Control and debug Firefox: navigate, fill forms, inspect network and console, profile.
Connect Runs on your machine
claude mcp add firefox-devtools-mcp -e FIREFOX_HEADLESS=<FIREFOX_HEADLESS> -e START_URL=<START_URL> -- npx -y @mozilla/[email protected]{
"mcpServers": {
"firefox-devtools-mcp": {
"command": "npx",
"args": [
"-y",
"@mozilla/[email protected]"
],
"env": {
"FIREFOX_HEADLESS": "<FIREFOX_HEADLESS>",
"START_URL": "<START_URL>"
}
}
}
}{
"mcpServers": {
"firefox-devtools-mcp": {
"command": "npx",
"args": [
"-y",
"@mozilla/[email protected]"
],
"env": {
"FIREFOX_HEADLESS": "<FIREFOX_HEADLESS>",
"START_URL": "<START_URL>"
}
}
}
}{
"servers": {
"firefox-devtools-mcp": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"@mozilla/[email protected]"
],
"env": {
"FIREFOX_HEADLESS": "<FIREFOX_HEADLESS>",
"START_URL": "<START_URL>"
}
}
}
}Replace the values in angle brackets with your own. Keys stay on your machine; we never see them.
Tools
This server runs locally, so its tools are listed by your MCP client once it starts.
Environment variables
| Name | Description |
|---|---|
FIREFOX_HEADLESSOptional | Set to true to run Firefox without a visible window. |
START_URLOptional | URL to open when the server starts. |
Details
| Package | @mozilla/[email protected] (NPM, stdio) |
| First published | 28 Oct 2026 |
| Last updated | 28 Oct 2026 |
| Registry name | io.github.mozilla/firefox-devtools-mcp |
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