CloakBrowser MCP: Playwright MCP tools with a CloakBrowser Chromium runtime

CloakBrowser MCP is an open-source Model Context Protocol server that integrates upstream Playwright MCP tools with the CloakBrowser Chromium runtime. The project generates a Playwright MCP configuration pointing `launchOptions.executablePath` to CloakBrowser, keeping the same browser automation tool surface while allowing users to run it with a different Chromium executable in local or Docker-backed agent workflows.

Browser automation is becoming one of the most useful tool categories for AI agents. If an agent can open a page, inspect the accessibility tree, click buttons, fill forms, read console output, and take screenshots, it can help with tasks that are hard to solve through APIs alone: debugging frontend flows, checking documentation, testing onboarding, validating generated UI, and reproducing browser-only bugs. Playwright MCP is already a strong foundation for that workflow. It gives MCP clients a browser automation surface built around Playwright. The question that led to CloakBrowser MCP was narrower: What if you want the same upstream Playwright MCP tools, but with a different Chromium runtime? That is what cloakbrowser-mcp does. cloakbrowser-mcp is an open-source Model Context Protocol server that runs upstream @playwright/mcp with the CloakBrowser Chromium executable. The project is intentionally thin: cloakbrowser-mcp generates a Playwright MCP config that points launchOptions.executablePath to CloakBrowserThose local tools are: cloakbrowser binary info cloakbrowser bridge info Everything else comes from upstream Playwright MCP. Repository: https://github.com/swimmwatch/cloakbrowser-mcp https://github.com/swimmwatch/cloakbrowser-mcp Docs: https://swimmwatch.github.io/cloakbrowser-mcp/ https://swimmwatch.github.io/cloakbrowser-mcp/ npm: https://www.npmjs.com/package/cloakbrowser-mcp https://www.npmjs.com/package/cloakbrowser-mcp This is not a custom browser automation API. It is not a fork that rewrites Playwright MCP tool contracts. It is not a CAPTCHA-solving service, and it should not be treated as a replacement for proper test-environment controls, allowlists, or site-owner-approved automation paths. The goal is narrower and more maintainable: keep the Playwright MCP surface familiar, while letting users run that surface with CloakBrowser Chromium in local or Docker-backed agent workflows. Browser MCP servers can become painful when every server invents a slightly different tool surface. If the tool names, schemas, and behavior drift, users have to relearn the same browser workflow for each runtime. Clients and prompts also become less portable. cloakbrowser-mcp takes the opposite approach. The bridge stays small and lets upstream Playwright MCP remain authoritative for browser tools. That matters for a few reasons: The project also runs parity checks against upstream default tools in CI, so changes to the forwarded tool surface are visible during development. Requires Node.js 20 or newer. npx -y cloakbrowser-mcp@latest --help npx -y cloakbrowser-mcp@latest doctor npx -y cloakbrowser-mcp@latest Use doctor first if you want a local diagnostic check before wiring the server into an MCP client: npx -y cloakbrowser-mcp@latest doctor --json The default transport is stdio, which is what most local MCP client configs expect. For Streamable HTTP: npx -y cloakbrowser-mcp@latest \ --transport streamable-http \ --http-port 3000 That exposes MCP at: http://127.0.0.1:3000/mcp It also provides health probes: curl http://127.0.0.1:3000/healthz curl http://127.0.0.1:3000/readyz Most MCP clients use the same stdio shape: command , args , and optional env . { "mcpServers": { "cloakbrowser": { "command": "npx", "args": "-y", "cloakbrowser-mcp@latest" , "env": { "PLAYWRIGHT MCP HEADLESS": "true", "PLAYWRIGHT MCP OUTPUT DIR": "/tmp/cloakbrowser-artifacts" } } } } Use the same pattern in clients such as Claude Desktop, Cursor, VS Code, Cline, Continue, Windsurf, Goose, Warp, and Codex, adjusting only the surrounding config format if the client uses TOML or YAML instead of JSON. Docker is useful when you want a repeatable runtime. The image is based on the pinned official Playwright MCP image and includes the bridge. docker pull swimmwatch/cloakbrowser-mcp:latest docker run --rm --init -i \ -v "$PWD/artifacts:/data" \ swimmwatch/cloakbrowser-mcp:latest For Streamable HTTP in Docker: docker run --rm --init -p 127.0.0.1:3000:3000 \ -v "$PWD/artifacts:/data" \ swimmwatch/cloakbrowser-mcp:latest \ --transport streamable-http \ --http-host 0.0.0.0 \ --http-port 3000 The same images are also published to GitHub Container Registry: ghcr.io/swimmwatch/cloakbrowser-mcp Ask your MCP client to list tools. You should see upstream Playwright MCP browser tools, such as: browser navigate browser click browser type browser snapshot browser take screenshot browser console messages browser network requests browser evaluate browser tabs You should also see the two local diagnostic tools: cloakbrowser binary info cloakbrowser bridge info The diagnostic tools are there to answer practical setup questions: The primary configuration namespace is the upstream Playwright MCP namespace: PLAYWRIGHT MCP For Cloak-specific bridge toggles: CLOAK PLAYWRIGHT MCP Common examples: PLAYWRIGHT MCP HEADLESS=true PLAYWRIGHT MCP OUTPUT DIR=/tmp/cloakbrowser-artifacts PLAYWRIGHT MCP OUTPUT MODE=stdout CLOAK PLAYWRIGHT MCP CONSOLE FALLBACK=true CLOAK PLAYWRIGHT MCP STEALTH ARGS=true For local HTTP transport: CLOAK PLAYWRIGHT MCP TRANSPORT=streamable-http CLOAK PLAYWRIGHT MCP HTTP HOST=127.0.0.1 CLOAK PLAYWRIGHT MCP HTTP PORT=3000 CLOAK PLAYWRIGHT MCP HTTP ENDPOINT=/mcp If you expose HTTP outside a local development machine, configure an auth token: CLOAK PLAYWRIGHT MCP HTTP AUTH TOKEN=... A few details are worth knowing before using it in a real workflow: -i so stdio stays connected. --init so browser child processes are reaped correctly. latest .Example: npx -y cloakbrowser-mcp@1.3.0 Or: docker run --rm --init -i \ -v "$PWD/artifacts:/data" \ swimmwatch/cloakbrowser-mcp:1.3.0 It is a good fit when you want: It is probably not the right fit if: The fastest path is: npx -y cloakbrowser-mcp@latest doctor Then add the stdio config to your MCP client: { "mcpServers": { "cloakbrowser": { "command": "npx", "args": "-y", "cloakbrowser-mcp@latest" } } } Project links: Feedback is welcome, especially from people already using Playwright MCP in local agent workflows.