feat(mcp-server): add DRAWIO_BASE_URL env for private deployments (#467)

* feat(mcp-server): add DRAWIO_BASE_URL env for private deployments

* Fix postMessage origin check and URL normalization

- Add getOrigin() function to extract scheme+host+port from DRAWIO_BASE_URL
- Use DRAWIO_ORIGIN for postMessage security check instead of full URL
- Add normalizeUrl() to remove trailing slash and avoid double slashes
- This fixes issues when users configure DRAWIO_BASE_URL with trailing slash or path

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

@@ -283,7 +283,7 @@ 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

components/model-config-dialog.tsx

@@ -21,7 +21,6 @@ import {
     Zap,
 } from "lucide-react"
 import { useCallback, useEffect, useRef, useState } from "react"
-import { toast } from "sonner"
 import {
     AlertDialog,
     AlertDialogAction,
@@ -517,7 +516,6 @@ export function ModelConfigDialog({
                     {/* Provider Details (Right Panel) */}
                     <div className="flex-1 min-w-0 flex flex-col overflow-auto [&::-webkit-scrollbar]:hidden ">
                         {selectedProvider ? (
-                            <>
                             <ScrollArea className="flex-1" ref={scrollRef}>
                                 <div className="p-6 space-y-8">
                                     {/* Provider Header */}
@@ -559,10 +557,7 @@ export function ModelConfigDialog({
                                             <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.verified}
-                                                            dict.modelConfig
-                                                                .verified
-                                                        }
                                                 </span>
                                             </div>
                                         )}
@@ -575,18 +570,13 @@ export function ModelConfigDialog({
                                             className="text-destructive hover:text-destructive hover:bg-destructive/10"
                                         >
                                             <Trash2 className="h-4 w-4 mr-1.5" />
-                                                {
+                                            {dict.modelConfig.deleteProvider}
-                                                    dict.modelConfig
-                                                        .deleteProvider
-                                                }
                                         </Button>
                                     </div>
 
                                     {/* Configuration Section */}
                                     <ConfigSection
-                                            title={
+                                        title={dict.modelConfig.configuration}
-                                                dict.modelConfig.configuration
-                                            }
                                         icon={Settings2}
                                     >
                                         <ConfigCard>
@@ -636,8 +626,7 @@ export function ModelConfigDialog({
                                                         >
                                                             <Key className="h-3.5 w-3.5 text-muted-foreground" />
                                                             {
-                                                                    dict
+                                                                dict.modelConfig
-                                                                        .modelConfig
                                                                     .awsAccessKeyId
                                                             }
                                                         </Label>
@@ -672,8 +661,7 @@ export function ModelConfigDialog({
                                                         >
                                                             <Key className="h-3.5 w-3.5 text-muted-foreground" />
                                                             {
-                                                                    dict
+                                                                dict.modelConfig
-                                                                        .modelConfig
                                                                     .awsSecretAccessKey
                                                             }
                                                         </Label>
@@ -689,13 +677,10 @@ export function ModelConfigDialog({
                                                                     selectedProvider.awsSecretAccessKey ||
                                                                     ""
                                                                 }
-                                                                    onChange={(
+                                                                onChange={(e) =>
-                                                                        e,
-                                                                    ) =>
                                                                     handleProviderUpdate(
                                                                         "awsSecretAccessKey",
-                                                                            e
+                                                                        e.target
-                                                                                .target
                                                                             .value,
                                                                     )
                                                                 }
@@ -737,8 +722,7 @@ export function ModelConfigDialog({
                                                         >
                                                             <Link2 className="h-3.5 w-3.5 text-muted-foreground" />
                                                             {
-                                                                    dict
+                                                                dict.modelConfig
-                                                                        .modelConfig
                                                                     .awsRegion
                                                             }
                                                         </Label>
@@ -817,8 +801,7 @@ export function ModelConfigDialog({
                                                                 </SelectItem>
                                                                 <SelectItem value="sa-east-1">
                                                                     sa-east-1
-                                                                        (São
+                                                                    (São Paulo)
-                                                                        Paulo)
                                                                 </SelectItem>
                                                             </SelectContent>
                                                         </Select>
@@ -865,8 +848,7 @@ export function ModelConfigDialog({
                                                                     }
                                                                 </>
                                                             ) : (
-                                                                    dict
+                                                                dict.modelConfig
-                                                                        .modelConfig
                                                                     .test
                                                             )}
                                                         </Button>
@@ -922,8 +904,7 @@ export function ModelConfigDialog({
                                                                     }
                                                                 </>
                                                             ) : (
-                                                                    dict
+                                                                dict.modelConfig
-                                                                        .modelConfig
                                                                     .test
                                                             )}
                                                         </Button>
@@ -949,8 +930,7 @@ export function ModelConfigDialog({
                                                         >
                                                             <Key className="h-3.5 w-3.5 text-muted-foreground" />
                                                             {
-                                                                    dict
+                                                                dict.modelConfig
-                                                                        .modelConfig
                                                                     .apiKey
                                                             }
                                                         </Label>
@@ -1067,8 +1047,7 @@ export function ModelConfigDialog({
                                                         >
                                                             <Link2 className="h-3.5 w-3.5 text-muted-foreground" />
                                                             {
-                                                                    dict
+                                                                dict.modelConfig
-                                                                        .modelConfig
                                                                     .baseUrl
                                                             }
                                                             <span className="text-muted-foreground font-normal">
@@ -1098,8 +1077,7 @@ export function ModelConfigDialog({
                                                                         .provider
                                                                 ]
                                                                     .defaultBaseUrl ||
-                                                                    dict
+                                                                dict.modelConfig
-                                                                        .modelConfig
                                                                     .customEndpoint
                                                             }
                                                             className="h-9 rounded-xl font-mono text-xs"
@@ -1122,13 +1100,10 @@ export function ModelConfigDialog({
                                                             dict.modelConfig
                                                                 .customModelId
                                                         }
-                                                            value={
+                                                        value={customModelInput}
-                                                                customModelInput
-                                                            }
                                                         onChange={(e) => {
                                                             setCustomModelInput(
-                                                                    e.target
+                                                                e.target.value,
-                                                                        .value,
                                                             )
                                                             if (
                                                                 duplicateError
@@ -1148,9 +1123,7 @@ export function ModelConfigDialog({
                                                                     handleAddModel(
                                                                         customModelInput.trim(),
                                                                     )
-                                                                    if (
+                                                                if (success) {
-                                                                        success
-                                                                    ) {
                                                                     setCustomModelInput(
                                                                         "",
                                                                     )
@@ -1195,9 +1168,7 @@ export function ModelConfigDialog({
                                                     <Plus className="h-3.5 w-3.5" />
                                                 </Button>
                                                 <Select
-                                                        onValueChange={(
+                                                    onValueChange={(value) => {
-                                                            value,
-                                                        ) => {
                                                         if (value) {
                                                             handleAddModel(
                                                                 value,
@@ -1233,9 +1204,7 @@ export function ModelConfigDialog({
                                                                     }
                                                                     className="font-mono text-xs"
                                                                 >
-                                                                        {
+                                                                    {modelId}
-                                                                            modelId
-                                                                        }
                                                                 </SelectItem>
                                                             ),
                                                         )}
@@ -1246,8 +1215,8 @@ export function ModelConfigDialog({
                                     >
                                         {/* Model List */}
                                         <div className="rounded-2xl border border-border-subtle bg-surface-2/30 overflow-hidden min-h-[120px]">
-                                                {selectedProvider.models
+                                            {selectedProvider.models.length ===
-                                                    .length === 0 ? (
+                                            0 ? (
                                                 <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" />
@@ -1264,9 +1233,7 @@ export function ModelConfigDialog({
                                                     {selectedProvider.models.map(
                                                         (model, index) => (
                                                             <div
-                                                                    key={
+                                                                key={model.id}
-                                                                        model.id
-                                                                    }
                                                                 className={cn(
                                                                     "transition-colors duration-150 hover:bg-interactive-hover/50",
                                                                 )}
@@ -1500,7 +1467,6 @@ export function ModelConfigDialog({
                                     </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-surface-2 mb-4">

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
+}

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)
         }