GitHub Spec Kit ↗

Editorial Notes

The primary open-source tool for practicing SDD. Spec Kit provides CLI commands for creating, validating, and managing specifications that drive AI-assisted implementation. Its four-phase gated workflow (Specify, Plan, Tasks, Implement) enforces the discipline that makes SDD effective — each phase must be completed before moving to the next. Works with GitHub Copilot, Claude Code, and Gemini CLI. Start here after reading the methodology articles to make SDD concrete rather than theoretical.