Never add Co-Authored-By: trailers crediting any AI tool to a git commit.
This includes Claude, Claude Code, GitHub Copilot, Cursor, Codeium, and any other AI assistant. Commits must list a human author only — AI tools are not co-authors.
You may add an Assisted-By: trailer naming the tool. Example:
Assisted-By: Claude Code
Use a short, plain tool name. No emails, no URLs, no marketing taglines ((1M context), Generated with ...). One trailer per commit is enough.
If you are running as an agent or sub-agent and your default commit template includes a Co-Authored-By: for an AI tool, strip it before git commit and replace it with Assisted-By: <tool> instead. This rule applies to all branches and to rewrites.