commit-historian

Point it at any file in your git repo. Get a short, vivid narrative of how it came to be.

commit-historian is a CLI code archaeologist. It feeds a file's git log (with patches) to Claude and asks for a story — with real commit SHAs as anchors — so you can read the why behind code, not just the what.

_{Image above is an illustrative example. Replace with a real capture from your repo after running it.}

Install

npx commit-historian <path>
# or globally
npm i -g commit-historian

Usage

commit-historian <path>                  # full history with patches
commit-historian <path> --short          # metadata only, faster + cheaper
commit-historian <path> --since v1.0     # limit to a ref or date
commit-historian <path> --model <id>     # override model
commit-historian <path> --dry-run        # print the prompt; no API call

Requires ANTHROPIC_API_KEY in your environment. Defaults to claude-sonnet-4-6.

Why

git log answers what changed. git blame answers who. Neither answers why this file is shaped the way it is — which is the actual question when you join a project, audit a module, or onboard onto a team's code. commit-historian does that, with citations.

How it works

1. Resolves the file inside your repo (follows renames).
2. Runs git log --follow -p --date=short and caps the patch payload.
3. Streams the log to Claude with a strict system prompt: anchor every claim to a real short SHA, surface tensions and reverts, keep it under ~450 words.
4. Streams the markdown narrative to stdout.

No data leaves your machine except the git log you pass to Anthropic's API.

License

MIT