tampermonkey

Write and debug Tampermonkey userscripts for browser automation, page modification, and web enhancement. Use whenever the user mentions userscripts, Tampermonkey, Greasemonkey, Violentmonkey, or wants to write a script that runs on a website - even if they don't say 'userscript' explicitly. Also trigger for: injecting JavaScript or CSS into web pages, modifying website behaviour, hiding page elements, form auto-fill, scraping page data, intercepting requests, detecting URL changes in SPAs, adding keyboard shortcuts to websites, tab audio control, or TypeScript userscripts. Covers all header tags (@match, @grant, @require, @run-in), GM_* synchronous APIs, GM.* promise-based APIs (recommended for new scripts), batch storage (GM.getValues/setValues v5.3+), binary data support (v5.4+), TypeScript setup via @types/tampermonkey, security sandboxing, and cross-browser compatibility (Chrome, Firefox, Edge). Do NOT use for Selenium/Puppeteer automation, browser extensions (WebExtensions/MV3), or server-side scripts.