chore: bump version to 0.4.7 (#416)

* chore: bump version to 0.4.7

* style: auto-format with Biome

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

.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

app/[lang]/page.tsx

@@ -1,4 +1,5 @@
 "use client"
+import { usePathname, useRouter } from "next/navigation"
 import { useCallback, useEffect, useRef, useState } from "react"
 import { DrawIoEmbed } from "react-drawio"
 import type { ImperativePanelHandle } from "react-resizable-panels"
@@ -10,6 +11,7 @@ import {
     ResizablePanelGroup,
 } from "@/components/ui/resizable"
 import { useDiagram } from "@/contexts/diagram-context"
+import { i18n, type Locale } from "@/lib/i18n/config"
 
 const drawioBaseUrl =
     process.env.NEXT_PUBLIC_DRAWIO_BASE_URL || "https://embed.diagrams.net"
@@ -24,6 +26,8 @@ export default function Home() {
         showSaveDialog,
         setShowSaveDialog,
     } = useDiagram()
+    const router = useRouter()
+    const pathname = usePathname()
     const [isMobile, setIsMobile] = useState(false)
     const [isChatVisible, setIsChatVisible] = useState(true)
     const [drawioUi, setDrawioUi] = useState<"min" | "sketch">("min")
@@ -58,6 +62,18 @@ export default function Home() {
 
     // Load preferences from localStorage after mount
     useEffect(() => {
+        // Restore saved locale and redirect if needed
+        const savedLocale = localStorage.getItem("next-ai-draw-io-locale")
+        if (savedLocale && i18n.locales.includes(savedLocale as Locale)) {
+            const pathParts = pathname.split("/").filter(Boolean)
+            const currentLocale = pathParts[0]
+            if (currentLocale !== savedLocale) {
+                pathParts[0] = savedLocale
+                router.replace(`/${pathParts.join("/")}`)
+                return // Wait for redirect
+            }
+        }
+
         const savedUi = localStorage.getItem("drawio-theme")
         if (savedUi === "min" || savedUi === "sketch") {
             setDrawioUi(savedUi)
@@ -84,7 +100,7 @@ export default function Home() {
         }
 
         setIsLoaded(true)
-    }, [])
+    }, [pathname, router])
 
     const handleDarkModeChange = async () => {
         await saveDiagramToStorage()

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 =
@@ -187,6 +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) {
@@ -506,12 +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
@@ -563,14 +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(
@@ -681,20 +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.inputTokenDetails?.cacheReadTokens ?? 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/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;
+    }
+}

components/ai-elements/model-selector.tsx

@@ -66,8 +66,22 @@ export const ModelSelectorInput = ({
 
 export type ModelSelectorListProps = ComponentProps<typeof CommandList>
 
-export const ModelSelectorList = (props: ModelSelectorListProps) => (
-    <CommandList {...props} />
+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>

components/chat-message-display.tsx

@@ -31,6 +31,7 @@ import { getApiEndpoint } from "@/lib/base-path"
 import {
     applyDiagramOperations,
     convertToLegalXml,
+    extractCompleteMxCells,
     isMxCellXmlComplete,
     replaceNodes,
     validateAndFixXml,
@@ -39,7 +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
 }
@@ -52,12 +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"),
     )
 }
 
@@ -78,20 +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}
@@ -315,12 +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) {
@@ -347,7 +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
@@ -360,18 +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(
@@ -603,17 +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

@@ -27,6 +27,7 @@ import {
     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 { getSelectedAIConfig, useModelConfig } from "@/hooks/use-model-config"
 import { getApiEndpoint } from "@/lib/base-path"
@@ -34,8 +35,9 @@ 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 { DevXmlSimulator } from "./dev-xml-simulator"
 
 // localStorage keys for persistence
 const STORAGE_MESSAGES_KEY = "next-ai-draw-io-messages"
@@ -76,6 +78,7 @@ interface ChatPanelProps {
 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
 
 /**
@@ -212,9 +215,6 @@ 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)
@@ -237,6 +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,
@@ -249,313 +259,47 @@ export default function ChatPanel({
         transport: new DefaultChatTransport({
             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)
@@ -632,22 +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
@@ -692,32 +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
-                continuationRetryCountRef.current = 0
-                partialXmlRef.current = ""
-                return false
-            }
-
-            const tpmCheck = quotaManager.checkTPMLimit()
-            if (!tpmCheck.allowed) {
-                quotaManager.showTPMLimitToast()
-                autoRetryCountRef.current = 0
-                continuationRetryCountRef.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(() => {
@@ -927,9 +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
@@ -1007,30 +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,
@@ -1080,7 +760,6 @@ Continue from EXACTLY where you stopped.`,
                 },
             },
         )
-        quotaManager.incrementRequestCount()
     }
 
     // Process files and append content to user text (handles PDF, text, and optionally images)
@@ -1168,13 +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) => {
@@ -1216,12 +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)
@@ -1371,6 +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`}

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/model-config-dialog.tsx

@@ -103,41 +103,40 @@ function ProviderLogo({
     )
 }
 
-// Reusable validation button component
-function ValidationButton({
-    status,
-    onClick,
-    disabled,
-    dict,
+// Configuration section with title and optional action
+function ConfigSection({
+    title,
+    icon: Icon,
+    action,
+    children,
 }: {
-    status: ValidationStatus
-    onClick: () => void
-    disabled: boolean
-    dict: ReturnType<typeof useDictionary>
+    title: string
+    icon: React.ComponentType<{ className?: string }>
+    action?: React.ReactNode
+    children: React.ReactNode
 }) {
     return (
-        <Button
-            variant={status === "success" ? "outline" : "default"}
-            size="sm"
-            onClick={onClick}
-            disabled={disabled}
-            className={cn(
-                "h-9 px-4 min-w-[80px]",
-                status === "success" &&
-                    "text-emerald-600 border-emerald-200 dark:border-emerald-800",
-            )}
-        >
-            {status === "validating" ? (
-                <Loader2 className="h-4 w-4 animate-spin" />
-            ) : status === "success" ? (
-                <>
-                    <Check className="h-4 w-4 mr-1.5" />
-                    {dict.modelConfig.verified}
-                </>
-            ) : (
-                dict.modelConfig.test
-            )}
-        </Button>
+        <div className="space-y-4">
+            <div className="flex items-center justify-between">
+                <div className="flex items-center gap-2">
+                    <Icon className="h-4 w-4 text-muted-foreground" />
+                    <span className="text-xs font-medium text-muted-foreground uppercase tracking-wider">
+                        {title}
+                    </span>
+                </div>
+                {action}
+            </div>
+            {children}
+        </div>
+    )
+}
+
+// Card wrapper with subtle depth
+function ConfigCard({ children }: { children: React.ReactNode }) {
+    return (
+        <div className="rounded-2xl border border-border-subtle bg-surface-2/50 p-5 space-y-5">
+            {children}
+        </div>
     )
 }
 
@@ -154,7 +153,6 @@ export function ModelConfigDialog({
     const [validationStatus, setValidationStatus] =
         useState<ValidationStatus>("idle")
     const [validationError, setValidationError] = useState<string>("")
-    const [scrollState, setScrollState] = useState({ top: false, bottom: true })
     const [customModelInput, setCustomModelInput] = useState("")
     const scrollRef = useRef<HTMLDivElement>(null)
     const validationResetTimeoutRef = useRef<ReturnType<
@@ -186,26 +184,6 @@ export function ModelConfigDialog({
         (p) => p.id === selectedProviderId,
     )
 
-    // Track scroll position for gradient shadows
-    useEffect(() => {
-        const scrollEl = scrollRef.current?.querySelector(
-            "[data-radix-scroll-area-viewport]",
-        ) as HTMLElement | null
-        if (!scrollEl) return
-
-        const handleScroll = () => {
-            const { scrollTop, scrollHeight, clientHeight } = scrollEl
-            setScrollState({
-                top: scrollTop > 10,
-                bottom: scrollTop < scrollHeight - clientHeight - 10,
-            })
-        }
-
-        handleScroll() // Initial check
-        scrollEl.addEventListener("scroll", handleScroll)
-        return () => scrollEl.removeEventListener("scroll", handleScroll)
-    }, [selectedProvider])
-
     // Cleanup validation reset timeout on unmount
     useEffect(() => {
         return () => {
@@ -390,34 +368,35 @@ export function ModelConfigDialog({
 
     return (
         <Dialog open={open} onOpenChange={onOpenChange}>
-            <DialogContent className="sm:max-w-3xl h-[75vh] max-h-[700px] overflow-hidden flex flex-col gap-0 p-0">
-                <DialogHeader className="px-6 pt-6 pb-4 border-b bg-gradient-to-r from-primary/5 via-primary/3 to-transparent">
-                    <DialogTitle className="flex items-center gap-2.5 text-xl font-semibold">
-                        <div className="p-1.5 rounded-lg bg-primary/10">
+            <DialogContent className="sm:max-w-4xl h-[80vh] max-h-[800px] overflow-hidden flex flex-col gap-0 p-0">
+                {/* Header */}
+                <DialogHeader className="px-6 pt-6 pb-4 shrink-0">
+                    <DialogTitle className="flex items-center gap-3">
+                        <div className="p-2 rounded-xl bg-surface-2">
                             <Server className="h-5 w-5 text-primary" />
                         </div>
                         {dict.modelConfig?.title || "AI Model Configuration"}
                     </DialogTitle>
-                    <DialogDescription className="text-sm">
+                    <DialogDescription className="mt-1">
                         {dict.modelConfig?.description ||
                             "Configure multiple AI providers and models for your workspace"}
                     </DialogDescription>
                 </DialogHeader>
 
-                <div className="flex flex-1 min-h-0 overflow-hidden">
+                <div className="flex flex-1 min-h-0 overflow-hidden border-t border-border-subtle">
                     {/* Provider List (Left Sidebar) */}
-                    <div className="w-56 flex-shrink-0 flex flex-col border-r bg-muted/20">
-                        <div className="px-4 py-3 border-b">
+                    <div className="w-60 shrink-0 flex flex-col bg-surface-1/50 border-r border-border-subtle">
+                        <div className="px-4 py-3">
                             <span className="text-xs font-medium text-muted-foreground uppercase tracking-wider">
                                 {dict.modelConfig.providers}
                             </span>
                         </div>
 
-                        <ScrollArea className="flex-1">
-                            <div className="p-2">
+                        <ScrollArea className="flex-1 px-2">
+                            <div className="space-y-1 pb-2">
                                 {config.providers.length === 0 ? (
                                     <div className="px-3 py-8 text-center">
-                                        <div className="inline-flex items-center justify-center w-10 h-10 rounded-full bg-muted mb-3">
+                                        <div className="inline-flex items-center justify-center w-10 h-10 rounded-full bg-surface-2 mb-3">
                                             <Plus className="h-5 w-5 text-muted-foreground" />
                                         </div>
                                         <p className="text-xs text-muted-foreground">
@@ -425,67 +404,74 @@ export function ModelConfigDialog({
                                         </p>
                                     </div>
                                 ) : (
-                                    <div className="flex flex-col gap-1">
-                                        {config.providers.map((provider) => (
-                                            <button
-                                                key={provider.id}
-                                                type="button"
-                                                onClick={() => {
-                                                    setSelectedProviderId(
-                                                        provider.id,
-                                                    )
-                                                    setValidationStatus(
-                                                        provider.validated
-                                                            ? "success"
-                                                            : "idle",
-                                                    )
-                                                    setShowApiKey(false)
-                                                }}
+                                    config.providers.map((provider) => (
+                                        <button
+                                            key={provider.id}
+                                            type="button"
+                                            onClick={() => {
+                                                setSelectedProviderId(
+                                                    provider.id,
+                                                )
+                                                setValidationStatus("idle")
+                                                setShowApiKey(false)
+                                            }}
+                                            className={cn(
+                                                "group flex items-center gap-3 px-3 py-2.5 rounded-xl w-full",
+                                                "text-left text-sm transition-all duration-150",
+                                                "hover:bg-interactive-hover",
+                                                "focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2",
+                                                selectedProviderId ===
+                                                    provider.id &&
+                                                    "bg-surface-0 shadow-sm ring-1 ring-border-subtle",
+                                            )}
+                                        >
+                                            <div
                                                 className={cn(
-                                                    "group flex items-center gap-3 px-3 py-2.5 rounded-lg text-left text-sm transition-all duration-150 hover:bg-accent focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2",
+                                                    "w-8 h-8 rounded-lg flex items-center justify-center",
+                                                    "bg-surface-2 transition-colors duration-150",
                                                     selectedProviderId ===
                                                         provider.id &&
-                                                        "bg-background shadow-sm ring-1 ring-border",
+                                                        "bg-primary/10",
                                                 )}
                                             >
                                                 <ProviderLogo
                                                     provider={provider.provider}
                                                     className="flex-shrink-0"
                                                 />
-                                                <span className="flex-1 truncate font-medium">
-                                                    {getProviderDisplayName(
-                                                        provider,
-                                                    )}
-                                                </span>
-                                                {provider.validated ? (
-                                                    <div className="flex-shrink-0 flex items-center justify-center w-5 h-5 rounded-full bg-emerald-500/10">
-                                                        <Check className="h-3 w-3 text-emerald-500" />
-                                                    </div>
-                                                ) : (
-                                                    <ChevronRight
-                                                        className={cn(
-                                                            "h-4 w-4 text-muted-foreground/50 transition-transform",
-                                                            selectedProviderId ===
-                                                                provider.id &&
-                                                                "translate-x-0.5",
-                                                        )}
-                                                    />
+                                            </div>
+                                            <span className="flex-1 truncate font-medium">
+                                                {getProviderDisplayName(
+                                                    provider,
                                                 )}
-                                            </button>
-                                        ))}
-                                    </div>
+                                            </span>
+                                            {provider.validated ? (
+                                                <div className="flex-shrink-0 flex items-center justify-center w-5 h-5 rounded-full bg-success-muted">
+                                                    <Check className="h-3 w-3 text-success" />
+                                                </div>
+                                            ) : (
+                                                <ChevronRight
+                                                    className={cn(
+                                                        "h-4 w-4 text-muted-foreground/50 transition-transform duration-150",
+                                                        selectedProviderId ===
+                                                            provider.id &&
+                                                            "translate-x-0.5",
+                                                    )}
+                                                />
+                                            )}
+                                        </button>
+                                    ))
                                 )}
                             </div>
                         </ScrollArea>
 
                         {/* Add Provider */}
-                        <div className="p-2 border-t">
+                        <div className="p-3 border-t border-border-subtle">
                             <Select
                                 onValueChange={(v) =>
                                     handleAddProvider(v as ProviderName)
                                 }
                             >
-                                <SelectTrigger className="h-9 bg-background hover:bg-accent">
+                                <SelectTrigger className="w-full h-9 rounded-xl bg-surface-0 border-border-subtle hover:bg-interactive-hover">
                                     <Plus className="h-4 w-4 mr-2 text-muted-foreground" />
                                     <SelectValue
                                         placeholder={
@@ -514,41 +500,23 @@ export function ModelConfigDialog({
                     </div>
 
                     {/* Provider Details (Right Panel) */}
-                    <div className="flex-1 min-w-0 overflow-hidden relative">
+                    <div className="flex-1 min-w-0 flex flex-col overflow-auto [&::-webkit-scrollbar]:hidden ">
                         {selectedProvider ? (
                             <>
-                                {/* Top gradient shadow */}
-                                <div
-                                    className={cn(
-                                        "absolute top-0 left-0 right-0 h-8 bg-gradient-to-b from-background to-transparent z-10 pointer-events-none transition-opacity duration-200",
-                                        scrollState.top
-                                            ? "opacity-100"
-                                            : "opacity-0",
-                                    )}
-                                />
-                                {/* Bottom gradient shadow */}
-                                <div
-                                    className={cn(
-                                        "absolute bottom-0 left-0 right-0 h-8 bg-gradient-to-t from-background to-transparent z-10 pointer-events-none transition-opacity duration-200",
-                                        scrollState.bottom
-                                            ? "opacity-100"
-                                            : "opacity-0",
-                                    )}
-                                />
-                                <ScrollArea className="h-full" ref={scrollRef}>
-                                    <div className="p-6 space-y-6">
+                                <ScrollArea className="flex-1" ref={scrollRef}>
+                                    <div className="p-6 space-y-8">
                                         {/* Provider Header */}
                                         <div className="flex items-center gap-3">
-                                            <div className="flex items-center justify-center w-10 h-10 rounded-lg bg-muted">
+                                            <div className="flex items-center justify-center w-12 h-12 rounded-xl bg-surface-2">
                                                 <ProviderLogo
                                                     provider={
                                                         selectedProvider.provider
                                                     }
-                                                    className="h-5 w-5"
+                                                    className="h-6 w-6"
                                                 />
                                             </div>
                                             <div className="flex-1 min-w-0">
-                                                <h3 className="font-semibold text-base">
+                                                <h3 className="font-semibold text-lg tracking-tight">
                                                     {
                                                         PROVIDER_INFO[
                                                             selectedProvider
@@ -556,7 +524,7 @@ export function ModelConfigDialog({
                                                         ].label
                                                     }
                                                 </h3>
-                                                <p className="text-xs text-muted-foreground">
+                                                <p className="text-sm text-muted-foreground">
                                                     {selectedProvider.models
                                                         .length === 0
                                                         ? dict.modelConfig
@@ -573,8 +541,8 @@ export function ModelConfigDialog({
                                                 </p>
                                             </div>
                                             {selectedProvider.validated && (
-                                                <div className="flex items-center gap-1.5 px-2.5 py-1 rounded-full bg-emerald-500/10 text-emerald-600 dark:text-emerald-400">
-                                                    <Check className="h-3.5 w-3.5" />
+                                                <div className="flex items-center gap-1.5 px-3 py-1.5 rounded-full bg-success-muted text-success">
+                                                    <Check className="h-3.5 w-3.5 animate-check-pop" />
                                                     <span className="text-xs font-medium">
                                                         {
                                                             dict.modelConfig
@@ -583,21 +551,30 @@ export function ModelConfigDialog({
                                                     </span>
                                                 </div>
                                             )}
+                                            <Button
+                                                variant="ghost"
+                                                size="sm"
+                                                onClick={() =>
+                                                    setDeleteConfirmOpen(true)
+                                                }
+                                                className="text-destructive hover:text-destructive hover:bg-destructive/10"
+                                            >
+                                                <Trash2 className="h-4 w-4 mr-1.5" />
+                                                {
+                                                    dict.modelConfig
+                                                        .deleteProvider
+                                                }
+                                            </Button>
                                         </div>
 
                                         {/* Configuration Section */}
-                                        <div className="space-y-4">
-                                            <div className="flex items-center gap-2 text-sm font-medium text-muted-foreground">
-                                                <Settings2 className="h-4 w-4" />
-                                                <span>
-                                                    {
-                                                        dict.modelConfig
-                                                            .configuration
-                                                    }
-                                                </span>
-                                            </div>
-
-                                            <div className="rounded-xl border bg-card p-4 space-y-4">
+                                        <ConfigSection
+                                            title={
+                                                dict.modelConfig.configuration
+                                            }
+                                            icon={Settings2}
+                                        >
+                                            <ConfigCard>
                                                 {/* Display Name */}
                                                 <div className="space-y-2">
                                                     <Label
@@ -856,7 +833,7 @@ export function ModelConfigDialog({
                                                                     "h-9 px-4",
                                                                     validationStatus ===
                                                                         "success" &&
-                                                                        "text-emerald-600 border-emerald-200 dark:border-emerald-800",
+                                                                        "text-success border-success/30 bg-success-muted hover:bg-success-muted",
                                                                 )}
                                                             >
                                                                 {validationStatus ===
@@ -865,7 +842,7 @@ export function ModelConfigDialog({
                                                                 ) : validationStatus ===
                                                                   "success" ? (
                                                                     <>
-                                                                        <Check className="h-4 w-4 mr-1.5" />
+                                                                        <Check className="h-4 w-4 mr-1.5 animate-check-pop" />
                                                                         {
                                                                             dict
                                                                                 .modelConfig
@@ -975,7 +952,7 @@ export function ModelConfigDialog({
                                                                         "h-9 px-4",
                                                                         validationStatus ===
                                                                             "success" &&
-                                                                            "text-emerald-600 border-emerald-200 dark:border-emerald-800",
+                                                                            "text-success border-success/30 bg-success-muted hover:bg-success-muted",
                                                                     )}
                                                                 >
                                                                     {validationStatus ===
@@ -984,7 +961,7 @@ export function ModelConfigDialog({
                                                                     ) : validationStatus ===
                                                                       "success" ? (
                                                                         <>
-                                                                            <Check className="h-4 w-4 mr-1.5" />
+                                                                            <Check className="h-4 w-4 mr-1.5 animate-check-pop" />
                                                                             {
                                                                                 dict
                                                                                     .modelConfig
@@ -1053,26 +1030,19 @@ export function ModelConfigDialog({
                                                                         .modelConfig
                                                                         .customEndpoint
                                                                 }
-                                                                className="h-9 font-mono text-xs"
+                                                                className="h-9 rounded-xl font-mono text-xs"
                                                             />
                                                         </div>
                                                     </>
                                                 )}
-                                            </div>
-                                        </div>
+                                            </ConfigCard>
+                                        </ConfigSection>
 
                                         {/* Models Section */}
-                                        <div className="space-y-4">
-                                            <div className="flex items-center justify-between">
-                                                <div className="flex items-center gap-2 text-sm font-medium text-muted-foreground">
-                                                    <Sparkles className="h-4 w-4" />
-                                                    <span>
-                                                        {
-                                                            dict.modelConfig
-                                                                .models
-                                                        }
-                                                    </span>
-                                                </div>
+                                        <ConfigSection
+                                            title={dict.modelConfig.models}
+                                            icon={Sparkles}
+                                            action={
                                                 <div className="flex items-center gap-2">
                                                     <div className="relative">
                                                         <Input
@@ -1088,7 +1058,6 @@ export function ModelConfigDialog({
                                                                     e.target
                                                                         .value,
                                                                 )
-                                                                // Clear duplicate error when typing
                                                                 if (
                                                                     duplicateError
                                                                 ) {
@@ -1117,12 +1086,11 @@ export function ModelConfigDialog({
                                                                 }
                                                             }}
                                                             className={cn(
-                                                                "h-8 w-48 font-mono text-xs",
+                                                                "h-8 w-44 rounded-lg font-mono text-xs",
                                                                 duplicateError &&
                                                                     "border-destructive focus-visible:ring-destructive",
                                                             )}
                                                         />
-                                                        {/* Show duplicate error for custom model input */}
                                                         {duplicateError && (
                                                             <p className="absolute top-full left-0 mt-1 text-[11px] text-destructive">
                                                                 {duplicateError}
@@ -1132,7 +1100,7 @@ export function ModelConfigDialog({
                                                     <Button
                                                         variant="outline"
                                                         size="sm"
-                                                        className="h-8"
+                                                        className="h-8 rounded-lg"
                                                         onClick={() => {
                                                             if (
                                                                 customModelInput.trim()
@@ -1169,7 +1137,7 @@ export function ModelConfigDialog({
                                                             0
                                                         }
                                                     >
-                                                        <SelectTrigger className="w-32 h-8 hover:bg-accent">
+                                                        <SelectTrigger className="w-28 h-8 rounded-lg hover:bg-interactive-hover">
                                                             <span className="text-xs">
                                                                 {availableSuggestions.length ===
                                                                 0
@@ -1202,14 +1170,14 @@ export function ModelConfigDialog({
                                                         </SelectContent>
                                                     </Select>
                                                 </div>
-                                            </div>
-
+                                            }
+                                        >
                                             {/* Model List */}
-                                            <div className="rounded-xl border bg-card overflow-hidden min-h-[120px]">
+                                            <div className="rounded-2xl border border-border-subtle bg-surface-2/30 overflow-hidden min-h-[120px]">
                                                 {selectedProvider.models
                                                     .length === 0 ? (
-                                                    <div className="p-4 text-center h-full flex flex-col items-center justify-center">
-                                                        <div className="inline-flex items-center justify-center w-10 h-10 rounded-full bg-muted mb-2">
+                                                    <div className="p-6 text-center h-full flex flex-col items-center justify-center">
+                                                        <div className="inline-flex items-center justify-center w-10 h-10 rounded-full bg-surface-2 mb-3">
                                                             <Sparkles className="h-5 w-5 text-muted-foreground" />
                                                         </div>
                                                         <p className="text-sm text-muted-foreground">
@@ -1220,7 +1188,7 @@ export function ModelConfigDialog({
                                                         </p>
                                                     </div>
                                                 ) : (
-                                                    <div className="divide-y">
+                                                    <div className="divide-y divide-border-subtle">
                                                         {selectedProvider.models.map(
                                                             (model, index) => (
                                                                 <div
@@ -1228,16 +1196,7 @@ export function ModelConfigDialog({
                                                                         model.id
                                                                     }
                                                                     className={cn(
-                                                                        "transition-colors hover:bg-muted/30",
-                                                                        index ===
-                                                                            0 &&
-                                                                            "rounded-t-xl",
-                                                                        index ===
-                                                                            selectedProvider
-                                                                                .models
-                                                                                .length -
-                                                                                1 &&
-                                                                            "rounded-b-xl",
+                                                                        "transition-colors duration-150 hover:bg-interactive-hover/50",
                                                                     )}
                                                                 >
                                                                     <div className="flex items-center gap-3 p-3 min-w-0">
@@ -1264,8 +1223,8 @@ export function ModelConfigDialog({
                                                                             ) : model.validated ===
                                                                               true ? (
                                                                                 // Valid
-                                                                                <div className="w-full h-full rounded-lg bg-emerald-500/10 flex items-center justify-center">
-                                                                                    <Check className="h-4 w-4 text-emerald-500" />
+                                                                                <div className="w-full h-full rounded-lg bg-success-muted flex items-center justify-center">
+                                                                                    <Check className="h-4 w-4 text-success" />
                                                                                 </div>
                                                                             ) : model.validated ===
                                                                               false ? (
@@ -1466,34 +1425,16 @@ export function ModelConfigDialog({
                                                     </div>
                                                 )}
                                             </div>
-                                        </div>
-
-                                        {/* Danger Zone */}
-                                        <div className="pt-4">
-                                            <Button
-                                                variant="ghost"
-                                                size="sm"
-                                                onClick={() =>
-                                                    setDeleteConfirmOpen(true)
-                                                }
-                                                className="text-muted-foreground hover:text-destructive hover:bg-destructive/10"
-                                            >
-                                                <Trash2 className="h-4 w-4 mr-2" />
-                                                {
-                                                    dict.modelConfig
-                                                        .deleteProvider
-                                                }
-                                            </Button>
-                                        </div>
+                                        </ConfigSection>
                                     </div>
                                 </ScrollArea>
                             </>
                         ) : (
                             <div className="h-full flex flex-col items-center justify-center p-8 text-center">
-                                <div className="inline-flex items-center justify-center w-16 h-16 rounded-2xl bg-gradient-to-br from-primary/10 to-primary/5 mb-4">
-                                    <Server className="h-8 w-8 text-primary/60" />
+                                <div className="inline-flex items-center justify-center w-16 h-16 rounded-2xl bg-surface-2 mb-4">
+                                    <Server className="h-8 w-8 text-muted-foreground" />
                                 </div>
-                                <h3 className="font-semibold mb-1">
+                                <h3 className="font-semibold text-lg tracking-tight mb-1">
                                     {dict.modelConfig.configureProviders}
                                 </h3>
                                 <p className="text-sm text-muted-foreground max-w-xs">
@@ -1505,7 +1446,7 @@ export function ModelConfigDialog({
                 </div>
 
                 {/* Footer */}
-                <div className="px-6 py-3 border-t bg-muted/20">
+                <div className="px-6 py-3 border-t border-border-subtle bg-surface-1/30 shrink-0">
                     <p className="text-xs text-muted-foreground text-center flex items-center justify-center gap-1.5">
                         <Key className="h-3 w-3" />
                         {dict.modelConfig.apiKeyStored}

components/model-selector.tsx

@@ -124,7 +124,7 @@ export function ModelSelector({
                 <ModelSelectorInput
                     placeholder={dict.modelConfig.searchModels}
                 />
-                <ModelSelectorList>
+                <ModelSelectorList className="[&::-webkit-scrollbar]:hidden [-ms-overflow-style:none] [scrollbar-width:none]">
                     <ModelSelectorEmpty>
                         {validatedModels.length === 0 && models.length > 0
                             ? dict.modelConfig.noVerifiedModels

components/settings-dialog.tsx

@@ -24,6 +24,32 @@ 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",
@@ -125,6 +151,9 @@ function SettingsContent({
     }, [open])
 
     const changeLanguage = (lang: string) => {
+        // Save locale to localStorage for persistence across restarts
+        localStorage.setItem("next-ai-draw-io-locale", lang)
+
         const parts = pathname.split("/")
         if (parts.length > 1 && i18n.locales.includes(parts[1] as Locale)) {
             parts[1] = lang
@@ -177,145 +206,154 @@ function SettingsContent({
     }
 
     return (
-        <DialogContent className="sm:max-w-md">
-            <DialogHeader>
+        <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>
+                <DialogDescription className="mt-1">
                     {dict.settings.description}
                 </DialogDescription>
             </DialogHeader>
-            <div className="space-y-4 py-2">
-                {accessCodeRequired && (
-                    <div className="space-y-2">
-                        <Label htmlFor="access-code">
-                            {dict.settings.accessCode}
-                        </Label>
-                        <div className="flex gap-2">
-                            <Input
-                                id="access-code"
-                                type="password"
-                                value={accessCode}
-                                onChange={(e) => setAccessCode(e.target.value)}
-                                onKeyDown={handleKeyDown}
-                                placeholder={
-                                    dict.settings.accessCodePlaceholder
-                                }
-                                autoComplete="off"
-                            />
-                            <Button
-                                onClick={handleSave}
-                                disabled={isVerifying || !accessCode.trim()}
-                            >
-                                {isVerifying ? "..." : dict.common.save}
-                            </Button>
+
+            {/* Content */}
+            <div className="px-6 pb-6">
+                <div className="divide-y divide-border-subtle">
+                    {/* Access Code (conditional) */}
+                    {accessCodeRequired && (
+                        <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"
+                                    type="password"
+                                    value={accessCode}
+                                    onChange={(e) =>
+                                        setAccessCode(e.target.value)
+                                    }
+                                    onKeyDown={handleKeyDown}
+                                    placeholder={
+                                        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>
+                            {error && (
+                                <p className="text-xs text-destructive">
+                                    {error}
+                                </p>
+                            )}
                         </div>
-                        <p className="text-[0.8rem] text-muted-foreground">
-                            {dict.settings.accessCodeDescription}
-                        </p>
-                        {error && (
-                            <p className="text-[0.8rem] text-destructive">
-                                {error}
-                            </p>
-                        )}
-                    </div>
-                )}
+                    )}
 
-                <div className="flex items-center justify-between">
-                    <div className="space-y-0.5">
-                        <Label htmlFor="language-select">
-                            {dict.settings.language}
-                        </Label>
-                        <p className="text-[0.8rem] text-muted-foreground">
-                            {dict.settings.languageDescription}
-                        </p>
-                    </div>
-                    <Select value={currentLang} onValueChange={changeLanguage}>
-                        <SelectTrigger id="language-select" className="w-32">
-                            <SelectValue />
-                        </SelectTrigger>
-                        <SelectContent>
-                            {i18n.locales.map((locale) => (
-                                <SelectItem key={locale} value={locale}>
-                                    {LANGUAGE_LABELS[locale]}
-                                </SelectItem>
-                            ))}
-                        </SelectContent>
-                    </Select>
-                </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>
-                    <Button
-                        id="theme-toggle"
-                        variant="outline"
-                        size="icon"
-                        onClick={onToggleDarkMode}
+                    {/* Language */}
+                    <SettingItem
+                        label={dict.settings.language}
+                        description={dict.settings.languageDescription}
                     >
-                        {darkMode ? (
-                            <Sun className="h-4 w-4" />
-                        ) : (
-                            <Moon className="h-4 w-4" />
-                        )}
-                    </Button>
-                </div>
+                        <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>
 
-                <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"
+                    {/* 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" />
+                            ) : (
+                                <Moon className="h-4 w-4" />
+                            )}
+                        </Button>
+                    </SettingItem>
+
+                    {/* Draw.io Style */}
+                    <SettingItem
+                        label={dict.settings.drawioStyle}
+                        description={`${dict.settings.drawioStyleDescription} ${
+                            drawioUi === "min"
                                 ? dict.settings.minimal
-                                : dict.settings.sketch}
-                        </p>
-                    </div>
-                    <Button
-                        id="drawio-ui"
-                        variant="outline"
-                        size="sm"
-                        onClick={onToggleDrawioUi}
+                                : dict.settings.sketch
+                        }`}
                     >
-                        {dict.settings.switchTo}{" "}
-                        {drawioUi === "min"
-                            ? dict.settings.sketch
-                            : dict.settings.minimal}
-                    </Button>
-                </div>
+                        <Button
+                            id="drawio-ui"
+                            variant="outline"
+                            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>
+                    </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>
-                    <Switch
-                        id="close-protection"
-                        checked={closeProtection}
-                        onCheckedChange={(checked) => {
-                            setCloseProtection(checked)
-                            localStorage.setItem(
-                                STORAGE_CLOSE_PROTECTION_KEY,
-                                checked.toString(),
-                            )
-                            onCloseProtectionChange?.(checked)
-                        }}
-                    />
+                    {/* Close Protection */}
+                    <SettingItem
+                        label={dict.settings.closeProtection}
+                        description={dict.settings.closeProtectionDescription}
+                    >
+                        <Switch
+                            id="close-protection"
+                            checked={closeProtection}
+                            onCheckedChange={(checked) => {
+                                setCloseProtection(checked)
+                                localStorage.setItem(
+                                    STORAGE_CLOSE_PROTECTION_KEY,
+                                    checked.toString(),
+                                )
+                                onCloseProtectionChange?.(checked)
+                            }}
+                        />
+                    </SettingItem>
                 </div>
             </div>
-            <div className="pt-4 border-t border-border/50">
-                <p className="text-[0.75rem] text-muted-foreground text-center">
+
+            {/* 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>
@@ -328,9 +366,9 @@ export function SettingsDialog(props: SettingsDialogProps) {
         <Dialog open={props.open} onOpenChange={props.onOpenChange}>
             <Suspense
                 fallback={
-                    <DialogContent className="sm:max-w-md">
-                        <div className="h-64 flex items-center justify-center">
-                            <div className="animate-spin h-8 w-8 border-4 border-primary border-t-transparent rounded-full" />
+                    <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>
                 }

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}

electron/main/port-manager.ts

@@ -3,16 +3,16 @@ import { app } from "electron"
 
 /**
  * Port configuration
+ * Using fixed ports to preserve localStorage across restarts
+ * (localStorage is origin-specific, so changing ports loses all saved data)
  */
 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
+    // Production mode uses fixed port (61337) to preserve localStorage
+    // Falls back to sequential ports if unavailable
+    production: 61337,
+    // Maximum attempts to find an available port (fallback)
     maxAttempts: 100,
 }
 
@@ -36,19 +36,11 @@ export function isPortAvailable(port: number): Promise<boolean> {
     })
 }
 
-/**
- * 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
+ * - In production: uses fixed port (61337) to preserve localStorage
+ * - Falls back to sequential ports if preferred port is unavailable
  *
  * @param reuseExisting If true, try to reuse the previously allocated port
  * @returns Promise<number> The available port
@@ -56,6 +48,9 @@ function getRandomPort(): number {
  */
 export async function findAvailablePort(reuseExisting = true): Promise<number> {
     const isDev = !app.isPackaged
+    const preferredPort = isDev
+        ? PORT_CONFIG.development
+        : PORT_CONFIG.production
 
     // Try to reuse cached port if requested and available
     if (reuseExisting && allocatedPort !== null) {
@@ -69,29 +64,22 @@ export async function findAvailablePort(reuseExisting = true): Promise<number> {
         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...`,
-        )
+    // Try preferred port first
+    if (await isPortAvailable(preferredPort)) {
+        allocatedPort = preferredPort
+        return preferredPort
     }
 
-    // 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()
+    console.warn(
+        `Preferred port ${preferredPort} is in use, finding alternative...`,
+    )
 
-        const available = await isPortAvailable(port)
-        if (available) {
+    // Fallback: try sequential ports starting from preferred + 1
+    for (let attempt = 1; attempt <= PORT_CONFIG.maxAttempts; attempt++) {
+        const port = preferredPort + attempt
+        if (await isPortAvailable(port)) {
             allocatedPort = port
-            console.log(`Allocated port: ${port}`)
+            console.log(`Allocated fallback port: ${port}`)
             return port
         }
     }

electron/settings/index.html

@@ -9,6 +9,12 @@
 </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">

electron/settings/settings.css

@@ -24,6 +24,39 @@
     }
 }
 
+.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;

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 }
+}

instrumentation.ts

@@ -14,22 +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.startsWith("RSC") ||
-                spanName.includes("BaseServer") ||
-                spanName.includes("handleRequest") ||
-                spanName.includes("resolve page") ||
-                spanName.includes("start response")
-            ) {
-                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
         },
     })
 

lib/ai-providers.ts

@@ -588,13 +588,15 @@ 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 }),
-                })
-                // Use Responses API (default) instead of .chat() to support reasoning
-                // for gpt-5, o1, o3, o4 models. Chat Completions API does not emit reasoning events.
+            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)

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/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/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

@@ -83,22 +83,24 @@ export const PROVIDER_INFO: Record<
 // Suggested models per provider for quick add
 export const SUGGESTED_MODELS: Record<ProviderName, string[]> = {
     openai: [
-        // GPT-4o series (latest)
+        "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",
-        "gpt-4o-2024-11-20",
-        // GPT-4 Turbo
-        "gpt-4-turbo",
-        "gpt-4-turbo-preview",
-        // o1/o3 reasoning models
-        "o1",
-        "o1-mini",
-        "o1-preview",
-        "o3-mini",
-        // GPT-4
-        "gpt-4",
-        // GPT-3.5
-        "gpt-3.5-turbo",
     ],
     anthropic: [
         // Claude 4.5 series (latest)

lib/use-quota-manager.tsx

@@ -1,11 +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 { useDictionary } from "@/hooks/use-dictionary"
 import { formatMessage } from "@/lib/i18n/utils"
-import { STORAGE_KEYS } from "@/lib/storage"
 
 export interface QuotaConfig {
     dailyRequestLimit: number
@@ -13,181 +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
-
     const dict = useDictionary()
 
-    // 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],
-    )
-
     // 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)}
                     />
                 ),
@@ -197,54 +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 ? `${tpmLimit / 1000}k` : String(tpmLimit)
-        const message = formatMessage(dict.quota.tpmMessageDetailed, {
-            limit: limitDisplay,
-            seconds: 60,
-        })
-        toast.error(message, { duration: 8000 })
-    }, [tpmLimit, dict])
+    const showTPMLimitToast = useCallback(
+        (limit?: number) => {
+            const effectiveLimit = limit ?? tpmLimit
+            const limitDisplay =
+                effectiveLimit >= 1000
+                    ? `${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)
@@ -1079,7 +1167,8 @@ export function autoFixXml(xml: string): { fixed: string; fixes: string[] } {
     }
 
     // 8c. Remove non-draw.io tags (after typo fixes so lowercase variants are fixed first)
-    // Valid draw.io tags: mxfile, diagram, mxGraphModel, root, mxCell, mxGeometry, mxPoint, Array, Object
+    // 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",
@@ -1092,25 +1181,59 @@ export function autoFixXml(xml: string): { fixed: string; fixes: string[] } {
         "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]
-        if (!validDrawioTags.has(tagName)) {
-            foreignTags.add(tagName)
-        }
+        // 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 (foreignTags.size > 0) {
-        console.log(
-            "[autoFixXml] Step 8c: 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"), "")
+
+    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(", ")}`,
@@ -1161,6 +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 }
@@ -1169,12 +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 }

package.json

@@ -1,6 +1,6 @@
 {
     "name": "next-ai-draw-io",
-    "version": "0.4.6",
+    "version": "0.4.7",
     "license": "Apache-2.0",
     "private": true,
     "main": "dist-electron/main/index.js",
@@ -32,6 +32,7 @@
         "@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",

packages/mcp-server/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@next-ai-drawio/mcp-server",
-    "version": "0.1.5",
+    "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/index.ts

@@ -265,14 +265,22 @@ server.registerTool(
             "- 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()
@@ -356,13 +364,13 @@ server.registerTool(
                     )
                     if (fixed) {
                         log.info(
-                            `Operation ${op.type} ${op.cell_id}: XML auto-fixed: ${fixes.join(", ")}`,
+                            `Operation ${op.operation} ${op.cell_id}: XML auto-fixed: ${fixes.join(", ")}`,
                         )
                         return { ...op, new_xml: fixed }
                     }
                     if (!valid && error) {
                         log.warn(
-                            `Operation ${op.type} ${op.cell_id}: XML validation failed: ${error}`,
+                            `Operation ${op.operation} ${op.cell_id}: XML validation failed: ${error}`,
                         )
                     }
                 }

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

@@ -459,7 +459,8 @@ export function autoFixXml(xml: string): { fixed: string; fixes: string[] } {
         fixes.push("Removed quotes around color values in style")
     }
 
-    // 10. Fix unescaped < in attribute values
+    // 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
@@ -471,10 +472,10 @@ export function autoFixXml(xml: string): { fixed: string; fixes: string[] } {
     }
     if (hasUnescapedLt) {
         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")
     }
 
     // 11. Fix invalid hex character references
@@ -903,24 +904,30 @@ export function validateAndFixXml(xml: string): {
 
 /**
  * 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 {
-    let trimmed = xml?.trim() || ""
+    const trimmed = xml?.trim() || ""
     if (!trimmed) return false
 
-    // Strip wrapper tags if present
-    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>")
 
-    return trimmed.endsWith("/>") || trimmed.endsWith("</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
+    }
+}

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(