GitHub Spec Kit

GitHub Spec Kit is the open-source toolkit for Spec-Driven Development (SDD): it structures AI coding workflows, ensuring agents like Copilot and Claude Code build exactly to a validated specification.

Spec Kit enforces a four-phase, spec-driven workflow: Specify, Plan, Tasks, and Implement. It eliminates 'vibe coding' by making the specification the single source of truth for AI agents. The kit includes the `Specify CLI` tool, ready-to-use templates, and carefully crafted steering prompts for models (e.g., GitHub Copilot, Gemini CLI). Developers use the CLI to bootstrap projects, defining project principles with a `constitution.md` file, then letting the AI generate a detailed spec, technical plan, and small, testable tasks. This structured approach guarantees high-quality, production-ready code tied directly to clear requirements.

https://github.com/github/spec-kit