If you're building AI agents that need to automate browsers, you've probably hit the same wall—sometimes you need a different Chromium build under Playwright's familiar tooling. Whether it's customization needs or wanting more control over your automation stack, swapping that engine isn't straightforward.

The Problem With Custom Browser MCP Servers

Browser automation is becoming essential for AI workflows—debugging frontend flows, testing onboarding, validating generated UI, reproducing browser-only bugs. Playwright MCP gives agents the tools to do this: navigate pages, click buttons, fill forms, inspect accessibility trees, take screenshots. But when you need a different Chromium build under the hood, you're stuck with upstream defaults.

Enter CloakBrowser MCP

CloakBrowser MCP solves a narrow but real problem: it lets you run Playwright's entire tool surface with CloakBrowser Chromium instead of the default build. The project is intentionally minimal—it doesn't rewrite tool contracts or invent new APIs. It generates a Playwright MCP config that points launchOptions.executablePath to CloakBrowser, then forwards all upstream browser tools unchanged.

Two Diagnostic Tools Added

The bridge adds exactly two local tools: cloakbrowser_binary_info and cloakbrowser_bridge_info. These answer practical setup questions—bridge version, upstream Playwright MCP package/version resolved, which browser engine is configured, where the CloakBrowser binary lives, output directory status.

Getting Started

Requires Node.js 20 or newer. Run npx -y cloakbrowser-mcp@latest doctor for local diagnostic checks before wiring into an MCP client. The default transport is stdio—works with Claude Desktop, Cursor, VS Code, Cline, Continue, Windsurf, Goose, Warp, and Codex.

Docker and HTTP Options

Docker support uses the pinned official Playwright MCP image plus the bridge: docker pull swimmwatch/cloakbrowser-mcp:latest. For Streamable HTTP on port 3000, expose at http://127.0.0.1:3000/mcp with health probes at /healthz and /readyz.

Key Takeaways

  • Preserves all Playwright MCP tool contracts—no relearning browser automation workflows
  • Swap the Chromium runtime without rewriting your agent's tooling
  • Two diagnostic tools for debugging setup issues
  • Works with Claude Desktop, Cursor, VS Code, Cline, Continue, and other MCP clients
  • Docker-ready for reproducible environments

The Bottom Line

If you're already invested in Playwright MCP workflows but need CloakBrowser's Chromium build, this bridge gives you the swap without the rewrite.