Simpod

Stream a booted iOS Simulator to the browser and drive it — from your IDE, an AI agent (Claude Code, Cursor, Codex), or the simpod CLI. Locally, over your LAN, or hosted on a remote Mac and tunneled anywhere.

simpod
# → Preview at http://127.0.0.1:5210

Simpod spawns a small native Swift helper that captures the simulator's framebuffer (VideoToolbox H.264 / MJPEG), injects HID input, and reads the accessibility tree. A Dart CLI orchestrates the helpers and serves a Flutter web dashboard on top. It works with any booted simulator — no Xcode plugin, no in-app instrumentation.

macOS only, Apple Silicon. It shells out to xcrun simctl and uses private CoreSimulator APIs. There is no Android support.

Features

  • Low-latency 60 FPS stream in the browser (H.264/AVCC with an MJPEG fallback).
  • Full control: tap, swipe, pinch, type, hardware buttons, rotation.
  • Accessibility inspection — read the live AX tree to find elements by label, and an in-browser overlay that highlights element frames.
  • Device controls: light/dark appearance, mock GPS, status-bar overrides, deep links, privacy permissions.
  • Live simulator system logs forwarded to the browser (and to agents).
  • Device bezels/chrome rendered from CoreSimulator assets.
  • Loopback is auto-trusted; LAN devices pair with a printed QR / token.
  • An Agent Skill that teaches AI agents the stable simpod workflow.

Why?

Hosted simulators are hard to iterate on. Simpod lets you run the streaming/control stack locally for fast iteration, then tunnel the served URL to share a simulator remotely — users interact with it as if it were on their own machine.

Install

Requires macOS 14+, Xcode command-line tools (xcrun simctl), and a booted simulator.

dart pub global activate simpod
simpod

The package embeds the native helper and the web dashboard, so no extra downloads are needed. Alternatively, build the self-contained build/simpod binary with ./build.sh, or run from source (below).

CLI

simpod [device...]                 Start the stream + web preview (default :5210)
simpod --detach -q                 Spawn in the background, print JSON, return
simpod --no-preview                Stream in the terminal, no web UI
simpod --list [-q]                 List running sessions
simpod --kill [-d <udid>]          Stop all sessions (or one device)

simpod tap <x> <y>                 Tap (normalized 0..1 coords)
simpod gesture '<json>'            Multi-step touch/pinch sequence
simpod type '<text>'               Type into the focused field (US keyboard)
simpod button [name]               home | app_switcher | lock | side_button | volume_up | volume_down | siri
simpod rotate <orientation>        portrait | portrait_upside_down | landscape_left | landscape_right
simpod rotate-left | rotate-right  Quarter-turn helpers

simpod boot <udid> | shutdown      Lifecycle
simpod appearance light|dark       Set appearance
simpod open-url <url>              Open a deep link / https URL
simpod location <lat> <lon>        Mock GPS
simpod status-bar --battery <n> --time <hh:mm> | --clear
simpod permissions <grant|revoke|reset> <service> [bundle]
simpod describe [--point <x> <y>]  Dump the accessibility tree (JSON)
simpod logs [--seconds <n>]        Tail the simulator system log

Options:
  -p, --port <port>   Preview server port (default 5210; helpers use 5400+)
      --host <host>   Bind interface (0.0.0.0 exposes on the LAN)
  -d, --device <udid> Target a specific simulator
  -q, --quiet         JSON-only output

Examples

simpod                                  # auto-detect a booted sim, open preview
simpod "iPhone 16 Pro"                  # target a device by name
simpod --detach -q                      # background server, returns JSON

simpod tap 0.5 0.5                      # tap center
simpod type "Hello, world!"             # type into the focused field
simpod button home                      # go home
simpod rotate landscape_left            # rotate
simpod appearance dark                  # dark mode
simpod open-url "myapp://checkout"      # deep link
simpod describe | jq                    # inspect the UI

simpod --kill                           # stop everything

Coordinates are normalized 0..1, (0,0) top-left. Device resolution when you don't name one: explicit device → first booted → boot the first available.

Agent Skill

An Agent Skill ships in skills/simpod. It teaches AI coding agents how to drive a simulator through the CLI — taps, gestures, hardware buttons, rotation, accessibility-driven taps, device controls, and handing the stream off to the host's preview pane. See the reference docs under skills/simpod/reference/ for gestures, buttons & rotation, end-to-end workflows, and the HTTP/WebSocket endpoints.

How it works

┌──────────────┐  capture+HID  ┌─────────────────────┐  HTTP/WS  ┌─────────┐
│ iOS Simulator│ ◀───────────▶ │ simpod-helper-bin    │ ◀──────▶ │ Browser │
└──────────────┘  (Swift,      │ (one per device,     │   live   └─────────┘
                  private API) │  :5400+)             │  stream
                               └─────────▲───────────┘
                                         │ spawns + proxies
                               ┌─────────┴───────────┐
                               │ simpod CLI / preview │  http://127.0.0.1:5210
                               │ server (:5210)       │
                               └─────────────────────┘

The browser connects directly to a helper's WebSocket (wsUrl) for the live stream and input; the CLI's preview server serves the dashboard and gates a JSON API. State (sessions, pid files) lives under $TMPDIR/simpod/.

Packages

Package Lang Role
packages/native Swift 6 simpod-helper-bin: frame capture/encode, HID injection, AX tree, bezel rendering, HTTP/WS server. One process per device.
packages/simpod Dart The simpod CLI + preview server: spawns/tracks helpers, serves the dashboard, gates the HTTP API.
packages/simpod_client Flutter web The dashboard: renders the stream, sends input over WebSocket, calls the API.
packages/simpod_core Dart Shared models (SimpodSession, DeviceInfo, AXNode, SimpodOrientation, …).

Development

Run from source (no released binary), iterating on each layer:

# 1. Build the native helper and stage it where the CLI loads it from
swift build -c release --package-path packages/native
cp -f packages/native/.build/release/simpod-helper-bin packages/simpod/lib/bin/

# 2. Run the CLI / preview server (MUST run from the package root; boot a sim first)
cd packages/simpod && dart pub get
dart run bin/simpod.dart          # preview UI at http://127.0.0.1:5210

# 3. Iterate on the web client (separate origin → pass the debug token)
cd ../simpod_client
flutter run -d chrome --web-port=8080 --dart-define=SIMPOD_TOKEN=<token-the-cli-printed>

./build.sh (repo root) runs the full release pipeline: swift build → copy bin → flutter build web --wasm → embed assets → dart compile exe -o build/simpod. The output embeds the helper + web build and self-extracts on first run, so it works from any directory.

License

See LICENSE.

Libraries

simpod