Sdd Harness

sdd-harness

A runtime-agnostic **Spec-Driven Development harness** that any AI can operate. Drop it into a repo and the team — humans and AIs alike — follow one disciplined loop: **spec first, code second, verify against spec**. The pre-commit hook makes it non-optional.

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Contents

• Why
• Install
• How it works
• Using it day to day
• What you get
• Proven in a real adoption
• Roadmap
• License · Read more

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Why

Most "AI in your repo" setups lock you into one assistant, drop ungoverned context, and let code drift from intent until nobody can explain why anything is the way it is.

sdd-harness fixes three things at once:

• Spec before code, enforced. A pre-commit hook blocks feature commits that change code without touching a spec or ADR. The discipline is structural, not a guideline people forget.
• Runtime-agnostic. The brain lives in .ai/. Any AI (Claude Code, Codex, Cursor, Copilot, Gemini, …) operates the project by reading it. Swapping assistants is a 5-line pointer file, not a migration. (See [ADR 0008](.ai/adrs/0008-runtime-agnost