Agent skill · writing content · aiskillstore
develop-userscripts
Use when building, debugging, packaging, or publishing browser userscripts for Tampermonkey or ScriptCat, including GM APIs, metadata blocks, permission issues, @match/@grant/@connect setup, ScriptCat background or scheduled scripts, UserConfig blocks, or subscription workflows.
Why this skill is useful
Provides specific guidance on userscript development for Tampermonkey and ScriptCat, including niche commands and metadata configurations.
What it needs
About 3k tokens when loaded. Last updated 2026-08-07. 405 stars on the source repository.
What this skill does
Userscript work usually breaks at the runtime and metadata boundary, not in the page logic. Choose the runtime first, declare the minimum permissions up front, then debug in the environment where the script actually runs. When to Use Use this skill for: writing or fixing a Tampermonkey or ScriptCat userscript debugging injection timing, missing permissions, CSP workarounds, update checks, or GM behavior deciding between a portable foreground script and ScriptCat-only @background or @crontab adding config UI with ==UserConfig== packaging a ScriptCat ==UserSubscribe== bundle or preparing a CloudCat-compatible script Do not use this skill for full browser extension development or general browser automation outside userscript managers. Runtime Selection Preflight Confirm the manager and browser. On Manifest V3 browsers, ScriptCat may require Allow User Scripts or browser developer mode before scripts run. Decide page script versus background script before writing code. ScriptCat background scripts cannot touch the DOM. Start with metadata, not implementation: @match, @grant, @connect, @run-at, and any update URLs. Prefer portable ==UserScript== patterns for ordinary page scripts. Only switch to ScriptCat-only headers when the requested behavior actually needs them. Workflow 1. Choose the runtime and metadata first. 2. Declare the smallest permission surface that fits the task. 3. Implement against the runtime you chose. 4. Debug where the code really runs. Foreground scripts: page console plus manager logs. ScriptCat background scripts: run log first, then background.html for real-environment debugging. 5. Publish with the right update model. Normal scripts: keep @version accurate and add @updateURL or @downloadURL only when needed. Subscription bundles: use ==UserSubscribe==, HTTPS URLs, and subscription-level @connect. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills aiskillstore/develop-userscripts