Implementation:Microsoft Playwright BidiPage

Knowledge Sources	Microsoft_Playwright
Domains	Page Automation, WebDriver BiDi Protocol
Last Updated	2026-02-12 00:00 GMT

Overview

Concrete tool for page-level automation via the WebDriver BiDi protocol provided by the Playwright library.

Description

The `BidiPage` class implements the `PageDelegate` interface for the WebDriver BiDi protocol. It manages a page's lifecycle including frame execution contexts, JavaScript evaluation (via `BidiExecutionContext`), input dispatching (mouse, keyboard, touchscreen via `RawKeyboardImpl`, `RawMouseImpl`, `RawTouchscreenImpl`), network management (via `BidiNetworkManager`), dialog handling, PDF generation (via `BidiPDF`), and init script injection. The class maintains realm-to-context mappings for both page and worker execution contexts, processes BiDi events for navigation, script evaluation, logging, and page lifecycle, and uses a utility world (`__playwright_utility_world__`) for isolated script execution.

Usage

Use this class as the BiDi protocol backend for page operations. It is created by `BidiBrowserContext` when a new page is opened and provides the bridge between Playwright's abstract page model and the BiDi protocol commands.

Code Reference

Source Location

• Repository: Microsoft_Playwright
• File: packages/playwright-core/src/server/bidi/bidiPage.ts

Signature

export class BidiPage implements PageDelegate {
  readonly rawMouse: RawMouseImpl;
  readonly rawKeyboard: RawKeyboardImpl;
  readonly rawTouchscreen: RawTouchscreenImpl;
  readonly _page: Page;
  readonly _session: BidiSession;
  readonly _opener: BidiPage | null;
  readonly _realmToContext: Map<string, dom.FrameExecutionContext>;
  readonly _browserContext: BidiBrowserContext;
  readonly _networkManager: BidiNetworkManager;

  constructor(browserContext: BidiBrowserContext, bidiSession: BidiSession, opener: BidiPage | null);
}

Import

import { BidiPage } from '../server/bidi/bidiPage';

I/O Contract

Inputs

Name	Type	Required	Description
browserContext	BidiBrowserContext	Yes	The browser context this page belongs to
bidiSession	BidiSession	Yes	BiDi session for protocol communication
opener	BidiPage or null	Yes	The page that opened this page, if any

Outputs

Name	Type	Description
_page	Page	The Playwright Page instance backed by this delegate
screenshots	Buffer	Screenshot data captured from the page
PDF	Buffer	PDF data generated from the page

Usage Examples

// Created internally by BidiBrowserContext
const bidiPage = new BidiPage(browserContext, bidiSession, openerPage);

// The page delegate is used via the Page abstraction
const page = bidiPage._page;
await page.goto('https://example.com');
await page.screenshot({ path: 'screenshot.png' });

Related Pages

• Environment:Microsoft_Playwright_Node_Runtime_Environment