# UserScripts Claude.ai > User scripting via claude.ai, through an MCP in this extension. For FREE! Canonical page: [https://chrome-stats.com/d/userscripts-claude-ai](https://chrome-stats.com/d/userscripts-claude-ai) ## Overview - **ID:** `userscripts-claude-ai` - **Platform:** Firefox - **Type:** Firefox add-on - **Status:** Available - **Publisher:** losnappas - **Category:** appearance,tabs - **Daily users:** 17 - **Weekly downloads:** 1 - **Version:** 1.3.0 - **Last updated:** 2026-06-05 - **First published:** 2025-11-27 - **Size:** 86 KB - **Data as of:** 2026-09-12 - **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/userscripts-claude-ai/) - **Website:** [https://github.com/losnappas/userscript-mcp-claude-webextension/issues](https://github.com/losnappas/userscript-mcp-claude-webextension/issues) ## Description 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:

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

## Rankings - #26,843 — Overall - #69 — claude ai - #81 — claude - #88 — script ## Permissions and access ### Permissions - `storage` - `activeTab` - `scripting` ### Host permissions - `` ## Safety - **Risk impact:** Moderate risk impact - **Risk likelihood:** Moderate risk likelihood ### Analysis details - Allows access to all websites, posing a significant security risk as it can monitor and modify data from any visited site. - This extension has low user count. Unpopular extensions may not be stable or safe. > Some risk analysis details are omitted from this free response. [Upgrade to view the full analysis](https://chrome-stats.com/pricing). ## Similar extensions and apps - [Magic Userscript+](https://chrome-stats.com/d/userscript-plus) — 710 users, 4.32 / 5 - [User Scripts Manager](https://chrome-stats.com/d/scripts-manager) — 1 users - [Script for Me](https://chrome-stats.com/d/script-for-me) — 28 users - [User Script Loader](https://chrome-stats.com/d/user-script-loader) — 14 users - [User Script Loader](https://chrome-stats.com/d/userscript) — 14 users - [ScriptCat Beta](https://chrome-stats.com/d/scriptcat-pre) — 329 users, 5.00 / 5 - [Scripts runner](https://chrome-stats.com/d/scripts-runner) — 58 users, 4.67 / 5 - [Ask Claude](https://chrome-stats.com/d/ask-claude) — 9 users - [BoostedScripts](https://chrome-stats.com/d/boostedscripts) — 1 users - [Script Menu](https://chrome-stats.com/d/script-menu) — 38 users, 4.67 / 5 - [run-a-script](https://chrome-stats.com/d/run-a-script) — 125 users, 5.00 / 5 - [ScriptCat](https://chrome-stats.com/d/scriptcat) — 10,664 users, 4.74 / 5 --- Source: [Chrome-Stats](https://chrome-stats.com/d/userscripts-claude-ai)