android-mcp-toolkit

Instructions

Implementation Reference

• src/tools/deviceTool.js:20-23 (schema)

  Zod input schema for the take-screenshot tool defining outputPath and optional timeoutMs.

  const screenshotSchema = z.object({
    outputPath: z.string().min(1).describe('Local path to save the screenshot (e.g. screenshot.png)'),
    timeoutMs: z.number().int().min(1000).max(20000).default(10000).describe('Timeout in milliseconds')
  });

• src/tools/deviceTool.js:94-107 (registration)

  MCP server registration of the take-screenshot tool, including inline handler function that uses ADB screencap to capture and save PNG screenshot.

  server.registerTool(
    'take-screenshot',
    {
      title: 'Take User Screenshot',
      description: 'Capture device screenshot and save to a local file.',
      inputSchema: screenshotSchema
    },
    async (params) => {
      const buffer = await runAdbCommandBinary(['exec-out', 'screencap', '-p'], params.timeoutMs);
      const absPath = path.resolve(params.outputPath);
      fs.writeFileSync(absPath, buffer);
      return { content: [{ type: 'text', text: `Screenshot saved to ${absPath}` }] };
    }
  );

• src/tools/deviceTool.js:65-76 (helper)

  Helper to run ADB binary commands (like screencap), returning buffer; used by take-screenshot handler.

  async function runAdbCommandBinary(args, timeoutMs) {
    try {
      const { stdout } = await execFileAsync('adb', args, {
        timeout: timeoutMs,
        encoding: 'buffer',
        maxBuffer: 20 * 1024 * 1024
      });
      return stdout;
    } catch (error) {
      throw new Error(`adb ${args.join(' ')} failed: ${error.message}`);
    }
  }