android-mcp-server

Instructions

Implementation Reference

• src/adb.ts:228-230 (handler)

  The low-level ADB execution handler for the screenshot tool. It runs `screencap -p` and returns the buffer.

  async screenshot(deviceId?: string): Promise<Buffer> {
    return this.execBuffer(["exec-out", "screencap", "-p"], deviceId);
  }

• src/index.ts:94-122 (registration)

  MCP tool registration and high-level handler for "screenshot", which orchestrates capturing via ADB, compressing the image, and optionally saving it to disk.

  server.tool(
    "screenshot",
    "Take a screenshot of the Android device. Returns the image for visual analysis. Optionally saves to a file path.",
    {
      device_id: z.string().optional().describe("Device ID (optional if only one device)"),
      save_path: z.string().optional().describe("Local file path to save the screenshot PNG (optional)"),
    },
    async ({ device_id, save_path }) => {
      const raw = await adb.screenshot(device_id);
      const compressed = await compressScreenshot(raw);
      const base64 = compressed.toString("base64");
      const metadata = await sharp(compressed).metadata();
  
      if (save_path) {
        await adb.saveScreenshot(compressed, save_path);
      }
  
      const info = `Screenshot: ${metadata.width}x${metadata.height} (${Math.round(compressed.length / 1024)}KB)`;
      return {
        content: [
          { type: "image", data: base64, mimeType: "image/png" },
          {
            type: "text",
            text: save_path ? `${info}\nSaved to: ${save_path}` : info,
          },
        ],
      };
    },
  );