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name: playwright-dev description: Explains how to develop Playwright - add APIs, MCP tools, CLI commands, and vendor dependencies.

Playwright Development Guide

See CLAUDE.md for monorepo structure, build/test/lint commands, and coding conventions.

Detailed Guides

• Library Architecture — client/server/dispatcher structure, protocol layer, DEPS rules
• Adding and Modifying APIs — define API docs, implement client/server, add tests
• MCP Tools and CLI Commands — add MCP tools, CLI commands, config options
• Vendor Dependencies & Bundling — utilsBundle, coreBundle, babelBundle; adding vendored npm packages; DEPS.list; check_deps
• Updating WebKit Safari Version — update the Safari version string in the WebKit user-agent
• WebView (iOS Safari) Backend — webkit/webview/ against stock Mobile Safari; provisional-target pause/resume; what's upstream vs Playwright patches; local + CI test setup
• Bisecting Across Published Versions — reproduce regressions side-by-side from npm and diff node_modules/playwright/lib/ between versions
• Dashboard - the UI powering the "playwright cli show" command, and how to work on it