UserScripts Claude.ai by losnappas
User scripting via claude.ai, through an MCP in this extension. For FREE!
Available on Firefox for Android™Available on Firefox for Android™
Extension Metadata
About this extension
Check the readme on https://github.com/losnappas/userscript-mcp-claude-webextension for usage notes.
Here it is for brevity, but I'm unlikely to update these steps here, just on the readme:
Here are some chats with claude, for show:
Here it is for brevity, but I'm unlikely to update these steps here, just on the readme:
Preliminary step: log into https://claude.ai, if you aren't already
Go to a page where you want to have a user script, e.g. https://example.org
Hit the extension button
Claude.ai opens in a new tab, and it has access to an MCP
Ask Claude to, for example, "make a user script to turn the background green"
Claude goes off, it will write the scripts, and instruct you to refresh example.org once done
Here are some chats with claude, for show:
- Basic "change background to green" example - https://claude.ai/share/53bf39b3-823a-4de9-a6cb-cb4632bc5032
- Fill reddit username (longer) - https://claude.ai/share/33b465ff-814e-4772-a75f-c943a4551ab0
- Had a mixup with claude (multiple iteration debug) - https://claude.ai/share/b9ddaae5-0f2d-47cd-8947-f2f18a5b4d2a
Rated 0 by 0 reviewers
Permissions and data
Optional permissions:
- Access your data for all websites
Data collection:
- The developer says this extension doesn't require data collection.
More information
- Add-on Links
- Version
- 1.0.5
- Size
- 83.76 KB
- Last updated
- 13 days ago (Dec 4, 2025)
- Related Categories
- License
- MIT License
- Version History
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