Electron Debug MCP Server

🌟 Overview

Electron Debug MCP is a local MCP server that gives AI coding agents eyes, hands, and Chrome DevTools inside your Electron app.

Instead of guessing from source alone, the agent can:

It speaks MCP over stdio (Cursor / Claude Desktop friendly), bridges to Chrome DevTools Protocol, buffers console + network on monitored page targets, and keeps stdout clean (all server logs go to stderr).

👤 Who it’s for

• 🧑‍💻 Cursor / Claude users pair-programming on Electron desktop apps

• 🐛 Maintainers tired of “white screen / silent exception” bugs agents can’t see

• 🧰 Tooling authors who need a stdio MCP ↔ CDP bridge for Electron/Chromium

💬 Example things you can ask the agent

“Start D:/apps/my-app on port 9222 and tell me if the renderer threw on boot.”
“Find my running Electron app, attach by PID, screenshot #sidebar, and dump localStorage.”
“Type into #email, press Enter, wait for Welcome, then list console errors.”
“Start a CDP trace, click through settings, stop tracing, and save the JSON.”
“Diagnose why this Electron window is blank.”

📊 At a glance

✅ Status

• 🟢 Ready for local agent-driven Electron debugging

• 🟢 E2E smoke: start → UI/automation → storage/cookies → tracing → find/attach-by-pid → stop

• 🟢 Windows binary repair: scripts/fix-electron.cmd when npm blocks postinstall

• 🟢 v1.5.0 — element screenshots, cookies/storage, tracing, attach-by-pid

Related MCP server: Electron Native MCP Server

📖 Table of contents

• Overview

• Why this exists

• Feature tour

• 60-second quick start

• Cursor & Claude Desktop setup

• How it works

• Complete tools cheatsheet

• Tools reference (all options)

• Resources

• Prompts

• Usage examples

• Configuration

• npm scripts

• Testing

• Project layout

• Security

• Troubleshooting

• Contributing

• License

✨ Why this exists

Electron bugs are often invisible to coding agents:

🚀 Feature tour

🔌 Lifecycle

• ▶️ start_app — launch with remote debugging (+ optional inspectMain)

• 🔗 attach — connect to an existing debug port

• 🆔 attach_by_pid — resolve port from process argv

• 🧭 find_apps — list Electron PIDs + debug ports

• 🔎 discover_apps — scan local CDP ports

• ⏹️ stop_app — kill owned / detach attached

• 📋 list_apps — sessions, ports, buffer counts

• 🩺 diagnose — port health + recent errors

🔍 Inspection

• 📸 screenshot / 💾 save_screenshot — full page or selector clip

• 🌳 get_dom / query_selector

• 🧮 evaluate / evaluate_main

• 🍪 get_cookies / set_cookie

• 🗄️ get_storage / set_storage

• 🧾 get_console_messages — log/warn/error/exceptions

• 🌐 get_network_log — request/response/fail

• 📜 get_logs — Electron stdout/stderr

• 🎯 list_targets / page_info

🖱️ Interaction

• 🧭 navigate + load wait

• ⏳ wait_for — selector / hidden / enabled / count / text / URL / console

• 🖱️ click left/right/middle

• ⌨️ type_text (+ clear / Enter) · press_key (+ modifiers)

• 🔄 reload · ⏸️ pause · ▶️ resume

• 🧹 clear_buffers

🧠 Agent UX & power

• 📝 MCP handshake instructions

• 💬 Prompts: blank window · exceptions · UI smoke

• 🏷️ Target roles: page / worker / browser / main

• 🔔 set_console_live + resource list-changed

• 📈 start_tracing / stop_tracing

• 🛡️ stderr-only diagnostics (stdio-safe)

• 🧰 cdp_command for any DevTools method

⚡ 60-second quick start

git clone https://github.com/amafjarkasi/electron-mcp-server.git
cd electron-mcp-server
npm install
npm run ensure-electron
npm run build
npm test

🪟 Windows binary missing?

If npm warns about allowScripts / Electron postinstall:

.\scripts\fix-electron.cmd

That reinstalls Electron, extracts electron.exe with system tar, then runs tests.

🖥️ Cursor & Claude Desktop setup

Cursor

1. npm run build

2. Open Cursor → MCP settings

3. Add (use your absolute path):

Windows

{
  "mcpServers": {
    "electron-debug": {
      "command": "node",
      "args": ["D:/GH/electron-mcp-server/build/index.js"]
    }
  }
}

macOS / Linux

{
  "mcpServers": {
    "electron-debug": {
      "command": "node",
      "args": ["/Users/you/code/electron-mcp-server/build/index.js"],
      "env": {
        "ELECTRON_MCP_NO_SANDBOX": "1"
      }
    }
  }
}

4. Restart Cursor

5. Confirm tools: start_app, attach, find_apps, screenshot, get_console_messages, click, start_tracing, …

📄 Template: examples/cursor-mcp.json

Claude Desktop

Same mcpServers block in claude_desktop_config.json, pointing at build/index.js.

⚠️ Don’t run node build/index.js in a normal terminal for daily use — it waits on stdio for an MCP client. Let Cursor/Claude spawn it.

🧩 How it works

┌──────────────────────────┐
│  Cursor / Claude / MCP   │
│  client (agent)          │
└────────────┬─────────────┘
             │ stdio JSON-RPC
             ▼
┌──────────────────────────┐
│  Electron Debug MCP      │
│  🛠️ tools (36)           │
│  📡 resources            │
│  💬 prompts              │
│  📣 logging / list-changed│
└────────────┬─────────────┘
             │ spawn / attach / PID resolve
             │ CDP WebSocket
             ▼
┌──────────────────────────┐
│  Electron application    │
│  --remote-debugging-port │
│  Runtime·Page·Network·…  │
│  optional --inspect (main)│
└──────────────────────────┘

After start_app / attach / attach_by_pid, page targets get Runtime / Log / Network / Page enabled so console + network events keep buffering between tool calls.

Finding a running app

1. find_apps — OS process scan (Electron PIDs + --remote-debugging-port from argv)

2. discover_apps — HTTP probe of local CDP ports (/json/version, /json/list)

3. attach / attach_by_pid — open a managed session (detach-only on stop_app)

🗂️ Complete tools cheatsheet

🛠️ Tools reference (all options)

All APIs below are MCP tools. Schemas match the live Zod definitions in src/index.ts.

🚀 Lifecycle

start_app

Launch Electron with remote debugging.

Auto flags: --remote-debugging-port, --enable-logging, --disable-gpu, and --no-sandbox when ELECTRON_MCP_NO_SANDBOX=1 / CI=true / no DISPLAY.

Returns: id, pid, debugPort, targets, attached: false, …

attach

stop_app on attached sessions detaches only (does not kill the external app).

attach_by_pid

Attach by OS process id. Resolves --remote-debugging-port from the process command line (Linux/macOS/ps, Windows PowerShell). Falls back to listening sockets owned by the PID on Linux when needed.

Tip: Prefer the main process PID from find_apps (helpers with --type=renderer / gpu-process are filtered unless they expose a debug port).

find_apps

List running Electron-like processes.

Returns: { apps: [{ pid, command, debugPort?, inspectPort?, likelyElectron }], count }

Use this when you launched the app yourself and don’t remember the port.

discover_apps

HTTP-probes each port for Chromium/Electron DevTools (/json/version + /json/list).

stop_app — { processId }

list_apps — no params

diagnose — optional { processId } (omit = all sessions)

diagnose reports port reachability, target role counts, recent console errors, and monitoring state.

🔍 Inspection

screenshot / save_screenshot

screenshot returns MCP image content (+ JSON meta including clip when used).
save_screenshot writes bytes to disk and returns { path, bytes, mimeType, clip? }.

get_dom — { processId, selector?, targetId? }

query_selector — { processId, selector, targetId?, limit?=20 }

evaluate

evaluate_main

Evaluate in the Electron main/node CDP target.

Requires a node-like target — start with inspectMain: true, or pass an explicit targetId from list_targets.

get_cookies

set_cookie

Note: Chromium often rejects cookies on file:// pages — use an http(s) URL or pass an explicit url/domain.

get_storage / set_storage

get_console_messages — { processId, tail?, level? }

get_network_log — { processId, tail? }

get_logs — { processId, tail? }

list_targets — { processId? }

page_info — { processId, targetId? } → url / title / readyState / userAgent

Console capture includes console.*, CDP Log entries, and Runtime.exceptionThrown.

🖱️ Interaction & control

navigate — { processId, url, targetId?, waitUntilLoad?=true, timeoutMs?=15000 }

wait_for

Provide at least one condition:

click — { processId, selector, targetId?, button?=left }

type_text — { processId, text, selector?, clear?, pressEnter?, targetId? }

press_key

set_console_live — { enabled }

Errors/asserts always emit MCP logs. When enabled, log/info/warn/debug also stream live.

reload — { processId, targetId?, ignoreCache?=false }

pause / resume — { processId, targetId? }

clear_buffers — { processId, console?=true, network?=true, logs?=false }

🧰 Power / tracing

start_tracing

Only one active trace per process session.

stop_tracing

Returns: { path, eventCount, elapsedMs, targetId, … }
Open the file in Chrome’s chrome://tracing (or Perfetto UI).

cdp_command — { processId, method:"Domain.method", targetId?, params? }

Escape hatch for any DevTools method not wrapped above.

📡 Resources (read-only)

💬 Prompts

📚 Usage examples

1️⃣ Start app → read title

// tool: start_app
{
  "appPath": "D:/apps/my-electron-app",
  "debugPort": 9222,
  "extraArgs": ["--no-sandbox"]
}

// tool: evaluate
{
  "processId": "electron-1710000000000",
  "expression": "document.title"
}

2️⃣ Attach to a running app (port)

electron . --remote-debugging-port=9222

// tool: attach
{ "debugPort": 9222, "name": "my-app" }

3️⃣ Find by PID → attach

// tool: find_apps
{}

// tool: attach_by_pid
{ "pid": 43210, "name": "my-app" }

4️⃣ Catch console errors (+ live stream)

// tool: set_console_live
{ "enabled": true }

// tool: get_console_messages
{
  "processId": "electron-1710000000000",
  "level": "error",
  "tail": 50
}

Also: resource electron://console/{processId}

5️⃣ Screenshot — full page, file, or element

// tool: screenshot
{ "processId": "electron-…", "format": "png" }

// tool: save_screenshot
{
  "processId": "electron-…",
  "path": "D:/tmp/app.png",
  "format": "png"
}

// tool: save_screenshot (element clip)
{
  "processId": "electron-…",
  "path": "D:/tmp/sidebar.png",
  "selector": "#sidebar"
}

6️⃣ UI automation flow

// wait_for
{ "processId": "electron-…", "selector": "#email", "timeoutMs": 8000 }

// type_text
{
  "processId": "electron-…",
  "selector": "#email",
  "text": "ada@example.com",
  "clear": true
}

// press_key
{ "processId": "electron-…", "key": "Enter" }

// click
{ "processId": "electron-…", "selector": "button[type=submit]" }

// wait_for (richer conditions)
{
  "processId": "electron-…",
  "text": "Welcome",
  "timeoutMs": 8000,
  "screenshotOnTimeout": true
}

// wait_for enabled / count / hidden
{ "processId": "electron-…", "enabled": "#submit" }

{
  "processId": "electron-…",
  "countSelector": ".row",
  "minCount": 3
}

{ "processId": "electron-…", "hidden": ".spinner" }

7️⃣ Cookies & storage

// set_storage
{
  "processId": "electron-…",
  "kind": "localStorage",
  "clear": true,
  "entries": { "theme": "dark", "onboardingDone": "1" }
}

// get_storage
{ "processId": "electron-…", "kind": "localStorage" }

// set_cookie
{
  "processId": "electron-…",
  "name": "session",
  "value": "abc",
  "url": "https://app.local/"
}

// get_cookies
{ "processId": "electron-…", "urls": ["https://app.local/"] }

8️⃣ Main-process evaluate

// start_app with inspectMain
{
  "appPath": "D:/apps/my-electron-app",
  "debugPort": 9222,
  "inspectMain": true
}

// evaluate_main
{
  "processId": "electron-…",
  "expression": "process.versions.electron"
}

9️⃣ Performance tracing

// start_tracing
{ "processId": "electron-…" }

…reproduce the slow interaction (click / navigate / wait_for)…

// stop_tracing
{
  "processId": "electron-…",
  "path": "D:/tmp/app-trace.json"
}

Open app-trace.json in chrome://tracing.

🔟 Diagnose a sick session

// tool: diagnose
{ "processId": "electron-1710000000000" }

1️⃣1️⃣ Navigate + page info

// navigate
{
  "processId": "electron-…",
  "url": "file:///path/to/renderer/settings.html",
  "waitUntilLoad": true
}

// page_info
{ "processId": "electron-…" }

1️⃣2️⃣ Raw CDP escape hatch

// cdp_command
{
  "processId": "electron-…",
  "method": "Page.captureScreenshot",
  "params": { "format": "png", "fromSurface": true }
}

1️⃣3️⃣ Recommended agent loop

find_apps / discover_apps / start_app / attach / attach_by_pid
    → diagnose
    → set_console_live(true)   # optional
    → get_console_messages(level="error")
    → screenshot / save_screenshot(selector?)
    → wait_for (if UI)
    → click / type_text / press_key / evaluate / get_dom
    → get_storage / get_cookies   # if state matters
    → start_tracing … stop_tracing   # if perf
    → stop_app

🔐 Configuration

Environment variables

Path allowlist example

$env:ELECTRON_MCP_ALLOWED_ROOTS="D:\apps;D:\GH"

📜 npm scripts

Windows helpers: scripts/fix-electron.cmd · scripts/fix-electron.ps1

🧪 Testing

npm test

Smoke path (v1.5):

initialize → tool/prompt/resource lists → start_app → evaluate → console/network/DOM → page_info / type_text / click / wait_for / press_key → save_screenshot (+ selector clip) → storage / cookies → start/stop_tracing → find_apps / attach_by_pid → screenshot → diagnose → attach → discover → stop

CI: .github/workflows/ci.yml (Ubuntu + Xvfb).

🗂️ Project layout

electron-mcp-server/
├── assets/logo.svg
├── examples/cursor-mcp.json
├── fixtures/minimal-electron-app/
├── scripts/ensure-electron.mjs · fix-electron.cmd · fix-electron.ps1
├── src/index.ts · process-manager.ts · events.ts · log.ts
├── test/mcp-smoke.mjs · unit-helpers.test.mjs
├── .github/workflows/ci.yml
└── README.md · LICENSE · package.json

🛡️ Security

• Can launch local binaries, evaluate JS in app contexts, read page content, cookies, and storage — treat as a powerful local debugger.

• Use ELECTRON_MCP_ALLOWED_ROOTS on shared machines.

• Don’t expose stdio over an open network without auth.

• Only attach / attach_by_pid to apps you trust (remote debugging is powerful).

• In-memory console/network buffers and exported traces may contain secrets from the app under test.

🧯 Troubleshooting

🤝 Contributing

1. Fork + branch

2. npm test

3. PR with tool/behavior notes

4. Keep stdout MCP-clean (log to stderr only)

📄 License

ISC © Electron Debug MCP contributors