AI Attribution in Git

Apr 17, 2026 – Filed as: Software⁷⁷

When making a git commit I’ve been looking for a way to record what AI model or coding agent harness I used to help me write the commit, ideally in a machine-readable way.

For AI-drafted code that I’ve reviewed or self-drafted code with significant AI revisions, I add one of the following trailers to my git commit message:

• Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
• Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
• Co-authored-by: Claude Haiku 4.5 <noreply@anthropic.com>
• Co-authored-by: GPT-5.3-Codex <noreply@openai.com>
• Co-authored-by: Google Gemini 3.1 Flash Image (Nano Banana 2)
  • TODO: Identify an email address to use for Gemini

Tip: I use text expansion macros like coa → "Co-authored-by: " and aco → "Claude Opus 4.6 <noreply@anthropic.com>" to type those trailers quickly.

For AI-drafted code that I’ve NOT reviewed (rare; mostly for internal or one-off tools):

• Author = one of the emails above, via git commit --author="AI Model <noreply@example.com>".
• Co-authored-by = me:
  • Co-authored-by: David Foster <david@dafoster.net>

If I ever want to make such unreviewed or minimally-reviewed AI-drafted code public, I can use git blame to easily identify which lines are principally AI-drafted, so that I can go back and review them carefully; I never publish AI-written code that I haven’t reviewed myself.

Tip: I use the Git Spotlight tool to quickly see which lines of code are written by AI (C4 = Claude Opus 4.6) or by me (DF = David Foster). See below:

Why the Co-authored-by pattern?

Claude Code introduced the convention of adding a Co-Authored-By: Claude <noreply@anthropic.com> trailer to any AI-authored commits by telling the AI to use such trailers in its system prompt, much to the annoyance of some users. GitHub recognizes that Co-Authored-By trailer and displays Claude as a co-author of the related commit.

I think that kind of attribution is lightweight and makes sense.