# Launch App

Launch an installed app on a Cloud Phone.
- **Preconditions**: the phone must be powered on and not held by another member.
- **Completion**: the response confirms the command reached the service, not that the app is in the foreground. There is no endpoint that reports a running app — verify with a screen capture or a shell command.
- **Retry**: no deduplication; a repeat call dispatches the command again.

Documented business errors: `33300`, `33301`. See [Error Codes](../Getting%20Started/error-codes.md) for what each code means. Any operation can additionally return the common codes.

Endpoint: POST /api/cloudphone/app/start
Version: 2026-09-05

## Request fields (application/json):

  - `id` (string, required)
    Cloud phone ID

  - `packageName` (string, required)
    App package name

## Response 200:

  - `200` (unknown)
    Success. `data` is always null for this operation; the outcome is carried by `code`.

## Response 200 fields (application/json):

  - `code` (integer)

  - `msg` (string | null)

  - `data` (null)

  - `requestId` (string)