Android MCP Server

Instructions

Implementation Reference

• src/handlers.ts:470-494 (handler)

  Main handler function for the android_uiautomator_double_click tool. Validates input arguments and delegates to ADBWrapper.doubleClickElementByResourceId for execution.

  export async function uiautomatorDoubleClickHandler(
    adb: ADBWrapper,
    args: any
  ): Promise<{ content: Array<{ type: string; text: string }> }> {
    const { resourceId, deviceSerial } = args as UIAutomatorDoubleClickArgs;
  
    if (!resourceId || typeof resourceId !== 'string') {
      throw new Error('Invalid resource ID: resourceId must be a non-empty string');
    }
  
    try {
      await adb.doubleClickElementByResourceId(resourceId, deviceSerial);
  
      return {
        content: [
          {
            type: 'text',
            text: `Successfully double-clicked element with resource-id: ${resourceId}`,
          },
        ],
      };
    } catch (error) {
      throw new Error(`UIAutomator double click failed: ${error instanceof Error ? error.message : String(error)}`);
    }
  }

• src/adb-wrapper.ts:668-695 (helper)

  Core helper method in ADBWrapper that implements the double-click logic: dumps UI hierarchy XML using uiautomator, parses bounds for the resource ID, computes center coordinates, and performs two rapid taps (100ms apart) at the center.

  async doubleClickElementByResourceId(resourceId: string, deviceSerial?: string): Promise<void> {
    const device = await this.getTargetDevice(deviceSerial);
    const hierarchyFile = '/sdcard/window_dump.xml';
    
    await this.exec(['shell', 'uiautomator', 'dump', hierarchyFile], device);
    const { stdout } = await this.exec(['shell', 'cat', hierarchyFile], device);
    await this.exec(['shell', 'rm', hierarchyFile], device);
    
    const boundsRegex = new RegExp(`resource-id="${resourceId}"[^>]*bounds="\\[(\\d+),(\\d+)\\]\\[(\\d+),(\\d+)\\]"`);
    const match = stdout.match(boundsRegex);
    
    if (match) {
      const x1 = parseInt(match[1], 10);
      const y1 = parseInt(match[2], 10);
      const x2 = parseInt(match[3], 10);
      const y2 = parseInt(match[4], 10);
      
      const centerX = Math.floor((x1 + x2) / 2);
      const centerY = Math.floor((y1 + y2) / 2);
      
      // Double click: two quick taps
      await this.touch(centerX, centerY, 100, device);
      await new Promise(resolve => setTimeout(resolve, 100));
      await this.touch(centerX, centerY, 100, device);
    } else {
      throw new Error(`Element with resource-id ${resourceId} not found in UI hierarchy`);
    }
  }

• src/index.ts:288-304 (schema)

  Tool schema definition including input schema for resourceId (required) and optional deviceSerial.

  {
    name: 'android_uiautomator_double_click',
    description: 'Perform a double click on a UI element by resource ID',
    inputSchema: {
      type: 'object',
      properties: {
        resourceId: {
          type: 'string',
          description: 'Resource ID of the element to double click',
        },
        deviceSerial: {
          type: 'string',
          description: 'Specific device serial number to target (optional)',
        },
      },
      required: ['resourceId'],
    },

• src/index.ts:488-489 (registration)

  Registration in the CallToolRequestSchema handler switch statement, dispatching to the uiautomatorDoubleClickHandler.

  case 'android_uiautomator_double_click':
    return await uiautomatorDoubleClickHandler(this.adb, args);

• src/handlers.ts:71-74 (schema)

  TypeScript interface defining the input arguments for the double-click handler.

  interface UIAutomatorDoubleClickArgs {
    resourceId: string;
    deviceSerial?: string;
  }