    openrouter: "openrouter",
+    deepseek: "deepseek",
+    siliconflow: "siliconflow",
+    gateway: "vercel",
+}
+
+// Group models by providerLabel (handles duplicate providers)
+function groupModelsByProvider(
+    models: FlattenedModel[],
+): Map<string, { provider: string; models: FlattenedModel[] }> {
+    const groups = new Map<
+        string,
+        { provider: string; models: FlattenedModel[] }
+    >()
+    for (const model of models) {
+        const key = model.providerLabel
+        const existing = groups.get(key)
+        if (existing) {
+            existing.models.push(model)
+        } else {
+            groups.set(key, { provider: model.provider, models: [model] })
+        }
+    }
+    return groups
+}
+
+export function ModelSelector({
+    models,
+    selectedModelId,
+    onSelect,
+    onConfigure,
+    disabled = false,
+}: ModelSelectorProps) {
+    const dict = useDictionary()
+    const [open, setOpen] = useState(false)
+    // Only show validated models in the selector
+    const validatedModels = useMemo(
+        () => models.filter((m) => m.validated === true),
+        [models],
+    )
+    const groupedModels = useMemo(
+        () => groupModelsByProvider(validatedModels),
+        [validatedModels],
+    )
+
+    // Find selected model for display
+    const selectedModel = useMemo(
+        () => models.find((m) => m.id === selectedModelId),
+        [models, selectedModelId],
+    )
+
+    const handleSelect = (value: string) => {
+        if (value === "__configure__") {
+            onConfigure()
+        } else if (value === "__server_default__") {
+            onSelect(undefined)
+        } else {
+            onSelect(value)
+        }
+        setOpen(false)
+    }
+
+    const tooltipContent = selectedModel
+        ? `${selectedModel.modelId} ${dict.modelConfig.clickToChange}`
+        : `${dict.modelConfig.usingServerDefault} ${dict.modelConfig.clickToChange}`
+
+    return (
+        <ModelSelectorRoot open={open} onOpenChange={setOpen}>
+            <ModelSelectorTrigger asChild>
+                <ButtonWithTooltip
+                    tooltipContent={tooltipContent}
+                    variant="ghost"
+                    size="sm"
+                    disabled={disabled}
+                    className="hover:bg-accent gap-1.5 h-8 max-w-[180px] px-2"
+                >
+                    <Bot className="h-4 w-4 flex-shrink-0 text-muted-foreground" />
+                    <span className="text-xs truncate">
+                        {selectedModel
+                            ? selectedModel.modelId
+                            : dict.modelConfig.default}
+                    </span>
+                    <ChevronDown className="h-3 w-3 flex-shrink-0 text-muted-foreground" />
+                </ButtonWithTooltip>
+            </ModelSelectorTrigger>
+            <ModelSelectorContent title={dict.modelConfig.selectModel}>
+                <ModelSelectorInput
+                    placeholder={dict.modelConfig.searchModels}
+                />
+                <ModelSelectorList className="[&::-webkit-scrollbar]:hidden [-ms-overflow-style:none] [scrollbar-width:none]">
+                    <ModelSelectorEmpty>
+                        {validatedModels.length === 0 && models.length > 0
+                            ? dict.modelConfig.noVerifiedModels
+                            : dict.modelConfig.noModelsFound}
+                    </ModelSelectorEmpty>
+
+                    {/* Server Default Option */}
+                    <ModelSelectorGroup heading={dict.modelConfig.default}>
+                        <ModelSelectorItem
+                            value="__server_default__"
+                            onSelect={handleSelect}
+                            className={cn(
+                                "cursor-pointer",
+                                !selectedModelId && "bg-accent",
+                            )}
+                        >
+                            <Check
+                                className={cn(
+                                    "mr-2 h-4 w-4",
+                                    !selectedModelId
+                                        ? "opacity-100"
+                                        : "opacity-0",
+                                )}
+                            />
+                            <Server className="mr-2 h-4 w-4 text-muted-foreground" />
+                            <ModelSelectorName>
+                                {dict.modelConfig.serverDefault}
+                            </ModelSelectorName>
+                        </ModelSelectorItem>
+                    </ModelSelectorGroup>
+
+                    {/* Configured Models by Provider */}
+                    {Array.from(groupedModels.entries()).map(
+                        ([
+                            providerLabel,
+                            { provider, models: providerModels },
+                        ]) => (
+                            <ModelSelectorGroup
+                                key={providerLabel}
+                                heading={providerLabel}
+                            >
+                                {providerModels.map((model) => (
+                                    <ModelSelectorItem
+                                        key={model.id}
+                                        value={model.modelId}
+                                        onSelect={() => handleSelect(model.id)}
+                                        className="cursor-pointer"
+                                    >
+                                        <Check
+                                            className={cn(
+                                                "mr-2 h-4 w-4",
+                                                selectedModelId === model.id
+                                                    ? "opacity-100"
+                                                    : "opacity-0",
+                                            )}
+                                        />
+                                        <ModelSelectorLogo
+                                            provider={
+                                                PROVIDER_LOGO_MAP[provider] ||
+                                                provider
+                                            }
+                                            className="mr-2"
+                                        />
+                                        <ModelSelectorName>
+                                            {model.modelId}
+                                        </ModelSelectorName>
+                                    </ModelSelectorItem>
+                                ))}
+                            </ModelSelectorGroup>
+                        ),
+                    )}
+
+                    {/* Configure Option */}
+                    <ModelSelectorSeparator />
+                    <ModelSelectorGroup>
+                        <ModelSelectorItem
+                            value="__configure__"
+                            onSelect={handleSelect}
+                            className="cursor-pointer"
+                        >
+                            <Settings2 className="mr-2 h-4 w-4" />
+                            <ModelSelectorName>
+                                {dict.modelConfig.configureModels}
+                            </ModelSelectorName>
+                        </ModelSelectorItem>
+                    </ModelSelectorGroup>
+                    {/* Info text */}
+                    <div className="px-3 py-2 text-xs text-muted-foreground border-t">
+                        {dict.modelConfig.onlyVerifiedShown}
+                    </div>
+                </ModelSelectorList>
+            </ModelSelectorContent>
+        </ModelSelectorRoot>
+    )
+}

components/settings-dialog.tsx

@@ -1,7 +1,8 @@
 "use client"
 
 import { Moon, Sun } from "lucide-react"
-import { useEffect, useState } from "react"
+import { usePathname, useRouter, useSearchParams } from "next/navigation"
+import { Suspense, useEffect, useState } from "react"
 import { Button } from "@/components/ui/button"
 import {
     Dialog,
@@ -21,6 +22,40 @@ import {
 } from "@/components/ui/select"
 import { Switch } from "@/components/ui/switch"
 import { useDictionary } from "@/hooks/use-dictionary"
+import { getApiEndpoint } from "@/lib/base-path"
+import { i18n, type Locale } from "@/lib/i18n/config"
+import { cn } from "@/lib/utils"
+
+// Reusable setting item component for consistent layout
+function SettingItem({
+    label,
+    description,
+    children,
+}: {
+    label: string
+    description?: string
+    children: React.ReactNode
+}) {
+    return (
+        <div className="flex items-center justify-between py-4 first:pt-0 last:pb-0">
+            <div className="space-y-0.5 pr-4">
+                <Label className="text-sm font-medium">{label}</Label>
+                {description && (
+                    <p className="text-xs text-muted-foreground max-w-[260px]">
+                        {description}
+                    </p>
+                )}
+            </div>
+            <div className="shrink-0">{children}</div>
+        </div>
+    )
+}
+
+const LANGUAGE_LABELS: Record<Locale, string> = {
+    en: "English",
+    zh: "中文",
+    ja: "日本語",
+}
 
 interface SettingsDialogProps {
     open: boolean
@@ -35,10 +70,6 @@ interface SettingsDialogProps {
 export const STORAGE_ACCESS_CODE_KEY = "next-ai-draw-io-access-code"
 export const STORAGE_CLOSE_PROTECTION_KEY = "next-ai-draw-io-close-protection"
 const STORAGE_ACCESS_CODE_REQUIRED_KEY = "next-ai-draw-io-access-code-required"
-export const STORAGE_AI_PROVIDER_KEY = "next-ai-draw-io-ai-provider"
-export const STORAGE_AI_BASE_URL_KEY = "next-ai-draw-io-ai-base-url"
-export const STORAGE_AI_API_KEY_KEY = "next-ai-draw-io-ai-api-key"
-export const STORAGE_AI_MODEL_KEY = "next-ai-draw-io-ai-model"
 
 function getStoredAccessCodeRequired(): boolean | null {
     if (typeof window === "undefined") return null
@@ -47,7 +78,7 @@ function getStoredAccessCodeRequired(): boolean | null {
     return stored === "true"
 }
 
-export function SettingsDialog({
+function SettingsContent({
     open,
     onOpenChange,
     onCloseProtectionChange,
@@ -57,6 +88,9 @@ export function SettingsDialog({
     onToggleDarkMode,
 }: SettingsDialogProps) {
     const dict = useDictionary()
+    const router = useRouter()
+    const pathname = usePathname() || "/"
+    const search = useSearchParams()
     const [accessCode, setAccessCode] = useState("")
     const [closeProtection, setCloseProtection] = useState(true)
     const [isVerifying, setIsVerifying] = useState(false)
@@ -64,16 +98,13 @@ export function SettingsDialog({
     const [accessCodeRequired, setAccessCodeRequired] = useState(
         () => getStoredAccessCodeRequired() ?? false,
     )
-    const [provider, setProvider] = useState("")
-    const [baseUrl, setBaseUrl] = useState("")
-    const [apiKey, setApiKey] = useState("")
-    const [modelId, setModelId] = useState("")
+    const [currentLang, setCurrentLang] = useState("en")
 
     useEffect(() => {
         // Only fetch if not cached in localStorage
         if (getStoredAccessCodeRequired() !== null) return
 
-        fetch("/api/config")
+        fetch(getApiEndpoint("/api/config"))
             .then((res) => {
                 if (!res.ok) throw new Error(`HTTP ${res.status}`)
                 return res.json()
@@ -92,6 +123,17 @@ export function SettingsDialog({
             })
     }, [])
 
+    // Detect current language from pathname
+    useEffect(() => {
+        const seg = pathname.split("/").filter(Boolean)
+        const first = seg[0]
+        if (first && i18n.locales.includes(first as Locale)) {
+            setCurrentLang(first)
+        } else {
+            setCurrentLang(i18n.defaultLocale)
+        }
+    }, [pathname])
+
     useEffect(() => {
         if (open) {
             const storedCode =
@@ -104,16 +146,22 @@ export function SettingsDialog({
             // Default to true if not set
             setCloseProtection(storedCloseProtection !== "false")
 
-            // Load AI provider settings
-            setProvider(localStorage.getItem(STORAGE_AI_PROVIDER_KEY) || "")
-            setBaseUrl(localStorage.getItem(STORAGE_AI_BASE_URL_KEY) || "")
-            setApiKey(localStorage.getItem(STORAGE_AI_API_KEY_KEY) || "")
-            setModelId(localStorage.getItem(STORAGE_AI_MODEL_KEY) || "")
-
             setError("")
         }
     }, [open])
 
+    const changeLanguage = (lang: string) => {
+        const parts = pathname.split("/")
+        if (parts.length > 1 && i18n.locales.includes(parts[1] as Locale)) {
+            parts[1] = lang
+        } else {
+            parts.splice(1, 0, lang)
+        }
+        const newPath = parts.join("/") || "/"
+        const searchStr = search?.toString() ? `?${search.toString()}` : ""
+        router.push(newPath + searchStr)
+    }
+
     const handleSave = async () => {
         if (!accessCodeRequired) return
 
@@ -121,12 +169,15 @@ export function SettingsDialog({
         setIsVerifying(true)
 
         try {
-            const response = await fetch("/api/verify-access-code", {
-                method: "POST",
-                headers: {
-                    "x-access-code": accessCode.trim(),
+            const response = await fetch(
+                getApiEndpoint("/api/verify-access-code"),
+                {
+                    method: "POST",
+                    headers: {
+                        "x-access-code": accessCode.trim(),
+                    },
                 },
-            })
+            )
 
             const data = await response.json()
 
@@ -152,20 +203,32 @@ export function SettingsDialog({
     }
 
     return (
-        <Dialog open={open} onOpenChange={onOpenChange}>
-            <DialogContent className="sm:max-w-md">
-                <DialogHeader>
-                    <DialogTitle>{dict.settings.title}</DialogTitle>
-                    <DialogDescription>
-                        {dict.settings.description}
-                    </DialogDescription>
-                </DialogHeader>
-                <div className="space-y-4 py-2">
+        <DialogContent className="sm:max-w-lg p-0 gap-0">
+            {/* Header */}
+            <DialogHeader className="px-6 pt-6 pb-4">
+                <DialogTitle>{dict.settings.title}</DialogTitle>
+                <DialogDescription className="mt-1">
+                    {dict.settings.description}
+                </DialogDescription>
+            </DialogHeader>
+
+            {/* Content */}
+            <div className="px-6 pb-6">
+                <div className="divide-y divide-border-subtle">
+                    {/* Access Code (conditional) */}
                     {accessCodeRequired && (
-                        <div className="space-y-2">
-                            <Label htmlFor="access-code">
-                                {dict.settings.accessCode}
-                            </Label>
+                        <div className="py-4 first:pt-0 space-y-3">
+                            <div className="space-y-0.5">
+                                <Label
+                                    htmlFor="access-code"
+                                    className="text-sm font-medium"
+                                >
+                                    {dict.settings.accessCode}
+                                </Label>
+                                <p className="text-xs text-muted-foreground">
+                                    {dict.settings.accessCodeDescription}
+                                </p>
+                            </div>
                             <div className="flex gap-2">
                                 <Input
                                     id="access-code"
@@ -179,222 +242,60 @@ export function SettingsDialog({
                                         dict.settings.accessCodePlaceholder
                                     }
                                     autoComplete="off"
+                                    className="h-9"
                                 />
                                 <Button
                                     onClick={handleSave}
                                     disabled={isVerifying || !accessCode.trim()}
+                                    className="h-9 px-4 rounded-xl"
                                 >
                                     {isVerifying ? "..." : dict.common.save}
                                 </Button>
                             </div>
-                            <p className="text-[0.8rem] text-muted-foreground">
-                                {dict.settings.accessCodeDescription}
-                            </p>
                             {error && (
-                                <p className="text-[0.8rem] text-destructive">
+                                <p className="text-xs text-destructive">
                                     {error}
                                 </p>
                             )}
                         </div>
                     )}
-                    <div className="space-y-2">
-                        <Label>{dict.settings.aiProvider}</Label>
-                        <p className="text-[0.8rem] text-muted-foreground">
-                            {dict.settings.aiProviderDescription}
-                        </p>
-                        <div className="space-y-3 pt-2">
-                            <div className="space-y-2">
-                                <Label htmlFor="ai-provider">
-                                    {dict.settings.provider}
-                                </Label>
-                                <Select
-                                    value={provider || "default"}
-                                    onValueChange={(value) => {
-                                        const actualValue =
-                                            value === "default" ? "" : value
-                                        setProvider(actualValue)
-                                        localStorage.setItem(
-                                            STORAGE_AI_PROVIDER_KEY,
-                                            actualValue,
-                                        )
-                                    }}
-                                >
-                                    <SelectTrigger id="ai-provider">
-                                        <SelectValue
-                                            placeholder={
-                                                dict.settings.useServerDefault
-                                            }
-                                        />
-                                    </SelectTrigger>
-                                    <SelectContent>
-                                        <SelectItem value="default">
-                                            {dict.settings.useServerDefault}
-                                        </SelectItem>
-                                        <SelectItem value="openai">
-                                            {dict.providers.openai}
-                                        </SelectItem>
-                                        <SelectItem value="anthropic">
-                                            {dict.providers.anthropic}
-                                        </SelectItem>
-                                        <SelectItem value="google">
-                                            {dict.providers.google}
-                                        </SelectItem>
-                                        <SelectItem value="azure">
-                                            {dict.providers.azure}
-                                        </SelectItem>
-                                        <SelectItem value="openrouter">
-                                            {dict.providers.openrouter}
-                                        </SelectItem>
-                                        <SelectItem value="deepseek">
-                                            {dict.providers.deepseek}
-                                        </SelectItem>
-                                        <SelectItem value="siliconflow">
-                                            {dict.providers.siliconflow}
-                                        </SelectItem>
-                                    </SelectContent>
-                                </Select>
-                            </div>
-                            {provider && provider !== "default" && (
-                                <>
-                                    <div className="space-y-2">
-                                        <Label htmlFor="ai-model">
-                                            {dict.settings.modelId}
-                                        </Label>
-                                        <Input
-                                            id="ai-model"
-                                            value={modelId}
-                                            onChange={(e) => {
-                                                setModelId(e.target.value)
-                                                localStorage.setItem(
-                                                    STORAGE_AI_MODEL_KEY,
-                                                    e.target.value,
-                                                )
-                                            }}
-                                            placeholder={
-                                                provider === "openai"
-                                                    ? "e.g., gpt-4o"
-                                                    : provider === "anthropic"
-                                                      ? "e.g., claude-sonnet-4-5"
-                                                      : provider === "google"
-                                                        ? "e.g., gemini-2.0-flash-exp"
-                                                        : provider ===
-                                                            "deepseek"
-                                                          ? "e.g., deepseek-chat"
-                                                          : dict.settings
-                                                                .modelId
-                                            }
-                                        />
-                                    </div>
-                                    <div className="space-y-2">
-                                        <Label htmlFor="ai-api-key">
-                                            {dict.settings.apiKey}
-                                        </Label>
-                                        <Input
-                                            id="ai-api-key"
-                                            type="password"
-                                            value={apiKey}
-                                            onChange={(e) => {
-                                                setApiKey(e.target.value)
-                                                localStorage.setItem(
-                                                    STORAGE_AI_API_KEY_KEY,
-                                                    e.target.value,
-                                                )
-                                            }}
-                                            placeholder={
-                                                dict.settings.apiKeyPlaceholder
-                                            }
-                                            autoComplete="off"
-                                        />
-                                        <p className="text-[0.8rem] text-muted-foreground">
-                                            {dict.settings.overrides}{" "}
-                                            {provider === "openai"
-                                                ? "OPENAI_API_KEY"
-                                                : provider === "anthropic"
-                                                  ? "ANTHROPIC_API_KEY"
-                                                  : provider === "google"
-                                                    ? "GOOGLE_GENERATIVE_AI_API_KEY"
-                                                    : provider === "azure"
-                                                      ? "AZURE_API_KEY"
-                                                      : provider ===
-                                                          "openrouter"
-                                                        ? "OPENROUTER_API_KEY"
-                                                        : provider ===
-                                                            "deepseek"
-                                                          ? "DEEPSEEK_API_KEY"
-                                                          : provider ===
-                                                              "siliconflow"
-                                                            ? "SILICONFLOW_API_KEY"
-                                                            : "server API key"}
-                                        </p>
-                                    </div>
-                                    <div className="space-y-2">
-                                        <Label htmlFor="ai-base-url">
-                                            {dict.settings.baseUrl}
-                                        </Label>
-                                        <Input
-                                            id="ai-base-url"
-                                            value={baseUrl}
-                                            onChange={(e) => {
-                                                setBaseUrl(e.target.value)
-                                                localStorage.setItem(
-                                                    STORAGE_AI_BASE_URL_KEY,
-                                                    e.target.value,
-                                                )
-                                            }}
-                                            placeholder={
-                                                provider === "anthropic"
-                                                    ? "https://api.anthropic.com/v1"
-                                                    : provider === "siliconflow"
-                                                      ? "https://api.siliconflow.com/v1"
-                                                      : dict.settings
-                                                            .customEndpoint
-                                            }
-                                        />
-                                    </div>
-                                    <Button
-                                        variant="outline"
-                                        size="sm"
-                                        className="w-full"
-                                        onClick={() => {
-                                            localStorage.removeItem(
-                                                STORAGE_AI_PROVIDER_KEY,
-                                            )
-                                            localStorage.removeItem(
-                                                STORAGE_AI_BASE_URL_KEY,
-                                            )
-                                            localStorage.removeItem(
-                                                STORAGE_AI_API_KEY_KEY,
-                                            )
-                                            localStorage.removeItem(
-                                                STORAGE_AI_MODEL_KEY,
-                                            )
-                                            setProvider("")
-                                            setBaseUrl("")
-                                            setApiKey("")
-                                            setModelId("")
-                                        }}
-                                    >
-                                        {dict.settings.clearSettings}
-                                    </Button>
-                                </>
-                            )}
-                        </div>
-                    </div>
 
-                    <div className="flex items-center justify-between">
-                        <div className="space-y-0.5">
-                            <Label htmlFor="theme-toggle">
-                                {dict.settings.theme}
-                            </Label>
-                            <p className="text-[0.8rem] text-muted-foreground">
-                                {dict.settings.themeDescription}
-                            </p>
-                        </div>
+                    {/* Language */}
+                    <SettingItem
+                        label={dict.settings.language}
+                        description={dict.settings.languageDescription}
+                    >
+                        <Select
+                            value={currentLang}
+                            onValueChange={changeLanguage}
+                        >
+                            <SelectTrigger
+                                id="language-select"
+                                className="w-[120px] h-9 rounded-xl"
+                            >
+                                <SelectValue />
+                            </SelectTrigger>
+                            <SelectContent>
+                                {i18n.locales.map((locale) => (
+                                    <SelectItem key={locale} value={locale}>
+                                        {LANGUAGE_LABELS[locale]}
+                                    </SelectItem>
+                                ))}
+                            </SelectContent>
+                        </Select>
+                    </SettingItem>
+
+                    {/* Theme */}
+                    <SettingItem
+                        label={dict.settings.theme}
+                        description={dict.settings.themeDescription}
+                    >
                         <Button
                             id="theme-toggle"
                             variant="outline"
                             size="icon"
                             onClick={onToggleDarkMode}
+                            className="h-9 w-9 rounded-xl border-border-subtle hover:bg-interactive-hover"
                         >
                             {darkMode ? (
                                 <Sun className="h-4 w-4" />
@@ -402,42 +303,35 @@ export function SettingsDialog({
                                 <Moon className="h-4 w-4" />
                             )}
                         </Button>
-                    </div>
+                    </SettingItem>
 
-                    <div className="flex items-center justify-between">
-                        <div className="space-y-0.5">
-                            <Label htmlFor="drawio-ui">
-                                {dict.settings.drawioStyle}
-                            </Label>
-                            <p className="text-[0.8rem] text-muted-foreground">
-                                {dict.settings.drawioStyleDescription}{" "}
-                                {drawioUi === "min"
-                                    ? dict.settings.minimal
-                                    : dict.settings.sketch}
-                            </p>
-                        </div>
+                    {/* Draw.io Style */}
+                    <SettingItem
+                        label={dict.settings.drawioStyle}
+                        description={`${dict.settings.drawioStyleDescription} ${
+                            drawioUi === "min"
+                                ? dict.settings.minimal
+                                : dict.settings.sketch
+                        }`}
+                    >
                         <Button
                             id="drawio-ui"
                             variant="outline"
-                            size="sm"
                             onClick={onToggleDrawioUi}
+                            className="h-9 w-[120px] rounded-xl border-border-subtle hover:bg-interactive-hover font-normal"
                         >
                             {dict.settings.switchTo}{" "}
                             {drawioUi === "min"
                                 ? dict.settings.sketch
                                 : dict.settings.minimal}
                         </Button>
-                    </div>
+                    </SettingItem>
 
-                    <div className="flex items-center justify-between">
-                        <div className="space-y-0.5">
-                            <Label htmlFor="close-protection">
-                                {dict.settings.closeProtection}
-                            </Label>
-                            <p className="text-[0.8rem] text-muted-foreground">
-                                {dict.settings.closeProtectionDescription}
-                            </p>
-                        </div>
+                    {/* Close Protection */}
+                    <SettingItem
+                        label={dict.settings.closeProtection}
+                        description={dict.settings.closeProtectionDescription}
+                    >
                         <Switch
                             id="close-protection"
                             checked={closeProtection}
@@ -450,9 +344,34 @@ export function SettingsDialog({
                                 onCloseProtectionChange?.(checked)
                             }}
                         />
-                    </div>
+                    </SettingItem>
                 </div>
-            </DialogContent>
+            </div>
+
+            {/* Footer */}
+            <div className="px-6 py-4 border-t border-border-subtle bg-surface-1/50 rounded-b-2xl">
+                <p className="text-xs text-muted-foreground text-center">
+                    Version {process.env.APP_VERSION}
+                </p>
+            </div>
+        </DialogContent>
+    )
+}
+
+export function SettingsDialog(props: SettingsDialogProps) {
+    return (
+        <Dialog open={props.open} onOpenChange={props.onOpenChange}>
+            <Suspense
+                fallback={
+                    <DialogContent className="sm:max-w-lg p-0">
+                        <div className="h-80 flex items-center justify-center">
+                            <div className="animate-spin h-6 w-6 border-2 border-primary border-t-transparent rounded-full" />
+                        </div>
+                    </DialogContent>
+                }
+            >
+                <SettingsContent {...props} />
+            </Suspense>
         </Dialog>
     )
 }

components/ui/alert-dialog.tsx

@@ -0,0 +1,157 @@
+"use client"
+
+import * as React from "react"
+import * as AlertDialogPrimitive from "@radix-ui/react-alert-dialog"
+
+import { cn } from "@/lib/utils"
+import { buttonVariants } from "@/components/ui/button"
+
+function AlertDialog({
+  ...props
+}: React.ComponentProps<typeof AlertDialogPrimitive.Root>) {
+  return <AlertDialogPrimitive.Root data-slot="alert-dialog" {...props} />
+}
+
+function AlertDialogTrigger({
+  ...props
+}: React.ComponentProps<typeof AlertDialogPrimitive.Trigger>) {
+  return (
+    <AlertDialogPrimitive.Trigger data-slot="alert-dialog-trigger" {...props} />
+  )
+}
+
+function AlertDialogPortal({
+  ...props
+}: React.ComponentProps<typeof AlertDialogPrimitive.Portal>) {
+  return (
+    <AlertDialogPrimitive.Portal data-slot="alert-dialog-portal" {...props} />
+  )
+}
+
+function AlertDialogOverlay({
+  className,
+  ...props
+}: React.ComponentProps<typeof AlertDialogPrimitive.Overlay>) {
+  return (
+    <AlertDialogPrimitive.Overlay
+      data-slot="alert-dialog-overlay"
+      className={cn(
+        "data-[state=open]:animate-in data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=open]:fade-in-0 fixed inset-0 z-50 bg-black/50",
+        className
+      )}
+      {...props}
+    />
+  )
+}
+
+function AlertDialogContent({
+  className,
+  ...props
+}: React.ComponentProps<typeof AlertDialogPrimitive.Content>) {
+  return (
+    <AlertDialogPortal>
+      <AlertDialogOverlay />
+      <AlertDialogPrimitive.Content
+        data-slot="alert-dialog-content"
+        className={cn(
+          "bg-background data-[state=open]:animate-in data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=open]:fade-in-0 data-[state=closed]:zoom-out-95 data-[state=open]:zoom-in-95 fixed top-[50%] left-[50%] z-50 grid w-full max-w-[calc(100%-2rem)] translate-x-[-50%] translate-y-[-50%] gap-4 rounded-lg border p-6 shadow-lg duration-200 sm:max-w-lg",
+          className
+        )}
+        {...props}
+      />
+    </AlertDialogPortal>
+  )
+}
+
+function AlertDialogHeader({
+  className,
+  ...props
+}: React.ComponentProps<"div">) {
+  return (
+    <div
+      data-slot="alert-dialog-header"
+      className={cn("flex flex-col gap-2 text-center sm:text-left", className)}
+      {...props}
+    />
+  )
+}
+
+function AlertDialogFooter({
+  className,
+  ...props
+}: React.ComponentProps<"div">) {
+  return (
+    <div
+      data-slot="alert-dialog-footer"
+      className={cn(
+        "flex flex-col-reverse gap-2 sm:flex-row sm:justify-end",
+        className
+      )}
+      {...props}
+    />
+  )
+}
+
+function AlertDialogTitle({
+  className,
+  ...props
+}: React.ComponentProps<typeof AlertDialogPrimitive.Title>) {
+  return (
+    <AlertDialogPrimitive.Title
+      data-slot="alert-dialog-title"
+      className={cn("text-lg font-semibold", className)}
+      {...props}
+    />
+  )
+}
+
+function AlertDialogDescription({
+  className,
+  ...props
+}: React.ComponentProps<typeof AlertDialogPrimitive.Description>) {
+  return (
+    <AlertDialogPrimitive.Description
+      data-slot="alert-dialog-description"
+      className={cn("text-muted-foreground text-sm", className)}
+      {...props}
+    />
+  )
+}
+
+function AlertDialogAction({
+  className,
+  ...props
+}: React.ComponentProps<typeof AlertDialogPrimitive.Action>) {
+  return (
+    <AlertDialogPrimitive.Action
+      className={cn(buttonVariants(), className)}
+      {...props}
+    />
+  )
+}
+
+function AlertDialogCancel({
+  className,
+  ...props
+}: React.ComponentProps<typeof AlertDialogPrimitive.Cancel>) {
+  return (
+    <AlertDialogPrimitive.Cancel
+      className={cn(buttonVariants({ variant: "outline" }), className)}
+      {...props}
+    />
+  )
+}
+
+export {
+  AlertDialog,
+  AlertDialogPortal,
+  AlertDialogOverlay,
+  AlertDialogTrigger,
+  AlertDialogContent,
+  AlertDialogHeader,
+  AlertDialogFooter,
+  AlertDialogTitle,
+  AlertDialogDescription,
+  AlertDialogAction,
+  AlertDialogCancel,
+}

components/ui/command.tsx

@@ -0,0 +1,191 @@
+"use client"
+
+import * as React from "react"
+import { Command as CommandPrimitive } from "cmdk"
+import { SearchIcon } from "lucide-react"
+
+import { cn } from "@/lib/utils"
+import {
+  Dialog,
+  DialogContent,
+  DialogDescription,
+  DialogHeader,
+  DialogTitle,
+} from "@/components/ui/dialog"
+
+function Command({
+  className,
+  ...props
+}: React.ComponentProps<typeof CommandPrimitive>) {
+  return (
+    <CommandPrimitive
+      data-slot="command"
+      className={cn(
+        "bg-popover text-popover-foreground flex h-full w-full flex-col overflow-hidden rounded-md",
+        className
+      )}
+      {...props}
+    />
+  )
+}
+
+function CommandDialog({
+  title = "Command Palette",
+  description = "Search for a command to run...",
+  children,
+  className,
+  ...props
+}: React.ComponentProps<typeof Dialog> & {
+  title?: string
+  description?: string
+  className?: string
+}) {
+  return (
+    <Dialog {...props}>
+      <DialogHeader className="sr-only">
+        <DialogTitle>{title}</DialogTitle>
+        <DialogDescription>{description}</DialogDescription>
+      </DialogHeader>
+      <DialogContent className={cn("overflow-hidden p-0", className)}>
+        <Command className="[&_[cmdk-group-heading]]:text-muted-foreground **:data-[slot=command-input-wrapper]:h-12 [&_[cmdk-group-heading]]:px-2 [&_[cmdk-group-heading]]:font-medium [&_[cmdk-group]]:px-2 [&_[cmdk-group]:not([hidden])_~[cmdk-group]]:pt-0 [&_[cmdk-input-wrapper]_svg]:h-5 [&_[cmdk-input-wrapper]_svg]:w-5 [&_[cmdk-input]]:h-12 [&_[cmdk-item]]:px-2 [&_[cmdk-item]]:py-3 [&_[cmdk-item]_svg]:h-5 [&_[cmdk-item]_svg]:w-5">
+          {children}
+        </Command>
+      </DialogContent>
+    </Dialog>
+  )
+}
+
+function CommandInput({
+  className,
+  ...props
+}: React.ComponentProps<typeof CommandPrimitive.Input>) {
+  return (
+    <div
+      data-slot="command-input-wrapper"
+      className="flex h-9 items-center gap-2 border-b px-3"
+    >
+      <SearchIcon className="size-4 shrink-0 opacity-50" />
+      <CommandPrimitive.Input
+        data-slot="command-input"
+        className={cn(
+          "placeholder:text-muted-foreground flex h-10 w-full rounded-md bg-transparent py-3 text-sm outline-hidden disabled:cursor-not-allowed disabled:opacity-50",
+          className
+        )}
+        {...props}
+      />
+    </div>
+  )
+}
+
+function CommandList({
+  className,
+  ...props
+}: React.ComponentProps<typeof CommandPrimitive.List>) {
+  return (
+    <CommandPrimitive.List
+      data-slot="command-list"
+      className={cn(
+        "max-h-[300px] scroll-py-1 overflow-x-hidden overflow-y-auto",
+        className
+      )}
+      {...props}
+    />
+  )
+}
+
+function CommandEmpty({
+  ...props
+}: React.ComponentProps<typeof CommandPrimitive.Empty>) {
+  return (
+    <CommandPrimitive.Empty
+      data-slot="command-empty"
+      className="py-6 text-center text-sm"
+      {...props}
+    />
+  )
+}
+
+function CommandGroup({
+  className,
+  ...props
+}: React.ComponentProps<typeof CommandPrimitive.Group>) {
+  return (
+    <CommandPrimitive.Group
+      data-slot="command-group"
+      className={cn(
+        "text-foreground [&_[cmdk-group-heading]]:text-muted-foreground overflow-hidden p-1 [&_[cmdk-group-heading]]:px-2 [&_[cmdk-group-heading]]:py-1.5 [&_[cmdk-group-heading]]:text-xs [&_[cmdk-group-heading]]:font-medium",
+        className
+      )}
+      {...props}
+    />
+  )
+}
+
+function CommandSeparator({
+  className,
+  ...props
+}: React.ComponentProps<typeof CommandPrimitive.Separator>) {
+  return (
+    <CommandPrimitive.Separator
+      data-slot="command-separator"
+      className={cn("bg-border -mx-1 h-px", className)}
+      {...props}
+    />
+  )
+}
+
+function CommandItem({
+  className,
+  ...props
+}: React.ComponentProps<typeof CommandPrimitive.Item>) {
+  return (
+    <CommandPrimitive.Item
+      data-slot="command-item"
+      className={cn(
+        "data-[selected=true]:bg-accent data-[selected=true]:text-accent-foreground [&_svg:not([class*='text-'])]:text-muted-foreground relative flex cursor-default items-center gap-2 rounded-sm px-2 py-1.5 text-sm outline-hidden select-none data-[disabled=true]:pointer-events-none data-[disabled=true]:opacity-50 [&_svg]:pointer-events-none [&_svg]:shrink-0 [&_svg:not([class*='size-'])]:size-4",
+        className
+      )}
+      onMouseEnter={(e) => {
+        // Ensure hover updates selection for visual feedback
+        const item = e.currentTarget
+        item.setAttribute("data-selected", "true")
+        // Deselect siblings
+        const siblings = item.parentElement?.querySelectorAll("[cmdk-item]")
+        siblings?.forEach((sibling) => {
+          if (sibling !== item) {
+            sibling.setAttribute("data-selected", "false")
+          }
+        })
+      }}
+      {...props}
+    />
+  )
+}
+
+function CommandShortcut({
+  className,
+  ...props
+}: React.ComponentProps<"span">) {
+  return (
+    <span
+      data-slot="command-shortcut"
+      className={cn(
+        "text-muted-foreground ml-auto text-xs tracking-widest",
+        className
+      )}
+      {...props}
+    />
+  )
+}
+
+export {
+  Command,
+  CommandDialog,
+  CommandInput,
+  CommandList,
+  CommandEmpty,
+  CommandGroup,
+  CommandItem,
+  CommandShortcut,
+  CommandSeparator,
+}

components/ui/dialog.tsx

@@ -38,7 +38,10 @@ function DialogOverlay({
     <DialogPrimitive.Overlay
       data-slot="dialog-overlay"
       className={cn(
-        "data-[state=open]:animate-in data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=open]:fade-in-0 fixed inset-0 z-50 bg-black/50",
+        "fixed inset-0 z-50 bg-black/40 backdrop-blur-[2px]",
+        "data-[state=open]:animate-in data-[state=closed]:animate-out",
+        "data-[state=closed]:fade-out-0 data-[state=open]:fade-in-0",
+        "duration-200",
         className
       )}
       {...props}
@@ -57,13 +60,32 @@ function DialogContent({
       <DialogPrimitive.Content
         data-slot="dialog-content"
         className={cn(
-          "bg-background data-[state=open]:animate-in data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=open]:fade-in-0 data-[state=closed]:zoom-out-95 data-[state=open]:zoom-in-95 fixed top-[50%] left-[50%] z-50 grid w-full max-w-[calc(100%-2rem)] translate-x-[-50%] translate-y-[-50%] gap-4 rounded-lg border p-6 shadow-lg duration-200 sm:max-w-lg",
+          // Base styles
+          "fixed top-[50%] left-[50%] z-50 w-full",
+          "max-w-[calc(100%-2rem)] translate-x-[-50%] translate-y-[-50%]",
+          "grid gap-4 p-6",
+          // Refined visual treatment
+          "bg-surface-0 rounded-2xl border border-border-subtle shadow-dialog",
+          // Entry/exit animations
+          "data-[state=open]:animate-in data-[state=closed]:animate-out",
+          "data-[state=closed]:fade-out-0 data-[state=open]:fade-in-0",
+          "data-[state=closed]:zoom-out-[0.98] data-[state=open]:zoom-in-[0.98]",
+          "data-[state=closed]:slide-out-to-top-[2%] data-[state=open]:slide-in-from-top-[2%]",
+          "duration-200 sm:max-w-lg",
           className
         )}
         {...props}
       >
         {children}
-        <DialogPrimitive.Close className="ring-offset-background focus:ring-ring data-[state=open]:bg-accent data-[state=open]:text-muted-foreground absolute top-4 right-4 rounded-xs opacity-70 transition-opacity hover:opacity-100 focus:ring-2 focus:ring-offset-2 focus:outline-hidden disabled:pointer-events-none [&_svg]:pointer-events-none [&_svg]:shrink-0 [&_svg:not([class*='size-'])]:size-4">
+        <DialogPrimitive.Close className={cn(
+          "absolute top-4 right-4 rounded-xl p-1.5",
+          "text-muted-foreground/60 hover:text-foreground",
+          "hover:bg-interactive-hover",
+          "transition-all duration-150",
+          "focus:outline-none focus:ring-2 focus:ring-ring focus:ring-offset-2",
+          "disabled:pointer-events-none",
+          "[&_svg]:pointer-events-none [&_svg]:shrink-0 [&_svg]:size-4"
+        )}>
           <XIcon />
           <span className="sr-only">Close</span>
         </DialogPrimitive.Close>
@@ -102,7 +124,10 @@ function DialogTitle({
   return (
     <DialogPrimitive.Title
       data-slot="dialog-title"
-      className={cn("text-lg leading-none font-semibold", className)}
+      className={cn(
+        "text-xl font-semibold tracking-tight leading-tight",
+        className
+      )}
       {...props}
     />
   )
@@ -115,7 +140,10 @@ function DialogDescription({
   return (
     <DialogPrimitive.Description
       data-slot="dialog-description"
-      className={cn("text-muted-foreground text-sm", className)}
+      className={cn(
+        "text-sm text-muted-foreground leading-relaxed",
+        className
+      )}
       {...props}
     />
   )

components/ui/input.tsx

@@ -8,9 +8,30 @@ function Input({ className, type, ...props }: React.ComponentProps<"input">) {
       type={type}
       data-slot="input"
       className={cn(
-        "file:text-foreground placeholder:text-muted-foreground selection:bg-primary selection:text-primary-foreground dark:bg-input/30 border-input flex h-9 w-full min-w-0 rounded-md border bg-transparent px-3 py-1 text-base shadow-xs transition-[color,box-shadow] outline-none file:inline-flex file:h-7 file:border-0 file:bg-transparent file:text-sm file:font-medium disabled:pointer-events-none disabled:cursor-not-allowed disabled:opacity-50 md:text-sm",
-        "focus-visible:border-ring focus-visible:ring-ring/50 focus-visible:ring-[3px]",
-        "aria-invalid:ring-destructive/20 dark:aria-invalid:ring-destructive/40 aria-invalid:border-destructive",
+        // Base styles
+        "flex h-10 w-full min-w-0 rounded-xl px-3.5 py-2",
+        "border border-border-subtle bg-surface-1",
+        "text-sm text-foreground",
+        // Placeholder
+        "placeholder:text-muted-foreground/60",
+        // Selection
+        "selection:bg-primary selection:text-primary-foreground",
+        // Transitions
+        "transition-all duration-150 ease-out",
+        // Hover state
+        "hover:border-border-default",
+        // Focus state - refined ring
+        "focus:outline-none focus:border-primary focus:ring-2 focus:ring-primary/10",
+        // File input
+        "file:text-foreground file:inline-flex file:h-7 file:border-0",
+        "file:bg-transparent file:text-sm file:font-medium",
+        // Disabled
+        "disabled:pointer-events-none disabled:cursor-not-allowed disabled:opacity-50",
+        // Invalid state
+        "aria-invalid:border-destructive aria-invalid:ring-destructive/20",
+        "dark:aria-invalid:ring-destructive/40",
+        // Dark mode background
+        "dark:bg-surface-1",
         className
       )}
       {...props}

components/ui/popover.tsx

@@ -0,0 +1,48 @@
+"use client"
+
+import * as React from "react"
+import * as PopoverPrimitive from "@radix-ui/react-popover"
+
+import { cn } from "@/lib/utils"
+
+function Popover({
+  ...props
+}: React.ComponentProps<typeof PopoverPrimitive.Root>) {
+  return <PopoverPrimitive.Root data-slot="popover" {...props} />
+}
+
+function PopoverTrigger({
+  ...props
+}: React.ComponentProps<typeof PopoverPrimitive.Trigger>) {
+  return <PopoverPrimitive.Trigger data-slot="popover-trigger" {...props} />
+}
+
+function PopoverContent({
+  className,
+  align = "center",
+  sideOffset = 4,
+  ...props
+}: React.ComponentProps<typeof PopoverPrimitive.Content>) {
+  return (
+    <PopoverPrimitive.Portal>
+      <PopoverPrimitive.Content
+        data-slot="popover-content"
+        align={align}
+        sideOffset={sideOffset}
+        className={cn(
+          "bg-popover text-popover-foreground data-[state=open]:animate-in data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=open]:fade-in-0 data-[state=closed]:zoom-out-95 data-[state=open]:zoom-in-95 data-[side=bottom]:slide-in-from-top-2 data-[side=left]:slide-in-from-right-2 data-[side=right]:slide-in-from-left-2 data-[side=top]:slide-in-from-bottom-2 z-50 w-72 origin-(--radix-popover-content-transform-origin) rounded-md border p-4 shadow-md outline-hidden",
+          className
+        )}
+        {...props}
+      />
+    </PopoverPrimitive.Portal>
+  )
+}
+
+function PopoverAnchor({
+  ...props
+}: React.ComponentProps<typeof PopoverPrimitive.Anchor>) {
+  return <PopoverPrimitive.Anchor data-slot="popover-anchor" {...props} />
+}
+
+export { Popover, PopoverTrigger, PopoverContent, PopoverAnchor }

contexts/diagram-context.tsx

@@ -5,6 +5,7 @@ import { createContext, useContext, useEffect, useRef, useState } from "react"
 import type { DrawIoEmbedRef } from "react-drawio"
 import { STORAGE_DIAGRAM_XML_KEY } from "@/components/chat-panel"
 import type { ExportFormat } from "@/components/save-dialog"
+import { getApiEndpoint } from "@/lib/base-path"
 import { extractDiagramXML, validateAndFixXml } from "../lib/utils"
 
 interface DiagramContextType {
@@ -329,7 +330,7 @@ export function DiagramProvider({ children }: { children: React.ReactNode }) {
         sessionId?: string,
     ) => {
         try {
-            await fetch("/api/log-save", {
+            await fetch(getApiEndpoint("/api/log-save"), {
                 method: "POST",
                 headers: { "Content-Type": "application/json" },
                 body: JSON.stringify({ filename, format, sessionId }),

docker-compose.yml

@@ -7,6 +7,11 @@ services:
       context: .
       args:
         - NEXT_PUBLIC_DRAWIO_BASE_URL=http://localhost:8080
+        # Uncomment below for subdirectory deployment
+        # - NEXT_PUBLIC_BASE_PATH=/nextaidrawio
     ports: ["3000:3000"]
     env_file: .env
+    environment:
+      # For subdirectory deployment, uncomment and set your path:
+      # NEXT_PUBLIC_BASE_PATH: /nextaidrawio
     depends_on: [drawio]

electron-builder.yml

@@ -0,0 +1,96 @@
+appId: com.nextaidrawio.app
+productName: Next AI Draw.io
+copyright: Copyright © 2024 Next AI Draw.io
+electronVersion: 39.2.7
+
+directories:
+  output: release
+  buildResources: resources
+
+afterPack: ./scripts/afterPack.cjs
+
+files:
+  - dist-electron/**/*
+  - "!node_modules"
+
+asarUnpack:
+  - "**/*.node"
+
+extraResources:
+  # Copy prepared standalone directory (includes node_modules)
+  - from: electron-standalone/
+    to: standalone/
+  # Copy icon for runtime use (Windows/Linux)
+  - from: resources/icon.png
+    to: icon.png
+
+# macOS configuration
+mac:
+  category: public.app-category.productivity
+  icon: resources/icon.png
+  target:
+    - target: dmg
+      arch:
+        - x64
+        - arm64
+    - target: zip
+      arch:
+        - x64
+        - arm64
+  hardenedRuntime: true
+  gatekeeperAssess: false
+  entitlements: resources/entitlements.mac.plist
+  entitlementsInherit: resources/entitlements.mac.plist
+
+dmg:
+  contents:
+    - x: 130
+      y: 220
+    - x: 410
+      y: 220
+      type: link
+      path: /Applications
+  window:
+    width: 540
+    height: 380
+
+# Windows configuration
+win:
+  icon: resources/icon.png
+  target:
+    - target: nsis
+      arch:
+        - x64
+        - arm64
+    - target: portable
+      arch:
+        - x64
+        - arm64
+
+nsis:
+  oneClick: false
+  perMachine: false
+  allowToChangeInstallationDirectory: true
+  deleteAppDataOnUninstall: false
+  createDesktopShortcut: true
+  createStartMenuShortcut: true
+
+# Linux configuration
+linux:
+  icon: resources/icon.png
+  category: Office
+  maintainer: Next AI Draw.io <nextaidrawio@users.noreply.github.com>
+  target:
+    - target: AppImage
+      arch:
+        - x64
+        - arm64
+    - target: deb
+      arch:
+        - x64
+        - arm64
+
+# Publish configuration (optional)
+publish:
+  provider: github
+  releaseType: release

electron.d.ts

@@ -0,0 +1,74 @@
+/**
+ * Type declarations for Electron API exposed via preload script
+ */
+
+/** Configuration preset interface */
+interface ConfigPreset {
+    id: string
+    name: string
+    createdAt: number
+    updatedAt: number
+    config: {
+        AI_PROVIDER?: string
+        AI_MODEL?: string
+        AI_API_KEY?: string
+        AI_BASE_URL?: string
+        TEMPERATURE?: string
+        [key: string]: string | undefined
+    }
+}
+
+/** Result of applying a preset */
+interface ApplyPresetResult {
+    success: boolean
+    error?: string
+    env?: Record<string, string>
+}
+
+declare global {
+    interface Window {
+        /** Main window Electron API */
+        electronAPI?: {
+            /** Current platform (darwin, win32, linux) */
+            platform: NodeJS.Platform
+            /** Whether running in Electron environment */
+            isElectron: boolean
+            /** Get application version */
+            getVersion: () => Promise<string>
+            /** Minimize the window */
+            minimize: () => void
+            /** Maximize/restore the window */
+            maximize: () => void
+            /** Close the window */
+            close: () => void
+            /** Open file dialog and return file path */
+            openFile: () => Promise<string | null>
+            /** Save data to file via save dialog */
+            saveFile: (data: string) => Promise<boolean>
+        }
+
+        /** Settings window Electron API */
+        settingsAPI?: {
+            /** Get all configuration presets */
+            getPresets: () => Promise<ConfigPreset[]>
+            /** Get current preset ID */
+            getCurrentPresetId: () => Promise<string | null>
+            /** Get current preset */
+            getCurrentPreset: () => Promise<ConfigPreset | null>
+            /** Save (create or update) a preset */
+            savePreset: (preset: {
+                id?: string
+                name: string
+                config: Record<string, string | undefined>
+            }) => Promise<ConfigPreset>
+            /** Delete a preset */
+            deletePreset: (id: string) => Promise<boolean>
+            /** Apply a preset (sets environment variables and restarts server) */
+            applyPreset: (id: string) => Promise<ApplyPresetResult>
+            /** Close settings window */
+            close: () => void
+        }
+    }
+}
+
+export { ConfigPreset, ApplyPresetResult }

electron/main/app-menu.ts

@@ -0,0 +1,241 @@
+import {
+    app,
+    BrowserWindow,
+    dialog,
+    Menu,
+    type MenuItemConstructorOptions,
+    shell,
+} from "electron"
+import {
+    applyPresetToEnv,
+    getAllPresets,
+    getCurrentPresetId,
+    setCurrentPreset,
+} from "./config-manager"
+import { restartNextServer } from "./next-server"
+import { showSettingsWindow } from "./settings-window"
+
+/**
+ * Build and set the application menu
+ */
+export function buildAppMenu(): void {
+    const template = getMenuTemplate()
+    const menu = Menu.buildFromTemplate(template)
+    Menu.setApplicationMenu(menu)
+}
+
+/**
+ * Rebuild the menu (call this when presets change)
+ */
+export function rebuildAppMenu(): void {
+    buildAppMenu()
+}
+
+/**
+ * Get the menu template
+ */
+function getMenuTemplate(): MenuItemConstructorOptions[] {
+    const isMac = process.platform === "darwin"
+
+    const template: MenuItemConstructorOptions[] = []
+
+    // macOS app menu
+    if (isMac) {
+        template.push({
+            label: app.name,
+            submenu: [
+                { role: "about" },
+                { type: "separator" },
+                {
+                    label: "Settings...",
+                    accelerator: "CmdOrCtrl+,",
+                    click: () => {
+                        const win = BrowserWindow.getFocusedWindow()
+                        showSettingsWindow(win || undefined)
+                    },
+                },
+                { type: "separator" },
+                { role: "services" },
+                { type: "separator" },
+                { role: "hide" },
+                { role: "hideOthers" },
+                { role: "unhide" },
+                { type: "separator" },
+                { role: "quit" },
+            ],
+        })
+    }
+
+    // File menu
+    template.push({
+        label: "File",
+        submenu: [
+            ...(isMac
+                ? []
+                : [
+                      {
+                          label: "Settings",
+                          accelerator: "CmdOrCtrl+,",
+                          click: () => {
+                              const win = BrowserWindow.getFocusedWindow()
+                              showSettingsWindow(win || undefined)
+                          },
+                      },
+                      { type: "separator" } as MenuItemConstructorOptions,
+                  ]),
+            isMac ? { role: "close" } : { role: "quit" },
+        ],
+    })
+
+    // Edit menu
+    template.push({
+        label: "Edit",
+        submenu: [
+            { role: "undo" },
+            { role: "redo" },
+            { type: "separator" },
+            { role: "cut" },
+            { role: "copy" },
+            { role: "paste" },
+            ...(isMac
+                ? [
+                      {
+                          role: "pasteAndMatchStyle",
+                      } as MenuItemConstructorOptions,
+                      { role: "delete" } as MenuItemConstructorOptions,
+                      { role: "selectAll" } as MenuItemConstructorOptions,
+                  ]
+                : [
+                      { role: "delete" } as MenuItemConstructorOptions,
+                      { type: "separator" } as MenuItemConstructorOptions,
+                      { role: "selectAll" } as MenuItemConstructorOptions,
+                  ]),
+        ],
+    })
+
+    // View menu
+    template.push({
+        label: "View",
+        submenu: [
+            { role: "reload" },
+            { role: "forceReload" },
+            { role: "toggleDevTools" },
+            { type: "separator" },
+            { role: "resetZoom" },
+            { role: "zoomIn" },
+            { role: "zoomOut" },
+            { type: "separator" },
+            { role: "togglefullscreen" },
+        ],
+    })
+
+    // Configuration menu with presets
+    template.push(buildConfigMenu())
+
+    // Window menu
+    template.push({
+        label: "Window",
+        submenu: [
+            { role: "minimize" },
+            { role: "zoom" },
+            ...(isMac
+                ? [
+                      { type: "separator" } as MenuItemConstructorOptions,
+                      { role: "front" } as MenuItemConstructorOptions,
+                  ]
+                : [{ role: "close" } as MenuItemConstructorOptions]),
+        ],
+    })
+
+    // Help menu
+    template.push({
+        label: "Help",
+        submenu: [
+            {
+                label: "Documentation",
+                click: async () => {
+                    await shell.openExternal(
+                        "https://github.com/dayuanjiang/next-ai-draw-io",
+                    )
+                },
+            },
+            {
+                label: "Report Issue",
+                click: async () => {
+                    await shell.openExternal(
+                        "https://github.com/dayuanjiang/next-ai-draw-io/issues",
+                    )
+                },
+            },
+        ],
+    })
+
+    return template
+}
+
+/**
+ * Build the Configuration menu with presets
+ */
+function buildConfigMenu(): MenuItemConstructorOptions {
+    const presets = getAllPresets()
+    const currentPresetId = getCurrentPresetId()
+
+    const presetItems: MenuItemConstructorOptions[] = presets.map((preset) => ({
+        label: preset.name,
+        type: "radio",
+        checked: preset.id === currentPresetId,
+        click: async () => {
+            const previousPresetId = getCurrentPresetId()
+            const env = applyPresetToEnv(preset.id)
+
+            if (env) {
+                try {
+                    await restartNextServer()
+                    rebuildAppMenu() // Rebuild menu to update checkmarks
+                } catch (error) {
+                    console.error("Failed to restart server:", error)
+
+                    // Revert to previous preset on failure
+                    if (previousPresetId) {
+                        applyPresetToEnv(previousPresetId)
+                    } else {
+                        setCurrentPreset(null)
+                    }
+
+                    // Rebuild menu to restore previous checkmark state
+                    rebuildAppMenu()
+
+                    // Show error dialog to notify user
+                    dialog.showErrorBox(
+                        "Configuration Error",
+                        `Failed to apply preset "${preset.name}". The server could not be restarted.\n\nThe previous configuration has been restored.\n\nError: ${error instanceof Error ? error.message : String(error)}`,
+                    )
+                }
+            }
+        },
+    }))
+
+    return {
+        label: "Configuration",
+        submenu: [
+            ...(presetItems.length > 0
+                ? [
+                      { label: "Switch Preset", enabled: false },
+                      { type: "separator" } as MenuItemConstructorOptions,
+                      ...presetItems,
+                      { type: "separator" } as MenuItemConstructorOptions,
+                  ]
+                : []),
+            {
+                label:
+                    presetItems.length > 0
+                        ? "Manage Presets..."
+                        : "Add Configuration Preset...",
+                click: () => {
+                    const win = BrowserWindow.getFocusedWindow()
+                    showSettingsWindow(win || undefined)
+                },
+            },
+        ],
+    }
+}

electron/main/config-manager.ts

@@ -0,0 +1,460 @@
+import { randomUUID } from "node:crypto"
+import { existsSync, mkdirSync, readFileSync, writeFileSync } from "node:fs"
+import path from "node:path"
+import { app, safeStorage } from "electron"
+
+/**
+ * Fields that contain sensitive data and should be encrypted
+ */
+const SENSITIVE_FIELDS = ["AI_API_KEY"] as const
+
+/**
+ * Prefix to identify encrypted values
+ */
+const ENCRYPTED_PREFIX = "encrypted:"
+
+/**
+ * Check if safeStorage encryption is available
+ */
+function isEncryptionAvailable(): boolean {
+    return safeStorage.isEncryptionAvailable()
+}
+
+/**
+ * Track if we've already warned about plaintext storage
+ */
+let hasWarnedAboutPlaintext = false
+
+/**
+ * Encrypt a sensitive value using safeStorage
+ * Warns if encryption is not available (API key stored in plaintext)
+ */
+function encryptValue(value: string): string {
+    if (!value) {
+        return value
+    }
+
+    if (!isEncryptionAvailable()) {
+        if (!hasWarnedAboutPlaintext) {
+            console.warn(
+                "⚠️ SECURITY WARNING: safeStorage not available. " +
+                    "API keys will be stored in PLAINTEXT. " +
+                    "On Linux, install gnome-keyring or similar for secure storage.",
+            )
+            hasWarnedAboutPlaintext = true
+        }
+        return value
+    }
+
+    try {
+        const encrypted = safeStorage.encryptString(value)
+        return ENCRYPTED_PREFIX + encrypted.toString("base64")
+    } catch (error) {
+        console.error("Encryption failed:", error)
+        // Fail secure: don't store if encryption fails
+        throw new Error(
+            "Failed to encrypt API key. Cannot securely store credentials.",
+        )
+    }
+}
+
+/**
+ * Decrypt a sensitive value using safeStorage
+ * Returns the original value if it's not encrypted or decryption fails
+ */
+function decryptValue(value: string): string {
+    if (!value || !value.startsWith(ENCRYPTED_PREFIX)) {
+        return value
+    }
+    if (!isEncryptionAvailable()) {
+        console.warn(
+            "Cannot decrypt value: safeStorage encryption is not available",
+        )
+        return value
+    }
+    try {
+        const base64Data = value.slice(ENCRYPTED_PREFIX.length)
+        const buffer = Buffer.from(base64Data, "base64")
+        return safeStorage.decryptString(buffer)
+    } catch (error) {
+        console.error("Failed to decrypt value:", error)
+        return value
+    }
+}
+
+/**
+ * Encrypt sensitive fields in a config object
+ */
+function encryptConfig(
+    config: Record<string, string | undefined>,
+): Record<string, string | undefined> {
+    const encrypted = { ...config }
+    for (const field of SENSITIVE_FIELDS) {
+        if (encrypted[field]) {
+            encrypted[field] = encryptValue(encrypted[field] as string)
+        }
+    }
+    return encrypted
+}
+
+/**
+ * Decrypt sensitive fields in a config object
+ */
+function decryptConfig(
+    config: Record<string, string | undefined>,
+): Record<string, string | undefined> {
+    const decrypted = { ...config }
+    for (const field of SENSITIVE_FIELDS) {
+        if (decrypted[field]) {
+            decrypted[field] = decryptValue(decrypted[field] as string)
+        }
+    }
+    return decrypted
+}
+
+/**
+ * Configuration preset interface
+ */
+export interface ConfigPreset {
+    id: string
+    name: string
+    createdAt: number
+    updatedAt: number
+    config: {
+        AI_PROVIDER?: string
+        AI_MODEL?: string
+        AI_API_KEY?: string
+        AI_BASE_URL?: string
+        TEMPERATURE?: string
+        [key: string]: string | undefined
+    }
+}
+
+/**
+ * Configuration file structure
+ */
+interface ConfigPresetsFile {
+    version: 1
+    currentPresetId: string | null
+    presets: ConfigPreset[]
+}
+
+const CONFIG_FILE_NAME = "config-presets.json"
+
+/**
+ * Get the path to the config file
+ */
+function getConfigFilePath(): string {
+    const userDataPath = app.getPath("userData")
+    return path.join(userDataPath, CONFIG_FILE_NAME)
+}
+
+/**
+ * Load presets from the config file
+ * Decrypts sensitive fields automatically
+ */
+export function loadPresets(): ConfigPresetsFile {
+    const configPath = getConfigFilePath()
+
+    if (!existsSync(configPath)) {
+        return {
+            version: 1,
+            currentPresetId: null,
+            presets: [],
+        }
+    }
+
+    try {
+        const content = readFileSync(configPath, "utf-8")
+        const data = JSON.parse(content) as ConfigPresetsFile
+
+        // Decrypt sensitive fields in each preset
+        data.presets = data.presets.map((preset) => ({
+            ...preset,
+            config: decryptConfig(preset.config) as ConfigPreset["config"],
+        }))
+
+        return data
+    } catch (error) {
+        console.error("Failed to load config presets:", error)
+        return {
+            version: 1,
+            currentPresetId: null,
+            presets: [],
+        }
+    }
+}
+
+/**
+ * Save presets to the config file
+ * Encrypts sensitive fields automatically
+ */
+export function savePresets(data: ConfigPresetsFile): void {
+    const configPath = getConfigFilePath()
+    const userDataPath = app.getPath("userData")
+
+    // Ensure the directory exists
+    if (!existsSync(userDataPath)) {
+        mkdirSync(userDataPath, { recursive: true })
+    }
+
+    // Encrypt sensitive fields before saving
+    const dataToSave: ConfigPresetsFile = {
+        ...data,
+        presets: data.presets.map((preset) => ({
+            ...preset,
+            config: encryptConfig(preset.config) as ConfigPreset["config"],
+        })),
+    }
+
+    try {
+        writeFileSync(configPath, JSON.stringify(dataToSave, null, 2), "utf-8")
+    } catch (error) {
+        console.error("Failed to save config presets:", error)
+        throw error
+    }
+}
+
+/**
+ * Get all presets
+ */
+export function getAllPresets(): ConfigPreset[] {
+    const data = loadPresets()
+    return data.presets
+}
+
+/**
+ * Get current preset ID
+ */
+export function getCurrentPresetId(): string | null {
+    const data = loadPresets()
+    return data.currentPresetId
+}
+
+/**
+ * Get current preset
+ */
+export function getCurrentPreset(): ConfigPreset | null {
+    const data = loadPresets()
+    if (!data.currentPresetId) {
+        return null
+    }
+    return data.presets.find((p) => p.id === data.currentPresetId) || null
+}
+
+/**
+ * Create a new preset
+ */
+export function createPreset(
+    preset: Omit<ConfigPreset, "id" | "createdAt" | "updatedAt">,
+): ConfigPreset {
+    const data = loadPresets()
+    const now = Date.now()
+
+    const newPreset: ConfigPreset = {
+        id: randomUUID(),
+        name: preset.name,
+        config: preset.config,
+        createdAt: now,
+        updatedAt: now,
+    }
+
+    data.presets.push(newPreset)
+    savePresets(data)
+
+    return newPreset
+}
+
+/**
+ * Update an existing preset
+ */
+export function updatePreset(
+    id: string,
+    updates: Partial<Omit<ConfigPreset, "id" | "createdAt">>,
+): ConfigPreset | null {
+    const data = loadPresets()
+    const index = data.presets.findIndex((p) => p.id === id)
+
+    if (index === -1) {
+        return null
+    }
+
+    const updatedPreset: ConfigPreset = {
+        ...data.presets[index],
+        ...updates,
+        updatedAt: Date.now(),
+    }
+
+    data.presets[index] = updatedPreset
+    savePresets(data)
+
+    return updatedPreset
+}
+
+/**
+ * Delete a preset
+ */
+export function deletePreset(id: string): boolean {
+    const data = loadPresets()
+    const index = data.presets.findIndex((p) => p.id === id)
+
+    if (index === -1) {
+        return false
+    }
+
+    data.presets.splice(index, 1)
+
+    // Clear current preset if it was deleted
+    if (data.currentPresetId === id) {
+        data.currentPresetId = null
+    }
+
+    savePresets(data)
+    return true
+}
+
+/**
+ * Set the current preset
+ */
+export function setCurrentPreset(id: string | null): boolean {
+    const data = loadPresets()
+
+    if (id !== null) {
+        const preset = data.presets.find((p) => p.id === id)
+        if (!preset) {
+            return false
+        }
+    }
+
+    data.currentPresetId = id
+    savePresets(data)
+    return true
+}
+
+/**
+ * Map generic AI_API_KEY and AI_BASE_URL to provider-specific environment variables
+ */
+const PROVIDER_ENV_MAP: Record<string, { apiKey: string; baseUrl: string }> = {
+    openai: { apiKey: "OPENAI_API_KEY", baseUrl: "OPENAI_BASE_URL" },
+    anthropic: { apiKey: "ANTHROPIC_API_KEY", baseUrl: "ANTHROPIC_BASE_URL" },
+    google: {
+        apiKey: "GOOGLE_GENERATIVE_AI_API_KEY",
+        baseUrl: "GOOGLE_BASE_URL",
+    },
+    azure: { apiKey: "AZURE_API_KEY", baseUrl: "AZURE_BASE_URL" },
+    openrouter: {
+        apiKey: "OPENROUTER_API_KEY",
+        baseUrl: "OPENROUTER_BASE_URL",
+    },
+    deepseek: { apiKey: "DEEPSEEK_API_KEY", baseUrl: "DEEPSEEK_BASE_URL" },
+    siliconflow: {
+        apiKey: "SILICONFLOW_API_KEY",
+        baseUrl: "SILICONFLOW_BASE_URL",
+    },
+    gateway: { apiKey: "AI_GATEWAY_API_KEY", baseUrl: "AI_GATEWAY_BASE_URL" },
+    // bedrock and ollama don't use API keys in the same way
+    bedrock: { apiKey: "", baseUrl: "" },
+    ollama: { apiKey: "", baseUrl: "OLLAMA_BASE_URL" },
+}
+
+/**
+ * Apply preset environment variables to the current process
+ * Returns the environment variables that were applied
+ */
+export function applyPresetToEnv(id: string): Record<string, string> | null {
+    const data = loadPresets()
+    const preset = data.presets.find((p) => p.id === id)
+
+    if (!preset) {
+        return null
+    }
+
+    const appliedEnv: Record<string, string> = {}
+    const provider = preset.config.AI_PROVIDER?.toLowerCase()
+
+    for (const [key, value] of Object.entries(preset.config)) {
+        if (value !== undefined && value !== "") {
+            // Map generic AI_API_KEY to provider-specific key
+            if (
+                key === "AI_API_KEY" &&
+                provider &&
+                PROVIDER_ENV_MAP[provider]
+            ) {
+                const providerApiKey = PROVIDER_ENV_MAP[provider].apiKey
+                if (providerApiKey) {
+                    process.env[providerApiKey] = value
+                    appliedEnv[providerApiKey] = value
+                }
+            }
+            // Map generic AI_BASE_URL to provider-specific key
+            else if (
+                key === "AI_BASE_URL" &&
+                provider &&
+                PROVIDER_ENV_MAP[provider]
+            ) {
+                const providerBaseUrl = PROVIDER_ENV_MAP[provider].baseUrl
+                if (providerBaseUrl) {
+                    process.env[providerBaseUrl] = value
+                    appliedEnv[providerBaseUrl] = value
+                }
+            }
+            // Apply other env vars directly
+            else {
+                process.env[key] = value
+                appliedEnv[key] = value
+            }
+        }
+    }
+
+    // Set as current preset
+    data.currentPresetId = id
+    savePresets(data)
+
+    return appliedEnv
+}
+
+/**
+ * Get environment variables from current preset
+ * Maps generic AI_API_KEY/AI_BASE_URL to provider-specific keys
+ */
+export function getCurrentPresetEnv(): Record<string, string> {
+    const preset = getCurrentPreset()
+    if (!preset) {
+        return {}
+    }
+
+    const env: Record<string, string> = {}
+    const provider = preset.config.AI_PROVIDER?.toLowerCase()
+
+    for (const [key, value] of Object.entries(preset.config)) {
+        if (value !== undefined && value !== "") {
+            // Map generic AI_API_KEY to provider-specific key
+            if (
+                key === "AI_API_KEY" &&
+                provider &&
+                PROVIDER_ENV_MAP[provider]
+            ) {
+                const providerApiKey = PROVIDER_ENV_MAP[provider].apiKey
+                if (providerApiKey) {
+                    env[providerApiKey] = value
+                }
+            }
+            // Map generic AI_BASE_URL to provider-specific key
+            else if (
+                key === "AI_BASE_URL" &&
+                provider &&
+                PROVIDER_ENV_MAP[provider]
+            ) {
+                const providerBaseUrl = PROVIDER_ENV_MAP[provider].baseUrl
+                if (providerBaseUrl) {
+                    env[providerBaseUrl] = value
+                }
+            }
+            // Apply other env vars directly
+            else {
+                env[key] = value
+            }
+        }
+    }
+    return env
+}

electron/main/env-loader.ts

@@ -0,0 +1,67 @@
+import fs from "node:fs"
+import path from "node:path"
+import { app } from "electron"
+
+/**
+ * Load environment variables from .env file
+ * Searches multiple locations in priority order
+ */
+export function loadEnvFile(): void {
+    const possiblePaths = [
+        // Next to the executable (for portable installations)
+        path.join(path.dirname(app.getPath("exe")), ".env"),
+        // User data directory (persists across updates)
+        path.join(app.getPath("userData"), ".env"),
+        // Development: project root
+        path.join(app.getAppPath(), ".env.local"),
+        path.join(app.getAppPath(), ".env"),
+    ]
+
+    for (const envPath of possiblePaths) {
+        if (fs.existsSync(envPath)) {
+            console.log(`Loading environment from: ${envPath}`)
+            loadEnvFromFile(envPath)
+            return
+        }
+    }
+
+    console.log("No .env file found, using system environment variables")
+}
+
+/**
+ * Parse and load environment variables from a file
+ */
+function loadEnvFromFile(filePath: string): void {
+    try {
+        const content = fs.readFileSync(filePath, "utf-8")
+        const lines = content.split("\n")
+
+        for (const line of lines) {
+            const trimmed = line.trim()
+
+            // Skip comments and empty lines
+            if (!trimmed || trimmed.startsWith("#")) continue
+
+            const equalIndex = trimmed.indexOf("=")
+            if (equalIndex === -1) continue
+
+            const key = trimmed.slice(0, equalIndex).trim()
+            let value = trimmed.slice(equalIndex + 1).trim()
+
+            // Remove surrounding quotes
+            if (
+                (value.startsWith('"') && value.endsWith('"')) ||
+                (value.startsWith("'") && value.endsWith("'"))
+            ) {
+                value = value.slice(1, -1)
+            }
+
+            // Don't override existing environment variables
+            if (!(key in process.env)) {
+                process.env[key] = value
+            }
+        }
+    } catch (error) {
+        console.error(`Failed to load env file ${filePath}:`, error)
+    }
+}

electron/main/index.ts

@@ -0,0 +1,105 @@
+import { app, BrowserWindow, dialog, shell } from "electron"
+import { buildAppMenu } from "./app-menu"
+import { getCurrentPresetEnv } from "./config-manager"
+import { loadEnvFile } from "./env-loader"
+import { registerIpcHandlers } from "./ipc-handlers"
+import { startNextServer, stopNextServer } from "./next-server"
+import { registerSettingsWindowHandlers } from "./settings-window"
+import { createWindow, getMainWindow } from "./window-manager"
+
+// Single instance lock
+const gotTheLock = app.requestSingleInstanceLock()
+
+if (!gotTheLock) {
+    app.quit()
+} else {
+    app.on("second-instance", () => {
+        const mainWindow = getMainWindow()
+        if (mainWindow) {
+            if (mainWindow.isMinimized()) mainWindow.restore()
+            mainWindow.focus()
+        }
+    })
+
+    // Load environment variables from .env files
+    loadEnvFile()
+
+    // Apply saved preset environment variables (overrides .env)
+    const presetEnv = getCurrentPresetEnv()
+    for (const [key, value] of Object.entries(presetEnv)) {
+        process.env[key] = value
+    }
+
+    const isDev = process.env.NODE_ENV === "development"
+    let serverUrl: string | null = null
+
+    app.whenReady().then(async () => {
+        // Register IPC handlers
+        registerIpcHandlers()
+        registerSettingsWindowHandlers()
+
+        // Build application menu
+        buildAppMenu()
+
+        try {
+            if (isDev) {
+                // Development: use the dev server URL
+                serverUrl =
+                    process.env.ELECTRON_DEV_URL || "http://localhost:6002"
+                console.log(`Development mode: connecting to ${serverUrl}`)
+            } else {
+                // Production: start Next.js standalone server
+                serverUrl = await startNextServer()
+            }
+
+            // Create main window
+            createWindow(serverUrl)
+        } catch (error) {
+            console.error("Failed to start application:", error)
+            dialog.showErrorBox(
+                "Startup Error",
+                `Failed to start the application: ${error instanceof Error ? error.message : "Unknown error"}`,
+            )
+            app.quit()
+        }
+
+        app.on("activate", () => {
+            if (BrowserWindow.getAllWindows().length === 0) {
+                if (serverUrl) {
+                    createWindow(serverUrl)
+                }
+            }
+        })
+    })
+
+    app.on("window-all-closed", () => {
+        if (process.platform !== "darwin") {
+            stopNextServer()
+            app.quit()
+        }
+    })
+
+    app.on("before-quit", () => {
+        stopNextServer()
+    })
+
+    // Open external links in default browser
+    app.on("web-contents-created", (_, contents) => {
+        contents.setWindowOpenHandler(({ url }) => {
+            // Allow diagrams.net iframe
+            if (
+                url.includes("diagrams.net") ||
+                url.includes("draw.io") ||
+                url.startsWith("http://localhost")
+            ) {
+                return { action: "allow" }
+            }
+            // Open other links in external browser
+            if (url.startsWith("http://") || url.startsWith("https://")) {
+                shell.openExternal(url)
+                return { action: "deny" }
+            }
+            return { action: "allow" }
+        })
+    })
+}

electron/main/ipc-handlers.ts

@@ -0,0 +1,212 @@
+import { app, BrowserWindow, dialog, ipcMain } from "electron"
+import {
+    applyPresetToEnv,
+    type ConfigPreset,
+    createPreset,
+    deletePreset,
+    getAllPresets,
+    getCurrentPreset,
+    getCurrentPresetId,
+    setCurrentPreset,
+    updatePreset,
+} from "./config-manager"
+import { restartNextServer } from "./next-server"
+
+/**
+ * Allowed configuration keys for presets
+ * This whitelist prevents arbitrary environment variable injection
+ */
+const ALLOWED_CONFIG_KEYS = new Set([
+    "AI_PROVIDER",
+    "AI_MODEL",
+    "AI_API_KEY",
+    "AI_BASE_URL",
+    "TEMPERATURE",
+])
+
+/**
+ * Sanitize preset config to only include allowed keys
+ */
+function sanitizePresetConfig(
+    config: Record<string, string | undefined>,
+): Record<string, string | undefined> {
+    const sanitized: Record<string, string | undefined> = {}
+    for (const key of ALLOWED_CONFIG_KEYS) {
+        if (key in config && typeof config[key] === "string") {
+            sanitized[key] = config[key]
+        }
+    }
+    return sanitized
+}
+
+/**
+ * Register all IPC handlers
+ */
+export function registerIpcHandlers(): void {
+    // ==================== App Info ====================
+
+    ipcMain.handle("get-version", () => {
+        return app.getVersion()
+    })
+
+    // ==================== Window Controls ====================
+
+    ipcMain.on("window-minimize", (event) => {
+        const win = BrowserWindow.fromWebContents(event.sender)
+        win?.minimize()
+    })
+
+    ipcMain.on("window-maximize", (event) => {
+        const win = BrowserWindow.fromWebContents(event.sender)
+        if (win?.isMaximized()) {
+            win.unmaximize()
+        } else {
+            win?.maximize()
+        }
+    })
+
+    ipcMain.on("window-close", (event) => {
+        const win = BrowserWindow.fromWebContents(event.sender)
+        win?.close()
+    })
+
+    // ==================== File Dialogs ====================
+
+    ipcMain.handle("dialog-open-file", async (event) => {
+        const win = BrowserWindow.fromWebContents(event.sender)
+        if (!win) return null
+
+        const result = await dialog.showOpenDialog(win, {
+            properties: ["openFile"],
+            filters: [
+                { name: "Draw.io Files", extensions: ["drawio", "xml"] },
+                { name: "All Files", extensions: ["*"] },
+            ],
+        })
+
+        if (result.canceled || result.filePaths.length === 0) {
+            return null
+        }
+
+        // Read the file content
+        const fs = await import("node:fs/promises")
+        try {
+            const content = await fs.readFile(result.filePaths[0], "utf-8")
+            return content
+        } catch (error) {
+            console.error("Failed to read file:", error)
+            return null
+        }
+    })
+
+    ipcMain.handle("dialog-save-file", async (event, data: string) => {
+        const win = BrowserWindow.fromWebContents(event.sender)
+        if (!win) return false
+
+        const result = await dialog.showSaveDialog(win, {
+            filters: [
+                { name: "Draw.io Files", extensions: ["drawio"] },
+                { name: "XML Files", extensions: ["xml"] },
+            ],
+        })
+
+        if (result.canceled || !result.filePath) {
+            return false
+        }
+
+        const fs = await import("node:fs/promises")
+        try {
+            await fs.writeFile(result.filePath, data, "utf-8")
+            return true
+        } catch (error) {
+            console.error("Failed to save file:", error)
+            return false
+        }
+    })
+
+    // ==================== Config Presets ====================
+
+    ipcMain.handle("config-presets:get-all", () => {
+        return getAllPresets()
+    })
+
+    ipcMain.handle("config-presets:get-current", () => {
+        return getCurrentPreset()
+    })
+
+    ipcMain.handle("config-presets:get-current-id", () => {
+        return getCurrentPresetId()
+    })
+
+    ipcMain.handle(
+        "config-presets:save",
+        (
+            _event,
+            preset: Omit<ConfigPreset, "id" | "createdAt" | "updatedAt"> & {
+                id?: string
+            },
+        ) => {
+            // Validate preset name
+            if (typeof preset.name !== "string" || !preset.name.trim()) {
+                throw new Error("Invalid preset name")
+            }
+
+            // Sanitize config to only allow whitelisted keys
+            const sanitizedConfig = sanitizePresetConfig(preset.config ?? {})
+
+            if (preset.id) {
+                // Update existing preset
+                return updatePreset(preset.id, {
+                    name: preset.name.trim(),
+                    config: sanitizedConfig,
+                })
+            }
+            // Create new preset
+            return createPreset({
+                name: preset.name.trim(),
+                config: sanitizedConfig,
+            })
+        },
+    )
+
+    ipcMain.handle("config-presets:delete", (_event, id: string) => {
+        return deletePreset(id)
+    })
+
+    ipcMain.handle("config-presets:apply", async (_event, id: string) => {
+        const env = applyPresetToEnv(id)
+        if (!env) {
+            return { success: false, error: "Preset not found" }
+        }
+
+        const isDev = process.env.NODE_ENV === "development"
+
+        if (isDev) {
+            // In development mode, the config file change will trigger
+            // the file watcher in electron-dev.mjs to restart Next.js
+            // We just need to save the preset (already done in applyPresetToEnv)
+            return { success: true, env, devMode: true }
+        }
+
+        // Production mode: restart the Next.js server to apply new environment variables
+        try {
+            await restartNextServer()
+            return { success: true, env }
+        } catch (error) {
+            return {
+                success: false,
+                error:
+                    error instanceof Error
+                        ? error.message
+                        : "Failed to restart server",
+            }
+        }
+    })
+
+    ipcMain.handle(
+        "config-presets:set-current",
+        (_event, id: string | null) => {
+            return setCurrentPreset(id)
+        },
+    )
+}

electron/main/next-server.ts

@@ -0,0 +1,161 @@
+import { existsSync } from "node:fs"
+import path from "node:path"
+import { app, type UtilityProcess, utilityProcess } from "electron"
+import {
+    findAvailablePort,
+    getAllocatedPort,
+    getServerUrl,
+    isPortAvailable,
+} from "./port-manager"
+
+let serverProcess: UtilityProcess | null = null
+
+/**
+ * Get the path to the standalone server resources
+ * In packaged app: resources/standalone
+ * In development: .next/standalone
+ */
+function getResourcePath(): string {
+    if (app.isPackaged) {
+        return path.join(process.resourcesPath, "standalone")
+    }
+    return path.join(app.getAppPath(), ".next", "standalone")
+}
+
+/**
+ * Wait for the server to be ready by polling the health endpoint
+ */
+async function waitForServer(url: string, timeout = 30000): Promise<void> {
+    const start = Date.now()
+    while (Date.now() - start < timeout) {
+        try {
+            const response = await fetch(url)
+            if (response.ok || response.status < 500) {
+                return
+            }
+        } catch {
+            // Server not ready yet
+        }
+        await new Promise((resolve) => setTimeout(resolve, 100))
+    }
+    throw new Error(`Server startup timeout after ${timeout}ms`)
+}
+
+/**
+ * Start the Next.js standalone server using Electron's utilityProcess
+ * This API is designed for running Node.js code in the background
+ */
+export async function startNextServer(): Promise<string> {
+    const resourcePath = getResourcePath()
+    const serverPath = path.join(resourcePath, "server.js")
+
+    console.log(`Starting Next.js server from: ${resourcePath}`)
+    console.log(`Server script path: ${serverPath}`)
+
+    // Verify server script exists before attempting to start
+    if (!existsSync(serverPath)) {
+        throw new Error(
+            `Server script not found at ${serverPath}. ` +
+                "Please ensure the app was built correctly with 'npm run build'.",
+        )
+    }
+
+    // Find an available port (random in production, fixed in development)
+    const port = await findAvailablePort()
+    console.log(`Using port: ${port}`)
+
+    // Set up environment variables
+    const env: Record<string, string> = {
+        NODE_ENV: "production",
+        PORT: String(port),
+        HOSTNAME: "localhost",
+    }
+
+    // Set cache directory to a writable location (user's app data folder)
+    // This is necessary because the packaged app might be on a read-only volume
+    if (app.isPackaged) {
+        const cacheDir = path.join(app.getPath("userData"), "cache")
+        env.NEXT_CACHE_DIR = cacheDir
+    }
+
+    // Copy existing environment variables
+    for (const [key, value] of Object.entries(process.env)) {
+        if (value !== undefined && !env[key]) {
+            env[key] = value
+        }
+    }
+
+    // Use Electron's utilityProcess API for running Node.js in background
+    // This is the recommended way to run Node.js code in Electron
+    serverProcess = utilityProcess.fork(serverPath, [], {
+        cwd: resourcePath,
+        env,
+        stdio: "pipe",
+    })
+
+    serverProcess.stdout?.on("data", (data) => {
+        console.log(`[Next.js] ${data.toString().trim()}`)
+    })
+
+    serverProcess.stderr?.on("data", (data) => {
+        console.error(`[Next.js Error] ${data.toString().trim()}`)
+    })
+
+    serverProcess.on("exit", (code) => {
+        console.log(`Next.js server exited with code ${code}`)
+        serverProcess = null
+    })
+
+    const url = getServerUrl()
+    await waitForServer(url)
+    console.log(`Next.js server started at ${url}`)
+
+    return url
+}
+
+/**
+ * Stop the Next.js server process
+ */
+export function stopNextServer(): void {
+    if (serverProcess) {
+        console.log("Stopping Next.js server...")
+        serverProcess.kill()
+        serverProcess = null
+    }
+}
+
+/**
+ * Wait for the server to fully stop
+ */
+async function waitForServerStop(timeout = 5000): Promise<void> {
+    const port = getAllocatedPort()
+    if (port === null) {
+        return
+    }
+
+    const start = Date.now()
+    while (Date.now() - start < timeout) {
+        const available = await isPortAvailable(port)
+        if (available) {
+            return
+        }
+        await new Promise((resolve) => setTimeout(resolve, 100))
+    }
+    console.warn("Server stop timeout, port may still be in use")
+}
+
+/**
+ * Restart the Next.js server with new environment variables
+ */
+export async function restartNextServer(): Promise<string> {
+    console.log("Restarting Next.js server...")
+
+    // Stop the current server
+    stopNextServer()
+
+    // Wait for the port to be released
+    await waitForServerStop()
+
+    // Start the server again
+    return startNextServer()
+}

electron/main/port-manager.ts

@@ -0,0 +1,129 @@
+import net from "node:net"
+import { app } from "electron"
+
+/**
+ * Port configuration
+ */
+const PORT_CONFIG = {
+    // Development mode uses fixed port for hot reload compatibility
+    development: 6002,
+    // Production mode port range (will find first available)
+    production: {
+        min: 10000,
+        max: 65535,
+    },
+    // Maximum attempts to find an available port
+    maxAttempts: 100,
+}
+
+/**
+ * Currently allocated port (cached after first allocation)
+ */
+let allocatedPort: number | null = null
+
+/**
+ * Check if a specific port is available
+ */
+export function isPortAvailable(port: number): Promise<boolean> {
+    return new Promise((resolve) => {
+        const server = net.createServer()
+        server.once("error", () => resolve(false))
+        server.once("listening", () => {
+            server.close()
+            resolve(true)
+        })
+        server.listen(port, "127.0.0.1")
+    })
+}
+
+/**
+ * Generate a random port within the production range
+ */
+function getRandomPort(): number {
+    const { min, max } = PORT_CONFIG.production
+    return Math.floor(Math.random() * (max - min + 1)) + min
+}
+
+/**
+ * Find an available port
+ * - In development: uses fixed port (6002)
+ * - In production: finds a random available port
+ * - If a port was previously allocated, verifies it's still available
+ *
+ * @param reuseExisting If true, try to reuse the previously allocated port
+ * @returns Promise<number> The available port
+ * @throws Error if no available port found after max attempts
+ */
+export async function findAvailablePort(reuseExisting = true): Promise<number> {
+    const isDev = !app.isPackaged
+
+    // Try to reuse cached port if requested and available
+    if (reuseExisting && allocatedPort !== null) {
+        const available = await isPortAvailable(allocatedPort)
+        if (available) {
+            return allocatedPort
+        }
+        console.warn(
+            `Previously allocated port ${allocatedPort} is no longer available`,
+        )
+        allocatedPort = null
+    }
+
+    if (isDev) {
+        // Development mode: use fixed port
+        const port = PORT_CONFIG.development
+        const available = await isPortAvailable(port)
+        if (available) {
+            allocatedPort = port
+            return port
+        }
+        console.warn(
+            `Development port ${port} is in use, finding alternative...`,
+        )
+    }
+
+    // Production mode or dev port unavailable: find random available port
+    for (let attempt = 0; attempt < PORT_CONFIG.maxAttempts; attempt++) {
+        const port = isDev
+            ? PORT_CONFIG.development + attempt + 1
+            : getRandomPort()
+
+        const available = await isPortAvailable(port)
+        if (available) {
+            allocatedPort = port
+            console.log(`Allocated port: ${port}`)
+            return port
+        }
+    }
+
+    throw new Error(
+        `Failed to find available port after ${PORT_CONFIG.maxAttempts} attempts`,
+    )
+}
+
+/**
+ * Get the currently allocated port
+ * Returns null if no port has been allocated yet
+ */
+export function getAllocatedPort(): number | null {
+    return allocatedPort
+}
+
+/**
+ * Reset the allocated port (useful for testing or restart scenarios)
+ */
+export function resetAllocatedPort(): void {
+    allocatedPort = null
+}
+
+/**
+ * Get the server URL with the allocated port
+ */
+export function getServerUrl(): string {
+    if (allocatedPort === null) {
+        throw new Error(
+            "No port allocated yet. Call findAvailablePort() first.",
+        )
+    }
+    return `http://localhost:${allocatedPort}`
+}

electron/main/settings-window.ts

@@ -0,0 +1,78 @@
+import path from "node:path"
+import { app, BrowserWindow, ipcMain } from "electron"
+
+let settingsWindow: BrowserWindow | null = null
+
+/**
+ * Create and show the settings window
+ */
+export function showSettingsWindow(parentWindow?: BrowserWindow): void {
+    // If settings window already exists, focus it
+    if (settingsWindow && !settingsWindow.isDestroyed()) {
+        settingsWindow.focus()
+        return
+    }
+
+    // Determine path to settings preload script
+    // In compiled output: dist-electron/preload/settings.js
+    const preloadPath = path.join(__dirname, "..", "preload", "settings.js")
+
+    // Determine path to settings HTML
+    // In packaged app: app.asar/dist-electron/settings/index.html
+    // In development: electron/settings/index.html
+    const settingsHtmlPath = app.isPackaged
+        ? path.join(__dirname, "..", "settings", "index.html")
+        : path.join(__dirname, "..", "..", "electron", "settings", "index.html")
+
+    settingsWindow = new BrowserWindow({
+        width: 600,
+        height: 700,
+        minWidth: 500,
+        minHeight: 500,
+        parent: parentWindow,
+        modal: false,
+        show: false,
+        title: "Settings - Next AI Draw.io",
+        webPreferences: {
+            preload: preloadPath,
+            contextIsolation: true,
+            nodeIntegration: false,
+            sandbox: true,
+        },
+    })
+    settingsWindow.loadFile(settingsHtmlPath)
+
+    settingsWindow.once("ready-to-show", () => {
+        settingsWindow?.show()
+    })
+
+    settingsWindow.on("closed", () => {
+        settingsWindow = null
+    })
+}
+
+/**
+ * Close the settings window if it exists
+ */
+export function closeSettingsWindow(): void {
+    if (settingsWindow && !settingsWindow.isDestroyed()) {
+        settingsWindow.close()
+        settingsWindow = null
+    }
+}
+
+/**
+ * Check if settings window is open
+ */
+export function isSettingsWindowOpen(): boolean {
+    return settingsWindow !== null && !settingsWindow.isDestroyed()
+}
+
+/**
+ * Register settings window IPC handlers
+ */
+export function registerSettingsWindowHandlers(): void {
+    ipcMain.on("settings:close", () => {
+        closeSettingsWindow()
+    })
+}

electron/main/window-manager.ts

@@ -0,0 +1,84 @@
+import path from "node:path"
+import { app, BrowserWindow, screen } from "electron"
+
+let mainWindow: BrowserWindow | null = null
+
+/**
+ * Get the icon path based on platform
+ * Note: electron-builder converts icon.png during packaging,
+ * but at runtime we use PNG directly - Electron handles it
+ */
+function getIconPath(): string | undefined {
+    // macOS doesn't need explicit icon - it's embedded in the app bundle
+    if (process.platform === "darwin" && app.isPackaged) {
+        return undefined
+    }
+
+    const iconName = "icon.png"
+
+    if (app.isPackaged) {
+        return path.join(process.resourcesPath, iconName)
+    }
+
+    // Development: use icon.png from resources
+    return path.join(__dirname, "../../resources/icon.png")
+}
+
+/**
+ * Create the main application window
+ */
+export function createWindow(serverUrl: string): BrowserWindow {
+    const { width, height } = screen.getPrimaryDisplay().workAreaSize
+
+    mainWindow = new BrowserWindow({
+        width: Math.min(1400, Math.floor(width * 0.9)),
+        height: Math.min(900, Math.floor(height * 0.9)),
+        minWidth: 800,
+        minHeight: 600,
+        title: "Next AI Draw.io",
+        icon: getIconPath(),
+        show: false, // Don't show until ready
+        webPreferences: {
+            preload: path.join(__dirname, "../preload/index.js"),
+            contextIsolation: true,
+            nodeIntegration: false,
+            sandbox: true,
+            webSecurity: true,
+        },
+    })
+
+    // Load the Next.js application
+    mainWindow.loadURL(serverUrl)
+
+    // Show window when ready to prevent flashing
+    mainWindow.once("ready-to-show", () => {
+        mainWindow?.show()
+    })
+
+    // Open DevTools in development
+    if (process.env.NODE_ENV === "development") {
+        mainWindow.webContents.openDevTools()
+    }
+
+    mainWindow.on("closed", () => {
+        mainWindow = null
+    })
+
+    // Handle page title updates
+    mainWindow.webContents.on("page-title-updated", (event, title) => {
+        if (title && !title.includes("localhost")) {
+            mainWindow?.setTitle(title)
+        } else {
+            event.preventDefault()
+        }
+    })
+
+    return mainWindow
+}
+
+/**
+ * Get the main window instance
+ */
+export function getMainWindow(): BrowserWindow | null {
+    return mainWindow
+}

electron/preload/index.ts

@@ -0,0 +1,24 @@
+import { contextBridge, ipcRenderer } from "electron"
+
+/**
+ * Expose safe APIs to the renderer process
+ */
+contextBridge.exposeInMainWorld("electronAPI", {
+    // Platform information
+    platform: process.platform,
+
+    // Check if running in Electron
+    isElectron: true,
+
+    // Application version
+    getVersion: () => ipcRenderer.invoke("get-version"),
+
+    // Window controls (optional, for custom title bar)
+    minimize: () => ipcRenderer.send("window-minimize"),
+    maximize: () => ipcRenderer.send("window-maximize"),
+    close: () => ipcRenderer.send("window-close"),
+
+    // File operations
+    openFile: () => ipcRenderer.invoke("dialog-open-file"),
+    saveFile: (data: string) => ipcRenderer.invoke("dialog-save-file", data),
+})

electron/preload/settings.ts

@@ -0,0 +1,35 @@
+/**
+ * Preload script for settings window
+ * Exposes APIs for managing configuration presets
+ */
+import { contextBridge, ipcRenderer } from "electron"
+
+// Expose settings API to the renderer process
+contextBridge.exposeInMainWorld("settingsAPI", {
+    // Get all presets
+    getPresets: () => ipcRenderer.invoke("config-presets:get-all"),
+
+    // Get current preset ID
+    getCurrentPresetId: () =>
+        ipcRenderer.invoke("config-presets:get-current-id"),
+
+    // Get current preset
+    getCurrentPreset: () => ipcRenderer.invoke("config-presets:get-current"),
+
+    // Save (create or update) a preset
+    savePreset: (preset: {
+        id?: string
+        name: string
+        config: Record<string, string | undefined>
+    }) => ipcRenderer.invoke("config-presets:save", preset),
+
+    // Delete a preset
+    deletePreset: (id: string) =>
+        ipcRenderer.invoke("config-presets:delete", id),
+
+    // Apply a preset (sets environment variables and restarts server)
+    applyPreset: (id: string) => ipcRenderer.invoke("config-presets:apply", id),
+
+    // Close settings window
+    close: () => ipcRenderer.send("settings:close"),
+})

electron/settings/index.html

@@ -0,0 +1,116 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <meta http-equiv="Content-Security-Policy" content="default-src 'self'; script-src 'self'; style-src 'self';">
+    <title>Settings - Next AI Draw.io</title>
+    <link rel="stylesheet" href="./settings.css">
+</head>
+<body>
+    <div class="container">
+        <div class="deprecation-notice">
+            <strong>⚠️ Deprecation Notice</strong>
+            <p>This settings panel will be removed in a future update.</p>
+            <p>Please use the <strong>AI Model Configuration</strong> button (left of the Send button in the chat panel) to configure your AI providers. Your settings there will persist across updates.</p>
+        </div>
+
+        <h1>Configuration Presets</h1>
+
+        <div class="section">
+            <h2>Presets</h2>
+            <div id="preset-list" class="preset-list">
+                <!-- Presets will be loaded here -->
+            </div>
+            <button id="add-preset-btn" class="btn btn-primary">
+                + Add New Preset
+            </button>
+        </div>
+    </div>
+
+    <!-- Add/Edit Preset Modal -->
+    <div id="preset-modal" class="modal-overlay">
+        <div class="modal">
+            <div class="modal-header">
+                <h3 id="modal-title">Add Preset</h3>
+            </div>
+            <div class="modal-body">
+                <form id="preset-form">
+                    <input type="hidden" id="preset-id">
+
+                    <div class="form-group">
+                        <label for="preset-name">Preset Name *</label>
+                        <input type="text" id="preset-name" required placeholder="e.g., Work, Personal, Testing">
+                    </div>
+
+                    <div class="form-group">
+                        <label for="ai-provider">AI Provider</label>
+                        <select id="ai-provider">
+                            <option value="">-- Select Provider --</option>
+                            <option value="openai">OpenAI</option>
+                            <option value="anthropic">Anthropic (Claude)</option>
+                            <option value="google">Google AI (Gemini)</option>
+                            <option value="azure">Azure OpenAI</option>
+                            <option value="bedrock">AWS Bedrock</option>
+                            <option value="openrouter">OpenRouter</option>
+                            <option value="deepseek">DeepSeek</option>
+                            <option value="siliconflow">SiliconFlow</option>
+                            <option value="ollama">Ollama (Local)</option>
+                        </select>
+                    </div>
+
+                    <div class="form-group">
+                        <label for="ai-model">Model ID</label>
+                        <input type="text" id="ai-model" placeholder="e.g., gpt-4o, claude-sonnet-4-5">
+                        <div class="hint">The model identifier to use with the selected provider</div>
+                    </div>
+
+                    <div class="form-group">
+                        <label for="ai-api-key">API Key</label>
+                        <input type="password" id="ai-api-key" placeholder="Your API key">
+                        <div class="hint">This will be stored locally on your device</div>
+                    </div>
+
+                    <div class="form-group">
+                        <label for="ai-base-url">Base URL (Optional)</label>
+                        <input type="text" id="ai-base-url" placeholder="https://api.example.com/v1">
+                        <div class="hint">Custom API endpoint URL</div>
+                    </div>
+
+                    <div class="form-group">
+                        <label for="temperature">Temperature (Optional)</label>
+                        <input type="text" id="temperature" placeholder="0.7">
+                        <div class="hint">Controls randomness (0.0 - 2.0)</div>
+                    </div>
+                </form>
+            </div>
+            <div class="modal-footer">
+                <button type="button" id="cancel-btn" class="btn btn-secondary">Cancel</button>
+                <button type="button" id="save-btn" class="btn btn-primary">Save</button>
+            </div>
+        </div>
+    </div>
+
+    <!-- Delete Confirmation Modal -->
+    <div id="delete-modal" class="modal-overlay">
+        <div class="modal">
+            <div class="modal-header">
+                <h3>Delete Preset</h3>
+            </div>
+            <div class="modal-body">
+                <p>Are you sure you want to delete "<span id="delete-preset-name"></span>"?</p>
+                <p class="delete-warning">This action cannot be undone.</p>
+            </div>
+            <div class="modal-footer">
+                <button type="button" id="delete-cancel-btn" class="btn btn-secondary">Cancel</button>
+                <button type="button" id="delete-confirm-btn" class="btn btn-danger">Delete</button>
+            </div>
+        </div>
+    </div>
+
+    <!-- Toast notification -->
+    <div id="toast" class="toast"></div>
+
+    <script src="./settings.js"></script>
+</body>
+</html>

electron/settings/settings.css

@@ -0,0 +1,344 @@
+:root {
+    --bg-primary: #ffffff;
+    --bg-secondary: #f5f5f5;
+    --bg-hover: #e8e8e8;
+    --text-primary: #1a1a1a;
+    --text-secondary: #666666;
+    --border-color: #e0e0e0;
+    --accent-color: #0066cc;
+    --accent-hover: #0052a3;
+    --danger-color: #dc3545;
+    --success-color: #28a745;
+}
+
+@media (prefers-color-scheme: dark) {
+    :root {
+        --bg-primary: #1a1a1a;
+        --bg-secondary: #2d2d2d;
+        --bg-hover: #3d3d3d;
+        --text-primary: #ffffff;
+        --text-secondary: #a0a0a0;
+        --border-color: #404040;
+        --accent-color: #4da6ff;
+        --accent-hover: #66b3ff;
+    }
+}
+
+.deprecation-notice {
+    background-color: #fff3cd;
+    border: 1px solid #ffc107;
+    border-radius: 8px;
+    padding: 16px;
+    margin-bottom: 20px;
+}
+
+.deprecation-notice strong {
+    color: #856404;
+    display: block;
+    margin-bottom: 8px;
+    font-size: 14px;
+}
+
+.deprecation-notice p {
+    color: #856404;
+    font-size: 13px;
+    margin: 4px 0;
+}
+
+@media (prefers-color-scheme: dark) {
+    .deprecation-notice {
+        background-color: #332701;
+        border-color: #665200;
+    }
+
+    .deprecation-notice strong,
+    .deprecation-notice p {
+        color: #ffc107;
+    }
+}
+
+* {
+    margin: 0;
+    padding: 0;
+    box-sizing: border-box;
+}
+
+body {
+    font-family:
+        -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu,
+        sans-serif;
+    background-color: var(--bg-primary);
+    color: var(--text-primary);
+    line-height: 1.5;
+}
+
+.container {
+    max-width: 560px;
+    margin: 0 auto;
+    padding: 24px;
+}
+
+h1 {
+    font-size: 24px;
+    font-weight: 600;
+    margin-bottom: 24px;
+    padding-bottom: 16px;
+    border-bottom: 1px solid var(--border-color);
+}
+
+h2 {
+    font-size: 16px;
+    font-weight: 600;
+    margin-bottom: 16px;
+    color: var(--text-secondary);
+}
+
+.section {
+    margin-bottom: 32px;
+}
+
+.preset-list {
+    display: flex;
+    flex-direction: column;
+    gap: 12px;
+    margin-bottom: 16px;
+}
+
+.preset-card {
+    background: var(--bg-secondary);
+    border: 1px solid var(--border-color);
+    border-radius: 8px;
+    padding: 16px;
+    cursor: pointer;
+    transition: all 0.2s ease;
+}
+
+.preset-card:hover {
+    background: var(--bg-hover);
+}
+
+.preset-card.active {
+    border-color: var(--accent-color);
+    box-shadow: 0 0 0 1px var(--accent-color);
+}
+
+.preset-header {
+    display: flex;
+    justify-content: space-between;
+    align-items: center;
+    margin-bottom: 8px;
+}
+
+.preset-name {
+    font-weight: 600;
+    font-size: 15px;
+}
+
+.preset-badge {
+    background: var(--accent-color);
+    color: white;
+    font-size: 11px;
+    padding: 2px 8px;
+    border-radius: 10px;
+}
+
+.preset-info {
+    font-size: 13px;
+    color: var(--text-secondary);
+}
+
+.preset-actions {
+    display: flex;
+    gap: 8px;
+    margin-top: 12px;
+}
+
+.btn {
+    padding: 8px 16px;
+    border: none;
+    border-radius: 6px;
+    font-size: 14px;
+    cursor: pointer;
+    transition: all 0.2s ease;
+    font-weight: 500;
+}
+
+.btn-primary {
+    background: var(--accent-color);
+    color: white;
+}
+
+.btn-primary:hover {
+    background: var(--accent-hover);
+}
+
+.btn-secondary {
+    background: var(--bg-secondary);
+    color: var(--text-primary);
+    border: 1px solid var(--border-color);
+}
+
+.btn-secondary:hover {
+    background: var(--bg-hover);
+}
+
+.btn-danger {
+    background: var(--danger-color);
+    color: white;
+}
+
+.btn-danger:hover {
+    opacity: 0.9;
+}
+
+.btn-sm {
+    padding: 6px 12px;
+    font-size: 13px;
+}
+
+.empty-state {
+    text-align: center;
+    padding: 40px 20px;
+    color: var(--text-secondary);
+}
+
+.empty-state p {
+    margin-bottom: 16px;
+}
+
+/* Modal */
+.modal-overlay {
+    display: none;
+    position: fixed;
+    top: 0;
+    left: 0;
+    right: 0;
+    bottom: 0;
+    background: rgba(0, 0, 0, 0.5);
+    z-index: 100;
+    align-items: center;
+    justify-content: center;
+}
+
+.modal-overlay.show {
+    display: flex;
+}
+
+.modal {
+    background: var(--bg-primary);
+    border-radius: 12px;
+    width: 90%;
+    max-width: 480px;
+    max-height: 90vh;
+    overflow-y: auto;
+    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
+}
+
+.modal-header {
+    padding: 20px 24px;
+    border-bottom: 1px solid var(--border-color);
+}
+
+.modal-header h3 {
+    font-size: 18px;
+    font-weight: 600;
+}
+
+.modal-body {
+    padding: 24px;
+}
+
+.modal-footer {
+    padding: 16px 24px;
+    border-top: 1px solid var(--border-color);
+    display: flex;
+    justify-content: flex-end;
+    gap: 12px;
+}
+
+.form-group {
+    margin-bottom: 20px;
+}
+
+.form-group label {
+    display: block;
+    font-size: 14px;
+    font-weight: 500;
+    margin-bottom: 6px;
+}
+
+.form-group input,
+.form-group select {
+    width: 100%;
+    padding: 10px 12px;
+    border: 1px solid var(--border-color);
+    border-radius: 6px;
+    font-size: 14px;
+    background: var(--bg-primary);
+    color: var(--text-primary);
+}
+
+.form-group input:focus,
+.form-group select:focus {
+    outline: none;
+    border-color: var(--accent-color);
+    box-shadow: 0 0 0 2px rgba(0, 102, 204, 0.2);
+}
+
+.form-group .hint {
+    font-size: 12px;
+    color: var(--text-secondary);
+    margin-top: 4px;
+}
+
+.loading {
+    display: inline-block;
+    width: 16px;
+    height: 16px;
+    border: 2px solid var(--border-color);
+    border-top-color: var(--accent-color);
+    border-radius: 50%;
+    animation: spin 0.8s linear infinite;
+}
+
+@keyframes spin {
+    to {
+        transform: rotate(360deg);
+    }
+}
+
+.toast {
+    position: fixed;
+    bottom: 24px;
+    left: 50%;
+    transform: translateX(-50%);
+    background: var(--text-primary);
+    color: var(--bg-primary);
+    padding: 12px 24px;
+    border-radius: 8px;
+    font-size: 14px;
+    z-index: 200;
+    opacity: 0;
+    transition: opacity 0.3s ease;
+}
+
+.toast.show {
+    opacity: 1;
+}
+
+.toast.success {
+    background: var(--success-color);
+    color: white;
+}
+
+.toast.error {
+    background: var(--danger-color);
+    color: white;
+}
+
+/* Inline style replacements */
+.delete-warning {
+    color: var(--text-secondary);
+    margin-top: 8px;
+    font-size: 14px;
+}

electron/settings/settings.js

@@ -0,0 +1,311 @@
+// Settings page JavaScript
+// This file handles the UI interactions for the settings window
+
+let presets = []
+let currentPresetId = null
+let editingPresetId = null
+let deletingPresetId = null
+
+// DOM Elements
+const presetList = document.getElementById("preset-list")
+const addPresetBtn = document.getElementById("add-preset-btn")
+const presetModal = document.getElementById("preset-modal")
+const deleteModal = document.getElementById("delete-modal")
+const presetForm = document.getElementById("preset-form")
+const modalTitle = document.getElementById("modal-title")
+const toast = document.getElementById("toast")
+
+// Form fields
+const presetIdField = document.getElementById("preset-id")
+const presetNameField = document.getElementById("preset-name")
+const aiProviderField = document.getElementById("ai-provider")
+const aiModelField = document.getElementById("ai-model")
+const aiApiKeyField = document.getElementById("ai-api-key")
+const aiBaseUrlField = document.getElementById("ai-base-url")
+const temperatureField = document.getElementById("temperature")
+
+// Buttons
+const cancelBtn = document.getElementById("cancel-btn")
+const saveBtn = document.getElementById("save-btn")
+const deleteCancelBtn = document.getElementById("delete-cancel-btn")
+const deleteConfirmBtn = document.getElementById("delete-confirm-btn")
+
+// Initialize
+document.addEventListener("DOMContentLoaded", async () => {
+    await loadPresets()
+    setupEventListeners()
+})
+
+// Load presets from main process
+async function loadPresets() {
+    try {
+        presets = await window.settingsAPI.getPresets()
+        currentPresetId = await window.settingsAPI.getCurrentPresetId()
+        renderPresets()
+    } catch (error) {
+        console.error("Failed to load presets:", error)
+        showToast("Failed to load presets", "error")
+    }
+}
+
+// Render presets list
+function renderPresets() {
+    if (presets.length === 0) {
+        presetList.innerHTML = `
+            <div class="empty-state">
+                <p>No presets configured yet.</p>
+                <p>Add a preset to quickly switch between different AI configurations.</p>
+            </div>
+        `
+        return
+    }
+
+    presetList.innerHTML = presets
+        .map((preset) => {
+            const isActive = preset.id === currentPresetId
+            const providerLabel = getProviderLabel(preset.config.AI_PROVIDER)
+
+            return `
+            <div class="preset-card ${isActive ? "active" : ""}" data-id="${preset.id}">
+                <div class="preset-header">
+                    <span class="preset-name">${escapeHtml(preset.name)}</span>
+                    ${isActive ? '<span class="preset-badge">Active</span>' : ""}
+                </div>
+                <div class="preset-info">
+                    ${providerLabel ? `Provider: ${providerLabel}` : "No provider configured"}
+                    ${preset.config.AI_MODEL ? ` • Model: ${escapeHtml(preset.config.AI_MODEL)}` : ""}
+                </div>
+                <div class="preset-actions">
+                    ${!isActive ? `<button class="btn btn-primary btn-sm apply-btn" data-id="${preset.id}">Apply</button>` : ""}
+                    <button class="btn btn-secondary btn-sm edit-btn" data-id="${preset.id}">Edit</button>
+                    <button class="btn btn-secondary btn-sm delete-btn" data-id="${preset.id}">Delete</button>
+                </div>
+            </div>
+        `
+        })
+        .join("")
+
+    // Add event listeners to buttons
+    presetList.querySelectorAll(".apply-btn").forEach((btn) => {
+        btn.addEventListener("click", (e) => {
+            e.stopPropagation()
+            applyPreset(btn.dataset.id)
+        })
+    })
+
+    presetList.querySelectorAll(".edit-btn").forEach((btn) => {
+        btn.addEventListener("click", (e) => {
+            e.stopPropagation()
+            openEditModal(btn.dataset.id)
+        })
+    })
+
+    presetList.querySelectorAll(".delete-btn").forEach((btn) => {
+        btn.addEventListener("click", (e) => {
+            e.stopPropagation()
+            openDeleteModal(btn.dataset.id)
+        })
+    })
+}
+
+// Setup event listeners
+function setupEventListeners() {
+    addPresetBtn.addEventListener("click", () => openAddModal())
+    cancelBtn.addEventListener("click", () => closeModal())
+    saveBtn.addEventListener("click", () => savePreset())
+    deleteCancelBtn.addEventListener("click", () => closeDeleteModal())
+    deleteConfirmBtn.addEventListener("click", () => confirmDelete())
+
+    // Close modal on overlay click
+    presetModal.addEventListener("click", (e) => {
+        if (e.target === presetModal) closeModal()
+    })
+    deleteModal.addEventListener("click", (e) => {
+        if (e.target === deleteModal) closeDeleteModal()
+    })
+
+    // Handle Enter key in form
+    presetForm.addEventListener("keydown", (e) => {
+        if (e.key === "Enter") {
+            e.preventDefault()
+            savePreset()
+        }
+    })
+}
+
+// Open add modal
+function openAddModal() {
+    editingPresetId = null
+    modalTitle.textContent = "Add Preset"
+    presetForm.reset()
+    presetIdField.value = ""
+    presetModal.classList.add("show")
+    presetNameField.focus()
+}
+
+// Open edit modal
+function openEditModal(id) {
+    const preset = presets.find((p) => p.id === id)
+    if (!preset) return
+
+    editingPresetId = id
+    modalTitle.textContent = "Edit Preset"
+
+    presetIdField.value = preset.id
+    presetNameField.value = preset.name
+    aiProviderField.value = preset.config.AI_PROVIDER || ""
+    aiModelField.value = preset.config.AI_MODEL || ""
+    aiApiKeyField.value = preset.config.AI_API_KEY || ""
+    aiBaseUrlField.value = preset.config.AI_BASE_URL || ""
+    temperatureField.value = preset.config.TEMPERATURE || ""
+
+    presetModal.classList.add("show")
+    presetNameField.focus()
+}
+
+// Close modal
+function closeModal() {
+    presetModal.classList.remove("show")
+    editingPresetId = null
+}
+
+// Open delete modal
+function openDeleteModal(id) {
+    const preset = presets.find((p) => p.id === id)
+    if (!preset) return
+
+    deletingPresetId = id
+    document.getElementById("delete-preset-name").textContent = preset.name
+    deleteModal.classList.add("show")
+}
+
+// Close delete modal
+function closeDeleteModal() {
+    deleteModal.classList.remove("show")
+    deletingPresetId = null
+}
+
+// Save preset
+async function savePreset() {
+    const name = presetNameField.value.trim()
+    if (!name) {
+        showToast("Please enter a preset name", "error")
+        presetNameField.focus()
+        return
+    }
+
+    const preset = {
+        id: editingPresetId || undefined,
+        name: name,
+        config: {
+            AI_PROVIDER: aiProviderField.value || undefined,
+            AI_MODEL: aiModelField.value.trim() || undefined,
+            AI_API_KEY: aiApiKeyField.value.trim() || undefined,
+            AI_BASE_URL: aiBaseUrlField.value.trim() || undefined,
+            TEMPERATURE: temperatureField.value.trim() || undefined,
+        },
+    }
+
+    // Remove undefined values
+    Object.keys(preset.config).forEach((key) => {
+        if (preset.config[key] === undefined) {
+            delete preset.config[key]
+        }
+    })
+
+    try {
+        saveBtn.disabled = true
+        saveBtn.innerHTML = '<span class="loading"></span>'
+
+        await window.settingsAPI.savePreset(preset)
+        await loadPresets()
+        closeModal()
+        showToast(
+            editingPresetId ? "Preset updated" : "Preset created",
+            "success",
+        )
+    } catch (error) {
+        console.error("Failed to save preset:", error)
+        showToast("Failed to save preset", "error")
+    } finally {
+        saveBtn.disabled = false
+        saveBtn.textContent = "Save"
+    }
+}
+
+// Confirm delete
+async function confirmDelete() {
+    if (!deletingPresetId) return
+
+    try {
+        deleteConfirmBtn.disabled = true
+        deleteConfirmBtn.innerHTML = '<span class="loading"></span>'
+
+        await window.settingsAPI.deletePreset(deletingPresetId)
+        await loadPresets()
+        closeDeleteModal()
+        showToast("Preset deleted", "success")
+    } catch (error) {
+        console.error("Failed to delete preset:", error)
+        showToast("Failed to delete preset", "error")
+    } finally {
+        deleteConfirmBtn.disabled = false
+        deleteConfirmBtn.textContent = "Delete"
+    }
+}
+
+// Apply preset
+async function applyPreset(id) {
+    try {
+        const btn = presetList.querySelector(`.apply-btn[data-id="${id}"]`)
+        if (btn) {
+            btn.disabled = true
+            btn.innerHTML = '<span class="loading"></span>'
+        }
+
+        const result = await window.settingsAPI.applyPreset(id)
+        if (result.success) {
+            currentPresetId = id
+            renderPresets()
+            showToast("Preset applied, server restarting...", "success")
+        } else {
+            showToast(result.error || "Failed to apply preset", "error")
+        }
+    } catch (error) {
+        console.error("Failed to apply preset:", error)
+        showToast("Failed to apply preset", "error")
+    }
+}
+
+// Get provider display label
+function getProviderLabel(provider) {
+    const labels = {
+        openai: "OpenAI",
+        anthropic: "Anthropic",
+        google: "Google AI",
+        azure: "Azure OpenAI",
+        bedrock: "AWS Bedrock",
+        openrouter: "OpenRouter",
+        deepseek: "DeepSeek",
+        siliconflow: "SiliconFlow",
+        ollama: "Ollama",
+    }
+    return labels[provider] || provider
+}
+
+// Show toast notification
+function showToast(message, type = "") {
+    toast.textContent = message
+    toast.className = "toast show" + (type ? ` ${type}` : "")
+
+    setTimeout(() => {
+        toast.classList.remove("show")
+    }, 3000)
+}
+
+// Escape HTML to prevent XSS
+function escapeHtml(text) {
+    const div = document.createElement("div")
+    div.textContent = text
+    return div.innerHTML
+}

electron/tsconfig.json

@@ -0,0 +1,18 @@
+{
+    "compilerOptions": {
+        "target": "ES2022",
+        "module": "CommonJS",
+        "moduleResolution": "node",
+        "lib": ["ES2022"],
+        "outDir": "../dist-electron",
+        "rootDir": ".",
+        "strict": true,
+        "esModuleInterop": true,
+        "skipLibCheck": true,
+        "resolveJsonModule": true,
+        "declaration": false,
+        "sourceMap": true
+    },
+    "include": ["./**/*.ts"],
+    "exclude": ["node_modules"]
+}

env.example

@@ -68,6 +68,10 @@ AI_MODEL=global.anthropic.claude-sonnet-4-5-20250929-v1:0
 # SILICONFLOW_API_KEY=sk-...
 # SILICONFLOW_BASE_URL=https://api.siliconflow.com/v1  # Optional: switch to https://api.siliconflow.cn/v1 if needed
 
+# SGLang Configuration (OpenAI-compatible)
+# SGLANG_API_KEY=your-sglang-api-key
+# SGLANG_BASE_URL=http://127.0.0.1:8000/v1  # Your SGLang endpoint
+
 # Vercel AI Gateway Configuration
 # Get your API key from: https://vercel.com/ai-gateway
 # Model format: "provider/model" e.g., "openai/gpt-4o", "anthropic/claude-sonnet-4-5"
@@ -93,6 +97,12 @@ AI_MODEL=global.anthropic.claude-sonnet-4-5-20250929-v1:0
 # NEXT_PUBLIC_DRAWIO_BASE_URL=https://embed.diagrams.net  # Default: https://embed.diagrams.net
 # Use this to point to a self-hosted draw.io instance
 
+# Subdirectory Deployment (Optional)
+# For deploying to a subdirectory (e.g., https://example.com/nextaidrawio)
+# Set this to your subdirectory path with leading slash (e.g., /nextaidrawio)
+# Leave empty for root deployment (default)
+# NEXT_PUBLIC_BASE_PATH=/nextaidrawio
+
 # PDF Input Feature (Optional)
 # Enable PDF file upload to extract text and generate diagrams
 # Enabled by default. Set to "false" to disable.

hooks/use-diagram-tool-handlers.ts

@@ -0,0 +1,383 @@
+import type { MutableRefObject } from "react"
+import { isMxCellXmlComplete, wrapWithMxFile } from "@/lib/utils"
+
+const DEBUG = process.env.NODE_ENV === "development"
+
+interface ToolCall {
+    toolCallId: string
+    toolName: string
+    input: unknown
+}
+
+type AddToolOutputSuccess = {
+    tool: string
+    toolCallId: string
+    state?: "output-available"
+    output: string
+    errorText?: undefined
+}
+
+type AddToolOutputError = {
+    tool: string
+    toolCallId: string
+    state: "output-error"
+    output?: undefined
+    errorText: string
+}
+
+type AddToolOutputParams = AddToolOutputSuccess | AddToolOutputError
+
+type AddToolOutputFn = (params: AddToolOutputParams) => void
+
+interface DiagramOperation {
+    operation: "update" | "add" | "delete"
+    cell_id: string
+    new_xml?: string
+}
+
+interface UseDiagramToolHandlersParams {
+    partialXmlRef: MutableRefObject<string>
+    editDiagramOriginalXmlRef: MutableRefObject<Map<string, string>>
+    chartXMLRef: MutableRefObject<string>
+    onDisplayChart: (xml: string, skipValidation?: boolean) => string | null
+    onFetchChart: (saveToHistory?: boolean) => Promise<string>
+    onExport: () => void
+}
+
+/**
+ * Hook that creates the onToolCall handler for diagram-related tools.
+ * Handles display_diagram, edit_diagram, and append_diagram tools.
+ *
+ * Note: addToolOutput is passed at call time (not hook init) because
+ * it comes from useChat which creates a circular dependency.
+ */
+export function useDiagramToolHandlers({
+    partialXmlRef,
+    editDiagramOriginalXmlRef,
+    chartXMLRef,
+    onDisplayChart,
+    onFetchChart,
+    onExport,
+}: UseDiagramToolHandlersParams) {
+    const handleToolCall = async (
+        { toolCall }: { toolCall: ToolCall },
+        addToolOutput: AddToolOutputFn,
+    ) => {
+        if (DEBUG) {
+            console.log(
+                `[onToolCall] Tool: ${toolCall.toolName}, CallId: ${toolCall.toolCallId}`,
+            )
+        }
+
+        if (toolCall.toolName === "display_diagram") {
+            await handleDisplayDiagram(toolCall, addToolOutput)
+        } else if (toolCall.toolName === "edit_diagram") {
+            await handleEditDiagram(toolCall, addToolOutput)
+        } else if (toolCall.toolName === "append_diagram") {
+            handleAppendDiagram(toolCall, addToolOutput)
+        }
+    }
+
+    const handleDisplayDiagram = async (
+        toolCall: ToolCall,
+        addToolOutput: AddToolOutputFn,
+    ) => {
+        const { xml } = toolCall.input as { xml: string }
+
+        // DEBUG: Log raw input to diagnose false truncation detection
+        if (DEBUG) {
+            console.log(
+                "[display_diagram] XML ending (last 100 chars):",
+                xml.slice(-100),
+            )
+            console.log("[display_diagram] XML length:", xml.length)
+        }
+
+        // Check if XML is truncated (incomplete mxCell indicates truncated output)
+        const isTruncated = !isMxCellXmlComplete(xml)
+        if (DEBUG) {
+            console.log("[display_diagram] isTruncated:", isTruncated)
+        }
+
+        if (isTruncated) {
+            // Store the partial XML for continuation via append_diagram
+            partialXmlRef.current = xml
+
+            // Tell LLM to use append_diagram to continue
+            const partialEnding = partialXmlRef.current.slice(-500)
+            addToolOutput({
+                tool: "display_diagram",
+                toolCallId: toolCall.toolCallId,
+                state: "output-error",
+                errorText: `Output was truncated due to length limits. Use the append_diagram tool to continue.
+
+Your output ended with:
+\`\`\`
+${partialEnding}
+\`\`\`
+
+NEXT STEP: Call append_diagram with the continuation XML.
+- Do NOT include wrapper tags or root cells (id="0", id="1")
+- Start from EXACTLY where you stopped
+- Complete all remaining mxCell elements`,
+            })
+            return
+        }
+
+        // Complete XML received - use it directly
+        // (continuation is now handled via append_diagram tool)
+        const finalXml = xml
+        partialXmlRef.current = "" // Reset any partial from previous truncation
+
+        // Wrap raw XML with full mxfile structure for draw.io
+        const fullXml = wrapWithMxFile(finalXml)
+
+        // loadDiagram validates and returns error if invalid
+        const validationError = onDisplayChart(fullXml)
+
+        if (validationError) {
+            console.warn("[display_diagram] Validation error:", validationError)
+            // Return error to model - sendAutomaticallyWhen will trigger retry
+            if (DEBUG) {
+                console.log(
+                    "[display_diagram] Adding tool output with state: output-error",
+                )
+            }
+            addToolOutput({
+                tool: "display_diagram",
+                toolCallId: toolCall.toolCallId,
+                state: "output-error",
+                errorText: `${validationError}
+
+Please fix the XML issues and call display_diagram again with corrected XML.
+
+Your failed XML:
+\`\`\`xml
+${finalXml}
+\`\`\``,
+            })
+        } else {
+            // Success - diagram will be rendered by chat-message-display
+            if (DEBUG) {
+                console.log(
+                    "[display_diagram] Success! Adding tool output with state: output-available",
+                )
+            }
+            addToolOutput({
+                tool: "display_diagram",
+                toolCallId: toolCall.toolCallId,
+                output: "Successfully displayed the diagram.",
+            })
+            if (DEBUG) {
+                console.log(
+                    "[display_diagram] Tool output added. Diagram should be visible now.",
+                )
+            }
+        }
+    }
+
+    const handleEditDiagram = async (
+        toolCall: ToolCall,
+        addToolOutput: AddToolOutputFn,
+    ) => {
+        const { operations } = toolCall.input as {
+            operations: DiagramOperation[]
+        }
+
+        let currentXml = ""
+        try {
+            // Use the original XML captured during streaming (shared with chat-message-display)
+            // This ensures we apply operations to the same base XML that streaming used
+            const originalXml = editDiagramOriginalXmlRef.current.get(
+                toolCall.toolCallId,
+            )
+            if (originalXml) {
+                currentXml = originalXml
+            } else {
+                // Fallback: use chartXML from ref if streaming didn't capture original
+                const cachedXML = chartXMLRef.current
+                if (cachedXML) {
+                    currentXml = cachedXML
+                } else {
+                    // Last resort: export from iframe
+                    currentXml = await onFetchChart(false)
+                }
+            }
+
+            const { applyDiagramOperations } = await import("@/lib/utils")
+            const { result: editedXml, errors } = applyDiagramOperations(
+                currentXml,
+                operations,
+            )
+
+            // Check for operation errors
+            if (errors.length > 0) {
+                const errorMessages = errors
+                    .map(
+                        (e) =>
+                            `- ${e.type} on cell_id="${e.cellId}": ${e.message}`,
+                    )
+                    .join("\n")
+
+                addToolOutput({
+                    tool: "edit_diagram",
+                    toolCallId: toolCall.toolCallId,
+                    state: "output-error",
+                    errorText: `Some operations failed:\n${errorMessages}
+
+Current diagram XML:
+\`\`\`xml
+${currentXml}
+\`\`\`
+
+Please check the cell IDs and retry.`,
+                })
+                // Clean up the shared original XML ref
+                editDiagramOriginalXmlRef.current.delete(toolCall.toolCallId)
+                return
+            }
+
+            // loadDiagram validates and returns error if invalid
+            const validationError = onDisplayChart(editedXml)
+            if (validationError) {
+                console.warn(
+                    "[edit_diagram] Validation error:",
+                    validationError,
+                )
+                addToolOutput({
+                    tool: "edit_diagram",
+                    toolCallId: toolCall.toolCallId,
+                    state: "output-error",
+                    errorText: `Edit produced invalid XML: ${validationError}
+
+Current diagram XML:
+\`\`\`xml
+${currentXml}
+\`\`\`
+
+Please fix the operations to avoid structural issues.`,
+                })
+                // Clean up the shared original XML ref
+                editDiagramOriginalXmlRef.current.delete(toolCall.toolCallId)
+                return
+            }
+            onExport()
+            addToolOutput({
+                tool: "edit_diagram",
+                toolCallId: toolCall.toolCallId,
+                output: `Successfully applied ${operations.length} operation(s) to the diagram.`,
+            })
+            // Clean up the shared original XML ref
+            editDiagramOriginalXmlRef.current.delete(toolCall.toolCallId)
+        } catch (error) {
+            console.error("[edit_diagram] Failed:", error)
+
+            const errorMessage =
+                error instanceof Error ? error.message : String(error)
+
+            addToolOutput({
+                tool: "edit_diagram",
+                toolCallId: toolCall.toolCallId,
+                state: "output-error",
+                errorText: `Edit failed: ${errorMessage}
+
+Current diagram XML:
+\`\`\`xml
+${currentXml || "No XML available"}
+\`\`\`
+
+Please check cell IDs and retry, or use display_diagram to regenerate.`,
+            })
+            // Clean up the shared original XML ref even on error
+            editDiagramOriginalXmlRef.current.delete(toolCall.toolCallId)
+        }
+    }
+
+    const handleAppendDiagram = (
+        toolCall: ToolCall,
+        addToolOutput: AddToolOutputFn,
+    ) => {
+        const { xml } = toolCall.input as { xml: string }
+
+        // Detect if LLM incorrectly started fresh instead of continuing
+        // LLM should only output bare mxCells now, so wrapper tags indicate error
+        const trimmed = xml.trim()
+        const isFreshStart =
+            trimmed.startsWith("<mxGraphModel") ||
+            trimmed.startsWith("<root") ||
+            trimmed.startsWith("<mxfile") ||
+            trimmed.startsWith('<mxCell id="0"') ||
+            trimmed.startsWith('<mxCell id="1"')
+
+        if (isFreshStart) {
+            addToolOutput({
+                tool: "append_diagram",
+                toolCallId: toolCall.toolCallId,
+                state: "output-error",
+                errorText: `ERROR: You started fresh with wrapper tags. Do NOT include wrapper tags or root cells (id="0", id="1").
+
+Continue from EXACTLY where the partial ended:
+\`\`\`
+${partialXmlRef.current.slice(-500)}
+\`\`\`
+
+Start your continuation with the NEXT character after where it stopped.`,
+            })
+            return
+        }
+
+        // Append to accumulated XML
+        partialXmlRef.current += xml
+
+        // Check if XML is now complete (last mxCell is complete)
+        const isComplete = isMxCellXmlComplete(partialXmlRef.current)
+
+        if (isComplete) {
+            // Wrap and display the complete diagram
+            const finalXml = partialXmlRef.current
+            partialXmlRef.current = "" // Reset
+
+            const fullXml = wrapWithMxFile(finalXml)
+            const validationError = onDisplayChart(fullXml)
+
+            if (validationError) {
+                addToolOutput({
+                    tool: "append_diagram",
+                    toolCallId: toolCall.toolCallId,
+                    state: "output-error",
+                    errorText: `Validation error after assembly: ${validationError}
+
+Assembled XML:
+\`\`\`xml
+${finalXml.substring(0, 2000)}...
+\`\`\`
+
+Please use display_diagram with corrected XML.`,
+                })
+            } else {
+                addToolOutput({
+                    tool: "append_diagram",
+                    toolCallId: toolCall.toolCallId,
+                    output: "Diagram assembly complete and displayed successfully.",
+                })
+            }
+        } else {
+            // Still incomplete - signal to continue
+            addToolOutput({
+                tool: "append_diagram",
+                toolCallId: toolCall.toolCallId,
+                state: "output-error",
+                errorText: `XML still incomplete (mxCell not closed). Call append_diagram again to continue.
+
+Current ending:
+\`\`\`
+${partialXmlRef.current.slice(-500)}
+\`\`\`
+
+Continue from EXACTLY where you stopped.`,
+            })
+        }
+    }
+
+    return { handleToolCall }
+}

hooks/use-model-config.ts

@@ -0,0 +1,373 @@
+"use client"
+
+import { useCallback, useEffect, useState } from "react"
+import { STORAGE_KEYS } from "@/lib/storage"
+import {
+    createEmptyConfig,
+    createModelConfig,
+    createProviderConfig,
+    type FlattenedModel,
+    findModelById,
+    flattenModels,
+    type ModelConfig,
+    type MultiModelConfig,
+    PROVIDER_INFO,
+    type ProviderConfig,
+    type ProviderName,
+} from "@/lib/types/model-config"
+
+// Old storage keys for migration
+const OLD_KEYS = {
+    aiProvider: "next-ai-draw-io-ai-provider",
+    aiBaseUrl: "next-ai-draw-io-ai-base-url",
+    aiApiKey: "next-ai-draw-io-ai-api-key",
+    aiModel: "next-ai-draw-io-ai-model",
+}
+
+/**
+ * Migrate from old single-provider format to new multi-model format
+ */
+function migrateOldConfig(): MultiModelConfig | null {
+    if (typeof window === "undefined") return null
+
+    const oldProvider = localStorage.getItem(OLD_KEYS.aiProvider)
+    const oldApiKey = localStorage.getItem(OLD_KEYS.aiApiKey)
+    const oldModel = localStorage.getItem(OLD_KEYS.aiModel)
+
+    // No old config to migrate
+    if (!oldProvider || !oldApiKey || !oldModel) return null
+
+    const oldBaseUrl = localStorage.getItem(OLD_KEYS.aiBaseUrl)
+
+    // Create new config from old format
+    const provider = createProviderConfig(oldProvider as ProviderName)
+    provider.apiKey = oldApiKey
+    if (oldBaseUrl) provider.baseUrl = oldBaseUrl
+
+    const model = createModelConfig(oldModel)
+    provider.models.push(model)
+
+    const config: MultiModelConfig = {
+        version: 1,
+        providers: [provider],
+        selectedModelId: model.id,
+    }
+
+    // Clear old keys after migration
+    localStorage.removeItem(OLD_KEYS.aiProvider)
+    localStorage.removeItem(OLD_KEYS.aiBaseUrl)
+    localStorage.removeItem(OLD_KEYS.aiApiKey)
+    localStorage.removeItem(OLD_KEYS.aiModel)
+
+    return config
+}
+
+/**
+ * Load config from localStorage
+ */
+function loadConfig(): MultiModelConfig {
+    if (typeof window === "undefined") return createEmptyConfig()
+
+    // First, check if new format exists
+    const stored = localStorage.getItem(STORAGE_KEYS.modelConfigs)
+    if (stored) {
+        try {
+            return JSON.parse(stored) as MultiModelConfig
+        } catch {
+            console.error("Failed to parse model config")
+        }
+    }
+
+    // Try migration from old format
+    const migrated = migrateOldConfig()
+    if (migrated) {
+        // Save migrated config
+        localStorage.setItem(
+            STORAGE_KEYS.modelConfigs,
+            JSON.stringify(migrated),
+        )
+        return migrated
+    }
+
+    return createEmptyConfig()
+}
+
+/**
+ * Save config to localStorage
+ */
+function saveConfig(config: MultiModelConfig): void {
+    if (typeof window === "undefined") return
+    localStorage.setItem(STORAGE_KEYS.modelConfigs, JSON.stringify(config))
+}
+
+export interface UseModelConfigReturn {
+    // State
+    config: MultiModelConfig
+    isLoaded: boolean
+
+    // Getters
+    models: FlattenedModel[]
+    selectedModel: FlattenedModel | undefined
+    selectedModelId: string | undefined
+
+    // Actions
+    setSelectedModelId: (modelId: string | undefined) => void
+    addProvider: (provider: ProviderName) => ProviderConfig
+    updateProvider: (
+        providerId: string,
+        updates: Partial<ProviderConfig>,
+    ) => void
+    deleteProvider: (providerId: string) => void
+    addModel: (providerId: string, modelId: string) => ModelConfig
+    updateModel: (
+        providerId: string,
+        modelConfigId: string,
+        updates: Partial<ModelConfig>,
+    ) => void
+    deleteModel: (providerId: string, modelConfigId: string) => void
+    resetConfig: () => void
+}
+
+export function useModelConfig(): UseModelConfigReturn {
+    const [config, setConfig] = useState<MultiModelConfig>(createEmptyConfig)
+    const [isLoaded, setIsLoaded] = useState(false)
+
+    // Load config on mount
+    useEffect(() => {
+        const loaded = loadConfig()
+        setConfig(loaded)
+        setIsLoaded(true)
+    }, [])
+
+    // Save config whenever it changes (after initial load)
+    useEffect(() => {
+        if (isLoaded) {
+            saveConfig(config)
+        }
+    }, [config, isLoaded])
+
+    // Derived state
+    const models = flattenModels(config)
+    const selectedModel = config.selectedModelId
+        ? findModelById(config, config.selectedModelId)
+        : undefined
+
+    // Actions
+    const setSelectedModelId = useCallback((modelId: string | undefined) => {
+        setConfig((prev) => ({
+            ...prev,
+            selectedModelId: modelId,
+        }))
+    }, [])
+
+    const addProvider = useCallback(
+        (provider: ProviderName): ProviderConfig => {
+            const newProvider = createProviderConfig(provider)
+            setConfig((prev) => ({
+                ...prev,
+                providers: [...prev.providers, newProvider],
+            }))
+            return newProvider
+        },
+        [],
+    )
+
+    const updateProvider = useCallback(
+        (providerId: string, updates: Partial<ProviderConfig>) => {
+            setConfig((prev) => ({
+                ...prev,
+                providers: prev.providers.map((p) =>
+                    p.id === providerId ? { ...p, ...updates } : p,
+                ),
+            }))
+        },
+        [],
+    )
+
+    const deleteProvider = useCallback((providerId: string) => {
+        setConfig((prev) => {
+            const provider = prev.providers.find((p) => p.id === providerId)
+            const modelIds = provider?.models.map((m) => m.id) || []
+
+            // Clear selected model if it belongs to deleted provider
+            const newSelectedId =
+                prev.selectedModelId && modelIds.includes(prev.selectedModelId)
+                    ? undefined
+                    : prev.selectedModelId
+
+            return {
+                ...prev,
+                providers: prev.providers.filter((p) => p.id !== providerId),
+                selectedModelId: newSelectedId,
+            }
+        })
+    }, [])
+
+    const addModel = useCallback(
+        (providerId: string, modelId: string): ModelConfig => {
+            const newModel = createModelConfig(modelId)
+            setConfig((prev) => ({
+                ...prev,
+                providers: prev.providers.map((p) =>
+                    p.id === providerId
+                        ? { ...p, models: [...p.models, newModel] }
+                        : p,
+                ),
+            }))
+            return newModel
+        },
+        [],
+    )
+
+    const updateModel = useCallback(
+        (
+            providerId: string,
+            modelConfigId: string,
+            updates: Partial<ModelConfig>,
+        ) => {
+            setConfig((prev) => ({
+                ...prev,
+                providers: prev.providers.map((p) =>
+                    p.id === providerId
+                        ? {
+                              ...p,
+                              models: p.models.map((m) =>
+                                  m.id === modelConfigId
+                                      ? { ...m, ...updates }
+                                      : m,
+                              ),
+                          }
+                        : p,
+                ),
+            }))
+        },
+        [],
+    )
+
+    const deleteModel = useCallback(
+        (providerId: string, modelConfigId: string) => {
+            setConfig((prev) => ({
+                ...prev,
+                providers: prev.providers.map((p) =>
+                    p.id === providerId
+                        ? {
+                              ...p,
+                              models: p.models.filter(
+                                  (m) => m.id !== modelConfigId,
+                              ),
+                          }
+                        : p,
+                ),
+                // Clear selected model if it was deleted
+                selectedModelId:
+                    prev.selectedModelId === modelConfigId
+                        ? undefined
+                        : prev.selectedModelId,
+            }))
+        },
+        [],
+    )
+
+    const resetConfig = useCallback(() => {
+        setConfig(createEmptyConfig())
+    }, [])
+
+    return {
+        config,
+        isLoaded,
+        models,
+        selectedModel,
+        selectedModelId: config.selectedModelId,
+        setSelectedModelId,
+        addProvider,
+        updateProvider,
+        deleteProvider,
+        addModel,
+        updateModel,
+        deleteModel,
+        resetConfig,
+    }
+}
+
+/**
+ * Get the AI config for the currently selected model.
+ * Returns format compatible with existing getAIConfig() usage.
+ */
+export function getSelectedAIConfig(): {
+    accessCode: string
+    aiProvider: string
+    aiBaseUrl: string
+    aiApiKey: string
+    aiModel: string
+    // AWS Bedrock credentials
+    awsAccessKeyId: string
+    awsSecretAccessKey: string
+    awsRegion: string
+    awsSessionToken: string
+} {
+    const empty = {
+        accessCode: "",
+        aiProvider: "",
+        aiBaseUrl: "",
+        aiApiKey: "",
+        aiModel: "",
+        awsAccessKeyId: "",
+        awsSecretAccessKey: "",
+        awsRegion: "",
+        awsSessionToken: "",
+    }
+
+    if (typeof window === "undefined") return empty
+
+    // Get access code (separate from model config)
+    const accessCode = localStorage.getItem(STORAGE_KEYS.accessCode) || ""
+
+    // Load multi-model config
+    const stored = localStorage.getItem(STORAGE_KEYS.modelConfigs)
+    if (!stored) {
+        // Fallback to old format for backward compatibility
+        return {
+            accessCode,
+            aiProvider: localStorage.getItem(OLD_KEYS.aiProvider) || "",
+            aiBaseUrl: localStorage.getItem(OLD_KEYS.aiBaseUrl) || "",
+            aiApiKey: localStorage.getItem(OLD_KEYS.aiApiKey) || "",
+            aiModel: localStorage.getItem(OLD_KEYS.aiModel) || "",
+            // Old format didn't support AWS
+            awsAccessKeyId: "",
+            awsSecretAccessKey: "",
+            awsRegion: "",
+            awsSessionToken: "",
+        }
+    }
+
+    let config: MultiModelConfig
+    try {
+        config = JSON.parse(stored)
+    } catch {
+        return { ...empty, accessCode }
+    }
+
+    // No selected model = use server default
+    if (!config.selectedModelId) {
+        return { ...empty, accessCode }
+    }
+
+    // Find selected model
+    const model = findModelById(config, config.selectedModelId)
+    if (!model) {
+        return { ...empty, accessCode }
+    }
+
+    return {
+        accessCode,
+        aiProvider: model.provider,
+        aiBaseUrl: model.baseUrl || "",
+        aiApiKey: model.apiKey,
+        aiModel: model.modelId,
+        // AWS Bedrock credentials
+        awsAccessKeyId: model.awsAccessKeyId || "",
+        awsSecretAccessKey: model.awsSecretAccessKey || "",
+        awsRegion: model.awsRegion || "",
+        awsSessionToken: model.awsSessionToken || "",
+    }
+}

instrumentation.ts

@@ -14,19 +14,14 @@ export function register() {
         publicKey: process.env.LANGFUSE_PUBLIC_KEY,
         secretKey: process.env.LANGFUSE_SECRET_KEY,
         baseUrl: process.env.LANGFUSE_BASEURL,
-        // Filter out Next.js HTTP request spans so AI SDK spans become root traces
+        // Whitelist approach: only export AI-related spans
         shouldExportSpan: ({ otelSpan }) => {
             const spanName = otelSpan.name
-            // Skip Next.js HTTP infrastructure spans
-            if (
-                spanName.startsWith("POST /") ||
-                spanName.startsWith("GET /") ||
-                spanName.includes("BaseServer") ||
-                spanName.includes("handleRequest")
-            ) {
-                return false
+            // Only export AI SDK spans (ai.*) and our explicit "chat" wrapper
+            if (spanName === "chat" || spanName.startsWith("ai.")) {
+                return true
             }
-            return true
+            return false
         },
     })
 
@@ -36,4 +31,5 @@ export function register() {
 
     // Register globally so AI SDK's telemetry also uses this processor
     tracerProvider.register()
+    console.log("[Langfuse] Instrumentation initialized successfully")
 }

lib/ai-providers.ts

@@ -19,6 +19,7 @@ export type ProviderName =
     | "openrouter"
     | "deepseek"
     | "siliconflow"
+    | "sglang"
     | "gateway"
 
 interface ModelConfig {
@@ -33,6 +34,11 @@ export interface ClientOverrides {
     baseUrl?: string | null
     apiKey?: string | null
     modelId?: string | null
+    // AWS Bedrock credentials
+    awsAccessKeyId?: string | null
+    awsSecretAccessKey?: string | null
+    awsRegion?: string | null
+    awsSessionToken?: string | null
 }
 
 // Providers that can be used with client-provided API keys
@@ -41,9 +47,11 @@ const ALLOWED_CLIENT_PROVIDERS: ProviderName[] = [
     "anthropic",
     "google",
     "azure",
+    "bedrock",
     "openrouter",
     "deepseek",
     "siliconflow",
+    "sglang",
     "gateway",
 ]
 
@@ -87,8 +95,8 @@ function parseIntSafe(
  * Supports various AI SDK providers with their unique configuration options
  *
  * Environment variables:
- * - OPENAI_REASONING_EFFORT: OpenAI reasoning effort level (minimal/low/medium/high) - for o1/o3/gpt-5
- * - OPENAI_REASONING_SUMMARY: OpenAI reasoning summary (none/brief/detailed) - auto-enabled for o1/o3/gpt-5
+ * - OPENAI_REASONING_EFFORT: OpenAI reasoning effort level (minimal/low/medium/high) - for o1/o3/o4/gpt-5
+ * - OPENAI_REASONING_SUMMARY: OpenAI reasoning summary (auto/detailed) - auto-enabled for o1/o3/o4/gpt-5
  * - ANTHROPIC_THINKING_BUDGET_TOKENS: Anthropic thinking budget in tokens (1024-64000)
  * - ANTHROPIC_THINKING_TYPE: Anthropic thinking type (enabled)
  * - GOOGLE_THINKING_BUDGET: Google Gemini 2.5 thinking budget in tokens (1024-100000)
@@ -110,18 +118,19 @@ function buildProviderOptions(
             const reasoningEffort = process.env.OPENAI_REASONING_EFFORT
             const reasoningSummary = process.env.OPENAI_REASONING_SUMMARY
 
-            // OpenAI reasoning models (o1, o3, gpt-5) need reasoningSummary to return thoughts
+            // OpenAI reasoning models (o1, o3, o4, gpt-5) need reasoningSummary to return thoughts
             if (
                 modelId &&
                 (modelId.includes("o1") ||
                     modelId.includes("o3") ||
+                    modelId.includes("o4") ||
                     modelId.includes("gpt-5"))
             ) {
                 options.openai = {
-                    // Auto-enable reasoning summary for reasoning models (default: detailed)
+                    // Auto-enable reasoning summary for reasoning models
+                    // Use 'auto' as default since not all models support 'detailed'
                     reasoningSummary:
-                        (reasoningSummary as "none" | "brief" | "detailed") ||
-                        "detailed",
+                        (reasoningSummary as "auto" | "detailed") || "auto",
                 }
 
                 // Optionally configure reasoning effort
@@ -144,8 +153,7 @@ function buildProviderOptions(
                 }
                 if (reasoningSummary) {
                     options.openai.reasoningSummary = reasoningSummary as
-                        | "none"
-                        | "brief"
+                        | "auto"
                         | "detailed"
                 }
             }
@@ -337,6 +345,7 @@ function buildProviderOptions(
         case "deepseek":
         case "openrouter":
         case "siliconflow":
+        case "sglang":
         case "gateway": {
             // These providers don't have reasoning configs in AI SDK yet
             // Gateway passes through to underlying providers which handle their own configs
@@ -361,6 +370,7 @@ const PROVIDER_ENV_VARS: Record<ProviderName, string | null> = {
     openrouter: "OPENROUTER_API_KEY",
     deepseek: "DEEPSEEK_API_KEY",
     siliconflow: "SILICONFLOW_API_KEY",
+    sglang: "SGLANG_API_KEY",
     gateway: "AI_GATEWAY_API_KEY",
 }
 
@@ -426,7 +436,7 @@ function validateProviderCredentials(provider: ProviderName): void {
  * Get the AI model based on environment variables
  *
  * Environment variables:
- * - AI_PROVIDER: The provider to use (bedrock, openai, anthropic, google, azure, ollama, openrouter, deepseek, siliconflow)
+ * - AI_PROVIDER: The provider to use (bedrock, openai, anthropic, google, azure, ollama, openrouter, deepseek, siliconflow, sglang, gateway)
  * - AI_MODEL: The model ID/name for the selected provider
  *
  * Provider-specific env vars:
@@ -442,6 +452,8 @@ function validateProviderCredentials(provider: ProviderName): void {
  * - DEEPSEEK_BASE_URL: DeepSeek endpoint (optional)
  * - SILICONFLOW_API_KEY: SiliconFlow API key
  * - SILICONFLOW_BASE_URL: SiliconFlow endpoint (optional, defaults to https://api.siliconflow.com/v1)
+ * - SGLANG_API_KEY: SGLang API key
+ * - SGLANG_BASE_URL: SGLang endpoint (optional)
  */
 export function getAIModel(overrides?: ClientOverrides): ModelConfig {
     // SECURITY: Prevent SSRF attacks (GHSA-9qf7-mprq-9qgm)
@@ -510,6 +522,7 @@ export function getAIModel(overrides?: ClientOverrides): ModelConfig {
                         `- OPENROUTER_API_KEY for OpenRouter\n` +
                         `- AZURE_API_KEY for Azure\n` +
                         `- SILICONFLOW_API_KEY for SiliconFlow\n` +
+                        `- SGLANG_API_KEY for SGLang\n` +
                         `Or set AI_PROVIDER=ollama for local Ollama.`,
                 )
             } else {
@@ -537,12 +550,25 @@ export function getAIModel(overrides?: ClientOverrides): ModelConfig {
 
     switch (provider) {
         case "bedrock": {
-            // Use credential provider chain for IAM role support (Lambda, EC2, etc.)
-            // Falls back to env vars (AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY) for local dev
-            const bedrockProvider = createAmazonBedrock({
-                region: process.env.AWS_REGION || "us-west-2",
-                credentialProvider: fromNodeProviderChain(),
-            })
+            // Use client-provided credentials if available, otherwise fall back to IAM/env vars
+            const hasClientCredentials =
+                overrides?.awsAccessKeyId && overrides?.awsSecretAccessKey
+            const bedrockRegion =
+                overrides?.awsRegion || process.env.AWS_REGION || "us-west-2"
+
+            const bedrockProvider = hasClientCredentials
+                ? createAmazonBedrock({
+                      region: bedrockRegion,
+                      accessKeyId: overrides.awsAccessKeyId!,
+                      secretAccessKey: overrides.awsSecretAccessKey!,
+                      ...(overrides?.awsSessionToken && {
+                          sessionToken: overrides.awsSessionToken,
+                      }),
+                  })
+                : createAmazonBedrock({
+                      region: bedrockRegion,
+                      credentialProvider: fromNodeProviderChain(),
+                  })
             model = bedrockProvider(modelId)
             // Add Anthropic beta options if using Claude models via Bedrock
             if (modelId.includes("anthropic.claude")) {
@@ -562,12 +588,16 @@ export function getAIModel(overrides?: ClientOverrides): ModelConfig {
         case "openai": {
             const apiKey = overrides?.apiKey || process.env.OPENAI_API_KEY
             const baseURL = overrides?.baseUrl || process.env.OPENAI_BASE_URL
-            if (baseURL || overrides?.apiKey) {
-                const customOpenAI = createOpenAI({
-                    apiKey,
-                    ...(baseURL && { baseURL }),
-                })
+            if (baseURL) {
+                // Custom base URL = third-party proxy, use Chat Completions API
+                // for compatibility (most proxies don't support /responses endpoint)
+                const customOpenAI = createOpenAI({ apiKey, baseURL })
                 model = customOpenAI.chat(modelId)
+            } else if (overrides?.apiKey) {
+                // Custom API key but official OpenAI endpoint, use Responses API
+                // to support reasoning for gpt-5, o1, o3, o4 models
+                const customOpenAI = createOpenAI({ apiKey })
+                model = customOpenAI(modelId)
             } else {
                 model = openai(modelId)
             }
@@ -679,6 +709,112 @@ export function getAIModel(overrides?: ClientOverrides): ModelConfig {
             break
         }
 
+        case "sglang": {
+            const apiKey = overrides?.apiKey || process.env.SGLANG_API_KEY
+            const baseURL = overrides?.baseUrl || process.env.SGLANG_BASE_URL
+
+            const sglangProvider = createOpenAI({
+                apiKey,
+                baseURL,
+                // Add a custom fetch wrapper to intercept and fix the stream from sglang
+                fetch: async (url, options) => {
+                    const response = await fetch(url, options)
+                    if (!response.body) {
+                        return response
+                    }
+
+                    // Create a transform stream to fix the non-compliant sglang stream
+                    let buffer = ""
+                    const decoder = new TextDecoder()
+
+                    const transformStream = new TransformStream({
+                        transform(chunk, controller) {
+                            buffer += decoder.decode(chunk, { stream: true })
+                            // Process all complete messages in the buffer
+                            let messageEndPos
+                            while (
+                                (messageEndPos = buffer.indexOf("\n\n")) !== -1
+                            ) {
+                                const message = buffer.substring(
+                                    0,
+                                    messageEndPos,
+                                )
+                                buffer = buffer.substring(messageEndPos + 2) // Move past the '\n\n'
+
+                                if (message.startsWith("data: ")) {
+                                    const jsonStr = message.substring(6).trim()
+                                    if (jsonStr === "[DONE]") {
+                                        controller.enqueue(
+                                            new TextEncoder().encode(
+                                                message + "\n\n",
+                                            ),
+                                        )
+                                        continue
+                                    }
+                                    try {
+                                        const data = JSON.parse(jsonStr)
+                                        const delta = data.choices?.[0]?.delta
+
+                                        if (delta) {
+                                            // Fix 1: remove invalid empty role
+                                            if (delta.role === "") {
+                                                delete delta.role
+                                            }
+                                            // Fix 2: remove non-standard reasoning_content field
+                                            if ("reasoning_content" in delta) {
+                                                delete delta.reasoning_content
+                                            }
+                                        }
+
+                                        // Re-serialize and forward the corrected data with the correct SSE format
+                                        controller.enqueue(
+                                            new TextEncoder().encode(
+                                                `data: ${JSON.stringify(data)}\n\n`,
+                                            ),
+                                        )
+                                    } catch (e) {
+                                        // If parsing fails, forward the original message to avoid breaking the stream.
+                                        controller.enqueue(
+                                            new TextEncoder().encode(
+                                                message + "\n\n",
+                                            ),
+                                        )
+                                    }
+                                } else if (message.trim() !== "") {
+                                    // Pass through other message types (e.g., 'event: ...')
+                                    controller.enqueue(
+                                        new TextEncoder().encode(
+                                            message + "\n\n",
+                                        ),
+                                    )
+                                }
+                            }
+                        },
+                        flush(controller) {
+                            // If there's anything left in the buffer, forward it.
+                            if (buffer.trim()) {
+                                controller.enqueue(
+                                    new TextEncoder().encode(buffer),
+                                )
+                            }
+                        },
+                    })
+
+                    const transformedBody =
+                        response.body.pipeThrough(transformStream)
+
+                    // Return a new response with the transformed body
+                    return new Response(transformedBody, {
+                        status: response.status,
+                        statusText: response.statusText,
+                        headers: response.headers,
+                    })
+                },
+            })
+            model = sglangProvider.chat(modelId)
+            break
+        }
+
         case "gateway": {
             // Vercel AI Gateway - unified access to multiple AI providers
             // Model format: "provider/model" e.g., "openai/gpt-4o", "anthropic/claude-sonnet-4-5"
@@ -702,7 +838,7 @@ export function getAIModel(overrides?: ClientOverrides): ModelConfig {
 
         default:
             throw new Error(
-                `Unknown AI provider: ${provider}. Supported providers: bedrock, openai, anthropic, google, azure, ollama, openrouter, deepseek, siliconflow, gateway`,
+                `Unknown AI provider: ${provider}. Supported providers: bedrock, openai, anthropic, google, azure, ollama, openrouter, deepseek, siliconflow, sglang, gateway`,
             )
     }
 

lib/base-path.ts

@@ -0,0 +1,37 @@
+/**
+ * Get the base path for API calls and static assets
+ * This is used for subdirectory deployment support
+ *
+ * Example: If deployed at https://example.com/nextaidrawio, this returns "/nextaidrawio"
+ * For root deployment, this returns ""
+ *
+ * Set NEXT_PUBLIC_BASE_PATH environment variable to your subdirectory path (e.g., /nextaidrawio)
+ */
+export function getBasePath(): string {
+    // Read from environment variable (must start with NEXT_PUBLIC_ to be available on client)
+    const basePath = process.env.NEXT_PUBLIC_BASE_PATH || ""
+    if (basePath && !basePath.startsWith("/")) {
+        console.warn("NEXT_PUBLIC_BASE_PATH should start with /")
+    }
+    return basePath
+}
+
+/**
+ * Get full API endpoint URL
+ * @param endpoint - API endpoint path (e.g., "/api/chat", "/api/config")
+ * @returns Full API path with base path prefix
+ */
+export function getApiEndpoint(endpoint: string): string {
+    const basePath = getBasePath()
+    return `${basePath}${endpoint}`
+}
+
+/**
+ * Get full static asset URL
+ * @param assetPath - Asset path (e.g., "/example.png", "/chain-of-thought.txt")
+ * @returns Full asset path with base path prefix
+ */
+export function getAssetUrl(assetPath: string): string {
+    const basePath = getBasePath()
+    return `${basePath}${assetPath}`
+}

lib/dynamo-quota-manager.ts

@@ -0,0 +1,297 @@
+import {
+    ConditionalCheckFailedException,
+    DynamoDBClient,
+    GetItemCommand,
+    UpdateItemCommand,
+} from "@aws-sdk/client-dynamodb"
+
+// Quota tracking is OPT-IN: only enabled if DYNAMODB_QUOTA_TABLE is explicitly set
+// OSS users who don't need quota tracking can simply not set this env var
+const TABLE = process.env.DYNAMODB_QUOTA_TABLE
+const DYNAMODB_REGION = process.env.DYNAMODB_REGION || "ap-northeast-1"
+// Timezone for daily quota reset (e.g., "Asia/Tokyo" for JST midnight reset)
+// Defaults to UTC if not set
+let QUOTA_TIMEZONE = process.env.QUOTA_TIMEZONE || "UTC"
+
+// Validate timezone at module load
+try {
+    new Intl.DateTimeFormat("en-CA", { timeZone: QUOTA_TIMEZONE }).format(
+        new Date(),
+    )
+} catch {
+    console.warn(
+        `[quota] Invalid QUOTA_TIMEZONE "${QUOTA_TIMEZONE}", using UTC`,
+    )
+    QUOTA_TIMEZONE = "UTC"
+}
+
+/**
+ * Get today's date string in the configured timezone (YYYY-MM-DD format)
+ */
+function getTodayInTimezone(): string {
+    return new Intl.DateTimeFormat("en-CA", {
+        timeZone: QUOTA_TIMEZONE,
+    }).format(new Date())
+}
+
+// Only create client if quota is enabled
+const client = TABLE ? new DynamoDBClient({ region: DYNAMODB_REGION }) : null
+
+/**
+ * Check if server-side quota tracking is enabled.
+ * Quota is opt-in: only enabled when DYNAMODB_QUOTA_TABLE env var is set.
+ */
+export function isQuotaEnabled(): boolean {
+    return !!TABLE
+}
+
+interface QuotaLimits {
+    requests: number // Daily request limit
+    tokens: number // Daily token limit
+    tpm: number // Tokens per minute
+}
+
+interface QuotaCheckResult {
+    allowed: boolean
+    error?: string
+    type?: "request" | "token" | "tpm"
+    used?: number
+    limit?: number
+}
+
+/**
+ * Check all quotas and increment request count atomically.
+ * Uses ConditionExpression to prevent race conditions.
+ * Returns which limit was exceeded if any.
+ */
+export async function checkAndIncrementRequest(
+    ip: string,
+    limits: QuotaLimits,
+): Promise<QuotaCheckResult> {
+    // Skip if quota tracking not enabled
+    if (!client || !TABLE) {
+        return { allowed: true }
+    }
+
+    const today = getTodayInTimezone()
+    const currentMinute = Math.floor(Date.now() / 60000).toString()
+    const ttl = Math.floor(Date.now() / 1000) + 7 * 24 * 60 * 60
+
+    try {
+        // First, try to reset counts if it's a new day (atomic day reset)
+        // This will succeed only if lastResetDate < today or doesn't exist
+        try {
+            await client.send(
+                new UpdateItemCommand({
+                    TableName: TABLE,
+                    Key: { PK: { S: `IP#${ip}` } },
+                    // Reset all counts to 1/0 for the new day
+                    UpdateExpression: `
+                        SET lastResetDate = :today,
+                            dailyReqCount = :one,
+                            dailyTokenCount = :zero,
+                            lastMinute = :minute,
+                            tpmCount = :zero,
+                            #ttl = :ttl
+                    `,
+                    // Only succeed if it's a new day (or new item)
+                    ConditionExpression: `
+                        attribute_not_exists(lastResetDate) OR lastResetDate < :today
+                    `,
+                    ExpressionAttributeNames: { "#ttl": "ttl" },
+                    ExpressionAttributeValues: {
+                        ":today": { S: today },
+                        ":zero": { N: "0" },
+                        ":one": { N: "1" },
+                        ":minute": { S: currentMinute },
+                        ":ttl": { N: String(ttl) },
+                    },
+                }),
+            )
+            // New day reset successful
+            return { allowed: true }
+        } catch (resetError: any) {
+            // If condition failed, it's the same day - continue to increment logic
+            if (!(resetError instanceof ConditionalCheckFailedException)) {
+                throw resetError // Re-throw unexpected errors
+            }
+        }
+
+        // Same day - increment request count with limit checks
+        await client.send(
+            new UpdateItemCommand({
+                TableName: TABLE,
+                Key: { PK: { S: `IP#${ip}` } },
+                // Increment request count, handle minute boundary for TPM
+                UpdateExpression: `
+                    SET lastMinute = :minute,
+                        tpmCount = if_not_exists(tpmCount, :zero),
+                        #ttl = :ttl
+                    ADD dailyReqCount :one
+                `,
+                // Check all limits before allowing increment
+                ConditionExpression: `
+                    lastResetDate = :today AND
+                    (attribute_not_exists(dailyReqCount) OR dailyReqCount < :reqLimit) AND
+                    (attribute_not_exists(dailyTokenCount) OR dailyTokenCount < :tokenLimit) AND
+                    (attribute_not_exists(lastMinute) OR lastMinute <> :minute OR
+                     attribute_not_exists(tpmCount) OR tpmCount < :tpmLimit)
+                `,
+                ExpressionAttributeNames: { "#ttl": "ttl" },
+                ExpressionAttributeValues: {
+                    ":today": { S: today },
+                    ":zero": { N: "0" },
+                    ":one": { N: "1" },
+                    ":minute": { S: currentMinute },
+                    ":ttl": { N: String(ttl) },
+                    ":reqLimit": { N: String(limits.requests || 999999) },
+                    ":tokenLimit": { N: String(limits.tokens || 999999) },
+                    ":tpmLimit": { N: String(limits.tpm || 999999) },
+                },
+            }),
+        )
+
+        return { allowed: true }
+    } catch (e: any) {
+        // Condition failed - need to determine which limit was exceeded
+        if (e instanceof ConditionalCheckFailedException) {
+            // Get current counts to determine which limit was hit
+            try {
+                const getResult = await client.send(
+                    new GetItemCommand({
+                        TableName: TABLE,
+                        Key: { PK: { S: `IP#${ip}` } },
+                    }),
+                )
+
+                const item = getResult.Item
+                const storedDate = item?.lastResetDate?.S
+                const storedMinute = item?.lastMinute?.S
+                const isNewDay = !storedDate || storedDate < today
+
+                const dailyReqCount = isNewDay
+                    ? 0
+                    : Number(item?.dailyReqCount?.N || 0)
+                const dailyTokenCount = isNewDay
+                    ? 0
+                    : Number(item?.dailyTokenCount?.N || 0)
+                const tpmCount =
+                    storedMinute !== currentMinute
+                        ? 0
+                        : Number(item?.tpmCount?.N || 0)
+
+                // Determine which limit was exceeded
+                if (limits.requests > 0 && dailyReqCount >= limits.requests) {
+                    return {
+                        allowed: false,
+                        type: "request",
+                        error: "Daily request limit exceeded",
+                        used: dailyReqCount,
+                        limit: limits.requests,
+                    }
+                }
+                if (limits.tokens > 0 && dailyTokenCount >= limits.tokens) {
+                    return {
+                        allowed: false,
+                        type: "token",
+                        error: "Daily token limit exceeded",
+                        used: dailyTokenCount,
+                        limit: limits.tokens,
+                    }
+                }
+                if (limits.tpm > 0 && tpmCount >= limits.tpm) {
+                    return {
+                        allowed: false,
+                        type: "tpm",
+                        error: "Rate limit exceeded (tokens per minute)",
+                        used: tpmCount,
+                        limit: limits.tpm,
+                    }
+                }
+
+                // Condition failed but no limit clearly exceeded - race condition edge case
+                // Fail safe by allowing (could be a reset race)
+                console.warn(
+                    `[quota] Condition failed but no limit exceeded for IP prefix: ${ip.slice(0, 8)}...`,
+                )
+                return { allowed: true }
+            } catch (getError: any) {
+                console.error(
+                    `[quota] Failed to get quota details after condition failure, IP prefix: ${ip.slice(0, 8)}..., error: ${getError.message}`,
+                )
+                return { allowed: true } // Fail open
+            }
+        }
+
+        // Other DynamoDB errors - fail open
+        console.error(
+            `[quota] DynamoDB error (fail-open), IP prefix: ${ip.slice(0, 8)}..., error: ${e.message}`,
+        )
+        return { allowed: true }
+    }
+}
+
+/**
+ * Record token usage after response completes.
+ * Uses atomic operations to update both daily token count and TPM count.
+ * Handles minute boundaries atomically to prevent race conditions.
+ */
+export async function recordTokenUsage(
+    ip: string,
+    tokens: number,
+): Promise<void> {
+    // Skip if quota tracking not enabled
+    if (!client || !TABLE) return
+    if (!Number.isFinite(tokens) || tokens <= 0) return
+
+    const currentMinute = Math.floor(Date.now() / 60000).toString()
+    const ttl = Math.floor(Date.now() / 1000) + 7 * 24 * 60 * 60
+
+    try {
+        // Try to update assuming same minute (most common case)
+        // Uses condition to ensure we're in the same minute
+        await client.send(
+            new UpdateItemCommand({
+                TableName: TABLE,
+                Key: { PK: { S: `IP#${ip}` } },
+                UpdateExpression:
+                    "SET #ttl = :ttl ADD dailyTokenCount :tokens, tpmCount :tokens",
+                ConditionExpression: "lastMinute = :minute",
+                ExpressionAttributeNames: { "#ttl": "ttl" },
+                ExpressionAttributeValues: {
+                    ":minute": { S: currentMinute },
+                    ":tokens": { N: String(tokens) },
+                    ":ttl": { N: String(ttl) },
+                },
+            }),
+        )
+    } catch (e: any) {
+        if (e instanceof ConditionalCheckFailedException) {
+            // Different minute - reset TPM count and set new minute
+            try {
+                await client.send(
+                    new UpdateItemCommand({
+                        TableName: TABLE,
+                        Key: { PK: { S: `IP#${ip}` } },
+                        UpdateExpression:
+                            "SET lastMinute = :minute, tpmCount = :tokens, #ttl = :ttl ADD dailyTokenCount :tokens",
+                        ExpressionAttributeNames: { "#ttl": "ttl" },
+                        ExpressionAttributeValues: {
+                            ":minute": { S: currentMinute },
+                            ":tokens": { N: String(tokens) },
+                            ":ttl": { N: String(ttl) },
+                        },
+                    }),
+                )
+            } catch (retryError: any) {
+                console.error(
+                    `[quota] Failed to record tokens (retry), IP prefix: ${ip.slice(0, 8)}..., tokens: ${tokens}, error: ${retryError.message}`,
+                )
+            }
+        } else {
+            console.error(
+                `[quota] Failed to record tokens, IP prefix: ${ip.slice(0, 8)}..., tokens: ${tokens}, error: ${e.message}`,
+            )
+        }
+    }
+}

lib/i18n/dictionaries/en.json

@@ -14,6 +14,7 @@
         "about": "About",
         "editor": "Editor",
         "newChat": "Start fresh chat",
+        "github": "GitHub",
         "settings": "Settings",
         "hidePanel": "Hide chat panel (Ctrl+B)",
         "showPanel": "Show chat panel (Ctrl+B)",
@@ -87,6 +88,8 @@
         "overrides": "Overrides",
         "clearSettings": "Clear Settings",
         "useServerDefault": "Use Server Default",
+        "language": "Language",
+        "languageDescription": "Choose your interface language.",
         "theme": "Theme",
         "themeDescription": "Dark/Light mode for interface and DrawIO canvas.",
         "drawioStyle": "DrawIO Style",
@@ -147,6 +150,7 @@
         "tokenLimit": "Daily Token Limit Reached",
         "tpmLimit": "Rate Limit",
         "tpmMessage": "Too many requests. Please wait a moment.",
+        "tpmMessageDetailed": "Rate limit reached ({limit} tokens/min). Please wait {seconds} seconds before sending another request.",
         "messageApi": "Oops — you've reached the daily API limit for this demo! As an indie developer covering all the API costs myself, I have to set these limits to keep things sustainable.",
         "messageToken": "Oops — you've reached the daily token limit for this demo! As an indie developer covering all the API costs myself, I have to set these limits to keep things sustainable.",
         "tip": "<strong>Tip:</strong> You can use your own API key (click the Settings icon) or self-host the project to bypass these limits.",
@@ -180,5 +184,65 @@
         "seekingSponsorship": "Call for Sponsorship",
         "contactMe": "Contact Me",
         "usageNotice": "Due to high usage, I have changed the model from Claude to minimax-m2 and added some usage limits. See About page for details."
+    },
+    "modelConfig": {
+        "title": "AI Model Configuration",
+        "description": "Configure multiple AI providers and models",
+        "configure": "Configure",
+        "addProvider": "Add Provider",
+        "addModel": "Add Model",
+        "modelId": "Model ID",
+        "modelLabel": "Display Label",
+        "streaming": "Enable Streaming",
+        "deleteProvider": "Delete Provider",
+        "deleteModel": "Delete Model",
+        "noModels": "No models configured. Add a model to get started.",
+        "selectProvider": "Select a provider or add a new one",
+        "configureMultiple": "Configure multiple AI providers and switch between them easily",
+        "apiKeyStored": "API keys are stored locally in your browser",
+        "test": "Test",
+        "validationError": "Validation failed",
+        "addModelFirst": "Add at least one model to validate",
+        "providers": "Providers",
+        "addProviderHint": "Add a provider to get started",
+        "verified": "Verified",
+        "configuration": "Configuration",
+        "displayName": "Display Name",
+        "awsAccessKeyId": "AWS Access Key ID",
+        "awsSecretAccessKey": "AWS Secret Access Key",
+        "awsRegion": "AWS Region",
+        "selectRegion": "Select region",
+        "apiKey": "API Key",
+        "enterApiKey": "Enter your API key",
+        "enterSecretKey": "Enter your secret access key",
+        "baseUrl": "Base URL",
+        "optional": "(optional)",
+        "customEndpoint": "Custom endpoint URL",
+        "models": "Models",
+        "customModelId": "Custom model ID...",
+        "allAdded": "All added",
+        "suggested": "Suggested",
+        "noModelsConfigured": "No models configured",
+        "modelIdEmpty": "Model ID cannot be empty",
+        "modelIdExists": "This model ID already exists",
+        "configureProviders": "Configure AI Providers",
+        "selectProviderHint": "Select a provider from the list or add a new one to configure API keys and models",
+        "deleteConfirmDesc": "Are you sure you want to delete {name}? This will remove all configured models and cannot be undone.",
+        "typeToConfirm": "Type \"{name}\" to confirm",
+        "typeProviderName": "Type provider name...",
+        "modelsConfiguredCount": "{count} model(s) configured",
+        "validationFailedCount": "{count} model(s) failed validation",
+        "cancel": "Cancel",
+        "delete": "Delete",
+        "clickToChange": "(click to change)",
+        "usingServerDefault": "Using server default model",
+        "selectModel": "Select Model",
+        "searchModels": "Search models...",
+        "noVerifiedModels": "No verified models. Test your models first.",
+        "noModelsFound": "No models found.",
+        "default": "Default",
+        "serverDefault": "Server Default",
+        "configureModels": "Configure Models...",
+        "onlyVerifiedShown": "Only verified models are shown"
     }
 }

lib/i18n/dictionaries/ja.json

@@ -14,6 +14,7 @@
         "about": "概要",
         "editor": "エディタ",
         "newChat": "新しいチャットを開始",
+        "github": "GitHub",
         "settings": "設定",
         "hidePanel": "チャットパネルを非表示 (Ctrl+B)",
         "showPanel": "チャットパネルを表示 (Ctrl+B)",
@@ -87,6 +88,8 @@
         "overrides": "上書き",
         "clearSettings": "設定をクリア",
         "useServerDefault": "サーバーデフォルトを使用",
+        "language": "言語",
+        "languageDescription": "インターフェース言語を選択します。",
         "theme": "テーマ",
         "themeDescription": "インターフェースと DrawIO キャンバスのダーク/ライトモード。",
         "drawioStyle": "DrawIO スタイル",
@@ -147,6 +150,7 @@
         "tokenLimit": "1日のトークン制限に達しました",
         "tpmLimit": "レート制限",
         "tpmMessage": "リクエストが多すぎます。しばらくお待ちください。",
+        "tpmMessageDetailed": "レート制限に達しました（{limit}トークン/分）。{seconds}秒待ってからもう一度リクエストしてください。",
         "messageApi": "おっと — このデモの1日の API 制限に達しました！個人開発者として API コストをすべて負担しているため、持続可能性を保つためにこれらの制限を設定する必要があります。",
         "messageToken": "おっと — このデモの1日のトークン制限に達しました！個人開発者として API コストをすべて負担しているため、持続可能性を保つためにこれらの制限を設定する必要があります。",
         "tip": "<strong>ヒント：</strong>独自の API キーを使用する（設定アイコンをクリック）か、プロジェクトをセルフホストしてこれらの制限を回避できます。",
@@ -180,5 +184,65 @@
         "seekingSponsorship": "スポンサー募集",
         "contactMe": "お問い合わせ",
         "usageNotice": "利用量の増加に伴い、コスト削減のためモデルを Claude から minimax-m2 に変更し、いくつかの利用制限を設けました。詳細は概要ページをご覧ください。"
+    },
+    "modelConfig": {
+        "title": "AIモデル設定",
+        "description": "複数のAIプロバイダーとモデルを設定",
+        "configure": "設定",
+        "addProvider": "プロバイダーを追加",
+        "addModel": "モデルを追加",
+        "modelId": "モデルID",
+        "modelLabel": "表示名",
+        "streaming": "ストリーミングを有効",
+        "deleteProvider": "プロバイダーを削除",
+        "deleteModel": "モデルを削除",
+        "noModels": "モデルが設定されていません。モデルを追加してください。",
+        "selectProvider": "プロバイダーを選択または追加してください",
+        "configureMultiple": "複数のAIプロバイダーを設定して簡単に切り替え",
+        "apiKeyStored": "APIキーはブラウザにローカル保存されます",
+        "test": "テスト",
+        "validationError": "検証に失敗しました",
+        "addModelFirst": "検証するには少なくとも1つのモデルを追加してください",
+        "providers": "プロバイダー",
+        "addProviderHint": "プロバイダーを追加して開始",
+        "verified": "検証済み",
+        "configuration": "設定",
+        "displayName": "表示名",
+        "awsAccessKeyId": "AWS アクセスキー ID",
+        "awsSecretAccessKey": "AWS シークレットアクセスキー",
+        "awsRegion": "AWS リージョン",
+        "selectRegion": "リージョンを選択",
+        "apiKey": "API キー",
+        "enterApiKey": "API キーを入力",
+        "enterSecretKey": "シークレットアクセスキーを入力",
+        "baseUrl": "ベース URL",
+        "optional": "（オプション）",
+        "customEndpoint": "カスタムエンドポイント URL",
+        "models": "モデル",
+        "customModelId": "カスタムモデル ID...",
+        "allAdded": "すべて追加済み",
+        "suggested": "おすすめ",
+        "noModelsConfigured": "モデルが設定されていません",
+        "modelIdEmpty": "モデル ID は空にできません",
+        "modelIdExists": "このモデル ID は既に存在します",
+        "configureProviders": "AI プロバイダーを設定",
+        "selectProviderHint": "リストからプロバイダーを選択するか、新規追加して API キーとモデルを設定",
+        "deleteConfirmDesc": "{name} を削除してもよろしいですか？設定されたすべてのモデルが削除され、元に戻せません。",
+        "typeToConfirm": "確認のため「{name}」と入力",
+        "typeProviderName": "プロバイダー名を入力...",
+        "modelsConfiguredCount": "{count} 個のモデルを設定済み",
+        "validationFailedCount": "{count} 個のモデルの検証に失敗",
+        "cancel": "キャンセル",
+        "delete": "削除",
+        "clickToChange": "（クリックして変更）",
+        "usingServerDefault": "サーバーデフォルトモデルを使用中",
+        "selectModel": "モデルを選択",
+        "searchModels": "モデルを検索...",
+        "noVerifiedModels": "検証済みのモデルがありません。先にモデルをテストしてください。",
+        "noModelsFound": "モデルが見つかりません。",
+        "default": "デフォルト",
+        "serverDefault": "サーバーデフォルト",
+        "configureModels": "モデルを設定...",
+        "onlyVerifiedShown": "検証済みのモデルのみ表示"
     }
 }

lib/i18n/dictionaries/zh.json

@@ -14,6 +14,7 @@
         "about": "关于",
         "editor": "编辑器",
         "newChat": "开始新对话",
+        "github": "GitHub",
         "settings": "设置",
         "hidePanel": "隐藏聊天面板 (Ctrl+B)",
         "showPanel": "显示聊天面板 (Ctrl+B)",
@@ -87,6 +88,8 @@
         "overrides": "覆盖",
         "clearSettings": "清除设置",
         "useServerDefault": "使用服务器默认值",
+        "language": "语言",
+        "languageDescription": "选择界面语言。",
         "theme": "主题",
         "themeDescription": "界面和 DrawIO 画布的深色/浅色模式。",
         "drawioStyle": "DrawIO 样式",
@@ -147,6 +150,7 @@
         "tokenLimit": "已达每日令牌限制",
         "tpmLimit": "速率限制",
         "tpmMessage": "请求过多。请稍等片刻。",
+        "tpmMessageDetailed": "达到速率限制（{limit} 令牌/分钟）。请等待 {seconds} 秒后再发送请求。",
         "messageApi": "糟糕 — 您已达到此演示的每日 API 限制！作为一名独立开发者，我自己承担所有 API 费用，因此必须设置这些限制以保持可持续性。",
         "messageToken": "糟糕 — 您已达到此演示的每日令牌限制！作为一名独立开发者，我自己承担所有 API 费用，因此必须设置这些限制以保持可持续性。",
         "tip": "<strong>提示：</strong>您可以使用自己的 API 密钥（点击设置图标）或自托管项目来绕过这些限制。",
@@ -180,5 +184,65 @@
         "seekingSponsorship": "寻求赞助（求大佬捞一把）",
         "contactMe": "联系我",
         "usageNotice": "由于使用量过高，我已将模型从 Claude 更换为 minimax-m2，并设置了一些用量限制。详情请查看关于页面。"
+    },
+    "modelConfig": {
+        "title": "AI 模型配置",
+        "description": "配置多个 AI 提供商和模型",
+        "configure": "配置",
+        "addProvider": "添加提供商",
+        "addModel": "添加模型",
+        "modelId": "模型 ID",
+        "modelLabel": "显示名称",
+        "streaming": "启用流式输出",
+        "deleteProvider": "删除提供商",
+        "deleteModel": "删除模型",
+        "noModels": "尚未配置模型。添加模型以开始使用。",
+        "selectProvider": "选择一个提供商或添加新的",
+        "configureMultiple": "配置多个 AI 提供商并轻松切换",
+        "apiKeyStored": "API 密钥存储在您的浏览器本地",
+        "test": "测试",
+        "validationError": "验证失败",
+        "addModelFirst": "请先添加至少一个模型以进行验证",
+        "providers": "提供商",
+        "addProviderHint": "添加提供商即可开始使用",
+        "verified": "已验证",
+        "configuration": "配置",
+        "displayName": "显示名称",
+        "awsAccessKeyId": "AWS 访问密钥 ID",
+        "awsSecretAccessKey": "AWS Secret Access Key",
+        "awsRegion": "AWS 区域",
+        "selectRegion": "选择区域",
+        "apiKey": "API 密钥",
+        "enterApiKey": "输入您的 API 密钥",
+        "enterSecretKey": "输入您的 Secret Key",
+        "baseUrl": "基础 URL",
+        "optional": "（可选）",
+        "customEndpoint": "自定义端点 URL",
+        "models": "模型",
+        "customModelId": "自定义模型 ID...",
+        "allAdded": "已全部添加",
+        "suggested": "推荐",
+        "noModelsConfigured": "尚未配置模型",
+        "modelIdEmpty": "模型 ID 不能为空",
+        "modelIdExists": "此模型 ID 已存在",
+        "configureProviders": "配置 AI 提供商",
+        "selectProviderHint": "从列表中选择提供商或添加新的以配置 API 密钥和模型",
+        "deleteConfirmDesc": "确定要删除 {name} 吗？这将移除所有配置的模型且无法撤销。",
+        "typeToConfirm": "输入 \"{name}\" 以确认",
+        "typeProviderName": "输入提供商名称...",
+        "modelsConfiguredCount": "已配置 {count} 个模型",
+        "validationFailedCount": "{count} 个模型验证失败",
+        "cancel": "取消",
+        "delete": "删除",
+        "clickToChange": "（点击更改）",
+        "usingServerDefault": "使用服务器默认模型",
+        "selectModel": "选择模型",
+        "searchModels": "搜索模型...",
+        "noVerifiedModels": "没有已验证的模型。请先测试您的模型。",
+        "noModelsFound": "未找到模型。",
+        "default": "默认",
+        "serverDefault": "服务器默认",
+        "configureModels": "配置模型...",
+        "onlyVerifiedShown": "仅显示已验证的模型"
     }
 }

lib/langfuse.ts

@@ -21,9 +21,11 @@ export function getLangfuseClient(): LangfuseClient | null {
     return langfuseClient
 }
 
-// Check if Langfuse is configured
+// Check if Langfuse is configured (both keys required)
 export function isLangfuseEnabled(): boolean {
-    return !!process.env.LANGFUSE_PUBLIC_KEY
+    return !!(
+        process.env.LANGFUSE_PUBLIC_KEY && process.env.LANGFUSE_SECRET_KEY
+    )
 }
 
 // Update trace with input data at the start of request
@@ -43,34 +45,16 @@ export function setTraceInput(params: {
 }
 
 // Update trace with output and end the span
-export function setTraceOutput(
-    output: string,
-    usage?: { promptTokens?: number; completionTokens?: number },
-) {
+// Note: AI SDK 6 telemetry automatically reports token usage on its spans,
+// so we only need to set the output text and close our wrapper span
+export function setTraceOutput(output: string) {
     if (!isLangfuseEnabled()) return
 
     updateActiveTrace({ output })
 
+    // End the observe() wrapper span (AI SDK creates its own child spans with usage)
     const activeSpan = api.trace.getActiveSpan()
     if (activeSpan) {
-        // Manually set usage attributes since AI SDK Bedrock streaming doesn't provide them
-        if (usage?.promptTokens) {
-            activeSpan.setAttribute("ai.usage.promptTokens", usage.promptTokens)
-            activeSpan.setAttribute(
-                "gen_ai.usage.input_tokens",
-                usage.promptTokens,
-            )
-        }
-        if (usage?.completionTokens) {
-            activeSpan.setAttribute(
-                "ai.usage.completionTokens",
-                usage.completionTokens,
-            )
-            activeSpan.setAttribute(
-                "gen_ai.usage.output_tokens",
-                usage.completionTokens,
-            )
-        }
         activeSpan.end()
     }
 }

lib/storage.ts

@@ -24,4 +24,8 @@ export const STORAGE_KEYS = {
     aiBaseUrl: "next-ai-draw-io-ai-base-url",
     aiApiKey: "next-ai-draw-io-ai-api-key",
     aiModel: "next-ai-draw-io-ai-model",
+
+    // Multi-model configuration
+    modelConfigs: "next-ai-draw-io-model-configs",
+    selectedModelId: "next-ai-draw-io-selected-model-id",
 } as const

lib/system-prompts.ts

@@ -99,9 +99,9 @@ When using edit_diagram tool:
 - For update/add: provide cell_id and complete new_xml (full mxCell element including mxGeometry)
 - For delete: only cell_id is needed
 - Find the cell_id from "Current diagram XML" in system context
-- Example update: {"operations": [{"type": "update", "cell_id": "3", "new_xml": "<mxCell id=\\"3\\" value=\\"New Label\\" style=\\"rounded=1;\\" vertex=\\"1\\" parent=\\"1\\">\\n  <mxGeometry x=\\"100\\" y=\\"100\\" width=\\"120\\" height=\\"60\\" as=\\"geometry\\"/>\\n</mxCell>"}]}
-- Example delete: {"operations": [{"type": "delete", "cell_id": "5"}]}
-- Example add: {"operations": [{"type": "add", "cell_id": "new1", "new_xml": "<mxCell id=\\"new1\\" value=\\"New Box\\" style=\\"rounded=1;\\" vertex=\\"1\\" parent=\\"1\\">\\n  <mxGeometry x=\\"400\\" y=\\"200\\" width=\\"120\\" height=\\"60\\" as=\\"geometry\\"/>\\n</mxCell>"}]}
+- Example update: {"operations": [{"operation": "update", "cell_id": "3", "new_xml": "<mxCell id=\\"3\\" value=\\"New Label\\" style=\\"rounded=1;\\" vertex=\\"1\\" parent=\\"1\\">\\n  <mxGeometry x=\\"100\\" y=\\"100\\" width=\\"120\\" height=\\"60\\" as=\\"geometry\\"/>\\n</mxCell>"}]}
+- Example delete: {"operations": [{"operation": "delete", "cell_id": "5"}]}
+- Example add: {"operations": [{"operation": "add", "cell_id": "new1", "new_xml": "<mxCell id=\\"new1\\" value=\\"New Box\\" style=\\"rounded=1;\\" vertex=\\"1\\" parent=\\"1\\">\\n  <mxGeometry x=\\"400\\" y=\\"200\\" width=\\"120\\" height=\\"60\\" as=\\"geometry\\"/>\\n</mxCell>"}]}
 
 ⚠️ JSON ESCAPING: Every " inside new_xml MUST be escaped as \\". Example: id=\\"5\\" value=\\"Label\\"
 
@@ -282,9 +282,9 @@ edit_diagram uses ID-based operations to modify cells directly by their id attri
 \`\`\`json
 {
   "operations": [
-    {"type": "update", "cell_id": "3", "new_xml": "<mxCell ...complete element...>"},
-    {"type": "add", "cell_id": "new1", "new_xml": "<mxCell ...new element...>"},
-    {"type": "delete", "cell_id": "5"}
+    {"operation": "update", "cell_id": "3", "new_xml": "<mxCell ...complete element...>"},
+    {"operation": "add", "cell_id": "new1", "new_xml": "<mxCell ...new element...>"},
+    {"operation": "delete", "cell_id": "5"}
   ]
 }
 \`\`\`
@@ -293,17 +293,17 @@ edit_diagram uses ID-based operations to modify cells directly by their id attri
 
 Change label:
 \`\`\`json
-{"operations": [{"type": "update", "cell_id": "3", "new_xml": "<mxCell id=\\"3\\" value=\\"New Label\\" style=\\"rounded=1;\\" vertex=\\"1\\" parent=\\"1\\">\\n  <mxGeometry x=\\"100\\" y=\\"100\\" width=\\"120\\" height=\\"60\\" as=\\"geometry\\"/>\\n</mxCell>"}]}
+{"operations": [{"operation": "update", "cell_id": "3", "new_xml": "<mxCell id=\\"3\\" value=\\"New Label\\" style=\\"rounded=1;\\" vertex=\\"1\\" parent=\\"1\\">\\n  <mxGeometry x=\\"100\\" y=\\"100\\" width=\\"120\\" height=\\"60\\" as=\\"geometry\\"/>\\n</mxCell>"}]}
 \`\`\`
 
 Add new shape:
 \`\`\`json
-{"operations": [{"type": "add", "cell_id": "new1", "new_xml": "<mxCell id=\\"new1\\" value=\\"New Box\\" style=\\"rounded=1;fillColor=#dae8fc;\\" vertex=\\"1\\" parent=\\"1\\">\\n  <mxGeometry x=\\"400\\" y=\\"200\\" width=\\"120\\" height=\\"60\\" as=\\"geometry\\"/>\\n</mxCell>"}]}
+{"operations": [{"operation": "add", "cell_id": "new1", "new_xml": "<mxCell id=\\"new1\\" value=\\"New Box\\" style=\\"rounded=1;fillColor=#dae8fc;\\" vertex=\\"1\\" parent=\\"1\\">\\n  <mxGeometry x=\\"400\\" y=\\"200\\" width=\\"120\\" height=\\"60\\" as=\\"geometry\\"/>\\n</mxCell>"}]}
 \`\`\`
 
 Delete cell:
 \`\`\`json
-{"operations": [{"type": "delete", "cell_id": "5"}]}
+{"operations": [{"operation": "delete", "cell_id": "5"}]}
 \`\`\`
 
 **Error Recovery:**

lib/types/model-config.ts

@@ -0,0 +1,279 @@
+// Types for multi-provider model configuration
+
+export type ProviderName =
+    | "openai"
+    | "anthropic"
+    | "google"
+    | "azure"
+    | "bedrock"
+    | "openrouter"
+    | "deepseek"
+    | "siliconflow"
+    | "gateway"
+
+// Individual model configuration
+export interface ModelConfig {
+    id: string // UUID for this model
+    modelId: string // e.g., "gpt-4o", "claude-sonnet-4-5"
+    validated?: boolean // Has this model been validated
+    validationError?: string // Error message if validation failed
+}
+
+// Provider configuration
+export interface ProviderConfig {
+    id: string // UUID for this provider config
+    provider: ProviderName
+    name?: string // Custom display name (e.g., "OpenAI Production")
+    apiKey: string
+    baseUrl?: string
+    // AWS Bedrock specific fields
+    awsAccessKeyId?: string
+    awsSecretAccessKey?: string
+    awsRegion?: string
+    awsSessionToken?: string // Optional, for temporary credentials
+    models: ModelConfig[]
+    validated?: boolean // Has API key been validated
+}
+
+// The complete multi-model configuration
+export interface MultiModelConfig {
+    version: 1
+    providers: ProviderConfig[]
+    selectedModelId?: string // Currently selected model's UUID
+}
+
+// Flattened model for dropdown display
+export interface FlattenedModel {
+    id: string // Model config UUID
+    modelId: string // Actual model ID
+    provider: ProviderName
+    providerLabel: string // Provider display name
+    apiKey: string
+    baseUrl?: string
+    // AWS Bedrock specific fields
+    awsAccessKeyId?: string
+    awsSecretAccessKey?: string
+    awsRegion?: string
+    awsSessionToken?: string
+    validated?: boolean // Has this model been validated
+}
+
+// Provider metadata
+export const PROVIDER_INFO: Record<
+    ProviderName,
+    { label: string; defaultBaseUrl?: string }
+> = {
+    openai: { label: "OpenAI" },
+    anthropic: {
+        label: "Anthropic",
+        defaultBaseUrl: "https://api.anthropic.com/v1",
+    },
+    google: { label: "Google" },
+    azure: { label: "Azure OpenAI" },
+    bedrock: { label: "Amazon Bedrock" },
+    openrouter: { label: "OpenRouter" },
+    deepseek: { label: "DeepSeek" },
+    siliconflow: {
+        label: "SiliconFlow",
+        defaultBaseUrl: "https://api.siliconflow.com/v1",
+    },
+    gateway: { label: "AI Gateway" },
+}
+
+// Suggested models per provider for quick add
+export const SUGGESTED_MODELS: Record<ProviderName, string[]> = {
+    openai: [
+        "gpt-5.2-pro",
+        "gpt-5.2-chat-latest",
+        "gpt-5.2",
+        "gpt-5.1-codex-mini",
+        "gpt-5.1-codex",
+        "gpt-5.1-chat-latest",
+        "gpt-5.1",
+        "gpt-5-pro",
+        "gpt-5",
+        "gpt-5-mini",
+        "gpt-5-nano",
+        "gpt-5-codex",
+        "gpt-5-chat-latest",
+        "gpt-4.1",
+        "gpt-4.1-mini",
+        "gpt-4.1-nano",
+        "gpt-4o",
+        "gpt-4o-mini",
+    ],
+    anthropic: [
+        // Claude 4.5 series (latest)
+        "claude-opus-4-5-20250514",
+        "claude-sonnet-4-5-20250514",
+        // Claude 4 series
+        "claude-opus-4-20250514",
+        "claude-sonnet-4-20250514",
+        // Claude 3.7 series
+        "claude-3-7-sonnet-20250219",
+        // Claude 3.5 series
+        "claude-3-5-sonnet-20241022",
+        "claude-3-5-haiku-20241022",
+        // Claude 3 series
+        "claude-3-opus-20240229",
+        "claude-3-sonnet-20240229",
+        "claude-3-haiku-20240307",
+    ],
+    google: [
+        // Gemini 2.5 series
+        "gemini-2.5-pro",
+        "gemini-2.5-flash",
+        "gemini-2.5-flash-preview-05-20",
+        // Gemini 2.0 series
+        "gemini-2.0-flash",
+        "gemini-2.0-flash-exp",
+        "gemini-2.0-flash-lite",
+        // Gemini 1.5 series
+        "gemini-1.5-pro",
+        "gemini-1.5-flash",
+        // Legacy
+        "gemini-pro",
+    ],
+    azure: ["gpt-4o", "gpt-4o-mini", "gpt-4-turbo", "gpt-4", "gpt-35-turbo"],
+    bedrock: [
+        // Anthropic Claude
+        "anthropic.claude-opus-4-5-20250514-v1:0",
+        "anthropic.claude-sonnet-4-5-20250514-v1:0",
+        "anthropic.claude-opus-4-20250514-v1:0",
+        "anthropic.claude-sonnet-4-20250514-v1:0",
+        "anthropic.claude-3-7-sonnet-20250219-v1:0",
+        "anthropic.claude-3-5-sonnet-20241022-v2:0",
+        "anthropic.claude-3-5-haiku-20241022-v1:0",
+        "anthropic.claude-3-opus-20240229-v1:0",
+        "anthropic.claude-3-sonnet-20240229-v1:0",
+        "anthropic.claude-3-haiku-20240307-v1:0",
+        // Amazon Nova
+        "amazon.nova-pro-v1:0",
+        "amazon.nova-lite-v1:0",
+        "amazon.nova-micro-v1:0",
+        // Meta Llama
+        "meta.llama3-3-70b-instruct-v1:0",
+        "meta.llama3-1-405b-instruct-v1:0",
+        "meta.llama3-1-70b-instruct-v1:0",
+        // Mistral
+        "mistral.mistral-large-2411-v1:0",
+        "mistral.mistral-small-2503-v1:0",
+    ],
+    openrouter: [
+        // Anthropic
+        "anthropic/claude-sonnet-4",
+        "anthropic/claude-opus-4",
+        "anthropic/claude-3.5-sonnet",
+        "anthropic/claude-3.5-haiku",
+        // OpenAI
+        "openai/gpt-4o",
+        "openai/gpt-4o-mini",
+        "openai/o1",
+        "openai/o3-mini",
+        // Google
+        "google/gemini-2.5-pro",
+        "google/gemini-2.5-flash",
+        "google/gemini-2.0-flash-exp:free",
+        // Meta Llama
+        "meta-llama/llama-3.3-70b-instruct",
+        "meta-llama/llama-3.1-405b-instruct",
+        "meta-llama/llama-3.1-70b-instruct",
+        // DeepSeek
+        "deepseek/deepseek-chat",
+        "deepseek/deepseek-r1",
+        // Qwen
+        "qwen/qwen-2.5-72b-instruct",
+    ],
+    deepseek: ["deepseek-chat", "deepseek-reasoner", "deepseek-coder"],
+    siliconflow: [
+        // DeepSeek
+        "deepseek-ai/DeepSeek-V3",
+        "deepseek-ai/DeepSeek-R1",
+        "deepseek-ai/DeepSeek-V2.5",
+        // Qwen
+        "Qwen/Qwen2.5-72B-Instruct",
+        "Qwen/Qwen2.5-32B-Instruct",
+        "Qwen/Qwen2.5-Coder-32B-Instruct",
+        "Qwen/Qwen2.5-7B-Instruct",
+        "Qwen/Qwen2-VL-72B-Instruct",
+    ],
+    gateway: [
+        "openai/gpt-4o",
+        "openai/gpt-4o-mini",
+        "anthropic/claude-sonnet-4-5",
+        "anthropic/claude-3-5-sonnet",
+        "google/gemini-2.0-flash",
+    ],
+}
+
+// Helper to generate UUID
+export function generateId(): string {
+    return `${Date.now()}-${Math.random().toString(36).slice(2, 9)}`
+}
+
+// Create empty config
+export function createEmptyConfig(): MultiModelConfig {
+    return {
+        version: 1,
+        providers: [],
+        selectedModelId: undefined,
+    }
+}
+
+// Create new provider config
+export function createProviderConfig(provider: ProviderName): ProviderConfig {
+    return {
+        id: generateId(),
+        provider,
+        apiKey: "",
+        baseUrl: PROVIDER_INFO[provider].defaultBaseUrl,
+        models: [],
+        validated: false,
+    }
+}
+
+// Create new model config
+export function createModelConfig(modelId: string): ModelConfig {
+    return {
+        id: generateId(),
+        modelId,
+    }
+}
+
+// Get all models as flattened list for dropdown
+export function flattenModels(config: MultiModelConfig): FlattenedModel[] {
+    const models: FlattenedModel[] = []
+
+    for (const provider of config.providers) {
+        // Use custom name if provided, otherwise use default provider label
+        const providerLabel =
+            provider.name || PROVIDER_INFO[provider.provider].label
+
+        for (const model of provider.models) {
+            models.push({
+                id: model.id,
+                modelId: model.modelId,
+                provider: provider.provider,
+                providerLabel,
+                apiKey: provider.apiKey,
+                baseUrl: provider.baseUrl,
+                // AWS Bedrock fields
+                awsAccessKeyId: provider.awsAccessKeyId,
+                awsSecretAccessKey: provider.awsSecretAccessKey,
+                awsRegion: provider.awsRegion,
+                awsSessionToken: provider.awsSessionToken,
+                validated: model.validated,
+            })
+        }
+    }
+
+    return models
+}
+
+// Find model by ID
+export function findModelById(
+    config: MultiModelConfig,
+    modelId: string,
+): FlattenedModel | undefined {
+    return flattenModels(config).find((m) => m.id === modelId)
+}

lib/use-quota-manager.tsx

@@ -1,9 +1,10 @@
 "use client"
 
-import { useCallback, useMemo } from "react"
+import { useCallback } from "react"
 import { toast } from "sonner"
 import { QuotaLimitToast } from "@/components/quota-limit-toast"
-import { STORAGE_KEYS } from "@/lib/storage"
+import { useDictionary } from "@/hooks/use-dictionary"
+import { formatMessage } from "@/lib/i18n/utils"
 
 export interface QuotaConfig {
     dailyRequestLimit: number
@@ -11,179 +12,45 @@ export interface QuotaConfig {
     tpmLimit: number
 }
 
-export interface QuotaCheckResult {
-    allowed: boolean
-    remaining: number
-    used: number
-}
-
 /**
- * Hook for managing request/token quotas and rate limiting.
- * Handles three types of limits:
- * - Daily request limit
- * - Daily token limit
- * - Tokens per minute (TPM) rate limit
- *
- * Users with their own API key bypass all limits.
+ * Hook for displaying quota limit toasts.
+ * Server-side handles actual quota enforcement via DynamoDB.
+ * This hook only provides UI feedback when limits are exceeded.
  */
 export function useQuotaManager(config: QuotaConfig): {
-    hasOwnApiKey: () => boolean
-    checkDailyLimit: () => QuotaCheckResult
-    checkTokenLimit: () => QuotaCheckResult
-    checkTPMLimit: () => QuotaCheckResult
-    incrementRequestCount: () => void
-    incrementTokenCount: (tokens: number) => void
-    incrementTPMCount: (tokens: number) => void
-    showQuotaLimitToast: () => void
-    showTokenLimitToast: (used: number) => void
-    showTPMLimitToast: () => void
+    showQuotaLimitToast: (used?: number, limit?: number) => void
+    showTokenLimitToast: (used?: number, limit?: number) => void
+    showTPMLimitToast: (limit?: number) => void
 } {
     const { dailyRequestLimit, dailyTokenLimit, tpmLimit } = config
-
-    // Check if user has their own API key configured (bypass limits)
-    const hasOwnApiKey = useCallback((): boolean => {
-        const provider = localStorage.getItem(STORAGE_KEYS.aiProvider)
-        const apiKey = localStorage.getItem(STORAGE_KEYS.aiApiKey)
-        return !!(provider && apiKey)
-    }, [])
-
-    // Generic helper: Parse count from localStorage with NaN guard
-    const parseStorageCount = (key: string): number => {
-        const count = parseInt(localStorage.getItem(key) || "0", 10)
-        return Number.isNaN(count) ? 0 : count
-    }
-
-    // Generic helper: Create quota checker factory
-    const createQuotaChecker = useCallback(
-        (
-            getTimeKey: () => string,
-            timeStorageKey: string,
-            countStorageKey: string,
-            limit: number,
-        ) => {
-            return (): QuotaCheckResult => {
-                if (hasOwnApiKey())
-                    return { allowed: true, remaining: -1, used: 0 }
-                if (limit <= 0) return { allowed: true, remaining: -1, used: 0 }
-
-                const currentTime = getTimeKey()
-                const storedTime = localStorage.getItem(timeStorageKey)
-                let count = parseStorageCount(countStorageKey)
-
-                if (storedTime !== currentTime) {
-                    count = 0
-                    localStorage.setItem(timeStorageKey, currentTime)
-                    localStorage.setItem(countStorageKey, "0")
-                }
-
-                return {
-                    allowed: count < limit,
-                    remaining: limit - count,
-                    used: count,
-                }
-            }
-        },
-        [hasOwnApiKey],
-    )
-
-    // Generic helper: Create quota incrementer factory
-    const createQuotaIncrementer = useCallback(
-        (
-            getTimeKey: () => string,
-            timeStorageKey: string,
-            countStorageKey: string,
-            validateInput: boolean = false,
-        ) => {
-            return (tokens: number = 1): void => {
-                if (validateInput && (!Number.isFinite(tokens) || tokens <= 0))
-                    return
-
-                const currentTime = getTimeKey()
-                const storedTime = localStorage.getItem(timeStorageKey)
-                let count = parseStorageCount(countStorageKey)
-
-                if (storedTime !== currentTime) {
-                    count = 0
-                    localStorage.setItem(timeStorageKey, currentTime)
-                }
-
-                localStorage.setItem(countStorageKey, String(count + tokens))
-            }
-        },
-        [],
-    )
-
-    // Check daily request limit
-    const checkDailyLimit = useMemo(
-        () =>
-            createQuotaChecker(
-                () => new Date().toDateString(),
-                STORAGE_KEYS.requestDate,
-                STORAGE_KEYS.requestCount,
-                dailyRequestLimit,
-            ),
-        [createQuotaChecker, dailyRequestLimit],
-    )
-
-    // Increment request count
-    const incrementRequestCount = useMemo(
-        () =>
-            createQuotaIncrementer(
-                () => new Date().toDateString(),
-                STORAGE_KEYS.requestDate,
-                STORAGE_KEYS.requestCount,
-                false,
-            ),
-        [createQuotaIncrementer],
-    )
+    const dict = useDictionary()
 
     // Show quota limit toast (request-based)
-    const showQuotaLimitToast = useCallback(() => {
-        toast.custom(
-            (t) => (
-                <QuotaLimitToast
-                    used={dailyRequestLimit}
-                    limit={dailyRequestLimit}
-                    onDismiss={() => toast.dismiss(t)}
-                />
-            ),
-            { duration: 15000 },
-        )
-    }, [dailyRequestLimit])
-
-    // Check daily token limit
-    const checkTokenLimit = useMemo(
-        () =>
-            createQuotaChecker(
-                () => new Date().toDateString(),
-                STORAGE_KEYS.tokenDate,
-                STORAGE_KEYS.tokenCount,
-                dailyTokenLimit,
-            ),
-        [createQuotaChecker, dailyTokenLimit],
-    )
-
-    // Increment token count
-    const incrementTokenCount = useMemo(
-        () =>
-            createQuotaIncrementer(
-                () => new Date().toDateString(),
-                STORAGE_KEYS.tokenDate,
-                STORAGE_KEYS.tokenCount,
-                true, // Validate input tokens
-            ),
-        [createQuotaIncrementer],
+    const showQuotaLimitToast = useCallback(
+        (used?: number, limit?: number) => {
+            toast.custom(
+                (t) => (
+                    <QuotaLimitToast
+                        used={used ?? dailyRequestLimit}
+                        limit={limit ?? dailyRequestLimit}
+                        onDismiss={() => toast.dismiss(t)}
+                    />
+                ),
+                { duration: 15000 },
+            )
+        },
+        [dailyRequestLimit],
     )
 
     // Show token limit toast
     const showTokenLimitToast = useCallback(
-        (used: number) => {
+        (used?: number, limit?: number) => {
             toast.custom(
                 (t) => (
                     <QuotaLimitToast
                         type="token"
-                        used={used}
-                        limit={dailyTokenLimit}
+                        used={used ?? dailyTokenLimit}
+                        limit={limit ?? dailyTokenLimit}
                         onDismiss={() => toast.dismiss(t)}
                     />
                 ),
@@ -193,53 +60,24 @@ export function useQuotaManager(config: QuotaConfig): {
         [dailyTokenLimit],
     )
 
-    // Check TPM (tokens per minute) limit
-    const checkTPMLimit = useMemo(
-        () =>
-            createQuotaChecker(
-                () => Math.floor(Date.now() / 60000).toString(),
-                STORAGE_KEYS.tpmMinute,
-                STORAGE_KEYS.tpmCount,
-                tpmLimit,
-            ),
-        [createQuotaChecker, tpmLimit],
-    )
-
-    // Increment TPM count
-    const incrementTPMCount = useMemo(
-        () =>
-            createQuotaIncrementer(
-                () => Math.floor(Date.now() / 60000).toString(),
-                STORAGE_KEYS.tpmMinute,
-                STORAGE_KEYS.tpmCount,
-                true, // Validate input tokens
-            ),
-        [createQuotaIncrementer],
-    )
-
     // Show TPM limit toast
-    const showTPMLimitToast = useCallback(() => {
-        const limitDisplay =
-            tpmLimit >= 1000 ? `${tpmLimit / 1000}k` : String(tpmLimit)
-        toast.error(
-            `Rate limit reached (${limitDisplay} tokens/min). Please wait 60 seconds before sending another request.`,
-            { duration: 8000 },
-        )
-    }, [tpmLimit])
+    const showTPMLimitToast = useCallback(
+        (limit?: number) => {
+            const effectiveLimit = limit ?? tpmLimit
+            const limitDisplay =
+                effectiveLimit >= 1000
+                    ? `${effectiveLimit / 1000}k`
+                    : String(effectiveLimit)
+            const message = formatMessage(dict.quota.tpmMessageDetailed, {
+                limit: limitDisplay,
+                seconds: 60,
+            })
+            toast.error(message, { duration: 8000 })
+        },
+        [tpmLimit, dict],
+    )
 
     return {
-        // Check functions
-        hasOwnApiKey,
-        checkDailyLimit,
-        checkTokenLimit,
-        checkTPMLimit,
-
-        // Increment functions
-        incrementRequestCount,
-        incrementTokenCount,
-        incrementTPMCount,
-
-        // Toast functions
         showQuotaLimitToast,
         showTokenLimitToast,
         showTPMLimitToast,

lib/user-id.ts

@@ -0,0 +1,12 @@
+/**
+ * Generate a userId from request for tracking purposes.
+ * Uses base64url encoding of IP for URL-safe identifier.
+ * Note: base64 is reversible - this is NOT privacy protection.
+ */
+export function getUserIdFromRequest(req: Request): string {
+    const forwardedFor = req.headers.get("x-forwarded-for")
+    const rawIp = forwardedFor?.split(",")[0]?.trim() || "anonymous"
+    return rawIp === "anonymous"
+        ? rawIp
+        : `user-${Buffer.from(rawIp).toString("base64url")}`
+}

lib/utils.ts

@@ -36,29 +36,73 @@ const VALID_ENTITIES = new Set(["lt", "gt", "amp", "quot", "apos"])
 /**
  * Check if mxCell XML output is complete (not truncated).
  * Complete XML ends with a self-closing tag (/>) or closing mxCell tag.
- * Also handles function-calling wrapper tags that may be incorrectly included.
+ * Uses a robust approach that handles any LLM provider's wrapper tags
+ * by finding the last valid mxCell ending and checking if suffix is just closing tags.
  * @param xml - The XML string to check (can be undefined/null)
  * @returns true if XML appears complete, false if truncated or empty
  */
 export function isMxCellXmlComplete(xml: string | undefined | null): boolean {
-    let trimmed = xml?.trim() || ""
+    const trimmed = xml?.trim() || ""
     if (!trimmed) return false
 
-    // Strip Anthropic function-calling wrapper tags if present
-    // These can leak into tool input due to AI SDK parsing issues
-    // Use loop because tags are nested: </mxCell></mxParameter></invoke>
-    let prev = ""
-    while (prev !== trimmed) {
-        prev = trimmed
-        trimmed = trimmed
-            .replace(/<\/mxParameter>\s*$/i, "")
-            .replace(/<\/invoke>\s*$/i, "")
-            .replace(/<\/antml:parameter>\s*$/i, "")
-            .replace(/<\/antml:invoke>\s*$/i, "")
-            .trim()
+    // Find position of last complete mxCell ending (either /> or </mxCell>)
+    const lastSelfClose = trimmed.lastIndexOf("/>")
+    const lastMxCellClose = trimmed.lastIndexOf("</mxCell>")
+
+    const lastValidEnd = Math.max(lastSelfClose, lastMxCellClose)
+
+    // No valid ending found at all
+    if (lastValidEnd === -1) return false
+
+    // Check what comes after the last valid ending
+    // For />: add 2 chars, for </mxCell>: add 9 chars
+    const endOffset = lastMxCellClose > lastSelfClose ? 9 : 2
+    const suffix = trimmed.slice(lastValidEnd + endOffset)
+
+    // If suffix is empty or only contains closing tags (any provider's wrapper) or whitespace, it's complete
+    // This regex matches any sequence of closing XML tags like </foo>, </bar>, </｜DSML｜xyz>
+    return /^(\s*<\/[^>]+>)*\s*$/.test(suffix)
+}
+
+/**
+ * Extract only complete mxCell elements from partial/streaming XML.
+ * This allows progressive rendering during streaming by ignoring incomplete trailing elements.
+ * @param xml - The partial XML string (may contain incomplete trailing mxCell)
+ * @returns XML string containing only complete mxCell elements
+ */
+export function extractCompleteMxCells(xml: string | undefined | null): string {
+    if (!xml) return ""
+
+    const completeCells: Array<{ index: number; text: string }> = []
+
+    // Match self-closing mxCell tags: <mxCell ... />
+    // Also match mxCell with nested mxGeometry: <mxCell ...>...<mxGeometry .../></mxCell>
+    const selfClosingPattern = /<mxCell\s+[^>]*\/>/g
+    const nestedPattern = /<mxCell\s+[^>]*>[\s\S]*?<\/mxCell>/g
+
+    // Find all self-closing mxCell elements
+    let match: RegExpExecArray | null
+    while ((match = selfClosingPattern.exec(xml)) !== null) {
+        completeCells.push({ index: match.index, text: match[0] })
     }
 
-    return trimmed.endsWith("/>") || trimmed.endsWith("</mxCell>")
+    // Find all mxCell elements with nested content (like mxGeometry)
+    while ((match = nestedPattern.exec(xml)) !== null) {
+        completeCells.push({ index: match.index, text: match[0] })
+    }
+
+    // Sort by position to maintain order
+    completeCells.sort((a, b) => a.index - b.index)
+
+    // Remove duplicates (a self-closing match might overlap with nested match)
+    const seen = new Set<number>()
+    const uniqueCells = completeCells.filter((cell) => {
+        if (seen.has(cell.index)) return false
+        seen.add(cell.index)
+        return true
+    })
+
+    return uniqueCells.map((c) => c.text).join("\n")
 }
 
 // ============================================================================
@@ -221,6 +265,21 @@ export function convertToLegalXml(xmlString: string): string {
             "&amp;",
         )
 
+        // Fix unescaped < and > in attribute values for XML parsing
+        // HTML content in value attributes (e.g., <b>Title</b>) needs to be escaped
+        // This is critical because DOMParser will fail on unescaped < > in attributes
+        if (/=\s*"[^"]*<[^"]*"/.test(cellContent)) {
+            cellContent = cellContent.replace(
+                /=\s*"([^"]*)"/g,
+                (_match, value) => {
+                    const escaped = value
+                        .replace(/</g, "&lt;")
+                        .replace(/>/g, "&gt;")
+                    return `="${escaped}"`
+                },
+            )
+        }
+
         // Indent each line of the matched block for readability.
         const formatted = cellContent
             .split("\n")
@@ -265,6 +324,20 @@ export function wrapWithMxFile(xml: string): string {
         content = xml.replace(/<\/?root>/g, "").trim()
     }
 
+    // Strip trailing LLM wrapper tags (from any provider: Anthropic, DeepSeek, etc.)
+    // Find the last valid mxCell ending and remove everything after it
+    const lastSelfClose = content.lastIndexOf("/>")
+    const lastMxCellClose = content.lastIndexOf("</mxCell>")
+    const lastValidEnd = Math.max(lastSelfClose, lastMxCellClose)
+    if (lastValidEnd !== -1) {
+        const endOffset = lastMxCellClose > lastSelfClose ? 9 : 2
+        const suffix = content.slice(lastValidEnd + endOffset)
+        // If suffix is only closing tags (wrapper tags), strip it
+        if (/^(\s*<\/[^>]+>)*\s*$/.test(suffix)) {
+            content = content.slice(0, lastValidEnd + endOffset)
+        }
+    }
+
     // Remove any existing root cells from content (LLM shouldn't include them, but handle it gracefully)
     // Use flexible patterns that match both self-closing (/>) and non-self-closing (></mxCell>) formats
     content = content
@@ -382,7 +455,7 @@ export function replaceNodes(currentXML: string, nodes: string): string {
 // ============================================================================
 
 export interface DiagramOperation {
-    type: "update" | "add" | "delete"
+    operation: "update" | "add" | "delete"
     cell_id: string
     new_xml?: string
 }
@@ -455,7 +528,7 @@ export function applyDiagramOperations(
 
     // Process each operation
     for (const op of operations) {
-        if (op.type === "update") {
+        if (op.operation === "update") {
             const existingCell = cellMap.get(op.cell_id)
             if (!existingCell) {
                 errors.push({
@@ -507,7 +580,7 @@ export function applyDiagramOperations(
 
             // Update the map with the new element
             cellMap.set(op.cell_id, importedNode)
-        } else if (op.type === "add") {
+        } else if (op.operation === "add") {
             // Check if ID already exists
             if (cellMap.has(op.cell_id)) {
                 errors.push({
@@ -559,7 +632,7 @@ export function applyDiagramOperations(
 
             // Add to map
             cellMap.set(op.cell_id, importedNode)
-        } else if (op.type === "delete") {
+        } else if (op.operation === "delete") {
             const existingCell = cellMap.get(op.cell_id)
             if (!existingCell) {
                 errors.push({
@@ -869,6 +942,21 @@ export function autoFixXml(xml: string): { fixed: string; fixes: string[] } {
         fixes.push("Removed CDATA wrapper")
     }
 
+    // 1b. Strip trailing LLM wrapper tags (DeepSeek, Anthropic, etc.)
+    // These are closing tags after the last valid mxCell that break XML parsing
+    const lastSelfClose = fixed.lastIndexOf("/>")
+    const lastMxCellClose = fixed.lastIndexOf("</mxCell>")
+    const lastValidEnd = Math.max(lastSelfClose, lastMxCellClose)
+    if (lastValidEnd !== -1) {
+        const endOffset = lastMxCellClose > lastSelfClose ? 9 : 2
+        const suffix = fixed.slice(lastValidEnd + endOffset)
+        // If suffix contains only closing tags (wrapper tags) or whitespace, strip it
+        if (/^(\s*<\/[^>]+>)+\s*$/.test(suffix)) {
+            fixed = fixed.slice(0, lastValidEnd + endOffset)
+            fixes.push("Stripped trailing LLM wrapper tags")
+        }
+    }
+
     // 2. Remove text before XML declaration or root element (only if it's garbage text, not valid XML)
     const xmlStart = fixed.search(/<(\?xml|mxGraphModel|mxfile)/i)
     if (xmlStart > 0 && !/^<[a-zA-Z]/.test(fixed.trim())) {
@@ -974,8 +1062,8 @@ export function autoFixXml(xml: string): { fixed: string; fixes: string[] } {
         fixes.push("Removed quotes around color values in style")
     }
 
-    // 4. Fix unescaped < in attribute values
-    // This is tricky - we need to find < inside quoted attribute values
+    // 4. Fix unescaped < and > in attribute values
+    // < is required to be escaped, > is not strictly required but we escape for consistency
     const attrPattern = /(=\s*")([^"]*?)(<)([^"]*?)(")/g
     let attrMatch
     let hasUnescapedLt = false
@@ -986,12 +1074,12 @@ export function autoFixXml(xml: string): { fixed: string; fixes: string[] } {
         }
     }
     if (hasUnescapedLt) {
-        // Replace < with &lt; inside attribute values
+        // Replace < and > with &lt; and &gt; inside attribute values
         fixed = fixed.replace(/=\s*"([^"]*)"/g, (_match, value) => {
-            const escaped = value.replace(/</g, "&lt;")
+            const escaped = value.replace(/</g, "&lt;").replace(/>/g, "&gt;")
             return `="${escaped}"`
         })
-        fixes.push("Escaped < characters in attribute values")
+        fixes.push("Escaped <> characters in attribute values")
     }
 
     // 5. Fix invalid character references (remove malformed ones)
@@ -1054,46 +1142,7 @@ export function autoFixXml(xml: string): { fixed: string; fixes: string[] } {
         fixes.push("Fixed <Cell> tags to <mxCell>")
     }
 
-    // 8b. Remove non-draw.io tags (LLM sometimes includes Claude's function calling XML)
-    // Valid draw.io tags: mxfile, diagram, mxGraphModel, root, mxCell, mxGeometry, mxPoint, Array, Object
-    const validDrawioTags = new Set([
-        "mxfile",
-        "diagram",
-        "mxGraphModel",
-        "root",
-        "mxCell",
-        "mxGeometry",
-        "mxPoint",
-        "Array",
-        "Object",
-        "mxRectangle",
-    ])
-    const foreignTagPattern = /<\/?([a-zA-Z][a-zA-Z0-9_]*)[^>]*>/g
-    let foreignMatch
-    const foreignTags = new Set<string>()
-    while ((foreignMatch = foreignTagPattern.exec(fixed)) !== null) {
-        const tagName = foreignMatch[1]
-        if (!validDrawioTags.has(tagName)) {
-            foreignTags.add(tagName)
-        }
-    }
-    if (foreignTags.size > 0) {
-        console.log(
-            "[autoFixXml] Step 8b: Found foreign tags:",
-            Array.from(foreignTags),
-        )
-        for (const tag of foreignTags) {
-            // Remove opening tags (with or without attributes)
-            fixed = fixed.replace(new RegExp(`<${tag}[^>]*>`, "gi"), "")
-            // Remove closing tags
-            fixed = fixed.replace(new RegExp(`</${tag}>`, "gi"), "")
-        }
-        fixes.push(
-            `Removed foreign tags: ${Array.from(foreignTags).join(", ")}`,
-        )
-    }
-
-    // 9. Fix common closing tag typos
+    // 8b. Fix common closing tag typos (MUST run before foreign tag removal)
     const tagTypos = [
         { wrong: /<\/mxElement>/gi, right: "</mxCell>", name: "</mxElement>" },
         { wrong: /<\/mxcell>/g, right: "</mxCell>", name: "</mxcell>" }, // case sensitivity
@@ -1110,12 +1159,87 @@ export function autoFixXml(xml: string): { fixed: string; fixes: string[] } {
         },
     ]
     for (const { wrong, right, name } of tagTypos) {
-        if (wrong.test(fixed)) {
-            fixed = fixed.replace(wrong, right)
+        const before = fixed
+        fixed = fixed.replace(wrong, right)
+        if (fixed !== before) {
             fixes.push(`Fixed typo ${name} to ${right}`)
         }
     }
 
+    // 8c. Remove non-draw.io tags (after typo fixes so lowercase variants are fixed first)
+    // IMPORTANT: Only remove tags at the element level, NOT inside quoted attribute values
+    // Tags like <b>, <br> inside value="<b>text</b>" should be preserved (they're HTML content)
+    const validDrawioTags = new Set([
+        "mxfile",
+        "diagram",
+        "mxGraphModel",
+        "root",
+        "mxCell",
+        "mxGeometry",
+        "mxPoint",
+        "Array",
+        "Object",
+        "mxRectangle",
+    ])
+
+    // Helper: Check if a position is inside a quoted attribute value
+    // by counting unescaped quotes before that position
+    const isInsideQuotes = (str: string, pos: number): boolean => {
+        let inQuote = false
+        let quoteChar = ""
+        for (let i = 0; i < pos && i < str.length; i++) {
+            const c = str[i]
+            if (inQuote) {
+                if (c === quoteChar) inQuote = false
+            } else if (c === '"' || c === "'") {
+                // Check if this quote is part of an attribute (preceded by =)
+                // Look back for = sign
+                let j = i - 1
+                while (j >= 0 && /\s/.test(str[j])) j--
+                if (j >= 0 && str[j] === "=") {
+                    inQuote = true
+                    quoteChar = c
+                }
+            }
+        }
+        return inQuote
+    }
+
+    const foreignTagPattern = /<\/?([a-zA-Z][a-zA-Z0-9_]*)[^>]*>/g
+    let foreignMatch
+    const foreignTags = new Set<string>()
+    const foreignTagPositions: Array<{
+        tag: string
+        start: number
+        end: number
+    }> = []
+
+    while ((foreignMatch = foreignTagPattern.exec(fixed)) !== null) {
+        const tagName = foreignMatch[1]
+        // Skip if this is a valid draw.io tag
+        if (validDrawioTags.has(tagName)) continue
+        // Skip if this tag is inside a quoted attribute value
+        if (isInsideQuotes(fixed, foreignMatch.index)) continue
+
+        foreignTags.add(tagName)
+        foreignTagPositions.push({
+            tag: tagName,
+            start: foreignMatch.index,
+            end: foreignMatch.index + foreignMatch[0].length,
+        })
+    }
+
+    if (foreignTagPositions.length > 0) {
+        // Remove tags from end to start to preserve indices
+        foreignTagPositions.sort((a, b) => b.start - a.start)
+        for (const { start, end } of foreignTagPositions) {
+            fixed = fixed.slice(0, start) + fixed.slice(end)
+        }
+        fixes.push(
+            `Removed foreign tags: ${Array.from(foreignTags).join(", ")}`,
+        )
+    }
+
     // 10. Fix unclosed tags by appending missing closing tags
     // Use parseXmlTags helper to track open tags
     const tagStack: string[] = []
@@ -1160,6 +1284,7 @@ export function autoFixXml(xml: string): { fixed: string; fixes: string[] } {
 
     // 10b. Remove extra closing tags (more closes than opens)
     // Need to properly count self-closing tags (they don't need closing tags)
+    // IMPORTANT: Only count tags at element level, NOT inside quoted attribute values
     const tagCounts = new Map<
         string,
         { opens: number; closes: number; selfClosing: number }
@@ -1168,12 +1293,18 @@ export function autoFixXml(xml: string): { fixed: string; fixes: string[] } {
     const fullTagPattern = /<(\/?[a-zA-Z][a-zA-Z0-9]*)[^>]*>/g
     let tagCountMatch
     while ((tagCountMatch = fullTagPattern.exec(fixed)) !== null) {
+        // Skip tags inside quoted attribute values (e.g., value="<b>Title</b>")
+        if (isInsideQuotes(fixed, tagCountMatch.index)) continue
+
         const fullMatch = tagCountMatch[0] // e.g., "<mxCell .../>" or "</mxCell>"
         const tagPart = tagCountMatch[1] // e.g., "mxCell" or "/mxCell"
         const isClosing = tagPart.startsWith("/")
         const isSelfClosing = fullMatch.endsWith("/>")
         const tagName = isClosing ? tagPart.slice(1) : tagPart
 
+        // Only count valid draw.io tags - skip partial/invalid tags like "mx" from streaming
+        if (!validDrawioTags.has(tagName)) continue
+
         let counts = tagCounts.get(tagName)
         if (!counts) {
             counts = { opens: 0, closes: 0, selfClosing: 0 }

next.config.ts

@@ -1,8 +1,19 @@
 import type { NextConfig } from "next"
+import packageJson from "./package.json"
 
 const nextConfig: NextConfig = {
     /* config options here */
     output: "standalone",
+    // Support for subdirectory deployment (e.g., https://example.com/nextaidrawio)
+    // Set NEXT_PUBLIC_BASE_PATH environment variable to your subdirectory path (e.g., /nextaidrawio)
+    basePath: process.env.NEXT_PUBLIC_BASE_PATH || "",
+    env: {
+        APP_VERSION: packageJson.version,
+    },
+    // Include instrumentation.ts in standalone build for Langfuse telemetry
+    outputFileTracingIncludes: {
+        "*": ["./instrumentation.ts"],
+    },
 }
 
 export default nextConfig

package.json

@@ -1,8 +1,9 @@
 {
     "name": "next-ai-draw-io",
-    "version": "0.4.3",
+    "version": "0.4.6",
     "license": "Apache-2.0",
     "private": true,
+    "main": "dist-electron/main/index.js",
     "scripts": {
         "dev": "next dev --turbopack --port 6002",
         "build": "next build",
@@ -10,40 +11,54 @@
         "lint": "biome lint .",
         "format": "biome check --write .",
         "check": "biome ci",
-        "prepare": "husky"
+        "prepare": "husky",
+        "electron:dev": "node scripts/electron-dev.mjs",
+        "electron:build": "npm run build && npm run electron:compile",
+        "electron:compile": "npx esbuild electron/main/index.ts electron/preload/index.ts electron/preload/settings.ts --bundle --platform=node --outdir=dist-electron --external:electron --sourcemap --packages=external && npx shx cp -r electron/settings dist-electron/",
+        "electron:start": "npx cross-env NODE_ENV=development npx electron .",
+        "electron:prepare": "node scripts/prepare-electron-build.mjs",
+        "dist": "npm run electron:build && npm run electron:prepare && npx electron-builder",
+        "dist:mac": "npm run electron:build && npm run electron:prepare && npx electron-builder --mac",
+        "dist:win": "npm run electron:build && npm run electron:prepare && npx electron-builder --win",
+        "dist:linux": "npm run electron:build && npm run electron:prepare && npx electron-builder --linux",
+        "dist:all": "npm run electron:build && npm run electron:prepare && npx electron-builder --mac --win --linux"
     },
     "dependencies": {
-        "@ai-sdk/amazon-bedrock": "^3.0.70",
-        "@ai-sdk/anthropic": "^2.0.44",
-        "@ai-sdk/azure": "^2.0.69",
-        "@ai-sdk/deepseek": "^1.0.30",
-        "@ai-sdk/gateway": "^2.0.21",
-        "@ai-sdk/google": "^2.0.0",
-        "@ai-sdk/openai": "^2.0.19",
-        "@ai-sdk/react": "^2.0.107",
+        "@ai-sdk/amazon-bedrock": "^4.0.1",
+        "@ai-sdk/anthropic": "^3.0.0",
+        "@ai-sdk/azure": "^3.0.0",
+        "@ai-sdk/deepseek": "^2.0.0",
+        "@ai-sdk/gateway": "^3.0.0",
+        "@ai-sdk/google": "^3.0.0",
+        "@ai-sdk/openai": "^3.0.0",
+        "@ai-sdk/react": "^3.0.1",
+        "@aws-sdk/client-dynamodb": "^3.957.0",
         "@aws-sdk/credential-providers": "^3.943.0",
         "@formatjs/intl-localematcher": "^0.7.2",
         "@langfuse/client": "^4.4.9",
         "@langfuse/otel": "^4.4.4",
         "@langfuse/tracing": "^4.4.9",
         "@next/third-parties": "^16.0.6",
-        "@openrouter/ai-sdk-provider": "^1.2.3",
+        "@openrouter/ai-sdk-provider": "^1.5.4",
         "@opentelemetry/exporter-trace-otlp-http": "^0.208.0",
         "@opentelemetry/sdk-trace-node": "^2.2.0",
+        "@radix-ui/react-alert-dialog": "^1.1.15",
         "@radix-ui/react-collapsible": "^1.1.12",
-        "@radix-ui/react-dialog": "^1.1.6",
+        "@radix-ui/react-dialog": "^1.1.15",
         "@radix-ui/react-label": "^2.1.8",
+        "@radix-ui/react-popover": "^1.1.15",
         "@radix-ui/react-scroll-area": "^1.2.3",
         "@radix-ui/react-select": "^2.2.6",
-        "@radix-ui/react-slot": "^1.1.2",
+        "@radix-ui/react-slot": "^1.2.4",
         "@radix-ui/react-switch": "^1.2.6",
         "@radix-ui/react-tooltip": "^1.1.8",
         "@radix-ui/react-use-controllable-state": "^1.2.2",
         "@xmldom/xmldom": "^0.9.8",
-        "ai": "^5.0.89",
+        "ai": "^6.0.1",
         "base-64": "^1.0.0",
         "class-variance-authority": "^0.7.1",
         "clsx": "^2.1.1",
+        "cmdk": "^1.1.1",
         "js-tiktoken": "^1.0.21",
         "jsdom": "^26.0.0",
         "jsonrepair": "^3.13.1",
@@ -76,7 +91,7 @@
     },
     "devDependencies": {
         "@anthropic-ai/tokenizer": "^0.0.4",
-        "@biomejs/biome": "^2.3.8",
+        "@biomejs/biome": "^2.3.10",
         "@tailwindcss/postcss": "^4",
         "@tailwindcss/typography": "^0.5.19",
         "@types/negotiator": "^0.6.4",
@@ -84,11 +99,23 @@
         "@types/pako": "^2.0.3",
         "@types/react": "^19",
         "@types/react-dom": "^19",
+        "concurrently": "^9.2.1",
+        "cross-env": "^10.1.0",
+        "electron": "^39.2.7",
+        "electron-builder": "^26.0.12",
+        "esbuild": "^0.27.2",
         "eslint": "9.39.1",
         "eslint-config-next": "16.0.5",
         "husky": "^9.1.7",
         "lint-staged": "^16.2.7",
+        "shx": "^0.4.0",
         "tailwindcss": "^4",
-        "typescript": "^5"
+        "typescript": "^5",
+        "wait-on": "^9.0.3"
+    },
+    "overrides": {
+        "@openrouter/ai-sdk-provider": {
+            "ai": "^6.0.1"
+        }
     }
 }

packages/mcp-server/README.md

@@ -86,6 +86,7 @@ Use the standard MCP configuration with:
 ## Features
 
 - **Real-time Preview**: Diagrams appear and update in your browser as the AI creates them
+- **Version History**: Restore previous diagram versions with visual thumbnails - click the clock button (bottom-right) to browse and restore earlier states
 - **Natural Language**: Describe diagrams in plain text - flowcharts, architecture diagrams, etc.
 - **Edit Support**: Modify existing diagrams with natural language instructions
 - **Export**: Save diagrams as `.drawio` files

packages/mcp-server/package-lock.json

@@ -1,12 +1,12 @@
 {
     "name": "@next-ai-drawio/mcp-server",
-    "version": "0.1.0",
+    "version": "0.1.5",
     "lockfileVersion": 3,
     "requires": true,
     "packages": {
         "": {
             "name": "@next-ai-drawio/mcp-server",
-            "version": "0.1.0",
+            "version": "0.1.5",
             "license": "Apache-2.0",
             "dependencies": {
                 "@modelcontextprotocol/sdk": "^1.0.4",

packages/mcp-server/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@next-ai-drawio/mcp-server",
-    "version": "0.1.2",
+    "version": "0.1.6",
     "description": "MCP server for Next AI Draw.io - AI-powered diagram generation with real-time browser preview",
     "type": "module",
     "main": "dist/index.js",

packages/mcp-server/src/diagram-operations.ts

@@ -4,7 +4,7 @@
  */
 
 export interface DiagramOperation {
-    type: "update" | "add" | "delete"
+    operation: "update" | "add" | "delete"
     cell_id: string
     new_xml?: string
 }
@@ -77,7 +77,7 @@ export function applyDiagramOperations(
 
     // Process each operation
     for (const op of operations) {
-        if (op.type === "update") {
+        if (op.operation === "update") {
             const existingCell = cellMap.get(op.cell_id)
             if (!existingCell) {
                 errors.push({
@@ -129,7 +129,7 @@ export function applyDiagramOperations(
 
             // Update the map with the new element
             cellMap.set(op.cell_id, importedNode)
-        } else if (op.type === "add") {
+        } else if (op.operation === "add") {
             // Check if ID already exists
             if (cellMap.has(op.cell_id)) {
                 errors.push({
@@ -181,7 +181,7 @@ export function applyDiagramOperations(
 
             // Add to map
             cellMap.set(op.cell_id, importedNode)
-        } else if (op.type === "delete") {
+        } else if (op.operation === "delete") {
             const existingCell = cellMap.get(op.cell_id)
             if (!existingCell) {
                 errors.push({

packages/mcp-server/src/history.ts

@@ -0,0 +1,62 @@
+/**
+ * Simple diagram history - matches Next.js app pattern
+ * Stores {xml, svg} entries in a circular buffer
+ */
+
+import { log } from "./logger.js"
+
+const MAX_HISTORY = 20
+const historyStore = new Map<string, Array<{ xml: string; svg: string }>>()
+
+export function addHistory(sessionId: string, xml: string, svg = ""): number {
+    let history = historyStore.get(sessionId)
+    if (!history) {
+        history = []
+        historyStore.set(sessionId, history)
+    }
+
+    // Dedupe: skip if same as last entry
+    const last = history[history.length - 1]
+    if (last?.xml === xml) {
+        return history.length - 1
+    }
+
+    history.push({ xml, svg })
+
+    // Circular buffer
+    if (history.length > MAX_HISTORY) {
+        history.shift()
+    }
+
+    log.debug(`History: session=${sessionId}, entries=${history.length}`)
+    return history.length - 1
+}
+
+export function getHistory(
+    sessionId: string,
+): Array<{ xml: string; svg: string }> {
+    return historyStore.get(sessionId) || []
+}
+
+export function getHistoryEntry(
+    sessionId: string,
+    index: number,
+): { xml: string; svg: string } | undefined {
+    const history = historyStore.get(sessionId)
+    return history?.[index]
+}
+
+export function clearHistory(sessionId: string): void {
+    historyStore.delete(sessionId)
+}
+
+export function updateLastHistorySvg(sessionId: string, svg: string): boolean {
+    const history = historyStore.get(sessionId)
+    if (!history || history.length === 0) return false
+    const last = history[history.length - 1]
+    if (!last.svg) {
+        last.svg = svg
+        return true
+    }
+    return false
+}

packages/mcp-server/src/http-server.ts

@@ -1,55 +1,77 @@
 /**
  * Embedded HTTP Server for MCP
- *
- * Serves a static HTML page with draw.io embed and handles state sync.
- * This eliminates the need for an external Next.js app.
+ * Serves draw.io embed with state sync and history UI
  */
 
 import http from "node:http"
+import {
+    addHistory,
+    clearHistory,
+    getHistory,
+    getHistoryEntry,
+    updateLastHistorySvg,
+} from "./history.js"
 import { log } from "./logger.js"
 
 interface SessionState {
     xml: string
     version: number
     lastUpdated: Date
+    svg?: string // Cached SVG from last browser save
+    syncRequested?: number // Timestamp when sync requested, cleared when browser responds
 }
 
-// In-memory state store (shared with MCP server in same process)
 export const stateStore = new Map<string, SessionState>()
 
 let server: http.Server | null = null
-let serverPort: number = 6002
-const MAX_PORT = 6020 // Don't retry beyond this port
-const SESSION_TTL = 60 * 60 * 1000 // 1 hour
+let serverPort = 6002
+const MAX_PORT = 6020
+const SESSION_TTL = 60 * 60 * 1000
 
-/**
- * Get state for a session
- */
 export function getState(sessionId: string): SessionState | undefined {
     return stateStore.get(sessionId)
 }
 
-/**
- * Set state for a session
- */
-export function setState(sessionId: string, xml: string): number {
+export function setState(sessionId: string, xml: string, svg?: string): number {
     const existing = stateStore.get(sessionId)
     const newVersion = (existing?.version || 0) + 1
-
     stateStore.set(sessionId, {
         xml,
         version: newVersion,
         lastUpdated: new Date(),
+        svg: svg || existing?.svg, // Preserve cached SVG if not provided
+        syncRequested: undefined, // Clear sync request when browser pushes state
     })
-
     log.debug(`State updated: session=${sessionId}, version=${newVersion}`)
     return newVersion
 }
 
-/**
- * Start the embedded HTTP server
- */
-export function startHttpServer(port: number = 6002): Promise<number> {
+export function requestSync(sessionId: string): boolean {
+    const state = stateStore.get(sessionId)
+    if (state) {
+        state.syncRequested = Date.now()
+        log.debug(`Sync requested for session=${sessionId}`)
+        return true
+    }
+    log.debug(`Sync requested for non-existent session=${sessionId}`)
+    return false
+}
+
+export async function waitForSync(
+    sessionId: string,
+    timeoutMs = 3000,
+): Promise<boolean> {
+    const start = Date.now()
+    while (Date.now() - start < timeoutMs) {
+        const state = stateStore.get(sessionId)
+        if (!state?.syncRequested) return true // Sync completed
+        await new Promise((r) => setTimeout(r, 100))
+    }
+    log.warn(`Sync timeout for session=${sessionId}`)
+    return false // Timeout
+}
+
+export function startHttpServer(port = 6002): Promise<number> {
     return new Promise((resolve, reject) => {
         if (server) {
             resolve(serverPort)
@@ -81,15 +103,12 @@ export function startHttpServer(port: number = 6002): Promise<number> {
 
         server.listen(port, () => {
             serverPort = port
-            log.info(`Embedded HTTP server running on http://localhost:${port}`)
+            log.info(`HTTP server running on http://localhost:${port}`)
             resolve(port)
         })
     })
 }
 
-/**
- * Stop the HTTP server
- */
 export function stopHttpServer(): void {
     if (server) {
         server.close()
@@ -97,39 +116,29 @@ export function stopHttpServer(): void {
     }
 }
 
-/**
- * Clean up expired sessions
- */
 function cleanupExpiredSessions(): void {
     const now = Date.now()
     for (const [sessionId, state] of stateStore) {
         if (now - state.lastUpdated.getTime() > SESSION_TTL) {
             stateStore.delete(sessionId)
+            clearHistory(sessionId)
             log.info(`Cleaned up expired session: ${sessionId}`)
         }
     }
 }
 
-// Run cleanup every 5 minutes
 setInterval(cleanupExpiredSessions, 5 * 60 * 1000)
 
-/**
- * Get the current server port
- */
 export function getServerPort(): number {
     return serverPort
 }
 
-/**
- * Handle HTTP requests
- */
 function handleRequest(
     req: http.IncomingMessage,
     res: http.ServerResponse,
 ): void {
     const url = new URL(req.url || "/", `http://localhost:${serverPort}`)
 
-    // CORS headers for local development
     res.setHeader("Access-Control-Allow-Origin", "*")
     res.setHeader("Access-Control-Allow-Methods", "GET, POST, OPTIONS")
     res.setHeader("Access-Control-Allow-Headers", "Content-Type")
@@ -140,43 +149,23 @@ function handleRequest(
         return
     }
 
-    // Route handling
     if (url.pathname === "/" || url.pathname === "/index.html") {
-        serveHtml(req, res, url)
-    } else if (
-        url.pathname === "/api/state" ||
-        url.pathname === "/api/mcp/state"
-    ) {
+        res.writeHead(200, { "Content-Type": "text/html" })
+        res.end(getHtmlPage(url.searchParams.get("mcp") || ""))
+    } else if (url.pathname === "/api/state") {
         handleStateApi(req, res, url)
-    } else if (
-        url.pathname === "/api/health" ||
-        url.pathname === "/api/mcp/health"
-    ) {
-        res.writeHead(200, { "Content-Type": "application/json" })
-        res.end(JSON.stringify({ status: "ok", mcp: true }))
+    } else if (url.pathname === "/api/history") {
+        handleHistoryApi(req, res, url)
+    } else if (url.pathname === "/api/restore") {
+        handleRestoreApi(req, res)
+    } else if (url.pathname === "/api/history-svg") {
+        handleHistorySvgApi(req, res)
     } else {
         res.writeHead(404)
         res.end("Not Found")
     }
 }
 
-/**
- * Serve the HTML page with draw.io embed
- */
-function serveHtml(
-    req: http.IncomingMessage,
-    res: http.ServerResponse,
-    url: URL,
-): void {
-    const sessionId = url.searchParams.get("mcp") || ""
-
-    res.writeHead(200, { "Content-Type": "text/html" })
-    res.end(getHtmlPage(sessionId))
-}
-
-/**
- * Handle state API requests
- */
 function handleStateApi(
     req: http.IncomingMessage,
     res: http.ServerResponse,
@@ -189,14 +178,13 @@ function handleStateApi(
             res.end(JSON.stringify({ error: "sessionId required" }))
             return
         }
-
         const state = stateStore.get(sessionId)
         res.writeHead(200, { "Content-Type": "application/json" })
         res.end(
             JSON.stringify({
                 xml: state?.xml || null,
                 version: state?.version || 0,
-                lastUpdated: state?.lastUpdated?.toISOString() || null,
+                syncRequested: !!state?.syncRequested,
             }),
         )
     } else if (req.method === "POST") {
@@ -206,14 +194,13 @@ function handleStateApi(
         })
         req.on("end", () => {
             try {
-                const { sessionId, xml } = JSON.parse(body)
+                const { sessionId, xml, svg } = JSON.parse(body)
                 if (!sessionId) {
                     res.writeHead(400, { "Content-Type": "application/json" })
                     res.end(JSON.stringify({ error: "sessionId required" }))
                     return
                 }
-
-                const version = setState(sessionId, xml)
+                const version = setState(sessionId, xml, svg)
                 res.writeHead(200, { "Content-Type": "application/json" })
                 res.end(JSON.stringify({ success: true, version }))
             } catch {
@@ -227,35 +214,179 @@ function handleStateApi(
     }
 }
 
-/**
- * Generate the HTML page with draw.io embed
- */
+function handleHistoryApi(
+    req: http.IncomingMessage,
+    res: http.ServerResponse,
+    url: URL,
+): void {
+    if (req.method !== "GET") {
+        res.writeHead(405)
+        res.end("Method Not Allowed")
+        return
+    }
+
+    const sessionId = url.searchParams.get("sessionId")
+    if (!sessionId) {
+        res.writeHead(400, { "Content-Type": "application/json" })
+        res.end(JSON.stringify({ error: "sessionId required" }))
+        return
+    }
+
+    const history = getHistory(sessionId)
+    res.writeHead(200, { "Content-Type": "application/json" })
+    res.end(
+        JSON.stringify({
+            entries: history.map((entry, i) => ({ index: i, svg: entry.svg })),
+            count: history.length,
+        }),
+    )
+}
+
+function handleRestoreApi(
+    req: http.IncomingMessage,
+    res: http.ServerResponse,
+): void {
+    if (req.method !== "POST") {
+        res.writeHead(405)
+        res.end("Method Not Allowed")
+        return
+    }
+
+    let body = ""
+    req.on("data", (chunk) => {
+        body += chunk
+    })
+    req.on("end", () => {
+        try {
+            const { sessionId, index } = JSON.parse(body)
+            if (!sessionId || index === undefined) {
+                res.writeHead(400, { "Content-Type": "application/json" })
+                res.end(
+                    JSON.stringify({ error: "sessionId and index required" }),
+                )
+                return
+            }
+
+            const entry = getHistoryEntry(sessionId, index)
+            if (!entry) {
+                res.writeHead(404, { "Content-Type": "application/json" })
+                res.end(JSON.stringify({ error: "Entry not found" }))
+                return
+            }
+
+            const newVersion = setState(sessionId, entry.xml)
+            addHistory(sessionId, entry.xml, entry.svg)
+
+            log.info(`Restored session ${sessionId} to index ${index}`)
+
+            res.writeHead(200, { "Content-Type": "application/json" })
+            res.end(JSON.stringify({ success: true, newVersion }))
+        } catch {
+            res.writeHead(400, { "Content-Type": "application/json" })
+            res.end(JSON.stringify({ error: "Invalid JSON" }))
+        }
+    })
+}
+
+function handleHistorySvgApi(
+    req: http.IncomingMessage,
+    res: http.ServerResponse,
+): void {
+    if (req.method !== "POST") {
+        res.writeHead(405)
+        res.end("Method Not Allowed")
+        return
+    }
+
+    let body = ""
+    req.on("data", (chunk) => {
+        body += chunk
+    })
+    req.on("end", () => {
+        try {
+            const { sessionId, svg } = JSON.parse(body)
+            if (!sessionId || !svg) {
+                res.writeHead(400, { "Content-Type": "application/json" })
+                res.end(JSON.stringify({ error: "sessionId and svg required" }))
+                return
+            }
+
+            updateLastHistorySvg(sessionId, svg)
+            res.writeHead(200, { "Content-Type": "application/json" })
+            res.end(JSON.stringify({ success: true }))
+        } catch {
+            res.writeHead(400, { "Content-Type": "application/json" })
+            res.end(JSON.stringify({ error: "Invalid JSON" }))
+        }
+    })
+}
+
 function getHtmlPage(sessionId: string): string {
     return `<!DOCTYPE html>
 <html lang="en">
 <head>
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
-    <title>Draw.io MCP - ${sessionId || "No Session"}</title>
+    <title>Draw.io MCP</title>
     <style>
         * { margin: 0; padding: 0; box-sizing: border-box; }
         html, body { width: 100%; height: 100%; overflow: hidden; }
         #container { width: 100%; height: 100%; display: flex; flex-direction: column; }
         #header {
-            padding: 8px 16px;
-            background: #1a1a2e;
-            color: #eee;
-            font-family: system-ui, sans-serif;
-            font-size: 14px;
-            display: flex;
-            justify-content: space-between;
-            align-items: center;
+            padding: 8px 16px; background: #1a1a2e; color: #eee;
+            font-family: system-ui, sans-serif; font-size: 14px;
+            display: flex; justify-content: space-between; align-items: center;
         }
         #header .session { color: #888; font-size: 12px; }
         #header .status { font-size: 12px; }
         #header .status.connected { color: #4ade80; }
         #header .status.disconnected { color: #f87171; }
         #drawio { flex: 1; border: none; }
+        #history-btn {
+            position: fixed; bottom: 24px; right: 24px;
+            width: 48px; height: 48px; border-radius: 50%;
+            background: #3b82f6; color: white; border: none; cursor: pointer;
+            box-shadow: 0 4px 12px rgba(0,0,0,0.3);
+            display: flex; align-items: center; justify-content: center;
+            z-index: 1000;
+        }
+        #history-btn:hover { background: #2563eb; }
+        #history-btn:disabled { background: #6b7280; cursor: not-allowed; }
+        #history-btn svg { width: 24px; height: 24px; }
+        #history-modal {
+            display: none; position: fixed; inset: 0;
+            background: rgba(0,0,0,0.5); z-index: 2000;
+            align-items: center; justify-content: center;
+        }
+        #history-modal.open { display: flex; }
+        .modal-content {
+            background: white; border-radius: 12px;
+            width: 90%; max-width: 500px; max-height: 70vh;
+            display: flex; flex-direction: column;
+        }
+        .modal-header { padding: 16px; border-bottom: 1px solid #e5e7eb; }
+        .modal-header h2 { font-size: 18px; margin: 0; }
+        .modal-body { flex: 1; overflow-y: auto; padding: 16px; }
+        .modal-footer { padding: 12px 16px; border-top: 1px solid #e5e7eb; display: flex; gap: 8px; justify-content: flex-end; }
+        .history-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; }
+        .history-item {
+            border: 2px solid #e5e7eb; border-radius: 8px; padding: 8px;
+            cursor: pointer; text-align: center;
+        }
+        .history-item:hover { border-color: #3b82f6; }
+        .history-item.selected { border-color: #3b82f6; box-shadow: 0 0 0 3px rgba(59,130,246,0.3); }
+        .history-item .thumb {
+            aspect-ratio: 4/3; background: #f3f4f6; border-radius: 4px;
+            display: flex; align-items: center; justify-content: center;
+            margin-bottom: 4px; overflow: hidden;
+        }
+        .history-item .thumb img { max-width: 100%; max-height: 100%; object-fit: contain; }
+        .history-item .label { font-size: 12px; color: #666; }
+        .btn { padding: 8px 16px; border-radius: 6px; font-size: 14px; cursor: pointer; border: none; }
+        .btn-primary { background: #3b82f6; color: white; }
+        .btn-primary:disabled { background: #93c5fd; cursor: not-allowed; }
+        .btn-secondary { background: #f3f4f6; color: #374151; }
+        .empty { text-align: center; padding: 40px; color: #666; }
     </style>
 </head>
 <body>
@@ -263,121 +394,191 @@ function getHtmlPage(sessionId: string): string {
         <div id="header">
             <div>
                 <strong>Draw.io MCP</strong>
-                <span class="session">${sessionId ? `Session: ${sessionId}` : "No MCP session"}</span>
+                <span class="session">${sessionId ? `Session: ${sessionId}` : "No session"}</span>
             </div>
             <div id="status" class="status disconnected">Connecting...</div>
         </div>
         <iframe id="drawio" src="https://embed.diagrams.net/?embed=1&proto=json&spin=1&libraries=1"></iframe>
     </div>
-
+    <button id="history-btn" title="History" ${sessionId ? "" : "disabled"}>
+        <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+            <circle cx="12" cy="12" r="10"></circle>
+            <polyline points="12 6 12 12 16 14"></polyline>
+        </svg>
+    </button>
+    <div id="history-modal">
+        <div class="modal-content">
+            <div class="modal-header"><h2>History</h2></div>
+            <div class="modal-body">
+                <div id="history-grid" class="history-grid"></div>
+                <div id="history-empty" class="empty" style="display:none;">No history yet</div>
+            </div>
+            <div class="modal-footer">
+                <button class="btn btn-secondary" id="cancel-btn">Cancel</button>
+                <button class="btn btn-primary" id="restore-btn" disabled>Restore</button>
+            </div>
+        </div>
+    </div>
     <script>
         const sessionId = "${sessionId}";
         const iframe = document.getElementById('drawio');
         const statusEl = document.getElementById('status');
+        let currentVersion = 0, isReady = false, pendingXml = null, lastXml = null;
+        let pendingSvgExport = null;
+        let pendingAiSvg = false;
 
-        let currentVersion = 0;
-        let isDrawioReady = false;
-        let pendingXml = null;
-        let lastLoadedXml = null;
-
-        // Listen for messages from draw.io
-        window.addEventListener('message', (event) => {
-            if (event.origin !== 'https://embed.diagrams.net') return;
-
+        window.addEventListener('message', (e) => {
+            if (e.origin !== 'https://embed.diagrams.net') return;
             try {
-                const msg = JSON.parse(event.data);
-                handleDrawioMessage(msg);
-            } catch (e) {
-                // Ignore non-JSON messages
-            }
+                const msg = JSON.parse(e.data);
+                if (msg.event === 'init') {
+                    isReady = true;
+                    statusEl.textContent = 'Ready';
+                    statusEl.className = 'status connected';
+                    if (pendingXml) { loadDiagram(pendingXml); pendingXml = null; }
+                } else if ((msg.event === 'save' || msg.event === 'autosave') && msg.xml && msg.xml !== lastXml) {
+                    // Request SVG export, then push state with SVG
+                    pendingSvgExport = msg.xml;
+                    iframe.contentWindow.postMessage(JSON.stringify({ action: 'export', format: 'svg' }), '*');
+                    // Fallback if export doesn't respond
+                    setTimeout(() => { if (pendingSvgExport === msg.xml) { pushState(msg.xml, ''); pendingSvgExport = null; } }, 2000);
+                } else if (msg.event === 'export' && msg.data) {
+                    // Handle sync export (XML format) - server requested fresh state
+                    if (pendingSyncExport && !msg.data.startsWith('data:') && !msg.data.startsWith('<svg')) {
+                        pendingSyncExport = false;
+                        pushState(msg.data, '');
+                        return;
+                    }
+                    // Handle SVG export
+                    let svg = msg.data;
+                    if (!svg.startsWith('data:')) svg = 'data:image/svg+xml;base64,' + btoa(unescape(encodeURIComponent(svg)));
+                    if (pendingSvgExport) {
+                        const xml = pendingSvgExport;
+                        pendingSvgExport = null;
+                        pushState(xml, svg);
+                    } else if (pendingAiSvg) {
+                        pendingAiSvg = false;
+                        fetch('/api/history-svg', {
+                            method: 'POST',
+                            headers: { 'Content-Type': 'application/json' },
+                            body: JSON.stringify({ sessionId, svg })
+                        }).catch(() => {});
+                    }
+                }
+            } catch {}
         });
 
-        function handleDrawioMessage(msg) {
-            if (msg.event === 'init') {
-                isDrawioReady = true;
-                statusEl.textContent = 'Ready';
-                statusEl.className = 'status connected';
-
-                // Load pending XML if any
-                if (pendingXml) {
-                    loadDiagram(pendingXml);
-                    pendingXml = null;
-                }
-            } else if (msg.event === 'save') {
-                // User saved - push to state
-                if (msg.xml && msg.xml !== lastLoadedXml) {
-                    pushState(msg.xml);
-                }
-            } else if (msg.event === 'export') {
-                // Export completed
-                if (msg.data) {
-                    pushState(msg.data);
-                }
-            } else if (msg.event === 'autosave') {
-                // Autosave - push to state
-                if (msg.xml && msg.xml !== lastLoadedXml) {
-                    pushState(msg.xml);
-                }
+        function loadDiagram(xml, capturePreview = false) {
+            if (!isReady) { pendingXml = xml; return; }
+            lastXml = xml;
+            iframe.contentWindow.postMessage(JSON.stringify({ action: 'load', xml, autosave: 1 }), '*');
+            if (capturePreview) {
+                setTimeout(() => {
+                    pendingAiSvg = true;
+                    iframe.contentWindow.postMessage(JSON.stringify({ action: 'export', format: 'svg' }), '*');
+                }, 500);
             }
         }
 
-        function loadDiagram(xml) {
-            if (!isDrawioReady) {
-                pendingXml = xml;
-                return;
-            }
-
-            lastLoadedXml = xml;
-            iframe.contentWindow.postMessage(JSON.stringify({
-                action: 'load',
-                xml: xml,
-                autosave: 1
-            }), '*');
-        }
-
-        async function pushState(xml) {
+        async function pushState(xml, svg = '') {
             if (!sessionId) return;
-
             try {
-                const response = await fetch('/api/state', {
+                const r = await fetch('/api/state', {
                     method: 'POST',
                     headers: { 'Content-Type': 'application/json' },
-                    body: JSON.stringify({ sessionId, xml })
+                    body: JSON.stringify({ sessionId, xml, svg })
                 });
-
-                if (response.ok) {
-                    const result = await response.json();
-                    currentVersion = result.version;
-                    lastLoadedXml = xml;
-                }
-            } catch (e) {
-                console.error('Failed to push state:', e);
-            }
+                if (r.ok) { const d = await r.json(); currentVersion = d.version; lastXml = xml; }
+            } catch (e) { console.error('Push failed:', e); }
         }
 
-        async function pollState() {
+        let pendingSyncExport = false;
+
+        async function poll() {
             if (!sessionId) return;
-
             try {
-                const response = await fetch('/api/state?sessionId=' + encodeURIComponent(sessionId));
-                if (!response.ok) return;
-
-                const state = await response.json();
-
-                if (state.version && state.version > currentVersion && state.xml) {
-                    currentVersion = state.version;
-                    loadDiagram(state.xml);
+                const r = await fetch('/api/state?sessionId=' + encodeURIComponent(sessionId));
+                if (!r.ok) return;
+                const s = await r.json();
+                // Handle sync request - server needs fresh state
+                if (s.syncRequested && !pendingSyncExport) {
+                    pendingSyncExport = true;
+                    iframe.contentWindow.postMessage(JSON.stringify({ action: 'export', format: 'xml' }), '*');
                 }
-            } catch (e) {
-                console.error('Failed to poll state:', e);
-            }
+                // Load new diagram from server
+                if (s.version > currentVersion && s.xml) {
+                    currentVersion = s.version;
+                    loadDiagram(s.xml, true);
+                }
+            } catch {}
         }
 
-        // Start polling if we have a session
-        if (sessionId) {
-            pollState();
-            setInterval(pollState, 2000);
+        if (sessionId) { poll(); setInterval(poll, 2000); }
+
+        // History UI
+        const historyBtn = document.getElementById('history-btn');
+        const historyModal = document.getElementById('history-modal');
+        const historyGrid = document.getElementById('history-grid');
+        const historyEmpty = document.getElementById('history-empty');
+        const restoreBtn = document.getElementById('restore-btn');
+        const cancelBtn = document.getElementById('cancel-btn');
+        let historyData = [], selectedIdx = null;
+
+        historyBtn.onclick = async () => {
+            if (!sessionId) return;
+            try {
+                const r = await fetch('/api/history?sessionId=' + encodeURIComponent(sessionId));
+                if (r.ok) {
+                    const d = await r.json();
+                    historyData = d.entries || [];
+                    renderHistory();
+                }
+            } catch {}
+            historyModal.classList.add('open');
+        };
+
+        cancelBtn.onclick = () => { historyModal.classList.remove('open'); selectedIdx = null; restoreBtn.disabled = true; };
+        historyModal.onclick = (e) => { if (e.target === historyModal) cancelBtn.onclick(); };
+
+        function renderHistory() {
+            if (historyData.length === 0) {
+                historyGrid.style.display = 'none';
+                historyEmpty.style.display = 'block';
+                return;
+            }
+            historyGrid.style.display = 'grid';
+            historyEmpty.style.display = 'none';
+            historyGrid.innerHTML = historyData.map((e, i) => \`
+                <div class="history-item" data-idx="\${e.index}">
+                    <div class="thumb">\${e.svg ? \`<img src="\${e.svg}">\` : '#' + e.index}</div>
+                    <div class="label">#\${e.index}</div>
+                </div>
+            \`).join('');
+            historyGrid.querySelectorAll('.history-item').forEach(item => {
+                item.onclick = () => {
+                    const idx = parseInt(item.dataset.idx);
+                    if (selectedIdx === idx) { selectedIdx = null; restoreBtn.disabled = true; }
+                    else { selectedIdx = idx; restoreBtn.disabled = false; }
+                    historyGrid.querySelectorAll('.history-item').forEach(el => el.classList.toggle('selected', parseInt(el.dataset.idx) === selectedIdx));
+                };
+            });
         }
+
+        restoreBtn.onclick = async () => {
+            if (selectedIdx === null) return;
+            restoreBtn.disabled = true;
+            restoreBtn.textContent = 'Restoring...';
+            try {
+                const r = await fetch('/api/restore', {
+                    method: 'POST',
+                    headers: { 'Content-Type': 'application/json' },
+                    body: JSON.stringify({ sessionId, index: selectedIdx })
+                });
+                if (r.ok) { cancelBtn.onclick(); await poll(); }
+                else { alert('Restore failed'); }
+            } catch { alert('Restore failed'); }
+            restoreBtn.textContent = 'Restore';
+        };
     </script>
 </body>
 </html>`

packages/mcp-server/src/index.ts

@@ -34,13 +34,16 @@ import {
     applyDiagramOperations,
     type DiagramOperation,
 } from "./diagram-operations.js"
+import { addHistory } from "./history.js"
 import {
-    getServerPort,
     getState,
+    requestSync,
     setState,
     startHttpServer,
+    waitForSync,
 } from "./http-server.js"
 import { log } from "./logger.js"
+import { validateAndFixXml } from "./xml-validation.js"
 
 // Server configuration
 const config = {
@@ -52,6 +55,7 @@ let currentSession: {
     id: string
     xml: string
     version: number
+    lastGetDiagramTime: number // Track when get_diagram was last called (for enforcing workflow)
 } | null = null
 
 // Create MCP server
@@ -117,6 +121,7 @@ server.registerTool(
                 id: sessionId,
                 xml: "",
                 version: 0,
+                lastGetDiagramTime: 0,
             }
 
             // Open browser
@@ -160,7 +165,7 @@ server.registerTool(
                 .describe("The draw.io XML to display (mxGraphModel format)"),
         },
     },
-    async ({ xml }) => {
+    async ({ xml: inputXml }) => {
         try {
             if (!currentSession) {
                 return {
@@ -174,8 +179,43 @@ server.registerTool(
                 }
             }
 
+            // Validate and auto-fix XML
+            let xml = inputXml
+            const { valid, error, fixed, fixes } = validateAndFixXml(xml)
+            if (fixed) {
+                xml = fixed
+                log.info(`XML auto-fixed: ${fixes.join(", ")}`)
+            }
+            if (!valid && error) {
+                log.error(`XML validation failed: ${error}`)
+                return {
+                    content: [
+                        {
+                            type: "text",
+                            text: `Error: XML validation failed - ${error}`,
+                        },
+                    ],
+                    isError: true,
+                }
+            }
+
             log.info(`Displaying diagram, ${xml.length} chars`)
 
+            // Sync from browser state first
+            const browserState = getState(currentSession.id)
+            if (browserState?.xml) {
+                currentSession.xml = browserState.xml
+            }
+
+            // Save user's state before AI overwrites (with cached SVG)
+            if (currentSession.xml) {
+                addHistory(
+                    currentSession.id,
+                    currentSession.xml,
+                    browserState?.svg || "",
+                )
+            }
+
             // Update session state
             currentSession.xml = xml
             currentSession.version++
@@ -183,6 +223,9 @@ server.registerTool(
             // Push to embedded server state
             setState(currentSession.id, xml)
 
+            // Save AI result (no SVG yet - will be captured by browser)
+            addHistory(currentSession.id, xml, "")
+
             log.info(`Diagram displayed successfully`)
 
             return {
@@ -210,23 +253,34 @@ server.registerTool(
     "edit_diagram",
     {
         description:
-            "Edit the current diagram by ID-based operations (update/add/delete cells). " +
-            "ALWAYS fetches the latest state from browser first, so user's manual changes are preserved.\n\n" +
-            "IMPORTANT workflow:\n" +
-            "- For ADD operations: Can use directly - just provide new unique cell_id and new_xml.\n" +
-            "- For UPDATE/DELETE: Call get_diagram FIRST to see current cell IDs, then edit.\n\n" +
+            "Edit the current diagram by ID-based operations (update/add/delete cells).\n\n" +
+            "⚠️ REQUIRED: You MUST call get_diagram BEFORE this tool!\n" +
+            "This fetches the latest state from the browser including any manual user edits.\n" +
+            "Skipping get_diagram WILL cause user's changes to be LOST.\n\n" +
+            "Workflow:\n" +
+            "1. Call get_diagram to see current cell IDs and structure\n" +
+            "2. Use the returned XML to construct your edit operations\n" +
+            "3. Call edit_diagram with your operations\n\n" +
             "Operations:\n" +
             "- add: Add a new cell. Provide cell_id (new unique id) and new_xml.\n" +
             "- update: Replace an existing cell by its id. Provide cell_id and complete new_xml.\n" +
             "- delete: Remove a cell by its id. Only cell_id is needed.\n\n" +
-            "For add/update, new_xml must be a complete mxCell element including mxGeometry.",
+            "For add/update, new_xml must be a complete mxCell element including mxGeometry.\n\n" +
+            "Example - Add a rectangle:\n" +
+            '{"operations": [{"operation": "add", "cell_id": "rect-1", "new_xml": "<mxCell id=\\"rect-1\\" value=\\"Hello\\" style=\\"rounded=0;\\" vertex=\\"1\\" parent=\\"1\\"><mxGeometry x=\\"100\\" y=\\"100\\" width=\\"120\\" height=\\"60\\" as=\\"geometry\\"/></mxCell>"}]}\n\n' +
+            "Example - Update a cell:\n" +
+            '{"operations": [{"operation": "update", "cell_id": "3", "new_xml": "<mxCell id=\\"3\\" value=\\"New Label\\" style=\\"rounded=1;\\" vertex=\\"1\\" parent=\\"1\\"><mxGeometry x=\\"100\\" y=\\"100\\" width=\\"120\\" height=\\"60\\" as=\\"geometry\\"/></mxCell>"}]}\n\n' +
+            "Example - Delete a cell:\n" +
+            '{"operations": [{"operation": "delete", "cell_id": "rect-1"}]}',
         inputSchema: {
             operations: z
                 .array(
                     z.object({
-                        type: z
+                        operation: z
                             .enum(["update", "add", "delete"])
-                            .describe("Operation type"),
+                            .describe(
+                                "Operation to perform: add, update, or delete",
+                            ),
                         cell_id: z.string().describe("The id of the mxCell"),
                         new_xml: z
                             .string()
@@ -253,6 +307,27 @@ server.registerTool(
                 }
             }
 
+            // Enforce workflow: require get_diagram to be called first
+            const timeSinceGet = Date.now() - currentSession.lastGetDiagramTime
+            if (timeSinceGet > 30000) {
+                // 30 seconds
+                log.warn(
+                    "edit_diagram called without recent get_diagram - rejecting to prevent data loss",
+                )
+                return {
+                    content: [
+                        {
+                            type: "text",
+                            text:
+                                "Error: You must call get_diagram first before edit_diagram.\n\n" +
+                                "This ensures you have the latest diagram state including any manual edits the user made in the browser. " +
+                                "Please call get_diagram, then use that XML to construct your edit operations.",
+                        },
+                    ],
+                    isError: true,
+                }
+            }
+
             // Fetch latest state from browser
             const browserState = getState(currentSession.id)
             if (browserState?.xml) {
@@ -274,10 +349,38 @@ server.registerTool(
 
             log.info(`Editing diagram with ${operations.length} operation(s)`)
 
+            // Save before editing (with cached SVG from browser)
+            addHistory(
+                currentSession.id,
+                currentSession.xml,
+                browserState?.svg || "",
+            )
+
+            // Validate and auto-fix new_xml for each operation
+            const validatedOps = operations.map((op) => {
+                if (op.new_xml) {
+                    const { valid, error, fixed, fixes } = validateAndFixXml(
+                        op.new_xml,
+                    )
+                    if (fixed) {
+                        log.info(
+                            `Operation ${op.operation} ${op.cell_id}: XML auto-fixed: ${fixes.join(", ")}`,
+                        )
+                        return { ...op, new_xml: fixed }
+                    }
+                    if (!valid && error) {
+                        log.warn(
+                            `Operation ${op.operation} ${op.cell_id}: XML validation failed: ${error}`,
+                        )
+                    }
+                }
+                return op
+            })
+
             // Apply operations
             const { result, errors } = applyDiagramOperations(
                 currentSession.xml,
-                operations as DiagramOperation[],
+                validatedOps as DiagramOperation[],
             )
 
             if (errors.length > 0) {
@@ -294,6 +397,9 @@ server.registerTool(
             // Push to embedded server
             setState(currentSession.id, result)
 
+            // Save AI result (no SVG yet - will be captured by browser)
+            addHistory(currentSession.id, result, "")
+
             log.info(`Diagram edited successfully`)
 
             const successMsg = `Diagram edited successfully!\n\nApplied ${operations.length} operation(s).`
@@ -345,6 +451,18 @@ server.registerTool(
                 }
             }
 
+            // Request browser to push fresh state and wait for it
+            const syncRequested = requestSync(currentSession.id)
+            if (syncRequested) {
+                const synced = await waitForSync(currentSession.id)
+                if (!synced) {
+                    log.warn("get_diagram: sync timeout - state may be stale")
+                }
+            }
+
+            // Mark that get_diagram was called (for edit_diagram workflow check)
+            currentSession.lastGetDiagramTime = Date.now()
+
             // Fetch latest state from browser
             const browserState = getState(currentSession.id)
             if (browserState?.xml) {

packages/mcp-server/src/xml-validation.ts

@@ -0,0 +1,933 @@
+/**
+ * XML Validation and Auto-Fix for draw.io diagrams
+ * Copied from lib/utils.ts to avoid cross-package imports
+ */
+
+// ============================================================================
+// Constants
+// ============================================================================
+
+/** Maximum XML size to process (1MB) - larger XMLs may cause performance issues */
+const MAX_XML_SIZE = 1_000_000
+
+/** Maximum iterations for aggressive cell dropping to prevent infinite loops */
+const MAX_DROP_ITERATIONS = 10
+
+/** Structural attributes that should not be duplicated in draw.io */
+const STRUCTURAL_ATTRS = [
+    "edge",
+    "parent",
+    "source",
+    "target",
+    "vertex",
+    "connectable",
+]
+
+/** Valid XML entity names */
+const VALID_ENTITIES = new Set(["lt", "gt", "amp", "quot", "apos"])
+
+// ============================================================================
+// XML Parsing Helpers
+// ============================================================================
+
+interface ParsedTag {
+    tag: string
+    tagName: string
+    isClosing: boolean
+    isSelfClosing: boolean
+    startIndex: number
+    endIndex: number
+}
+
+/**
+ * Parse XML tags while properly handling quoted strings
+ */
+function parseXmlTags(xml: string): ParsedTag[] {
+    const tags: ParsedTag[] = []
+    let i = 0
+
+    while (i < xml.length) {
+        const tagStart = xml.indexOf("<", i)
+        if (tagStart === -1) break
+
+        // Find matching > by tracking quotes
+        let tagEnd = tagStart + 1
+        let inQuote = false
+        let quoteChar = ""
+
+        while (tagEnd < xml.length) {
+            const c = xml[tagEnd]
+            if (inQuote) {
+                if (c === quoteChar) inQuote = false
+            } else {
+                if (c === '"' || c === "'") {
+                    inQuote = true
+                    quoteChar = c
+                } else if (c === ">") {
+                    break
+                }
+            }
+            tagEnd++
+        }
+
+        if (tagEnd >= xml.length) break
+
+        const tag = xml.substring(tagStart, tagEnd + 1)
+        i = tagEnd + 1
+
+        const tagMatch = /^<(\/?)([a-zA-Z][a-zA-Z0-9:_-]*)/.exec(tag)
+        if (!tagMatch) continue
+
+        tags.push({
+            tag,
+            tagName: tagMatch[2],
+            isClosing: tagMatch[1] === "/",
+            isSelfClosing: tag.endsWith("/>"),
+            startIndex: tagStart,
+            endIndex: tagEnd,
+        })
+    }
+
+    return tags
+}
+
+// ============================================================================
+// Validation Helper Functions
+// ============================================================================
+
+/** Check for duplicate structural attributes in a tag */
+function checkDuplicateAttributes(xml: string): string | null {
+    const structuralSet = new Set(STRUCTURAL_ATTRS)
+    const tagPattern = /<[^>]+>/g
+    let tagMatch
+    while ((tagMatch = tagPattern.exec(xml)) !== null) {
+        const tag = tagMatch[0]
+        const attrPattern = /\s([a-zA-Z_:][a-zA-Z0-9_:.-]*)\s*=/g
+        const attributes = new Map<string, number>()
+        let attrMatch
+        while ((attrMatch = attrPattern.exec(tag)) !== null) {
+            const attrName = attrMatch[1]
+            attributes.set(attrName, (attributes.get(attrName) || 0) + 1)
+        }
+        const duplicates = Array.from(attributes.entries())
+            .filter(([name, count]) => count > 1 && structuralSet.has(name))
+            .map(([name]) => name)
+        if (duplicates.length > 0) {
+            return `Invalid XML: Duplicate structural attribute(s): ${duplicates.join(", ")}. Remove duplicate attributes.`
+        }
+    }
+    return null
+}
+
+/** Check for duplicate IDs in XML */
+function checkDuplicateIds(xml: string): string | null {
+    const idPattern = /\bid\s*=\s*["']([^"']+)["']/gi
+    const ids = new Map<string, number>()
+    let idMatch
+    while ((idMatch = idPattern.exec(xml)) !== null) {
+        const id = idMatch[1]
+        ids.set(id, (ids.get(id) || 0) + 1)
+    }
+    const duplicateIds = Array.from(ids.entries())
+        .filter(([, count]) => count > 1)
+        .map(([id, count]) => `'${id}' (${count}x)`)
+    if (duplicateIds.length > 0) {
+        return `Invalid XML: Found duplicate ID(s): ${duplicateIds.slice(0, 3).join(", ")}. All id attributes must be unique.`
+    }
+    return null
+}
+
+/** Check for tag mismatches using parsed tags */
+function checkTagMismatches(xml: string): string | null {
+    const xmlWithoutComments = xml.replace(/<!--[\s\S]*?-->/g, "")
+    const tags = parseXmlTags(xmlWithoutComments)
+    const tagStack: string[] = []
+
+    for (const { tagName, isClosing, isSelfClosing } of tags) {
+        if (isClosing) {
+            if (tagStack.length === 0) {
+                return `Invalid XML: Closing tag </${tagName}> without matching opening tag`
+            }
+            const expected = tagStack.pop()
+            if (expected?.toLowerCase() !== tagName.toLowerCase()) {
+                return `Invalid XML: Expected closing tag </${expected}> but found </${tagName}>`
+            }
+        } else if (!isSelfClosing) {
+            tagStack.push(tagName)
+        }
+    }
+    if (tagStack.length > 0) {
+        return `Invalid XML: Document has ${tagStack.length} unclosed tag(s): ${tagStack.join(", ")}`
+    }
+    return null
+}
+
+/** Check for invalid character references */
+function checkCharacterReferences(xml: string): string | null {
+    const charRefPattern = /&#x?[^;]+;?/g
+    let charMatch
+    while ((charMatch = charRefPattern.exec(xml)) !== null) {
+        const ref = charMatch[0]
+        if (ref.startsWith("&#x")) {
+            if (!ref.endsWith(";")) {
+                return `Invalid XML: Missing semicolon after hex reference: ${ref}`
+            }
+            const hexDigits = ref.substring(3, ref.length - 1)
+            if (hexDigits.length === 0 || !/^[0-9a-fA-F]+$/.test(hexDigits)) {
+                return `Invalid XML: Invalid hex character reference: ${ref}`
+            }
+        } else if (ref.startsWith("&#")) {
+            if (!ref.endsWith(";")) {
+                return `Invalid XML: Missing semicolon after decimal reference: ${ref}`
+            }
+            const decDigits = ref.substring(2, ref.length - 1)
+            if (decDigits.length === 0 || !/^[0-9]+$/.test(decDigits)) {
+                return `Invalid XML: Invalid decimal character reference: ${ref}`
+            }
+        }
+    }
+    return null
+}
+
+/** Check for invalid entity references */
+function checkEntityReferences(xml: string): string | null {
+    const xmlWithoutComments = xml.replace(/<!--[\s\S]*?-->/g, "")
+    const bareAmpPattern = /&(?!(?:lt|gt|amp|quot|apos|#))/g
+    if (bareAmpPattern.test(xmlWithoutComments)) {
+        return "Invalid XML: Found unescaped & character(s). Replace & with &amp;"
+    }
+    const invalidEntityPattern = /&([a-zA-Z][a-zA-Z0-9]*);/g
+    let entityMatch
+    while (
+        (entityMatch = invalidEntityPattern.exec(xmlWithoutComments)) !== null
+    ) {
+        if (!VALID_ENTITIES.has(entityMatch[1])) {
+            return `Invalid XML: Invalid entity reference: &${entityMatch[1]}; - use only valid XML entities (lt, gt, amp, quot, apos)`
+        }
+    }
+    return null
+}
+
+/** Check for nested mxCell tags using regex */
+function checkNestedMxCells(xml: string): string | null {
+    const cellTagPattern = /<\/?mxCell[^>]*>/g
+    const cellStack: number[] = []
+    let cellMatch
+    while ((cellMatch = cellTagPattern.exec(xml)) !== null) {
+        const tag = cellMatch[0]
+        if (tag.startsWith("</mxCell>")) {
+            if (cellStack.length > 0) cellStack.pop()
+        } else if (!tag.endsWith("/>")) {
+            const isLabelOrGeometry =
+                /\sas\s*=\s*["'](valueLabel|geometry)["']/.test(tag)
+            if (!isLabelOrGeometry) {
+                cellStack.push(cellMatch.index)
+                if (cellStack.length > 1) {
+                    return "Invalid XML: Found nested mxCell tags. Cells should be siblings, not nested inside other mxCell elements."
+                }
+            }
+        }
+    }
+    return null
+}
+
+// ============================================================================
+// Main Validation Function
+// ============================================================================
+
+/**
+ * Validates draw.io XML structure for common issues
+ * Uses DOM parsing + additional regex checks for high accuracy
+ * @param xml - The XML string to validate
+ * @returns null if valid, error message string if invalid
+ */
+export function validateMxCellStructure(xml: string): string | null {
+    // Size check for performance
+    if (xml.length > MAX_XML_SIZE) {
+        console.warn(
+            `[validateMxCellStructure] XML size (${xml.length}) exceeds ${MAX_XML_SIZE} bytes, may cause performance issues`,
+        )
+    }
+
+    // 0. First use DOM parser to catch syntax errors (most accurate)
+    try {
+        const parser = new DOMParser()
+        const doc = parser.parseFromString(xml, "text/xml")
+        const parseError = doc.querySelector("parsererror")
+        if (parseError) {
+            return `Invalid XML: The XML contains syntax errors (likely unescaped special characters like <, >, & in attribute values). Please escape special characters: use &lt; for <, &gt; for >, &amp; for &, &quot; for ". Regenerate the diagram with properly escaped values.`
+        }
+
+        // DOM-based checks for nested mxCell
+        const allCells = doc.querySelectorAll("mxCell")
+        for (const cell of allCells) {
+            if (cell.parentElement?.tagName === "mxCell") {
+                const id = cell.getAttribute("id") || "unknown"
+                return `Invalid XML: Found nested mxCell (id="${id}"). Cells should be siblings, not nested inside other mxCell elements.`
+            }
+        }
+    } catch (error) {
+        console.warn(
+            "[validateMxCellStructure] DOMParser threw unexpected error, falling back to regex validation:",
+            error,
+        )
+    }
+
+    // 1. Check for CDATA wrapper (invalid at document root)
+    if (/^\s*<!\[CDATA\[/.test(xml)) {
+        return "Invalid XML: XML is wrapped in CDATA section - remove <![CDATA[ from start and ]]> from end"
+    }
+
+    // 2. Check for duplicate structural attributes
+    const dupAttrError = checkDuplicateAttributes(xml)
+    if (dupAttrError) {
+        return dupAttrError
+    }
+
+    // 3. Check for unescaped < in attribute values
+    const attrValuePattern = /=\s*"([^"]*)"/g
+    let attrValMatch
+    while ((attrValMatch = attrValuePattern.exec(xml)) !== null) {
+        const value = attrValMatch[1]
+        if (/</.test(value) && !/&lt;/.test(value)) {
+            return "Invalid XML: Unescaped < character in attribute values. Replace < with &lt;"
+        }
+    }
+
+    // 4. Check for duplicate IDs
+    const dupIdError = checkDuplicateIds(xml)
+    if (dupIdError) {
+        return dupIdError
+    }
+
+    // 5. Check for tag mismatches
+    const tagMismatchError = checkTagMismatches(xml)
+    if (tagMismatchError) {
+        return tagMismatchError
+    }
+
+    // 6. Check invalid character references
+    const charRefError = checkCharacterReferences(xml)
+    if (charRefError) {
+        return charRefError
+    }
+
+    // 7. Check for invalid comment syntax (-- inside comments)
+    const commentPattern = /<!--([\s\S]*?)-->/g
+    let commentMatch
+    while ((commentMatch = commentPattern.exec(xml)) !== null) {
+        if (/--/.test(commentMatch[1])) {
+            return "Invalid XML: Comment contains -- (double hyphen) which is not allowed"
+        }
+    }
+
+    // 8. Check for unescaped entity references and invalid entity names
+    const entityError = checkEntityReferences(xml)
+    if (entityError) {
+        return entityError
+    }
+
+    // 9. Check for empty id attributes on mxCell
+    if (/<mxCell[^>]*\sid\s*=\s*["']\s*["'][^>]*>/g.test(xml)) {
+        return "Invalid XML: Found mxCell element(s) with empty id attribute"
+    }
+
+    // 10. Check for nested mxCell tags
+    const nestedCellError = checkNestedMxCells(xml)
+    if (nestedCellError) {
+        return nestedCellError
+    }
+
+    return null
+}
+
+// ============================================================================
+// Auto-Fix Function
+// ============================================================================
+
+/**
+ * Attempts to auto-fix common XML issues in draw.io diagrams
+ * @param xml - The XML string to fix
+ * @returns Object with fixed XML and list of fixes applied
+ */
+export function autoFixXml(xml: string): { fixed: string; fixes: string[] } {
+    let fixed = xml
+    const fixes: string[] = []
+
+    // 0. Fix JSON-escaped XML
+    if (/=\\"/.test(fixed)) {
+        fixed = fixed.replace(/\\"/g, '"')
+        fixed = fixed.replace(/\\n/g, "\n")
+        fixes.push("Fixed JSON-escaped XML")
+    }
+
+    // 1. Remove CDATA wrapper
+    if (/^\s*<!\[CDATA\[/.test(fixed)) {
+        fixed = fixed.replace(/^\s*<!\[CDATA\[/, "").replace(/\]\]>\s*$/, "")
+        fixes.push("Removed CDATA wrapper")
+    }
+
+    // 2. Remove text before XML declaration or root element
+    const xmlStart = fixed.search(/<(\?xml|mxGraphModel|mxfile)/i)
+    if (xmlStart > 0 && !/^<[a-zA-Z]/.test(fixed.trim())) {
+        fixed = fixed.substring(xmlStart)
+        fixes.push("Removed text before XML root")
+    }
+
+    // 3. Fix duplicate attributes
+    let dupAttrFixed = false
+    fixed = fixed.replace(/<[^>]+>/g, (tag) => {
+        let newTag = tag
+        for (const attr of STRUCTURAL_ATTRS) {
+            const attrRegex = new RegExp(
+                `\\s${attr}\\s*=\\s*["'][^"']*["']`,
+                "gi",
+            )
+            const matches = tag.match(attrRegex)
+            if (matches && matches.length > 1) {
+                let firstKept = false
+                newTag = newTag.replace(attrRegex, (m) => {
+                    if (!firstKept) {
+                        firstKept = true
+                        return m
+                    }
+                    dupAttrFixed = true
+                    return ""
+                })
+            }
+        }
+        return newTag
+    })
+    if (dupAttrFixed) {
+        fixes.push("Removed duplicate structural attributes")
+    }
+
+    // 4. Fix unescaped & characters
+    const ampersandPattern =
+        /&(?!(?:lt|gt|amp|quot|apos|#[0-9]+|#x[0-9a-fA-F]+);)/g
+    if (ampersandPattern.test(fixed)) {
+        fixed = fixed.replace(
+            /&(?!(?:lt|gt|amp|quot|apos|#[0-9]+|#x[0-9a-fA-F]+);)/g,
+            "&amp;",
+        )
+        fixes.push("Escaped unescaped & characters")
+    }
+
+    // 5. Fix invalid entity names (double-escaping)
+    const invalidEntities = [
+        { pattern: /&ampquot;/g, replacement: "&quot;", name: "&ampquot;" },
+        { pattern: /&amplt;/g, replacement: "&lt;", name: "&amplt;" },
+        { pattern: /&ampgt;/g, replacement: "&gt;", name: "&ampgt;" },
+        { pattern: /&ampapos;/g, replacement: "&apos;", name: "&ampapos;" },
+        { pattern: /&ampamp;/g, replacement: "&amp;", name: "&ampamp;" },
+    ]
+    for (const { pattern, replacement, name } of invalidEntities) {
+        if (pattern.test(fixed)) {
+            fixed = fixed.replace(pattern, replacement)
+            fixes.push(`Fixed double-escaped entity ${name}`)
+        }
+    }
+
+    // 6. Fix malformed attribute quotes
+    const malformedQuotePattern = /(\s[a-zA-Z][a-zA-Z0-9_:-]*)=&quot;/
+    if (malformedQuotePattern.test(fixed)) {
+        fixed = fixed.replace(
+            /(\s[a-zA-Z][a-zA-Z0-9_:-]*)=&quot;([^&]*?)&quot;/g,
+            '$1="$2"',
+        )
+        fixes.push("Fixed malformed attribute quotes")
+    }
+
+    // 7. Fix malformed closing tags
+    const malformedClosingTag = /<\/([a-zA-Z][a-zA-Z0-9]*)\s*\/>/g
+    if (malformedClosingTag.test(fixed)) {
+        fixed = fixed.replace(/<\/([a-zA-Z][a-zA-Z0-9]*)\s*\/>/g, "</$1>")
+        fixes.push("Fixed malformed closing tags")
+    }
+
+    // 8. Fix missing space between attributes
+    const missingSpacePattern = /("[^"]*")([a-zA-Z][a-zA-Z0-9_:-]*=)/g
+    if (missingSpacePattern.test(fixed)) {
+        fixed = fixed.replace(/("[^"]*")([a-zA-Z][a-zA-Z0-9_:-]*=)/g, "$1 $2")
+        fixes.push("Added missing space between attributes")
+    }
+
+    // 9. Fix unescaped quotes in style color values
+    const quotedColorPattern = /;([a-zA-Z]*[Cc]olor)="#/
+    if (quotedColorPattern.test(fixed)) {
+        fixed = fixed.replace(/;([a-zA-Z]*[Cc]olor)="#/g, ";$1=#")
+        fixes.push("Removed quotes around color values in style")
+    }
+
+    // 10. Fix unescaped < and > in attribute values
+    // < is required to be escaped, > is not strictly required but we escape for consistency
+    const attrPattern = /(=\s*")([^"]*?)(<)([^"]*?)(")/g
+    let attrMatch
+    let hasUnescapedLt = false
+    while ((attrMatch = attrPattern.exec(fixed)) !== null) {
+        if (!attrMatch[3].startsWith("&lt;")) {
+            hasUnescapedLt = true
+            break
+        }
+    }
+    if (hasUnescapedLt) {
+        fixed = fixed.replace(/=\s*"([^"]*)"/g, (_match, value) => {
+            const escaped = value.replace(/</g, "&lt;").replace(/>/g, "&gt;")
+            return `="${escaped}"`
+        })
+        fixes.push("Escaped <> characters in attribute values")
+    }
+
+    // 11. Fix invalid hex character references
+    const invalidHexRefs: string[] = []
+    fixed = fixed.replace(/&#x([^;]*);/g, (match, hex) => {
+        if (/^[0-9a-fA-F]+$/.test(hex) && hex.length > 0) {
+            return match
+        }
+        invalidHexRefs.push(match)
+        return ""
+    })
+    if (invalidHexRefs.length > 0) {
+        fixes.push(
+            `Removed ${invalidHexRefs.length} invalid hex character reference(s)`,
+        )
+    }
+
+    // 12. Fix invalid decimal character references
+    const invalidDecRefs: string[] = []
+    fixed = fixed.replace(/&#([^x][^;]*);/g, (match, dec) => {
+        if (/^[0-9]+$/.test(dec) && dec.length > 0) {
+            return match
+        }
+        invalidDecRefs.push(match)
+        return ""
+    })
+    if (invalidDecRefs.length > 0) {
+        fixes.push(
+            `Removed ${invalidDecRefs.length} invalid decimal character reference(s)`,
+        )
+    }
+
+    // 13. Fix invalid comment syntax
+    fixed = fixed.replace(/<!--([\s\S]*?)-->/g, (match, content) => {
+        if (/--/.test(content)) {
+            let fixedContent = content
+            while (/--/.test(fixedContent)) {
+                fixedContent = fixedContent.replace(/--/g, "-")
+            }
+            fixes.push("Fixed invalid comment syntax")
+            return `<!--${fixedContent}-->`
+        }
+        return match
+    })
+
+    // 14. Fix <Cell> tags to <mxCell>
+    const hasCellTags = /<\/?Cell[\s>]/i.test(fixed)
+    if (hasCellTags) {
+        fixed = fixed.replace(/<Cell(\s)/gi, "<mxCell$1")
+        fixed = fixed.replace(/<Cell>/gi, "<mxCell>")
+        fixed = fixed.replace(/<\/Cell>/gi, "</mxCell>")
+        fixes.push("Fixed <Cell> tags to <mxCell>")
+    }
+
+    // 15. Fix common closing tag typos (MUST run before foreign tag removal)
+    const tagTypos = [
+        { wrong: /<\/mxElement>/gi, right: "</mxCell>", name: "</mxElement>" },
+        { wrong: /<\/mxcell>/g, right: "</mxCell>", name: "</mxcell>" },
+        {
+            wrong: /<\/mxgeometry>/g,
+            right: "</mxGeometry>",
+            name: "</mxgeometry>",
+        },
+        { wrong: /<\/mxpoint>/g, right: "</mxPoint>", name: "</mxpoint>" },
+        {
+            wrong: /<\/mxgraphmodel>/gi,
+            right: "</mxGraphModel>",
+            name: "</mxgraphmodel>",
+        },
+    ]
+    for (const { wrong, right, name } of tagTypos) {
+        const before = fixed
+        fixed = fixed.replace(wrong, right)
+        if (fixed !== before) {
+            fixes.push(`Fixed typo ${name} to ${right}`)
+        }
+    }
+
+    // 16. Remove non-draw.io tags (after typo fixes so lowercase variants are fixed first)
+    const validDrawioTags = new Set([
+        "mxfile",
+        "diagram",
+        "mxGraphModel",
+        "root",
+        "mxCell",
+        "mxGeometry",
+        "mxPoint",
+        "Array",
+        "Object",
+        "mxRectangle",
+    ])
+    const foreignTagPattern = /<\/?([a-zA-Z][a-zA-Z0-9_]*)[^>]*>/g
+    let foreignMatch
+    const foreignTags = new Set<string>()
+    while ((foreignMatch = foreignTagPattern.exec(fixed)) !== null) {
+        const tagName = foreignMatch[1]
+        if (!validDrawioTags.has(tagName)) {
+            foreignTags.add(tagName)
+        }
+    }
+    if (foreignTags.size > 0) {
+        for (const tag of foreignTags) {
+            fixed = fixed.replace(new RegExp(`<${tag}[^>]*>`, "gi"), "")
+            fixed = fixed.replace(new RegExp(`</${tag}>`, "gi"), "")
+        }
+        fixes.push(
+            `Removed foreign tags: ${Array.from(foreignTags).join(", ")}`,
+        )
+    }
+
+    // 17. Fix unclosed tags
+    const tagStack: string[] = []
+    const parsedTags = parseXmlTags(fixed)
+
+    for (const { tagName, isClosing, isSelfClosing } of parsedTags) {
+        if (isClosing) {
+            const lastIdx = tagStack.lastIndexOf(tagName)
+            if (lastIdx !== -1) {
+                tagStack.splice(lastIdx, 1)
+            }
+        } else if (!isSelfClosing) {
+            tagStack.push(tagName)
+        }
+    }
+
+    if (tagStack.length > 0) {
+        const tagsToClose: string[] = []
+        for (const tagName of tagStack.reverse()) {
+            const openCount = (
+                fixed.match(new RegExp(`<${tagName}[\\s>]`, "gi")) || []
+            ).length
+            const closeCount = (
+                fixed.match(new RegExp(`</${tagName}>`, "gi")) || []
+            ).length
+            if (openCount > closeCount) {
+                tagsToClose.push(tagName)
+            }
+        }
+        if (tagsToClose.length > 0) {
+            const closingTags = tagsToClose.map((t) => `</${t}>`).join("\n")
+            fixed = fixed.trimEnd() + "\n" + closingTags
+            fixes.push(
+                `Closed ${tagsToClose.length} unclosed tag(s): ${tagsToClose.join(", ")}`,
+            )
+        }
+    }
+
+    // 18. Remove extra closing tags
+    const tagCounts = new Map<
+        string,
+        { opens: number; closes: number; selfClosing: number }
+    >()
+    const fullTagPattern = /<(\/?[a-zA-Z][a-zA-Z0-9]*)[^>]*>/g
+    let tagCountMatch
+    while ((tagCountMatch = fullTagPattern.exec(fixed)) !== null) {
+        const fullMatch = tagCountMatch[0]
+        const tagPart = tagCountMatch[1]
+        const isClosing = tagPart.startsWith("/")
+        const isSelfClosing = fullMatch.endsWith("/>")
+        const tagName = isClosing ? tagPart.slice(1) : tagPart
+
+        let counts = tagCounts.get(tagName)
+        if (!counts) {
+            counts = { opens: 0, closes: 0, selfClosing: 0 }
+            tagCounts.set(tagName, counts)
+        }
+        if (isClosing) {
+            counts.closes++
+        } else if (isSelfClosing) {
+            counts.selfClosing++
+        } else {
+            counts.opens++
+        }
+    }
+
+    for (const [tagName, counts] of tagCounts) {
+        const extraCloses = counts.closes - counts.opens
+        if (extraCloses > 0) {
+            let removed = 0
+            const closeTagPattern = new RegExp(`</${tagName}>`, "g")
+            const matches = [...fixed.matchAll(closeTagPattern)]
+            for (
+                let i = matches.length - 1;
+                i >= 0 && removed < extraCloses;
+                i--
+            ) {
+                const match = matches[i]
+                const idx = match.index ?? 0
+                fixed = fixed.slice(0, idx) + fixed.slice(idx + match[0].length)
+                removed++
+            }
+            if (removed > 0) {
+                fixes.push(
+                    `Removed ${removed} extra </${tagName}> closing tag(s)`,
+                )
+            }
+        }
+    }
+
+    // 19. Remove trailing garbage after last XML tag
+    const closingTagPattern = /<\/[a-zA-Z][a-zA-Z0-9]*>|\/>/g
+    let lastValidTagEnd = -1
+    let closingMatch
+    while ((closingMatch = closingTagPattern.exec(fixed)) !== null) {
+        lastValidTagEnd = closingMatch.index + closingMatch[0].length
+    }
+    if (lastValidTagEnd > 0 && lastValidTagEnd < fixed.length) {
+        const trailing = fixed.slice(lastValidTagEnd).trim()
+        if (trailing) {
+            fixed = fixed.slice(0, lastValidTagEnd)
+            fixes.push("Removed trailing garbage after last XML tag")
+        }
+    }
+
+    // 20. Fix nested mxCell by flattening
+    const lines = fixed.split("\n")
+    let newLines: string[] = []
+    let nestedFixed = 0
+    let extraClosingToRemove = 0
+
+    for (let i = 0; i < lines.length; i++) {
+        const line = lines[i]
+        const nextLine = lines[i + 1]
+
+        if (
+            nextLine &&
+            /<mxCell\s/.test(line) &&
+            /<mxCell\s/.test(nextLine) &&
+            !line.includes("/>") &&
+            !nextLine.includes("/>")
+        ) {
+            const id1 = line.match(/\bid\s*=\s*["']([^"']+)["']/)?.[1]
+            const id2 = nextLine.match(/\bid\s*=\s*["']([^"']+)["']/)?.[1]
+
+            if (id1 && id1 === id2) {
+                nestedFixed++
+                extraClosingToRemove++
+                continue
+            }
+        }
+
+        if (extraClosingToRemove > 0 && /^\s*<\/mxCell>\s*$/.test(line)) {
+            extraClosingToRemove--
+            continue
+        }
+
+        newLines.push(line)
+    }
+
+    if (nestedFixed > 0) {
+        fixed = newLines.join("\n")
+        fixes.push(`Flattened ${nestedFixed} duplicate-ID nested mxCell(s)`)
+    }
+
+    // 21. Fix true nested mxCell (different IDs)
+    const lines2 = fixed.split("\n")
+    newLines = []
+    let trueNestedFixed = 0
+    let cellDepth = 0
+    let pendingCloseRemoval = 0
+
+    for (let i = 0; i < lines2.length; i++) {
+        const line = lines2[i]
+        const trimmed = line.trim()
+
+        const isOpenCell = /<mxCell\s/.test(trimmed) && !trimmed.endsWith("/>")
+        const isCloseCell = trimmed === "</mxCell>"
+
+        if (isOpenCell) {
+            if (cellDepth > 0) {
+                const indent = line.match(/^(\s*)/)?.[1] || ""
+                newLines.push(indent + "</mxCell>")
+                trueNestedFixed++
+                pendingCloseRemoval++
+            }
+            cellDepth = 1
+            newLines.push(line)
+        } else if (isCloseCell) {
+            if (pendingCloseRemoval > 0) {
+                pendingCloseRemoval--
+            } else {
+                cellDepth = Math.max(0, cellDepth - 1)
+                newLines.push(line)
+            }
+        } else {
+            newLines.push(line)
+        }
+    }
+
+    if (trueNestedFixed > 0) {
+        fixed = newLines.join("\n")
+        fixes.push(`Fixed ${trueNestedFixed} true nested mxCell(s)`)
+    }
+
+    // 22. Fix duplicate IDs by appending suffix
+    const seenIds = new Map<string, number>()
+    const duplicateIds: string[] = []
+
+    const idPattern = /\bid\s*=\s*["']([^"']+)["']/gi
+    let idMatch
+    while ((idMatch = idPattern.exec(fixed)) !== null) {
+        const id = idMatch[1]
+        seenIds.set(id, (seenIds.get(id) || 0) + 1)
+    }
+
+    for (const [id, count] of seenIds) {
+        if (count > 1) duplicateIds.push(id)
+    }
+
+    if (duplicateIds.length > 0) {
+        const idCounters = new Map<string, number>()
+        fixed = fixed.replace(/\bid\s*=\s*["']([^"']+)["']/gi, (match, id) => {
+            if (!duplicateIds.includes(id)) return match
+
+            const count = idCounters.get(id) || 0
+            idCounters.set(id, count + 1)
+
+            if (count === 0) return match
+
+            const newId = `${id}_dup${count}`
+            return match.replace(id, newId)
+        })
+        fixes.push(`Renamed ${duplicateIds.length} duplicate ID(s)`)
+    }
+
+    // 23. Fix empty id attributes
+    let emptyIdCount = 0
+    fixed = fixed.replace(
+        /<mxCell([^>]*)\sid\s*=\s*["']\s*["']([^>]*)>/g,
+        (_match, before, after) => {
+            emptyIdCount++
+            const newId = `cell_${Date.now()}_${emptyIdCount}`
+            return `<mxCell${before} id="${newId}"${after}>`
+        },
+    )
+    if (emptyIdCount > 0) {
+        fixes.push(`Generated ${emptyIdCount} missing ID(s)`)
+    }
+
+    // 24. Aggressive: drop broken mxCell elements
+    if (typeof DOMParser !== "undefined") {
+        let droppedCells = 0
+        let maxIterations = MAX_DROP_ITERATIONS
+        while (maxIterations-- > 0) {
+            const parser = new DOMParser()
+            const doc = parser.parseFromString(fixed, "text/xml")
+            const parseError = doc.querySelector("parsererror")
+            if (!parseError) break
+
+            const errText = parseError.textContent || ""
+            const match = errText.match(/(\d+):\d+:/)
+            if (!match) break
+
+            const errLine = parseInt(match[1], 10) - 1
+            const lines = fixed.split("\n")
+
+            let cellStart = errLine
+            let cellEnd = errLine
+
+            while (cellStart > 0 && !lines[cellStart].includes("<mxCell")) {
+                cellStart--
+            }
+
+            while (cellEnd < lines.length - 1) {
+                if (
+                    lines[cellEnd].includes("</mxCell>") ||
+                    lines[cellEnd].trim().endsWith("/>")
+                ) {
+                    break
+                }
+                cellEnd++
+            }
+
+            lines.splice(cellStart, cellEnd - cellStart + 1)
+            fixed = lines.join("\n")
+            droppedCells++
+        }
+        if (droppedCells > 0) {
+            fixes.push(`Dropped ${droppedCells} unfixable mxCell element(s)`)
+        }
+    }
+
+    return { fixed, fixes }
+}
+
+// ============================================================================
+// Combined Validation and Fix
+// ============================================================================
+
+/**
+ * Validates XML and attempts to fix if invalid
+ * @param xml - The XML string to validate and potentially fix
+ * @returns Object with validation result, fixed XML if applicable, and fixes applied
+ */
+export function validateAndFixXml(xml: string): {
+    valid: boolean
+    error: string | null
+    fixed: string | null
+    fixes: string[]
+} {
+    // First validation attempt
+    let error = validateMxCellStructure(xml)
+
+    if (!error) {
+        return { valid: true, error: null, fixed: null, fixes: [] }
+    }
+
+    // Try to fix
+    const { fixed, fixes } = autoFixXml(xml)
+
+    // Validate the fixed version
+    error = validateMxCellStructure(fixed)
+
+    if (!error) {
+        return { valid: true, error: null, fixed, fixes }
+    }
+
+    // Still invalid after fixes
+    return {
+        valid: false,
+        error,
+        fixed: fixes.length > 0 ? fixed : null,
+        fixes,
+    }
+}
+
+/**
+ * Check if mxCell XML output is complete (not truncated).
+ * Uses a robust approach that handles any LLM provider's wrapper tags
+ * by finding the last valid mxCell ending and checking if suffix is just closing tags.
+ * @param xml - The XML string to check (can be undefined/null)
+ * @returns true if XML appears complete, false if truncated or empty
+ */
+export function isMxCellXmlComplete(xml: string | undefined | null): boolean {
+    const trimmed = xml?.trim() || ""
+    if (!trimmed) return false
+
+    // Find position of last complete mxCell ending (either /> or </mxCell>)
+    const lastSelfClose = trimmed.lastIndexOf("/>")
+    const lastMxCellClose = trimmed.lastIndexOf("</mxCell>")
+
+    const lastValidEnd = Math.max(lastSelfClose, lastMxCellClose)
+
+    // No valid ending found at all
+    if (lastValidEnd === -1) return false
+
+    // Check what comes after the last valid ending
+    // For />: add 2 chars, for </mxCell>: add 9 chars
+    const endOffset = lastMxCellClose > lastSelfClose ? 9 : 2
+    const suffix = trimmed.slice(lastValidEnd + endOffset)
+
+    // If suffix is empty or only contains closing tags (any provider's wrapper) or whitespace, it's complete
+    // This regex matches any sequence of closing XML tags like </foo>, </bar>, </｜DSML｜xyz>
+    return /^(\s*<\/[^>]+>)*\s*$/.test(suffix)
+}

renovate.json

@@ -0,0 +1,40 @@
+{
+    "$schema": "https://docs.renovatebot.com/renovate-schema.json",
+    "extends": ["config:recommended"],
+    "schedule": ["after 10am on saturday"],
+    "timezone": "Asia/Tokyo",
+    "packageRules": [
+        {
+            "matchUpdateTypes": ["minor", "patch"],
+            "matchPackagePatterns": ["*"],
+            "groupName": "minor and patch dependencies",
+            "automerge": true
+        },
+        {
+            "matchUpdateTypes": ["major"],
+            "matchPackagePatterns": ["*"],
+            "automerge": false
+        },
+        {
+            "matchPackagePatterns": ["@ai-sdk/*"],
+            "groupName": "AI SDK packages"
+        },
+        {
+            "matchPackagePatterns": ["@radix-ui/*"],
+            "groupName": "Radix UI packages"
+        },
+        {
+            "matchPackagePatterns": ["electron", "electron-builder"],
+            "groupName": "Electron packages",
+            "automerge": false
+        },
+        {
+            "matchPackagePatterns": ["@ai-sdk/*", "ai", "next"],
+            "groupName": "Core framework packages",
+            "automerge": false
+        }
+    ],
+    "vulnerabilityAlerts": {
+        "enabled": true
+    }
+}

resources/entitlements.mac.plist

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+    <key>com.apple.security.cs.allow-jit</key>
+    <true/>
+    <key>com.apple.security.cs.allow-unsigned-executable-memory</key>
+    <true/>
+    <key>com.apple.security.cs.allow-dyld-environment-variables</key>
+    <true/>
+    <key>com.apple.security.network.client</key>
+    <true/>
+    <key>com.apple.security.network.server</key>
+    <true/>
+</dict>
+</plist>

scripts/afterPack.cjs

@@ -0,0 +1,43 @@
+/**
+ * electron-builder afterPack hook
+ * Copies node_modules to the standalone directory in the packaged app
+ */
+
+const { cpSync, existsSync } = require("fs")
+const path = require("path")
+
+module.exports = async (context) => {
+    const appOutDir = context.appOutDir
+    const resourcesDir = path.join(
+        appOutDir,
+        context.packager.platform.name === "mac"
+            ? `${context.packager.appInfo.productFilename}.app/Contents/Resources`
+            : "resources",
+    )
+    const standaloneDir = path.join(resourcesDir, "standalone")
+    const sourceNodeModules = path.join(
+        context.packager.projectDir,
+        "electron-standalone",
+        "node_modules",
+    )
+    const targetNodeModules = path.join(standaloneDir, "node_modules")
+
+    console.log(`[afterPack] Copying node_modules to ${targetNodeModules}`)
+
+    if (existsSync(sourceNodeModules) && existsSync(standaloneDir)) {
+        cpSync(sourceNodeModules, targetNodeModules, { recursive: true })
+        console.log("[afterPack] node_modules copied successfully")
+    } else {
+        console.error("[afterPack] Source or target directory not found!")
+        console.error(
+            `  Source: ${sourceNodeModules} exists: ${existsSync(sourceNodeModules)}`,
+        )
+        console.error(
+            `  Target dir: ${standaloneDir} exists: ${existsSync(standaloneDir)}`,
+        )
+        throw new Error(
+            "[afterPack] Failed: Required directories not found. " +
+                "Ensure 'npm run electron:prepare' was run before building.",
+        )
+    }
+}

scripts/electron-dev.mjs

@@ -0,0 +1,295 @@
+#!/usr/bin/env node
+
+/**
+ * Development script for running Electron with Next.js
+ * 1. Reads preset configuration (if exists)
+ * 2. Starts Next.js dev server with preset env vars
+ * 3. Waits for it to be ready
+ * 4. Compiles Electron TypeScript
+ * 5. Launches Electron
+ * 6. Watches for preset changes and restarts Next.js
+ */
+
+import { spawn } from "node:child_process"
+import { existsSync, readFileSync, watch } from "node:fs"
+import os from "node:os"
+import path from "node:path"
+import { fileURLToPath } from "node:url"
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url))
+const rootDir = path.join(__dirname, "..")
+
+const NEXT_PORT = 6002
+const NEXT_URL = `http://localhost:${NEXT_PORT}`
+
+/**
+ * Get the user data path (same as Electron's app.getPath("userData"))
+ */
+function getUserDataPath() {
+    const appName = "next-ai-draw-io"
+    switch (process.platform) {
+        case "darwin":
+            return path.join(
+                os.homedir(),
+                "Library",
+                "Application Support",
+                appName,
+            )
+        case "win32":
+            return path.join(
+                process.env.APPDATA ||
+                    path.join(os.homedir(), "AppData", "Roaming"),
+                appName,
+            )
+        default:
+            return path.join(os.homedir(), ".config", appName)
+    }
+}
+
+/**
+ * Load preset configuration from config file
+ */
+function loadPresetConfig() {
+    const configPath = path.join(getUserDataPath(), "config-presets.json")
+
+    if (!existsSync(configPath)) {
+        console.log("📋 No preset configuration found, using .env.local")
+        return null
+    }
+
+    try {
+        const content = readFileSync(configPath, "utf-8")
+        const data = JSON.parse(content)
+
+        if (!data.currentPresetId) {
+            console.log("📋 No active preset, using .env.local")
+            return null
+        }
+
+        const preset = data.presets.find((p) => p.id === data.currentPresetId)
+        if (!preset) {
+            console.log("📋 Active preset not found, using .env.local")
+            return null
+        }
+
+        console.log(`📋 Using preset: "${preset.name}"`)
+        return preset.config
+    } catch (error) {
+        console.error("Failed to load preset config:", error.message)
+        return null
+    }
+}
+
+/**
+ * Wait for the Next.js server to be ready
+ */
+async function waitForServer(url, timeout = 120000) {
+    const start = Date.now()
+    console.log(`Waiting for server at ${url}...`)
+
+    while (Date.now() - start < timeout) {
+        try {
+            const response = await fetch(url)
+            if (response.ok || response.status < 500) {
+                console.log("Server is ready!")
+                return true
+            }
+        } catch {
+            // Server not ready yet
+        }
+        await new Promise((r) => setTimeout(r, 500))
+        process.stdout.write(".")
+    }
+
+    throw new Error(`Timeout waiting for server at ${url}`)
+}
+
+/**
+ * Run a command and wait for it to complete
+ */
+function runCommand(command, args, options = {}) {
+    return new Promise((resolve, reject) => {
+        const proc = spawn(command, args, {
+            cwd: rootDir,
+            stdio: "inherit",
+            shell: true,
+            ...options,
+        })
+
+        proc.on("close", (code) => {
+            if (code === 0) {
+                resolve()
+            } else {
+                reject(new Error(`Command failed with code ${code}`))
+            }
+        })
+
+        proc.on("error", reject)
+    })
+}
+
+/**
+ * Start Next.js dev server with preset environment
+ */
+function startNextServer(presetEnv) {
+    const env = { ...process.env }
+
+    // Apply preset environment variables
+    if (presetEnv) {
+        for (const [key, value] of Object.entries(presetEnv)) {
+            if (value !== undefined && value !== "") {
+                env[key] = value
+            }
+        }
+    }
+
+    const nextProcess = spawn("npm", ["run", "dev"], {
+        cwd: rootDir,
+        stdio: "inherit",
+        shell: true,
+        env,
+    })
+
+    nextProcess.on("error", (err) => {
+        console.error("Failed to start Next.js:", err)
+    })
+
+    return nextProcess
+}
+
+/**
+ * Main entry point
+ */
+async function main() {
+    console.log("🚀 Starting Electron development environment...\n")
+
+    // Load preset configuration
+    const presetEnv = loadPresetConfig()
+
+    // Start Next.js dev server with preset env
+    console.log("1. Starting Next.js development server...")
+    let nextProcess = startNextServer(presetEnv)
+
+    // Wait for Next.js to be ready
+    try {
+        await waitForServer(NEXT_URL)
+        console.log("")
+    } catch (err) {
+        console.error("\n❌ Next.js server failed to start:", err.message)
+        nextProcess.kill()
+        process.exit(1)
+    }
+
+    // Compile Electron TypeScript
+    console.log("\n2. Compiling Electron code...")
+    try {
+        await runCommand("npm", ["run", "electron:compile"])
+    } catch (err) {
+        console.error("❌ Electron compilation failed:", err.message)
+        nextProcess.kill()
+        process.exit(1)
+    }
+
+    // Start Electron
+    console.log("\n3. Starting Electron...")
+    const electronProcess = spawn("npm", ["run", "electron:start"], {
+        cwd: rootDir,
+        stdio: "inherit",
+        shell: true,
+        env: {
+            ...process.env,
+            NODE_ENV: "development",
+            ELECTRON_DEV_URL: NEXT_URL,
+        },
+    })
+
+    // Watch for preset config changes
+    const configPath = path.join(getUserDataPath(), "config-presets.json")
+    let configWatcher = null
+    let restartPending = false
+
+    function setupConfigWatcher() {
+        if (!existsSync(path.dirname(configPath))) {
+            // Directory doesn't exist yet, check again later
+            setTimeout(setupConfigWatcher, 5000)
+            return
+        }
+
+        try {
+            configWatcher = watch(
+                configPath,
+                { persistent: false },
+                async (eventType) => {
+                    if (eventType === "change" && !restartPending) {
+                        restartPending = true
+                        console.log(
+                            "\n🔄 Preset configuration changed, restarting Next.js server...",
+                        )
+
+                        // Kill current Next.js process
+                        nextProcess.kill()
+
+                        // Wait a bit for process to die
+                        await new Promise((r) => setTimeout(r, 1000))
+
+                        // Reload preset and restart
+                        const newPresetEnv = loadPresetConfig()
+                        nextProcess = startNextServer(newPresetEnv)
+
+                        try {
+                            await waitForServer(NEXT_URL)
+                            console.log(
+                                "✅ Next.js server restarted with new configuration\n",
+                            )
+                        } catch (err) {
+                            console.error(
+                                "❌ Failed to restart Next.js:",
+                                err.message,
+                            )
+                        }
+
+                        restartPending = false
+                    }
+                },
+            )
+            console.log("👀 Watching for preset configuration changes...")
+        } catch (err) {
+            // File might not exist yet, that's ok
+            setTimeout(setupConfigWatcher, 5000)
+        }
+    }
+
+    // Start watching after a delay (config file might not exist yet)
+    setTimeout(setupConfigWatcher, 2000)
+
+    electronProcess.on("close", (code) => {
+        console.log(`\nElectron exited with code ${code}`)
+        if (configWatcher) configWatcher.close()
+        nextProcess.kill()
+        process.exit(code || 0)
+    })
+
+    electronProcess.on("error", (err) => {
+        console.error("Electron error:", err)
+        if (configWatcher) configWatcher.close()
+        nextProcess.kill()
+        process.exit(1)
+    })
+
+    // Handle termination signals
+    const cleanup = () => {
+        console.log("\n🛑 Shutting down...")
+        if (configWatcher) configWatcher.close()
+        electronProcess.kill()
+        nextProcess.kill()
+        process.exit(0)
+    }
+
+    process.on("SIGINT", cleanup)
+    process.on("SIGTERM", cleanup)
+}
+
+main().catch((err) => {
+    console.error("Fatal error:", err)
+    process.exit(1)
+})

scripts/prepare-electron-build.mjs

@@ -0,0 +1,41 @@
+#!/usr/bin/env node
+
+/**
+ * Prepare standalone directory for Electron packaging
+ * Copies the Next.js standalone output to a temp directory
+ * that electron-builder can properly include
+ */
+
+import { cpSync, existsSync, mkdirSync, rmSync } from "node:fs"
+import { join } from "node:path"
+import { fileURLToPath } from "node:url"
+
+const __dirname = fileURLToPath(new URL(".", import.meta.url))
+const rootDir = join(__dirname, "..")
+
+const standaloneDir = join(rootDir, ".next", "standalone")
+const staticDir = join(rootDir, ".next", "static")
+const targetDir = join(rootDir, "electron-standalone")
+
+console.log("Preparing Electron build...")
+
+// Clean target directory
+if (existsSync(targetDir)) {
+    console.log("Cleaning previous build...")
+    rmSync(targetDir, { recursive: true })
+}
+
+// Create target directory
+mkdirSync(targetDir, { recursive: true })
+
+// Copy standalone (includes node_modules)
+console.log("Copying standalone directory...")
+cpSync(standaloneDir, targetDir, { recursive: true })
+
+// Copy static files
+console.log("Copying static files...")
+const targetStaticDir = join(targetDir, ".next", "static")
+mkdirSync(targetStaticDir, { recursive: true })
+cpSync(staticDir, targetStaticDir, { recursive: true })
+
+console.log("Done! Files prepared in electron-standalone/")

scripts/test-diagram-operations.mjs

@@ -22,7 +22,7 @@ function applyDiagramOperations(xmlContent, operations) {
             result: xmlContent,
             errors: [
                 {
-                    type: "update",
+                    operation: "update",
                     cellId: "",
                     message: `XML parse error: ${parseError.textContent}`,
                 },
@@ -36,7 +36,7 @@ function applyDiagramOperations(xmlContent, operations) {
             result: xmlContent,
             errors: [
                 {
-                    type: "update",
+                    operation: "update",
                     cellId: "",
                     message: "Could not find <root> element in XML",
                 },
@@ -51,11 +51,11 @@ function applyDiagramOperations(xmlContent, operations) {
     })
 
     for (const op of operations) {
-        if (op.type === "update") {
+        if (op.operation === "update") {
             const existingCell = cellMap.get(op.cell_id)
             if (!existingCell) {
                 errors.push({
-                    type: "update",
+                    operation: "update",
                     cellId: op.cell_id,
                     message: `Cell with id="${op.cell_id}" not found`,
                 })
@@ -63,7 +63,7 @@ function applyDiagramOperations(xmlContent, operations) {
             }
             if (!op.new_xml) {
                 errors.push({
-                    type: "update",
+                    operation: "update",
                     cellId: op.cell_id,
                     message: "new_xml is required for update operation",
                 })
@@ -76,7 +76,7 @@ function applyDiagramOperations(xmlContent, operations) {
             const newCell = newDoc.querySelector("mxCell")
             if (!newCell) {
                 errors.push({
-                    type: "update",
+                    operation: "update",
                     cellId: op.cell_id,
                     message: "new_xml must contain an mxCell element",
                 })
@@ -85,7 +85,7 @@ function applyDiagramOperations(xmlContent, operations) {
             const newCellId = newCell.getAttribute("id")
             if (newCellId !== op.cell_id) {
                 errors.push({
-                    type: "update",
+                    operation: "update",
                     cellId: op.cell_id,
                     message: `ID mismatch: cell_id is "${op.cell_id}" but new_xml has id="${newCellId}"`,
                 })
@@ -94,10 +94,10 @@ function applyDiagramOperations(xmlContent, operations) {
             const importedNode = doc.importNode(newCell, true)
             existingCell.parentNode?.replaceChild(importedNode, existingCell)
             cellMap.set(op.cell_id, importedNode)
-        } else if (op.type === "add") {
+        } else if (op.operation === "add") {
             if (cellMap.has(op.cell_id)) {
                 errors.push({
-                    type: "add",
+                    operation: "add",
                     cellId: op.cell_id,
                     message: `Cell with id="${op.cell_id}" already exists`,
                 })
@@ -105,7 +105,7 @@ function applyDiagramOperations(xmlContent, operations) {
             }
             if (!op.new_xml) {
                 errors.push({
-                    type: "add",
+                    operation: "add",
                     cellId: op.cell_id,
                     message: "new_xml is required for add operation",
                 })
@@ -118,7 +118,7 @@ function applyDiagramOperations(xmlContent, operations) {
             const newCell = newDoc.querySelector("mxCell")
             if (!newCell) {
                 errors.push({
-                    type: "add",
+                    operation: "add",
                     cellId: op.cell_id,
                     message: "new_xml must contain an mxCell element",
                 })
@@ -127,7 +127,7 @@ function applyDiagramOperations(xmlContent, operations) {
             const newCellId = newCell.getAttribute("id")
             if (newCellId !== op.cell_id) {
                 errors.push({
-                    type: "add",
+                    operation: "add",
                     cellId: op.cell_id,
                     message: `ID mismatch: cell_id is "${op.cell_id}" but new_xml has id="${newCellId}"`,
                 })
@@ -136,11 +136,11 @@ function applyDiagramOperations(xmlContent, operations) {
             const importedNode = doc.importNode(newCell, true)
             root.appendChild(importedNode)
             cellMap.set(op.cell_id, importedNode)
-        } else if (op.type === "delete") {
+        } else if (op.operation === "delete") {
             const existingCell = cellMap.get(op.cell_id)
             if (!existingCell) {
                 errors.push({
-                    type: "delete",
+                    operation: "delete",
                     cellId: op.cell_id,
                     message: `Cell with id="${op.cell_id}" not found`,
                 })
@@ -201,7 +201,7 @@ function assert(condition, message) {
 test("Update operation changes cell value", () => {
     const { result, errors } = applyDiagramOperations(sampleXml, [
         {
-            type: "update",
+            operation: "update",
             cell_id: "2",
             new_xml:
                 '<mxCell id="2" value="Updated Box A" style="rounded=1;" vertex="1" parent="1"><mxGeometry x="100" y="100" width="120" height="60" as="geometry"/></mxCell>',
@@ -224,7 +224,7 @@ test("Update operation changes cell value", () => {
 test("Update operation fails for non-existent cell", () => {
     const { errors } = applyDiagramOperations(sampleXml, [
         {
-            type: "update",
+            operation: "update",
             cell_id: "999",
             new_xml: '<mxCell id="999" value="Test"/>',
         },
@@ -239,7 +239,7 @@ test("Update operation fails for non-existent cell", () => {
 test("Update operation fails on ID mismatch", () => {
     const { errors } = applyDiagramOperations(sampleXml, [
         {
-            type: "update",
+            operation: "update",
             cell_id: "2",
             new_xml: '<mxCell id="WRONG" value="Test"/>',
         },
@@ -254,7 +254,7 @@ test("Update operation fails on ID mismatch", () => {
 test("Add operation creates new cell", () => {
     const { result, errors } = applyDiagramOperations(sampleXml, [
         {
-            type: "add",
+            operation: "add",
             cell_id: "new1",
             new_xml:
                 '<mxCell id="new1" value="New Box" style="rounded=1;" vertex="1" parent="1"><mxGeometry x="500" y="100" width="120" height="60" as="geometry"/></mxCell>',
@@ -274,7 +274,7 @@ test("Add operation creates new cell", () => {
 test("Add operation fails for duplicate ID", () => {
     const { errors } = applyDiagramOperations(sampleXml, [
         {
-            type: "add",
+            operation: "add",
             cell_id: "2",
             new_xml: '<mxCell id="2" value="Duplicate"/>',
         },
@@ -289,7 +289,7 @@ test("Add operation fails for duplicate ID", () => {
 test("Add operation fails on ID mismatch", () => {
     const { errors } = applyDiagramOperations(sampleXml, [
         {
-            type: "add",
+            operation: "add",
             cell_id: "new1",
             new_xml: '<mxCell id="WRONG" value="Test"/>',
         },
@@ -303,7 +303,7 @@ test("Add operation fails on ID mismatch", () => {
 
 test("Delete operation removes cell", () => {
     const { result, errors } = applyDiagramOperations(sampleXml, [
-        { type: "delete", cell_id: "3" },
+        { operation: "delete", cell_id: "3" },
     ])
     assert(
         errors.length === 0,
@@ -315,7 +315,7 @@ test("Delete operation removes cell", () => {
 
 test("Delete operation fails for non-existent cell", () => {
     const { errors } = applyDiagramOperations(sampleXml, [
-        { type: "delete", cell_id: "999" },
+        { operation: "delete", cell_id: "999" },
     ])
     assert(errors.length === 1, "Should have one error")
     assert(
@@ -327,18 +327,18 @@ test("Delete operation fails for non-existent cell", () => {
 test("Multiple operations in sequence", () => {
     const { result, errors } = applyDiagramOperations(sampleXml, [
         {
-            type: "update",
+            operation: "update",
             cell_id: "2",
             new_xml:
                 '<mxCell id="2" value="Updated" style="rounded=1;" vertex="1" parent="1"><mxGeometry x="100" y="100" width="120" height="60" as="geometry"/></mxCell>',
         },
         {
-            type: "add",
+            operation: "add",
             cell_id: "new1",
             new_xml:
                 '<mxCell id="new1" value="Added" style="rounded=1;" vertex="1" parent="1"><mxGeometry x="500" y="100" width="120" height="60" as="geometry"/></mxCell>',
         },
-        { type: "delete", cell_id: "3" },
+        { operation: "delete", cell_id: "3" },
     ])
     assert(
         errors.length === 0,
@@ -354,14 +354,14 @@ test("Multiple operations in sequence", () => {
 
 test("Invalid XML returns parse error", () => {
     const { errors } = applyDiagramOperations("<not valid xml", [
-        { type: "delete", cell_id: "1" },
+        { operation: "delete", cell_id: "1" },
     ])
     assert(errors.length === 1, "Should have one error")
 })
 
 test("Missing root element returns error", () => {
     const { errors } = applyDiagramOperations("<mxfile></mxfile>", [
-        { type: "delete", cell_id: "1" },
+        { operation: "delete", cell_id: "1" },
     ])
     assert(errors.length === 1, "Should have one error")
     assert(

tsconfig.json

@@ -29,5 +29,5 @@
         ".next/types/**/*.ts",
         ".next/dev/types/**/*.ts"
     ],
-    "exclude": ["node_modules", "packages"]
+    "exclude": ["node_modules", "packages", "electron", "dist-electron"]
 }