WebMCP lets a page register its own functions as agent-callable tools via document.modelContext.registerTool(), replacing the agent's guess-the-button DOM scraping. Chrome opened an origin trial in 149 and estimates stable in 157; Edge followed in 150. But WebKit has formally opposed it ('an agent acting on a user's behalf is, in effect, assistive technology... the site should not single it out for different treatment') and Mozilla filed neutral. This post covers both APIs, where the security gates sit, and whether to invest now with one and a half engines behind it.
chrome-devtools-mcp, maintained by the Chrome team, packages DevTools capability as an MCP server: performance traces and insights, Lighthouse audits, heap snapshots, extension management — none of which @playwright/mcp exposes. It runs on Puppeteer, so interactions auto-wait; the costs are Chrome-only support and usage statistics reported to Google by default.
server-puppeteer is the Puppeteer wrapper in the official MCP servers monorepo — seven lean tools built around screenshots and evaluate. It has since been archived (moved to servers-archived, no longer published), so it is not a choice for new projects; if you want Puppeteer lineage in an MCP server today, look at the Chrome team's chrome-devtools-mcp.
When mobile Chrome keeps redirecting back to the login page after sign-in, the culprit isn't always OAuth or broken frontend state. In this case, the root cause was that the HTTP entry point for app-dev.daodao.so wasn't issuing a 301 redirect to HTTPS, so /auth/me requests sent with an http origin didn't include the auth_token cookie.
Claude Code gains browser control through the Claude in Chrome extension: read console logs and DOM state, click, type, upload files, record GIFs, and operate sites you're already signed into. The official prerequisites list Chrome, Edge, and Chromium-based browsers such as Brave, Arc, Vivaldi, and Opera, but WSL is not supported.