Implementation:Microsoft Playwright CrBrowser

Knowledge Sources	Microsoft_Playwright
Domains	Browser Automation, Chrome DevTools Protocol
Last Updated	2026-02-12 00:00 GMT

Overview

Concrete tool for Chromium browser management via CDP provided by the Playwright library.

Description

The `CRBrowser` class extends the abstract `Browser` base class to implement Chromium-specific browser management using the Chrome DevTools Protocol (CDP). It manages a `CRConnection` for protocol communication and maintains maps of browser contexts (`CRBrowserContext`), pages (`CRPage`), and service workers (`CRServiceWorker`). The class handles target discovery and attachment, tracing recording, CDP session management (including client-accessible CDP sessions), version detection, and browser-level operations like new context creation, cookie management, and PDF generation support. The `CRBrowserContext` inner class implements context-specific CDP operations for permissions, geolocation, network conditions, and caching.

Usage

Use this class as the Chromium-specific browser implementation for CDP-based automation. It is instantiated by the `Chromium` browser type class when launching or connecting to a Chromium browser.

Code Reference

Source Location

• Repository: Microsoft_Playwright
• File: packages/playwright-core/src/server/chromium/crBrowser.ts

Signature

export class CRBrowser extends Browser {
  readonly _connection: CRConnection;
  _session: CRSession;
  readonly _contexts: Map<string, CRBrowserContext>;
  _crPages: Map<string, CRPage>;
  _serviceWorkers: Map<string, CRServiceWorker>;
  _devtools?: CRDevTools;

  static async connect(parent: SdkObject, transport: ConnectionTransport, options: BrowserOptions, devtools?: CRDevTools): Promise<CRBrowser>;
}

export class CRBrowserContext extends BrowserContext {
  readonly _browser: CRBrowser;
  readonly _browserContextId: string | undefined;
}

Import

import { CRBrowser, CRBrowserContext } from '../server/chromium/crBrowser';

I/O Contract

Inputs

Name	Type	Required	Description
parent	SdkObject	Yes	Parent SDK object for instrumentation hierarchy
transport	ConnectionTransport	Yes	WebSocket or pipe transport to the Chromium process
options	BrowserOptions	Yes	Browser configuration including persistent context, proxy, etc.
devtools	CRDevTools	No	Optional DevTools integration instance

Outputs

Name	Type	Description
CRBrowser	CRBrowser	Connected Chromium browser with CDP session established
CRBrowserContext	CRBrowserContext	Isolated Chromium browser context
CDPSession	CDPSession	Client-accessible CDP session for direct protocol access

Usage Examples

import { CRBrowser } from 'playwright-core/lib/server/chromium/crBrowser';

const browser = await CRBrowser.connect(parent, wsTransport, browserOptions);

// Create a new isolated context
const context = await browser.newContext({ viewport: { width: 1280, height: 720 } });
const page = await context.newPage();

// Access CDP session directly
const cdpSession = await browser.newBrowserCDPSession();
await cdpSession.send('Performance.enable');

Related Pages

• Environment:Microsoft_Playwright_Node_Runtime_Environment