If Copilot is: - creating unnecessary tests - writing messy legacy code - not following your instructions

Say hello to Spec Kit. Spec Kit is GitHub's open source tool that brings spec-driven development to your existing codebase, not just new projects.

It works really well with Copilot (but it also works with any other agentic tool you’re using).

How Spec Kit works: - Define your intent (spec + plan) - Break plan into tasks - Let AI implement with YOUR rules ✨ - Review code that follows your architecture

The shift: Your spec becomes the source of truth. Code follows intent, not the other way around.

This means architecture rules, security constraints, and design decisions are baked in from the start, not bolted on afterwards.

Where spec-driven shines: ✅ Existing projects that need structure ✅ Adding features to complex codebases ✅ Legacy rebuilds ✅ Greenfield that won't turn into a mess

Your turn: Let’s spec it out together. github.com/github/spec-kit