feat(electron): bundle draw.io for offline support (#629)

* feat(electron): bundle draw.io for offline support

- Download draw.io static files during CI build (v29.3.5)
- Detect Electron and use local draw.io files instead of CDN
- Add offline=1 parameter to disable external service calls
- Skip /drawio path from i18n middleware redirect
- Add public/drawio/ to .gitignore (downloaded during build)

This allows the Electron app to work completely offline.

* chore: bump version to 0.4.12-beta.3 for offline test

* fix(electron): ad-hoc sign macOS app for bundled draw.io compatibility

* chore: bump version to 0.4.12-beta.4 for ad-hoc sign test

* fix(electron): disable electron-builder signing to use custom ad-hoc signing

* chore: bump version to 0.4.12-beta.5

.github/workflows/electron-release.yml

@@ -34,6 +34,15 @@ jobs:
           node-version: 24
           cache: "npm"
 
+      - name: Download draw.io static files for offline use
+        run: |
+          rm -rf public/drawio
+          git clone --depth 1 --branch v29.3.5 https://github.com/jgraph/drawio.git /tmp/drawio
+          mkdir -p public/drawio
+          cp -r /tmp/drawio/src/main/webapp/* public/drawio/
+          rm -rf public/drawio/WEB-INF
+          rm -rf public/drawio/META-INF
+
       - name: Install dependencies
         run: npm install
 
@@ -57,6 +66,16 @@ jobs:
           node-version: 24
           cache: "npm"
 
+      - name: Download draw.io static files for offline use
+        shell: bash
+        run: |
+          rm -rf public/drawio
+          git clone --depth 1 --branch v29.3.5 https://github.com/jgraph/drawio.git /tmp/drawio
+          mkdir -p public/drawio
+          cp -r /tmp/drawio/src/main/webapp/* public/drawio/
+          rm -rf public/drawio/WEB-INF
+          rm -rf public/drawio/META-INF
+
       - name: Install dependencies
         run: npm install
 

.gitignore

@@ -56,6 +56,8 @@ push-via-ec2.sh
 /dist-electron/
 /release/
 /electron-standalone/
+# Draw.io static files (downloaded during CI build)
+public/drawio/
 *.dmg
 *.exe
 *.AppImage

app/[lang]/page.tsx

@@ -12,9 +12,6 @@ import {
 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"
-
 export default function Home() {
     const { drawioRef, handleDiagramExport, onDrawioLoad, resetDrawioReady } =
         useDiagram()
@@ -28,6 +25,10 @@ export default function Home() {
     const [darkMode, setDarkMode] = useState(false)
     const [isLoaded, setIsLoaded] = useState(false)
     const [isDrawioReady, setIsDrawioReady] = useState(false)
+    const [isElectron, setIsElectron] = useState(false)
+    const [drawioBaseUrl, setDrawioBaseUrl] = useState(
+        process.env.NEXT_PUBLIC_DRAWIO_BASE_URL || "https://embed.diagrams.net",
+    )
 
     const chatPanelRef = useRef<ImperativePanelHandle>(null)
     const isMobileRef = useRef(false)
@@ -64,6 +65,17 @@ export default function Home() {
             document.documentElement.classList.toggle("dark", prefersDark)
         }
 
+        // Detect Electron and use bundled draw.io files for offline use
+        // Note: react-drawio uses `new URL(baseUrl)` so we need absolute URL
+        // Include /index.html because Next.js doesn't auto-serve index.html for directories
+        const electronDetected =
+            !process.env.NEXT_PUBLIC_DRAWIO_BASE_URL &&
+            !!(window as unknown as { electronAPI?: unknown }).electronAPI
+        if (electronDetected) {
+            setIsElectron(true)
+            setDrawioBaseUrl(`${window.location.origin}/drawio/index.html`)
+        }
+
         setIsLoaded(true)
     }, [pathname, router])
 
@@ -160,7 +172,7 @@ export default function Home() {
                                     className={`h-full w-full ${isDrawioReady ? "" : "invisible absolute inset-0"}`}
                                 >
                                     <DrawIoEmbed
-                                        key={`${drawioUi}-${darkMode}-${currentLang}`}
+                                        key={`${drawioUi}-${darkMode}-${currentLang}-${isElectron}`}
                                         ref={drawioRef}
                                         onExport={handleDiagramExport}
                                         onLoad={handleDrawioLoad}
@@ -174,6 +186,10 @@ export default function Home() {
                                             noExitBtn: true,
                                             dark: darkMode,
                                             lang: currentLang,
+                                            // Enable offline mode in Electron to disable external service calls
+                                            ...(isElectron && {
+                                                offline: true,
+                                            }),
                                         }}
                                     />
                                 </div>

electron/electron-builder.yml

@@ -37,10 +37,11 @@ mac:
       arch:
         - x64
         - arm64
-  hardenedRuntime: true
+  # Disable electron-builder's signing - we use custom ad-hoc signing in afterPack
+  # to properly sign nested bundles with --deep flag for bundled draw.io files
+  identity: null
+  hardenedRuntime: false
   gatekeeperAssess: false
-  entitlements: resources/entitlements.mac.plist
-  entitlementsInherit: resources/entitlements.mac.plist
 
 dmg:
   contents:

package-lock.json

@@ -1,12 +1,12 @@
 {
     "name": "next-ai-draw-io",
-    "version": "0.4.11",
+    "version": "0.4.12-beta.5",
     "lockfileVersion": 3,
     "requires": true,
     "packages": {
         "": {
             "name": "next-ai-draw-io",
-            "version": "0.4.11",
+            "version": "0.4.12-beta.5",
             "license": "Apache-2.0",
             "dependencies": {
                 "@ai-sdk/amazon-bedrock": "^4.0.1",

package.json

@@ -1,6 +1,6 @@
 {
     "name": "next-ai-draw-io",
-    "version": "0.4.11",
+    "version": "0.4.12-beta.5",
     "license": "Apache-2.0",
     "private": true,
     "main": "dist-electron/main/index.js",

proxy.ts

@@ -31,6 +31,7 @@ export function proxy(request: NextRequest) {
     if (
         pathname.startsWith("/api/") ||
         pathname.startsWith("/_next/") ||
+        pathname.startsWith("/drawio") ||
         pathname.includes("/favicon") ||
         /\.(.*)$/.test(pathname)
     ) {

scripts/afterPack.cjs

@@ -1,6 +1,7 @@
 /**
  * electron-builder afterPack hook
  * Copies node_modules to the standalone directory in the packaged app
+ * and ad-hoc signs macOS apps for offline draw.io bundle compatibility
  */
 
 const {
@@ -12,6 +13,7 @@ const {
     statSync,
 } = require("fs")
 const path = require("path")
+const { execSync } = require("child_process")
 
 /**
  * Copy directory recursively, converting symlinks to regular files/directories.
@@ -80,4 +82,22 @@ module.exports = async (context) => {
                 "Ensure 'npm run electron:prepare' was run before building.",
         )
     }
+
+    // Ad-hoc sign macOS apps to fix signature issues with bundled draw.io files
+    if (context.packager.platform.name === "mac") {
+        const appPath = path.join(
+            appOutDir,
+            `${context.packager.appInfo.productFilename}.app`,
+        )
+        console.log(`[afterPack] Ad-hoc signing macOS app: ${appPath}`)
+        try {
+            execSync(`codesign --force --deep --sign - "${appPath}"`, {
+                stdio: "inherit",
+            })
+            console.log("[afterPack] Ad-hoc signing completed successfully")
+        } catch (error) {
+            console.error("[afterPack] Ad-hoc signing failed:", error.message)
+            throw error
+        }
+    }
 }