Take Screenshot
mobile_take_screenshotRead-only
Capture screenshots from mobile devices to analyze on-screen content and identify interactive elements for mobile automation tasks.
Instructions
Take a screenshot of the mobile device. Use this to understand what's on screen, if you need to press an element that is available through view hierarchy then you must list elements on screen instead. Do not cache this result.
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| device | Yes | The device identifier to use. Use mobile_list_available_devices to find which devices are available to you. |
Implementation Reference
- src/server.ts:399-449 (handler)The complete handler and registration for the 'mobile_take_screenshot' tool. It captures a screenshot using the selected robot (device), validates the PNG, optionally resizes and compresses to JPEG using ImageMagick, encodes to base64, and returns as an image content block in the MCP tool response.
server.tool( "mobile_take_screenshot", "Take a screenshot of the mobile device. Use this to understand what's on screen, if you need to press an element that is available through view hierarchy then you must list elements on screen instead. Do not cache this result.", { noParams }, async ({}) => { requireRobot(); try { const screenSize = await robot!.getScreenSize(); let screenshot = await robot!.getScreenshot(); let mimeType = "image/png"; // validate we received a png, will throw exception otherwise const image = new PNG(screenshot); const pngSize = image.getDimensions(); if (pngSize.width <= 0 || pngSize.height <= 0) { throw new ActionableError("Screenshot is invalid. Please try again."); } if (isImageMagickInstalled()) { trace("ImageMagick is installed, resizing screenshot"); const image = Image.fromBuffer(screenshot); const beforeSize = screenshot.length; screenshot = image.resize(Math.floor(pngSize.width / screenSize.scale)) .jpeg({ quality: 75 }) .toBuffer(); const afterSize = screenshot.length; trace(`Screenshot resized from ${beforeSize} bytes to ${afterSize} bytes`); mimeType = "image/jpeg"; } const screenshot64 = screenshot.toString("base64"); trace(`Screenshot taken: ${screenshot.length} bytes`); return { content: [{ type: "image", data: screenshot64, mimeType }] }; } catch (err: any) { error(`Error taking screenshot: ${err.message} ${err.stack}`); return { content: [{ type: "text", text: `Error: ${err.message}` }], isError: true, }; } } );