Implementation:Microsoft Playwright CrNetworkManager

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

Overview

Concrete tool for managing Chromium network requests via CDP provided by the Playwright library.

Description

The `CRNetworkManager` class handles network event processing and request interception for Chromium browsers using the Chrome DevTools Protocol (CDP). It manages multiple CDP sessions (for OOPIF support), tracks in-flight requests via `InterceptableRequest` objects, and handles the complex interplay between `Network.requestWillBeSent` and `Fetch.requestPaused` events. The class supports request interception for route handling, HTTP authentication, offline mode, extra HTTP headers, and response extra info tracking via `ResponseExtraInfoTracker`. It correctly handles race conditions between network events and fetch events, and manages credentials with origin-based authentication.

Usage

Use this class internally when the Chromium backend needs to track, intercept, or modify network requests. It is instantiated by `CRPage` and `CRServiceWorker` to provide the network layer for CDP-based browser automation.

Code Reference

Source Location

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

Signature

export class CRNetworkManager {
  private _page: Page | null;
  private _serviceWorker: CRServiceWorker | null;
  private _requestIdToRequest: Map<string, InterceptableRequest>;
  private _credentials: { origin?: string, username: string, password: string } | null;
  private _userRequestInterceptionEnabled: boolean;
  private _protocolRequestInterceptionEnabled: boolean;
  private _offline: boolean;
  private _extraHTTPHeaders: types.HeadersArray;

  constructor(page: Page | null, serviceWorker: CRServiceWorker | null);
  async addSession(session: CRSession, isMain?: boolean, workerFrame?: frames.Frame): Promise<void>;
  async removeSession(session: CRSession): Promise<void>;
  async authenticate(credentials: { origin?: string, username: string, password: string } | null): Promise<void>;
  async setOffline(offline: boolean): Promise<void>;
  async setExtraHTTPHeaders(headers: types.HeadersArray): Promise<void>;
  async setRequestInterception(value: boolean): Promise<void>;
}

Import

import { CRNetworkManager } from '../server/chromium/crNetworkManager';

I/O Contract

Inputs

Name	Type	Required	Description
page	Page or null	Yes	The page instance (null for service worker contexts)
serviceWorker	CRServiceWorker or null	Yes	The service worker instance (null for page contexts)
session	CRSession	Yes	CDP session to add for network event monitoring
credentials	object	No	HTTP authentication credentials with optional origin
headers	types.HeadersArray	No	Extra HTTP headers to inject into requests
offline	boolean	No	Whether to emulate offline network mode

Outputs

Name	Type	Description
network.Request	network.Request	Playwright request objects emitted for tracked requests
network.Response	network.Response	Playwright response objects with header and body data

Usage Examples

// Internal usage within CRPage
const networkManager = new CRNetworkManager(page, null);

// Add CDP session for network tracking
await networkManager.addSession(crSession, true);

// Configure network
await networkManager.setRequestInterception(true);
await networkManager.setExtraHTTPHeaders([{ name: 'X-Custom', value: 'test' }]);
await networkManager.authenticate({ username: 'user', password: 'pass' });
await networkManager.setOffline(true);

Related Pages

• Environment:Microsoft_Playwright_Node_Runtime_Environment