Copilot CLI Extensions Cookbook: 15 Production-Ready Examples You Can Copy Today

I've been building Copilot CLI extensions for weeks now, and I keep discovering patterns I wish I'd had from day one. Not theory — actual working code that solves real problems. Every time I cracked a new pattern, I thought "someone should just publish a cookbook." So here it is. If you want the full architecture breakdown and API reference, check out the complete guide. This article is the companion cookbook — all code, all examples, ready to copy. No hand-waving, no pseudocode. Every snippet here is a complete, working extension you can drop into your project right now. The setup is the same for every example: create a file at .github/extensions/<name>/extension.mjs in your repo. The @github/copilot-sdk package is auto-resolved by the CLI runtime — no npm install needed. After creating or editing an extension, run extensions_reload in your session or type /clear to activate it. That's it. Let's build. Governance Extensions These extensions enforce rules automatically. They inte