Make Claude Prove You Understand Its Code Before It Ships
Sphinx is a free Git hook that quizzes you on what your coding agent just wrote before a push goes through. What it does, the two-command setup, how the quiz works, the skip switch, and a prompt to try it on your next change
Sphinx is an open-source Git hook for agent-assisted coding. When you or your agent pushes, a reviewer that never saw your chat reads the change and asks what it does when things go wrong. You answer before the push continues.
Here's how it works, how to set it up, and the catches.
How the quiz works
- You push, or your agent does. Git pauses on the branches you protect.
- Sphinx asks a question about your diff: what the change does when things go wrong.
- A right answer lets the push continue. A wrong one explains the problem and gives you a new scenario.
Set it up in two commands
- Check you have Node 22.19 or newer (macOS, Linux or WSL).
- Run: npm install -g sphinx-understand
- Run: sphinx install. It connects Git and your coding agents (Claude Code, Codex, Cursor, OpenCode, Pi) and asks which model should review.
- Push as usual with git push.
Free, for your email
Get the full setup steps + the copy-paste setup prompt
The rest of this guide (2 more sections, 1 copy-paste prompt) opens right here. The setup prompt, one paste into Claude that sets it all up, comes by email only. Use your real address.
50,000+ follow where these guides come from. No spam, unsubscribe in one click.