Firefox DevTools MCP for VS Code

io.github.mozilla/firefox-devtools-mcp

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

client:VS Code transport:stdio runtime:npm

Install Firefox DevTools MCP in VS Code

.vscode/mcp.json

{
  "inputs": [
    {
      "type": "promptString",
      "id": "firefox-headless",
      "description": "FIREFOX_HEADLESS",
      "password": true
    },
    {
      "type": "promptString",
      "id": "start-url",
      "description": "START_URL",
      "password": true
    }
  ],
  "servers": {
    "firefox-devtools-mcp": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@mozilla/firefox-devtools-mcp"
      ],
      "env": {
        "FIREFOX_HEADLESS": "${input:firefox-headless}",
        "START_URL": "${input:start-url}"
      }
    }
  }
}

VS Code prompts for each input the first time the server starts, so no secret is written to the file. VS Code docs

Firefox DevTools MCP in other clients

Firefox DevTools MCP MCP server