Appleシミュレーターのnpx serve。

Codex、Cursor、Claude Desktopなどのエージェントツールでシミュレーターをホストし、ローカルでもLAN経由でも、リモートMacでホストしてどこでもトンネルできます。

https://github.com/user-attachments/assets/fbf890f4-c8c7-4684-82be-d677b8a188f8

serve-simは小さなSwiftヘルパーを生成し、simctl ioを通じてシミュレーターのフレームバッファをキャプチャし、MJPEGストリーム+WebSocketコントロールチャネルとして公開し、その上にReactプレビューUIを提供します。起動したiOSシミュレーターなら、Xcodeプラグインやアプリ内のインストゥルメンテーションは使いません。

特徴

• ブラウザでフル60FPSの動画ストリーム。
• 下からスワイプして帰宅。
• オプションキーを押し続けることでピンチ(つまみ)を押し込むジェスチャー。
• シミュレーターログはブラウザに転送され、ブラウザ用のMCPツールが読み取れるようになります。
• 最近のシミュレーターのアクションはブラウザツールパネルおよびserve-sim event-logで利用可能です。
• 動画や画像をドラッグ&ドロップしてシミュレーターデバイスに追加する。
• キーボードコマンドとホットキーはシミュレーターに転送され、CMD+SHIFT+Hでホームに送られます。
• Apple Watch、iPad、iOS対応

なぜ?

serve-sim

The npx serve of Apple Simulators.

Host your simulator for use with Agent tools like Codex, Cursor, or Claude Desktop — locally, over your LAN, or host on a remote mac and tunnel anywhere.

npx serve-sim
# → Preview at http://localhost:3200

https://github.com/user-attachments/assets/fbf890f4-c8c7-4684-82be-d677b8a188f8

serve-sim spawns a small Swift helper that captures the simulator’s framebuffer via simctl io, exposes it as an MJPEG stream + WebSocket control channel, and serves a React preview UI on top. It works with any booted iOS Simulator — no Xcode plugin, no instrumentation in your app.

Features

• Full 60 FPS video stream in the browser.
• Swipe from the bottom to go home.
• gestures like pinch to zoom by holding the option key.
• Simulator logs are forwarded to the browser for browser-use MCP tools to read from.
• Recent simulator actions are available in the browser tools panel and serve-sim event-log.
• Drag and drop videos and images to add them to the simulator device.
• Keyboard commands and hot keys are forwarded to the simulator, including CMD+SHIFT+H to go home.
• Apple Watch, iPad, and iOS support.

Why?

Hosted simulators can be hard to test, serve-sim enables you to test the hosted infra locally first for faster iteration. When you’re ready to host a simulator remotely, simply tunnel the served URL and users can interact with the simulator as if it were running locally on their device.

I develop the Expo framework, but this tool is completely agnostic to React Native and can be used for any iOS interaction you need.

Install

Requires macOS with Xcode command line tools (xcrun simctl) and a maintained Node.js LTS release (currently Node 20+). Older or end-of-life Node versions are not supported. bun is not required to run the CLI. Camera injection uses a host-side helper built for macOS 14+.

Note: Apple Silicon (arm64) only. The bundled serve-sim-bin helper ships as an arm64 binary and does not run on Intel (x86_64) Macs.

Xcode 27 keyboard input: Device Hub must be running with the target simulator window visible and frontmost. macOS may also require the app that launched serve-sim (for example Terminal) to be enabled in System Settings → Privacy & Security → Accessibility. Xcode 26 and older keep using the legacy simulator HID path. Set SERVE_SIM_DISABLE_DEVICE_HUB_KEYBOARD=1 to opt out of the Xcode 27 bridge.

iPhone Duo

With Xcode 27.1 and the iOS 27.1 runtime, the preview exposes Closed, Book, and Open controls for iPhone Duo. Selecting one drives the simulator’s hinge and follows the active panel’s framebuffer. Touches use the panel’s own integrated digitizer; volume and power controls use a guest HID service.

serve-sim fold 0 -d 
serve-sim fold 180 -d       # flat, 180°
serve-sim fold 130 -d       # 130°
serve-sim fold 100 -d