remorses__playwriter/MCP.md

MCP Setup

Note: CLI is the recommended way to use Playwriter. See README.md for CLI usage.

Add to your MCP client settings:

{
  "mcpServers": {
    "playwriter": {
      "command": "npx",
      "args": ["-y", "playwriter@latest"]
    }
  }
}

Or auto-configure:

npx -y @playwriter/install-mcp playwriter@latest

Using the MCP

1. Enable the extension on at least one tab (click icon → turns green)
2. MCP automatically starts relay server and connects to enabled tabs
3. Use the execute tool to run Playwright code

The MCP exposes:

• execute tool - run Playwright code snippets
• reset tool - reconnect if connection issues occur

Environment Variables

PLAYWRITER_AUTO_ENABLE

Auto-create a tab when Playwright connects (no manual extension click needed).

Note: CLI enables this by default. This is only needed for MCP server usage.

{
  "mcpServers": {
    "playwriter": {
      "command": "npx",
      "args": ["-y", "playwriter@latest"],
      "env": {
        "PLAYWRITER_AUTO_ENABLE": "1"
      }
    }
  }
}

The auto-created tab starts at about:blank. Navigate it to any URL.

Direct CDP (no extension needed)

Connect directly to Chrome's DevTools Protocol without the extension. Set PLAYWRITER_DIRECT in your MCP config:

{
  "mcpServers": {
    "playwriter": {
      "command": "npx",
      "args": ["-y", "playwriter@latest"],
      "env": {
        "PLAYWRITER_DIRECT": "1"
      }
    }
  }
}

Enable debugging in Chrome first: open chrome://inspect/#remote-debugging or launch with --remote-debugging-port=9222.

Chrome 136+ may show an approval dialog the first time a connection is made.

You can also pass an explicit WebSocket endpoint: PLAYWRITER_DIRECT=ws://127.0.0.1:9222/devtools/browser/abc.

Limitation: screen recording is unavailable in direct mode.

Remote Agents (Devcontainers, VMs, SSH)

Run agents in isolated environments while controlling Chrome on your host.

On host (where Chrome runs):

npx -y playwriter serve --token <secret>

In container/VM (where agent runs):

{
  "mcpServers": {
    "playwriter": {
      "command": "npx",
      "args": ["-y", "playwriter@latest", "--host", "host.docker.internal", "--token", "<secret>"]
    }
  }
}

Or with environment variables:

{
  "mcpServers": {
    "playwriter": {
      "command": "npx",
      "args": ["-y", "playwriter@latest"],
      "env": {
        "PLAYWRITER_HOST": "host.docker.internal",
        "PLAYWRITER_TOKEN": "<secret>"
      }
    }
  }
}

Use host.docker.internal for devcontainers, or your host's IP for VMs/SSH.