# Firefox DevTools MCP v0.10.7 released

**URL:** <https://discourse.mozilla.org/t/firefox-devtools-mcp-v0-10-7-released/149991>\
**Category:** Firefox Tooling Announcements\
**Tags:** developer-tools\
**Created:** [October 28, 2026, 11:28am UTC](https://discourse.mozilla.org/t/firefox-devtools-mcp-v0-10-7-released/149991 "2026-10-28T11:28:29Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![jdescottes](https://sea1.discourse-cdn.com/flex001/user_avatar/discourse.mozilla.org/jdescottes/32/22185_2.png) [@jdescottes](https://discourse.mozilla.org/u/jdescottes)\
**Post date:** [October 28, 2026, 11:28am UTC](https://discourse.mozilla.org/t/firefox-devtools-mcp-v0-10-7-released/149991/1 "2026-10-28T11:28:29Z")

</div>

New release of Firefox DevTools MCP. Available on npm at [https://www.npmjs.com/package/@mozilla/firefox-devtools-mcp](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](https://github.com/mozilla/firefox-devtools-mcp/releases/tag/v0.10.7)  
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](https://github.com/mozilla/firefox-devtools-mcp)  
Public chatroom: [https://chat.mozilla.org/#/room/#firefox-devtools-mcp:mozilla.org](https://chat.mozilla.org/#/room/#firefox-devtools-mcp:mozilla.org)