Introduction

ScriptCat supports three types of scripts:

Type	When it runs
Page scripts	When you open a matching web page; these are what people usually call Tampermonkey scripts
Background scripts	Without any page, for as long as the browser is open; specific to ScriptCat
Scheduled scripts	On a cron schedule; specific to ScriptCat

Ways to develop

• The built-in editor: create a script on ScriptCat's "Installed Scripts" page; it takes effect when you save.
• VSCode: write in a familiar editor and have each save synced to ScriptCat; see Develop Scripts with VSCode.
• An AI coding agent: have Claude Code, Codex or another agent write the script following ScriptCat's rules, install it into ScriptCat and verify it in your browser; see Developing Scripts with AI.

Reference

• API: the Tampermonkey APIs and metadata ScriptCat supports.
• CatApi: ScriptCat's own extension APIs.
• Background scripts, subscriptions and user config: what only ScriptCat offers.

To learn userscript development step by step, see our Tampermonkey Script Development Guide. If you find gaps in the documentation, let us know on GitHub, or send a PR to help improve it.