app_record

This tool on every surface: CLI · MCP · Python · JavaScript · Go · Java · .NET

Record the screen to a video: start, stop with a path to save it, or omit the action to ask whether a recording is running. The saved file is checked by what it holds — its frame count and duration, read from its own header — and a recorder that could not finish is reported, not saved as if it had. Android records a frame only when the screen changes, so a still screen is one frame; that is not a failure. One recording per device; ending the session finishes and discards it. A real iPhone records WebDriverAgent's screen stream, about ten frames a second at full size.

Changes the device, the app or the session: readOnlyHint is false.

Arguments

Name	Type	Required	What it is
action	string: start, stop		start or stop. Omit to ask whether a recording is running.
device	string		Device serial to target, e.g. "emulator-5554". Omit when only one device is running.
driver	string: uiautomator2, uiautomator, wda		Driver to use: "uiautomator2" (default for Android; fast, installs a server APK on first use), "uiautomator" (Android, installs nothing, slower, cannot type), or "wda" (WebDriverAgent: iOS simulators and iPhones).
path	string		Where to save the video, on stop — an .mp4 on this machine.
return_data	boolean		On stop without a path: return the video, base64, instead of saving it — for a daemon on another machine; the CLI and pipe ask for it and save it where the caller said.

Examples

Each is the arguments of a tools/call request; the first is shown whole.

Start recording the screen

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "app_record",
    "arguments": {
      "action": "start"
    }
  }
}

On an Android 15 emulator the answer's text was:

recording — stop it with action "stop" and a path

Stop, and save the video

{
  "action": "stop",
  "path": "flow.mp4"
}

On an Android 15 emulator the answer's text was:

saved …/flow.mp4: 54 frames, 1.605s of video, recorded over 1.705s