Built a Conventional Commits CLI with free AI tools (zero cost)

Staring at a staged diff trying to summarize it in one sentence is a tax every developer pays. "fix stuff" and "wip" pile up in the history until a git blame six months later leaves you guessing.

That's why I built commit-sage.

What it is

commit-sage is a Python CLI that reads your staged git diff, sends it to an AI provider, and returns a ready-to-use Conventional Commit message — no manual writing.

Flow:

• Reads staged diff via git
• Sends diff to configured AI provider (OpenAI or Gemini)
• Parses response into Conventional Commit format
• You review before committing

Handles edge cases cleanly: missing API key, no staged files, API failures — all caught with clear error messages instead of crashes.

How it was built

Entire build used free AI-assisted coding tools, zero paid tooling. Started as a single-provider script, refactored into a dispatch pattern once a second backend was added.

Why it matters

Commit history is documentation. A clean log makes changelogs, code review, and debugging easier. commit-sage doesn't replace judgment — it still shows the message before commit — it just removes the blank-page problem.

Try it

MVP stage, feedback and PRs welcome.

👉 https://github.com/monobuildstudio/commit-sage