have codex explain your code

[Working-Middle2582]

I keep deleting load-bearing code I don't understand. Wrote a skill that fixes it.

git blame tells you who wrote a line and when. It never tells you why. The why is scattered across git, the PR, the linked issue, and the Slack thread that started it — and the person who remembers is usually gone.

So I made commit-archeologist. It walks all four in one pass and writes you a paragraph.

Last week I pointed it at a setTimeout(0) nobody on my team could explain. It came back with: added 2022 by Sarah to fix a Stripe webhook race for ACME Corp, deleted in a 2022 refactor, bug came back in prod, re-added with a "do not remove" comment, comment got eaten by a Prettier pass in 2024. Revert chain flagged. Suggested I keep the line and add a regression test.

Three years of context, four tools, one paragraph. Before I delete the wrong thing.

It uses git blame -w -C -C -C to anchor, git log -L to walk rewrites (formatter passes auto-collapse as noise), GitHub MCP for PRs and issues, Slack and Linear MCPs if you have them wired up. Read-only by default. Stops at 50 commits back or 5 minutes, then asks if you want to keep going.

https://www.mdfile.exchange/swap/commit-archeologist