import { FastMCP } from 'fastmcp/dist/FastMCP.js';
import { getDriver } from '../../session-store.js';
import { writeFile, mkdir } from 'fs/promises';
import { join, isAbsolute } from 'path';
import {
createUIResource,
createScreenshotViewerUI,
addUIResourceToResponse,
} from '../../ui/mcp-ui-utils.js';
/**
* Resolves the screenshot directory path.
* - If SCREENSHOTS_DIR is not set, returns process.cwd()
* - If SCREENSHOTS_DIR is absolute, returns it as-is
* - If SCREENSHOTS_DIR is relative, joins it with process.cwd()
*/
export function resolveScreenshotDir(): string {
const screenshotDir = process.env.SCREENSHOTS_DIR;
if (!screenshotDir) {
return process.cwd();
}
if (isAbsolute(screenshotDir)) {
return screenshotDir;
}
return join(process.cwd(), screenshotDir);
}
export interface ScreenshotDeps {
getDriver: () => { getScreenshot: () => Promise<string> } | null;
writeFile: typeof writeFile;
mkdir: typeof mkdir;
resolveScreenshotDir: typeof resolveScreenshotDir;
dateNow: () => number;
}
const defaultDeps: ScreenshotDeps = {
getDriver,
writeFile,
mkdir,
resolveScreenshotDir,
dateNow: () => Date.now(),
};
export async function executeScreenshot(
deps: ScreenshotDeps = defaultDeps
): Promise<any> {
const driver = deps.getDriver();
if (!driver) {
throw new Error('No driver found');
}
try {
const screenshotBase64 = await driver.getScreenshot();
// Convert base64 to buffer
const screenshotBuffer = Buffer.from(screenshotBase64, 'base64');
// Generate filename with timestamp
const timestamp = deps.dateNow();
const filename = `screenshot_${timestamp}.png`;
const screenshotDir = deps.resolveScreenshotDir();
// Create a directory if it doesn't exist
await deps.mkdir(screenshotDir, { recursive: true });
const filepath = join(screenshotDir, filename);
// Save screenshot to disk
await deps.writeFile(filepath, screenshotBuffer);
const textResponse = {
content: [
{
type: 'text',
text: `Screenshot saved successfully to: ${filepath}`,
},
],
};
// Add interactive screenshot viewer UI
const uiResource = createUIResource(
`ui://appium-mcp/screenshot-viewer/${Date.now()}`,
createScreenshotViewerUI(screenshotBase64, filepath)
);
return addUIResourceToResponse(textResponse, uiResource);
} catch (err: any) {
return {
content: [
{
type: 'text',
text: `Failed to take screenshot. err: ${err.toString()}`,
},
],
};
}
}
export default function screenshot(server: FastMCP): void {
server.addTool({
name: 'appium_screenshot',
description:
'Take a screenshot of the current screen and return as PNG image',
annotations: {
readOnlyHint: false,
openWorldHint: false,
},
execute: async (): Promise<any> => executeScreenshot(),
});
}
