fix: prevent flash of example panel and animations on page refresh

- Add isRestored state to track when localStorage restoration completes
- Show example panel only after confirming no saved messages exist
- Skip message animations for restored messages
- Default tool calls and reasoning blocks to collapsed for restored messages

app/[lang]/page.tsx

@@ -28,11 +28,14 @@ export default function Home() {
     } = useDiagram()
     const router = useRouter()
     const pathname = usePathname()
+    // Extract current language from pathname (e.g., "/zh/about" → "zh")
+    const currentLang = (pathname.split("/")[1] || i18n.defaultLocale) as Locale
     const [isMobile, setIsMobile] = useState(false)
     const [isChatVisible, setIsChatVisible] = useState(true)
     const [drawioUi, setDrawioUi] = useState<"min" | "sketch">("min")
     const [darkMode, setDarkMode] = useState(false)
     const [isLoaded, setIsLoaded] = useState(false)
+    const [isDrawioReady, setIsDrawioReady] = useState(false)
     const [closeProtection, setCloseProtection] = useState(false)
 
     const chatPanelRef = useRef<ImperativePanelHandle>(null)
@@ -102,12 +105,18 @@ export default function Home() {
         setIsLoaded(true)
     }, [pathname, router])
 
+    const handleDrawioLoad = useCallback(() => {
+        setIsDrawioReady(true)
+        onDrawioLoad()
+    }, [onDrawioLoad])
+
     const handleDarkModeChange = async () => {
         await saveDiagramToStorage()
         const newValue = !darkMode
         setDarkMode(newValue)
         localStorage.setItem("next-ai-draw-io-dark-mode", String(newValue))
         document.documentElement.classList.toggle("dark", newValue)
+        setIsDrawioReady(false)
         resetDrawioReady()
     }
 
@@ -116,6 +125,7 @@ export default function Home() {
         const newUi = drawioUi === "min" ? "sketch" : "min"
         localStorage.setItem("drawio-theme", newUi)
         setDrawioUi(newUi)
+        setIsDrawioReady(false)
         resetDrawioReady()
     }
 
@@ -129,6 +139,7 @@ export default function Home() {
                 newIsMobile !== isMobileRef.current
             ) {
                 saveDiagramToStorage().catch(() => {})
+                setIsDrawioReady(false)
                 resetDrawioReady()
             }
             isMobileRef.current = newIsMobile
@@ -204,27 +215,35 @@ export default function Home() {
                             mouseOverDrawioRef.current = false
                         }}
                     >
-                        <div className="h-full rounded-xl overflow-hidden shadow-soft-lg border border-border/30">
-                            {isLoaded ? (
-                                <DrawIoEmbed
-                                    key={`${drawioUi}-${darkMode}`}
-                                    ref={drawioRef}
-                                    onExport={handleDiagramExport}
-                                    onLoad={onDrawioLoad}
-                                    onSave={handleDrawioSave}
-                                    baseUrl={drawioBaseUrl}
-                                    urlParameters={{
-                                        ui: drawioUi,
-                                        spin: true,
-                                        libraries: false,
-                                        saveAndExit: false,
-                                        noExitBtn: true,
-                                        dark: darkMode,
-                                    }}
-                                />
-                            ) : (
-                                <div className="h-full w-full flex items-center justify-center bg-background">
-                                    <div className="animate-spin h-8 w-8 border-4 border-primary border-t-transparent rounded-full" />
+                        <div className="h-full rounded-xl overflow-hidden shadow-soft-lg border border-border/30 relative">
+                            {isLoaded && (
+                                <div
+                                    className={`h-full w-full ${isDrawioReady ? "" : "invisible absolute inset-0"}`}
+                                >
+                                    <DrawIoEmbed
+                                        key={`${drawioUi}-${darkMode}-${currentLang}`}
+                                        ref={drawioRef}
+                                        onExport={handleDiagramExport}
+                                        onLoad={handleDrawioLoad}
+                                        onSave={handleDrawioSave}
+                                        baseUrl={drawioBaseUrl}
+                                        urlParameters={{
+                                            ui: drawioUi,
+                                            spin: false,
+                                            libraries: false,
+                                            saveAndExit: false,
+                                            noExitBtn: true,
+                                            dark: darkMode,
+                                            lang: currentLang,
+                                        }}
+                                    />
+                                </div>
+                            )}
+                            {(!isLoaded || !isDrawioReady) && (
+                                <div className="h-full w-full bg-background flex items-center justify-center">
+                                    <span className="text-muted-foreground">
+                                        Draw.io panel is loading...
+                                    </span>
                                 </div>
                             )}
                         </div>

app/api/chat/route.ts

@@ -12,7 +12,11 @@ import fs from "fs/promises"
 import { jsonrepair } from "jsonrepair"
 import path from "path"
 import { z } from "zod"
-import { getAIModel, supportsPromptCaching } from "@/lib/ai-providers"
+import {
+    getAIModel,
+    supportsImageInput,
+    supportsPromptCaching,
+} from "@/lib/ai-providers"
 import { findCachedResponse } from "@/lib/cached-responses"
 import {
     checkAndIncrementRequest,
@@ -295,6 +299,17 @@ async function handleChatRequest(req: Request): Promise<Response> {
         lastUserMessage?.parts?.filter((part: any) => part.type === "file") ||
         []
 
+    // Check if user is sending images to a model that doesn't support them
+    // AI SDK silently drops unsupported parts, so we need to catch this early
+    if (fileParts.length > 0 && !supportsImageInput(modelId)) {
+        return Response.json(
+            {
+                error: `The model "${modelId}" does not support image input. Please use a vision-capable model (e.g., GPT-4o, Claude, Gemini) or remove the image.`,
+            },
+            { status: 400 },
+        )
+    }
+
     // User input only - XML is now in a separate cached system message
     const formattedUserInput = `User input:
 """md

biome.json

@@ -1,5 +1,5 @@
 {
-    "$schema": "https://biomejs.dev/schemas/2.3.8/schema.json",
+    "$schema": "https://biomejs.dev/schemas/2.3.10/schema.json",
     "vcs": {
         "enabled": true,
         "clientKind": "git",

components/chat-message-display.tsx

@@ -193,6 +193,7 @@ interface ChatMessageDisplayProps {
     onRegenerate?: (messageIndex: number) => void
     onEditMessage?: (messageIndex: number, newText: string) => void
     status?: "streaming" | "submitted" | "idle" | "error" | "ready"
+    isRestored?: boolean
 }
 
 export function ChatMessageDisplay({
@@ -205,6 +206,7 @@ export function ChatMessageDisplay({
     onRegenerate,
     onEditMessage,
     status = "idle",
+    isRestored = false,
 }: ChatMessageDisplayProps) {
     const dict = useDictionary()
     const { chartXML, loadDiagram: onDisplayChart } = useDiagram()
@@ -250,6 +252,15 @@ export function ChatMessageDisplay({
     const [expandedPdfSections, setExpandedPdfSections] = useState<
         Record<string, boolean>
     >({})
+    // Track message IDs that were restored from localStorage (skip animation for these)
+    const restoredMessageIdsRef = useRef<Set<string> | null>(null)
+
+    // Capture restored message IDs once when isRestored becomes true
+    useEffect(() => {
+        if (isRestored && restoredMessageIdsRef.current === null) {
+            restoredMessageIdsRef.current = new Set(messages.map((m) => m.id))
+        }
+    }, [isRestored, messages])
 
     const setCopyState = (
         messageId: string,
@@ -283,7 +294,7 @@ export function ChatMessageDisplay({
         try {
             await navigator.clipboard.writeText(text)
             setCopyState(messageId, isToolCall, true)
-        } catch (err) {
+        } catch (_err) {
             // Fallback for non-secure contexts (HTTP) or permission denied
             const textarea = document.createElement("textarea")
             textarea.value = text
@@ -669,7 +680,8 @@ export function ChatMessageDisplay({
     const renderToolPart = (part: ToolPartLike) => {
         const callId = part.toolCallId
         const { state, input, output } = part
-        const isExpanded = expandedTools[callId] ?? true
+        // Default to collapsed if tool is complete, expanded if still streaming
+        const isExpanded = expandedTools[callId] ?? state !== "output-available"
         const toolName = part.type?.replace("tool-", "")
         const isCopied = copiedToolCallId === callId
 
@@ -859,9 +871,9 @@ export function ChatMessageDisplay({
 
     return (
         <ScrollArea className="h-full w-full scrollbar-thin">
-            {messages.length === 0 ? (
+            {messages.length === 0 && isRestored ? (
                 <ExamplePanel setInput={setInput} setFiles={setFiles} />
-            ) : (
+            ) : messages.length === 0 ? null : (
                 <div className="py-4 px-4 space-y-4">
                     {messages.map((message, messageIndex) => {
                         const userMessageText =
@@ -881,13 +893,23 @@ export function ChatMessageDisplay({
                                     .slice(messageIndex + 1)
                                     .every((m) => m.role !== "user"))
                         const isEditing = editingMessageId === message.id
+                        // Skip animation for restored messages
+                        // If isRestored but ref not set yet, we're in first render after restoration - treat all as restored
+                        const isRestoredMessage =
+                            isRestored &&
+                            (restoredMessageIdsRef.current === null ||
+                                restoredMessageIdsRef.current.has(message.id))
                         return (
                             <div
                                 key={message.id}
-                                className={`flex w-full ${message.role === "user" ? "justify-end" : "justify-start"} animate-message-in`}
-                                style={{
-                                    animationDelay: `${messageIndex * 50}ms`,
-                                }}
+                                className={`flex w-full ${message.role === "user" ? "justify-end" : "justify-start"} ${isRestoredMessage ? "" : "animate-message-in"}`}
+                                style={
+                                    isRestoredMessage
+                                        ? undefined
+                                        : {
+                                              animationDelay: `${messageIndex * 50}ms`,
+                                          }
+                                }
                             >
                                 {message.role === "user" &&
                                     userMessageText &&
@@ -984,6 +1006,9 @@ export function ChatMessageDisplay({
                                                             isStreaming={
                                                                 isStreamingReasoning
                                                             }
+                                                            defaultOpen={
+                                                                !isRestoredMessage
+                                                            }
                                                         >
                                                             <ReasoningTrigger />
                                                             <ReasoningContent>

components/chat-panel.tsx

@@ -201,6 +201,7 @@ export default function ChatPanel({
 
     // Flag to track if we've restored from localStorage
     const hasRestoredRef = useRef(false)
+    const [isRestored, setIsRestored] = useState(false)
 
     // Ref to track latest chartXML for use in callbacks (avoids stale closure)
     const chartXMLRef = useRef(chartXML)
@@ -457,6 +458,8 @@ export default function ChatPanel({
             localStorage.removeItem(STORAGE_MESSAGES_KEY)
             localStorage.removeItem(STORAGE_XML_SNAPSHOTS_KEY)
             toast.error(dict.errors.sessionCorrupted)
+        } finally {
+            setIsRestored(true)
         }
     }, [setMessages])
 
@@ -905,7 +908,6 @@ export default function ChatPanel({
                     className="text-sm font-medium text-muted-foreground mt-8 tracking-wide"
                     style={{
                         writingMode: "vertical-rl",
-                        transform: "rotate(180deg)",
                     }}
                 >
                     {dict.nav.aiChat}
@@ -1007,6 +1009,7 @@ export default function ChatPanel({
                     onRegenerate={handleRegenerate}
                     status={status}
                     onEditMessage={handleEditMessage}
+                    isRestored={isRestored}
                 />
             </main>
 

hooks/use-model-config.ts

@@ -11,7 +11,6 @@ import {
     flattenModels,
     type ModelConfig,
     type MultiModelConfig,
-    PROVIDER_INFO,
     type ProviderConfig,
     type ProviderName,
 } from "@/lib/types/model-config"

lib/ai-providers.ts

@@ -786,7 +786,7 @@ export function getAIModel(overrides?: ClientOverrides): ModelConfig {
                                                 `data: ${JSON.stringify(data)}\n\n`,
                                             ),
                                         )
-                                    } catch (e) {
+                                    } catch (_e) {
                                         // If parsing fails, forward the original message to avoid breaking the stream.
                                         controller.enqueue(
                                             new TextEncoder().encode(
@@ -906,3 +906,34 @@ export function supportsPromptCaching(modelId: string): boolean {
         modelId.startsWith("eu.anthropic")
     )
 }
+
+/**
+ * Check if a model supports image/vision input.
+ * Some models silently drop image parts without error (AI SDK warning only).
+ */
+export function supportsImageInput(modelId: string): boolean {
+    const lowerModelId = modelId.toLowerCase()
+
+    // Helper to check if model has vision capability indicator
+    const hasVisionIndicator =
+        lowerModelId.includes("vision") || lowerModelId.includes("vl")
+
+    // Models that DON'T support image/vision input (unless vision variant)
+    // Kimi K2 models don't support images
+    if (lowerModelId.includes("kimi") && !hasVisionIndicator) {
+        return false
+    }
+
+    // DeepSeek text models (not vision variants)
+    if (lowerModelId.includes("deepseek") && !hasVisionIndicator) {
+        return false
+    }
+
+    // Qwen text models (not vision variants like qwen-vl)
+    if (lowerModelId.includes("qwen") && !hasVisionIndicator) {
+        return false
+    }
+
+    // Default: assume model supports images
+    return true
+}

package-lock.json

@@ -93,6 +93,11 @@
                 "typescript": "^5",
                 "wait-on": "^9.0.3",
                 "wrangler": "4.54.0"
+            },
+            "optionalDependencies": {
+                "@tailwindcss/oxide-linux-x64-gnu": "^4.1.18",
+                "lightningcss": "^1.30.2",
+                "lightningcss-linux-x64-gnu": "^1.30.2"
             }
         },
         "node_modules/@acemir/cssom": {
@@ -8714,6 +8719,22 @@
                 "node": ">= 10"
             }
         },
+        "node_modules/@tailwindcss/oxide-linux-x64-gnu": {
+            "version": "4.1.18",
+            "resolved": "https://registry.npmjs.org/@tailwindcss/oxide-linux-x64-gnu/-/oxide-linux-x64-gnu-4.1.18.tgz",
+            "integrity": "sha512-v3gyT0ivkfBLoZGF9LyHmts0Isc8jHZyVcbzio6Wpzifg/+5ZJpDiRiUhDLkcr7f/r38SWNe7ucxmGW3j3Kb/g==",
+            "cpu": [
+                "x64"
+            ],
+            "license": "MIT",
+            "optional": true,
+            "os": [
+                "linux"
+            ],
+            "engines": {
+                "node": ">= 10"
+            }
+        },
         "node_modules/@tailwindcss/postcss": {
             "version": "4.1.18",
             "resolved": "https://registry.npmjs.org/@tailwindcss/postcss/-/postcss-4.1.18.tgz",
@@ -15122,7 +15143,7 @@
             "version": "1.30.2",
             "resolved": "https://registry.npmjs.org/lightningcss/-/lightningcss-1.30.2.tgz",
             "integrity": "sha512-utfs7Pr5uJyyvDETitgsaqSyjCb2qNRAtuqUeWIAKztsOYdcACf2KtARYXg2pSvhkt+9NfoaNY7fxjl6nuMjIQ==",
-            "dev": true,
+            "devOptional": true,
             "license": "MPL-2.0",
             "dependencies": {
                 "detect-libc": "^2.0.3"
@@ -15155,7 +15176,6 @@
             "cpu": [
                 "arm64"
             ],
-            "dev": true,
             "license": "MPL-2.0",
             "optional": true,
             "os": [
@@ -15169,6 +15189,26 @@
                 "url": "https://opencollective.com/parcel"
             }
         },
+        "node_modules/lightningcss-linux-x64-gnu": {
+            "version": "1.30.2",
+            "resolved": "https://registry.npmjs.org/lightningcss-linux-x64-gnu/-/lightningcss-linux-x64-gnu-1.30.2.tgz",
+            "integrity": "sha512-Cfd46gdmj1vQ+lR6VRTTadNHu6ALuw2pKR9lYq4FnhvgBc4zWY1EtZcAc6EffShbb1MFrIPfLDXD6Xprbnni4w==",
+            "cpu": [
+                "x64"
+            ],
+            "license": "MPL-2.0",
+            "optional": true,
+            "os": [
+                "linux"
+            ],
+            "engines": {
+                "node": ">= 12.0.0"
+            },
+            "funding": {
+                "type": "opencollective",
+                "url": "https://opencollective.com/parcel"
+            }
+        },
         "node_modules/lint-staged": {
             "version": "16.2.7",
             "resolved": "https://registry.npmjs.org/lint-staged/-/lint-staged-16.2.7.tgz",
@@ -17972,9 +18012,9 @@
             }
         },
         "node_modules/qs": {
-            "version": "6.14.0",
-            "resolved": "https://registry.npmjs.org/qs/-/qs-6.14.0.tgz",
-            "integrity": "sha512-YWWTjgABSKcvs/nWBi9PycY/JiPJqOD4JA6o9Sej2AtvSGarXxKC3OQSk4pAarbdQlKAh5D4FCQkJNkW+GAn3w==",
+            "version": "6.14.1",
+            "resolved": "https://registry.npmjs.org/qs/-/qs-6.14.1.tgz",
+            "integrity": "sha512-4EK3+xJl8Ts67nLYNwqw/dsFVnCf+qR7RgXSK9jEEm9unao3njwMDdmsdvoKBKHzxd7tCYz5e5M+SnMjdtXGQQ==",
             "license": "BSD-3-Clause",
             "dependencies": {
                 "side-channel": "^1.1.0"

packages/mcp-server/README.md

@@ -90,7 +90,7 @@ Use the standard MCP configuration with:
 - **Natural Language**: Describe diagrams in plain text - flowcharts, architecture diagrams, etc.
 - **Edit Support**: Modify existing diagrams with natural language instructions
 - **Export**: Save diagrams as `.drawio` files
-- **Self-contained**: Embedded server, works offline (except draw.io UI which loads from embed.diagrams.net)
+- **Self-contained**: Embedded server, works offline (except draw.io UI which loads from `embed.diagrams.net` by default, configurable via `DRAWIO_BASE_URL`)
 
 ## Available Tools
 
@@ -130,6 +130,33 @@ Use the standard MCP configuration with:
 | Variable | Default | Description |
 |----------|---------|-------------|
 | `PORT` | `6002` | Port for the embedded HTTP server |
+| `DRAWIO_BASE_URL` | `https://embed.diagrams.net` | Base URL for the draw.io embed. Set this to use a self-hosted draw.io instance for private deployments. |
+
+### Private Deployment (Self-hosted draw.io)
+
+For security-sensitive environments that require private deployment of draw.io:
+
+```json
+{
+  "mcpServers": {
+    "drawio": {
+      "command": "npx",
+      "args": ["@next-ai-drawio/mcp-server@latest"],
+      "env": { 
+        "DRAWIO_BASE_URL": "https://drawio.your-company.com"
+      }
+    }
+  }
+}
+```
+
+You can deploy your own draw.io instance using the official Docker image:
+
+```bash
+docker run -d -p 8080:8080 jgraph/drawio
+```
+
+Then set `DRAWIO_BASE_URL=http://localhost:8080` (or your server's URL).
 
 ## Troubleshooting
 

packages/mcp-server/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@next-ai-drawio/mcp-server",
-    "version": "0.1.10",
+    "version": "0.1.11",
     "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/http-server.ts

@@ -13,6 +13,28 @@ import {
 } from "./history.js"
 import { log } from "./logger.js"
 
+// Configurable draw.io embed URL for private deployments
+const DRAWIO_BASE_URL =
+    process.env.DRAWIO_BASE_URL || "https://embed.diagrams.net"
+
+// Extract origin (scheme + host + port) from URL for postMessage security check
+function getOrigin(url: string): string {
+    try {
+        const parsed = new URL(url)
+        return `${parsed.protocol}//${parsed.host}`
+    } catch {
+        return url // Fallback if parsing fails
+    }
+}
+
+const DRAWIO_ORIGIN = getOrigin(DRAWIO_BASE_URL)
+
+// Normalize URL for iframe src - ensure no double slashes
+function normalizeUrl(url: string): string {
+    // Remove trailing slash to avoid double slashes
+    return url.replace(/\/$/, "")
+}
+
 interface SessionState {
     xml: string
     version: number
@@ -127,7 +149,12 @@ function cleanupExpiredSessions(): void {
     }
 }
 
-setInterval(cleanupExpiredSessions, 5 * 60 * 1000)
+const cleanupIntervalId = setInterval(cleanupExpiredSessions, 5 * 60 * 1000)
+
+export function shutdown(): void {
+    clearInterval(cleanupIntervalId)
+    stopHttpServer()
+}
 
 export function getServerPort(): number {
     return serverPort
@@ -398,7 +425,7 @@ function getHtmlPage(sessionId: string): string {
             </div>
             <div id="status" class="status disconnected">Connecting...</div>
         </div>
-        <iframe id="drawio" src="https://embed.diagrams.net/?embed=1&proto=json&spin=1&libraries=1"></iframe>
+        <iframe id="drawio" src="${normalizeUrl(DRAWIO_BASE_URL)}/?embed=1&proto=json&spin=1&libraries=1"></iframe>
     </div>
     <button id="history-btn" title="History" ${sessionId ? "" : "disabled"}>
         <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
@@ -428,7 +455,7 @@ function getHtmlPage(sessionId: string): string {
         let pendingAiSvg = false;
 
         window.addEventListener('message', (e) => {
-            if (e.origin !== 'https://embed.diagrams.net') return;
+            if (e.origin !== '${DRAWIO_ORIGIN}') return;
             try {
                 const msg = JSON.parse(e.data);
                 if (msg.event === 'init') {

packages/mcp-server/src/index.ts

@@ -39,6 +39,7 @@ import {
     getState,
     requestSync,
     setState,
+    shutdown,
     startHttpServer,
     waitForSync,
 } from "./http-server.js"
@@ -47,7 +48,7 @@ import { validateAndFixXml } from "./xml-validation.js"
 
 // Server configuration
 const config = {
-    port: parseInt(process.env.PORT || "6002"),
+    port: parseInt(process.env.PORT || "6002", 10),
 }
 
 // Session state (single session for simplicity)
@@ -618,6 +619,31 @@ server.registerTool(
     },
 )
 
+// Graceful shutdown handler
+let isShuttingDown = false
+function gracefulShutdown(reason: string) {
+    if (isShuttingDown) return
+    isShuttingDown = true
+    log.info(`Shutting down: ${reason}`)
+    shutdown()
+    process.exit(0)
+}
+
+// Handle stdin close (primary method - works on all platforms including Windows)
+process.stdin.on("close", () => gracefulShutdown("stdin closed"))
+process.stdin.on("end", () => gracefulShutdown("stdin ended"))
+
+// Handle signals (may not work reliably on Windows)
+process.on("SIGINT", () => gracefulShutdown("SIGINT"))
+process.on("SIGTERM", () => gracefulShutdown("SIGTERM"))
+
+// Handle broken pipe (writing to closed stdout)
+process.stdout.on("error", (err) => {
+    if (err.code === "EPIPE" || err.code === "ERR_STREAM_DESTROYED") {
+        gracefulShutdown("stdout error")
+    }
+})
+
 // Start the MCP server
 async function main() {
     log.info("Starting MCP server for Next AI Draw.io (embedded mode)...")

scripts/electron-dev.mjs

@@ -253,7 +253,7 @@ async function main() {
                 },
             )
             console.log("👀 Watching for preset configuration changes...")
-        } catch (err) {
+        } catch (_err) {
             // File might not exist yet, that's ok
             setTimeout(setupConfigWatcher, 5000)
         }