Firefox DevTools MCP v0.10.7 released

Firefox Tooling Announcements
1

New release of Firefox DevTools MCP. Available on npm at https://www.npmjs.com/package/@mozilla/firefox-devtools-mcp

Added

  • New --idle-timeout option (IDLE_TIMEOUT). It sets how many seconds a --connect-existing session waits without tool calls before it releases Firefox. The default stays 1800 seconds (30 minutes). Firefox accepts one client at a time, so a shorter delay lets other clients connect sooner

Fixed

  • upload_file_by_uid works again. Since 0.10.5 it did not set any file. It now uses WebDriver BiDi input.setFiles, and no longer changes the style of a hidden file input
  • --connect-existing now fails at once with a clear error when another WebDriver session already holds Firefox. Before, it failed after about 60 seconds with “unknown error”
  • --connect-existing now gives up after 45 seconds when Firefox asks the user to allow the session and nobody answers. Before, it waited forever. The error points at the prompt
  • Shutting down the server while Firefox waits for the user to allow the session no longer leaves geckodriver running
  • set_viewport_size now only changes the viewport of the selected tab, instead of resizing the whole window. With --connect-existing, the resized tabs are reset when the session closes
  • evaluate_script with a timeout above 10 seconds no longer stops after 10 seconds with a generic BiDi timeout error

Changed

  • navigate_history now uses WebDriver BiDi
  • BiDi command errors now include the message sent by Firefox
  • The README explains how to run a --connect-existing Firefox in a dedicated profile, next to your everyday Firefox

Full changelog: Release v0.10.7 · mozilla/firefox-devtools-mcp · GitHub
Repository and issues: GitHub - mozilla/firefox-devtools-mcp: Model Context Protocol server for Firefox DevTools - enables AI assistants to inspect and control Firefox browser through WebDriver BiDi · GitHub
Public chatroom: https://chat.mozilla.org/#/room/#firefox-devtools-mcp:mozilla.org