[potsrevennil]

Agents run git dozens of times per session, and git's defaults are written for people: hint paragraphs and long-form status. In a scratch repo, git status goes from 7 lines to 2, git init from 14 to 1, and an unmerged git branch -d from 3 to 1.

users/home/git/agent.gitconfig includes the normal config (identity, editor, commit template), then turns on short status and turns off hint text. home-manager links a Nix store copy to ~/.config/git-agent/config, and Claude Code will select it through GIT_CONFIG_GLOBAL in its settings env, so interactive git is unchanged. Config only trims status and hints. The larger savings (log, show, diff) come from command choice, which will be instructions in ~/.claude/CLAUDE.md, outside this repo.

• Look at: why it's a store copy and not out-of-store like ~/.config/git. If GIT_CONFIG_GLOBAL names a missing file, git silently drops the whole global config and agents lose user.email. An out-of-store link would disappear whenever the main checkout is on a branch without the file. The store copy also makes an agent's git config --global fail instead of editing a tracked file. The cost is that edits need make home.
• Not overridden on purpose: pager, color and delta. Agents' output is never a TTY, so git already skips them.
• Verify:

  GIT_CONFIG_GLOBAL=$PWD/users/home/git/agent.gitconfig git status

  GIT_CONFIG_GLOBAL=$PWD/users/home/git/agent.gitconfig git config user.email

  nix eval --raw '.#homeConfigurations.thing-hanlim.config.xdg.configFile."git-agent/config".source'

• Out of scope: after merge and make home, two hand edits: "env": {"GIT_CONFIG_GLOBAL": "/Users/thing-hanlim/.config/git-agent/config"} in ~/.claude/settings.json, and the agent git rules in ~/.claude/CLAUDE.md. Also out: output proxies such as rtk, and gh output.

🤖 Generated with Claude Code