app-screen-mcp

Instructions

Implementation Reference

• src/index.ts:601-611 (handler)

  The handler function that executes the `launch_app` tool logic using `xcrun simctl`.

  private async launchApp(bundleId: string, udid?: string) {
    const target = await resolveUdid(udid);
    try {
      const { stdout } = await execAsync(`xcrun simctl launch ${target} ${bundleId}`);
      return {
        content: [{ type: 'text', text: `Launched ${bundleId} on ${target}. ${stdout.trim()}` }],
      };
    } catch (error: any) {
      throw new McpError(ErrorCode.InternalError, `Failed to launch app: ${error.message}`);
    }
  }

• src/index.ts:310-320 (schema)

  The schema definition for the `launch_app` tool.

  name: 'launch_app',
  description: 'Launch an app on a simulator',
  inputSchema: {
    type: 'object',
    properties: {
      bundle_id: { type: 'string', description: 'App bundle identifier (e.g. com.example.myapp)' },
      udid: { type: 'string', description: 'Simulator UDID (optional, defaults to booted simulator)' },
    },
    required: ['bundle_id'],
    additionalProperties: false,
  },

• src/index.ts:498-499 (registration)

  The tool registration handler that maps the `launch_app` tool call to the `launchApp` function.

  case 'launch_app':
    return this.launchApp(args.bundle_id as string, args.udid);