Sphinx Git Hook Quizzes Developers on AI-Generated Code Diffs Before Shipping

Sphinx is a free Git hook designed for agent-assisted software development that pauses code pushes on protected branches to test the developer's understanding of the changes before shipping. When a developer or coding agent attempts to push code, an independent model that never saw the coding chat reads the diff and asks a scenario-based question about how the code behaves when errors or edge cases occur. If the developer answers incorrectly, Sphinx explains the flaw and generates a new scenario until the logic is understood, though users can bypass the check using the logged "sphinx yolo" command. The tool installs via npm as "sphinx-understand" and works alongside Codex, Claude Code, Cursor, OpenCode, Pi, or standard Git workflows using minimal tokens through OpenRouter or any OpenAI-compatible endpoint. To maintain local security and context isolation, developer responses are never sent back to the coding agent, and the hook never opens .env files or private keys.