extensionContextFactory.ts•2.45 kB
/**
* Copyright (c) Microsoft Corporation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import debug from 'debug';
import * as playwright from 'playwright';
import { startHttpServer } from '../httpServer.js';
import { CDPRelayServer } from './cdpRelay.js';
import type { BrowserContextFactory, ClientInfo } from '../browserContextFactory.js';
const debugLogger = debug('pw:mcp:relay');
export class ExtensionContextFactory implements BrowserContextFactory {
name = 'extension';
description = 'Connect to a browser using the Playwright MCP extension';
private _browserChannel: string;
constructor(browserChannel: string) {
this._browserChannel = browserChannel;
}
async createContext(clientInfo: ClientInfo, abortSignal: AbortSignal): Promise<{ browserContext: playwright.BrowserContext, close: () => Promise<void> }> {
const browser = await this._obtainBrowser(clientInfo, abortSignal);
return {
browserContext: browser.contexts()[0],
close: async () => {
debugLogger('close() called for browser context');
await browser.close();
}
};
}
private async _obtainBrowser(clientInfo: ClientInfo, abortSignal: AbortSignal): Promise<playwright.Browser> {
const relay = await this._startRelay(abortSignal);
await relay.ensureExtensionConnectionForMCPContext(clientInfo, abortSignal);
return await playwright.chromium.connectOverCDP(relay.cdpEndpoint());
}
private async _startRelay(abortSignal: AbortSignal) {
const httpServer = await startHttpServer({});
if (abortSignal.aborted) {
httpServer.close();
throw new Error(abortSignal.reason);
}
const cdpRelayServer = new CDPRelayServer(httpServer, this._browserChannel);
abortSignal.addEventListener('abort', () => cdpRelayServer.stop());
debugLogger(`CDP relay server started, extension endpoint: ${cdpRelayServer.extensionEndpoint()}.`);
return cdpRelayServer;
}
}