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Cursor

Firefox DevTools MCP for Cursor

io.github.mozilla/firefox-devtools-mcp

Control and debug Firefox: navigate, fill forms, inspect network and console, profile.

client:Cursor transport:stdio runtime:npm

Install Firefox DevTools MCP in Cursor

~/.cursor/mcp.json · windows: %USERPROFILE%\.cursor\mcp.json

Held in this page only — never stored, logged, or sent anywhere but back to your screen. 

{
  "mcpServers": {
    "firefox-devtools-mcp": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@mozilla/firefox-devtools-mcp"
      ],
      "env": {
        "FIREFOX_HEADLESS": "<FIREFOX_HEADLESS>",
        "START_URL": "<START_URL>"
      }
    }
  }
}

Use .cursor/mcp.json in a project root instead to scope it to that project. Cursor merges both. Cursor docs

Firefox DevTools MCP in other clients

Firefox DevTools MCP MCP server