Two Git ignore files nobody told me about

One of my many bad habits is carrying untracked files around in the repositories I work on. I did learn, some time ago, that those files must never contain secrets, because sooner or later they get committed by mistake. I learned it the easy way, by watching a colleague learn it the hard way: furiously rewriting history to cover his tracks, then rotating cloud credentials in a panic. These days the untracked files are harmless. Random markdown notes and, more often than not, agent plans. I haven't started committing those yet. They go stale fast, and I'm not convinced they're worth the effort. So why put up with a permanently dirty working tree? Because until very recently, the only way I knew to ignore a file in git was to add it to .gitignore. And .gitignore gets committed. That's exactly right for things everyone cloning the repo will have, like the classic .env, but pushing the silly filename I picked for my private notes to a remote repository feels unclean. So I did nothing, and the untracked files piled up. About ten plans at the last count. But then Claude asked, out of the blue, something along the lines of "would you like me to add these files to .git/info/exclude?" Wait, what? What's that? The three ignore files It turns out git reads ignore patterns from three places, all with the same syntax. The per-repo one, .git/info/exclude, is the one I'm giddy about. It lives inside .git, so it can't be committed even by accident, and nobody else ever sees it. I'll probably move some things into ~/.config/git/ignore soon too; editor clutter has no business in any project's .gitignore, and yet there it is, in most of them. Using them The two new ones are plain text files that take the same patterns as .gitignore. There's no dedicated git command; you just append to them. Per repo, from the repository root: echo 'plans/' >> .git/info/exclude echo '*.notes.md' >> .git/info/exclude Patterns are matched relative to the repository root, exactly as they would be in a top-level .gitignore. The file is usually already there, with a few commented-out examples in it. One catch: in a linked git worktree, .git is a file rather than a directory, so the path above won't work. The exclude file lives in the main repository's .git/info/exclude and covers every worktree. This resolves to the right file from the main repository and from any linked worktree: echo 'plans/' >> "$(git rev-parse --git-common-dir)/info/exclude" Globally: mkdir -p ~/.config/git echo '.DS_Store' >> ~/.config/git/ignore echo '.idea/' >> ~/.config/git/ignore Git reads ~/.config/git/ignore automatically if it exists (or $XDG_CONFIG_HOME/git/ignore, if you set that variable); nothing to configure. If you'd rather keep it somewhere else, point git at it once: git config --global core.excludesFile ~/.gitignore_global Whichever file you use, git status stops listing the files immediately, as long as they weren't already tracked; ignore rules never apply to tracked files. A note on Claude Code Since ignoring agent plans has been the running example: by default, Claude Code leaves ignored files out of the autocomplete you get when you reference a file with @, so the moment your plans go into .git/info/exclude they vanish from the picker. To get them back, add this to your settings.json (or flip Respect .gitignore in file picker in /config): { "respectGitignore": false } This is only about the @ autocomplete. Claude Code can read the files regardless of the setting; it just won't offer them as you type. The settings reference has the details. So yeah, there you go. If, like me, you only knew about .gitignore and were skittish about sharing your note-taking habits with everyone on the project, you can now have a clean working tree without feeling exposed. AI usage disclaimer English is not my first language, and I'm not a talented writer in any language, so I use AI to polish my writing. The ideas, the setup, the mistakes and the opinions are all mine. They reach the AI as thorough notes in half-broken English, and it fixes the English. It doesn't supply the thinking, though it is a trusty research assistant.