CODEOWNERS Generator
Map paths to users and teams and generate a valid CODEOWNERS file.
What is CODEOWNERS?
A CODEOWNERS generator. It builds the file GitHub uses to request reviews automatically, validates each rule as it goes, and warns about the two things that quietly break CODEOWNERS: a catch-all rule placed after specific ones, and owners who do not have write access.
How it works
Rules are kept in the order you arrange them, because GitHub uses the last matching pattern. Patterns are checked for `!` negation (unsupported) and comments mid-pattern; owners are validated against GitHub's username, team and email forms; duplicate patterns are reported; and a `*` fallback is added if none exists. The file can be copied or downloaded for the .github/CODEOWNERS location GitHub prefers.
- Paste or fill in the input. Drop in a commit message, a diff, a package.json, a path list or a set of options. The tool reads it locally — nothing is uploaded and no repository is contacted.
- Adjust the rules to match your project. Every linter here takes its convention from a setting you can change: allowed commit types, header length, target branch length, known branch names. Set them once to what your team actually uses.
- Copy the result. Generated files copy straight to the clipboard or download as a real file with the right name (.gitignore, CODEOWNERS, LICENSE, COMMIT_EDITMSG), and Reset returns every field to its default.
Examples
A commit message that fails CI
"Updated(auth): Fixed the expired-token redirect." is rejected by release automation and reported here with the exact reasons: unknown type, capitalised description, past tense and a trailing period.
A .gitignore that only half works
The Checker shows which rule decides a path — and why `!keep.txt` inside an ignored directory never fires, the mistake that sends people to Stack Overflow.
A dependency bump nobody reviewed
The package.json Diff separates added, removed and changed entries per section, so a caret bump of a runtime dependency does not hide inside a lockfile-sized pull request.
A diff pasted from a code review comment
The Diff Viewer understands several `diff --git` blocks, mode-only changes, renames and binary stubs, and calls out a pasted `--stat` summary instead of rendering an empty box.
Common mistakes
Committing a .gitignore without checking it
Rules look right and behave differently: a pattern containing a slash is anchored to the root, a trailing slash means directories only, and a file inside an ignored directory cannot be re-included. Check the paths that matter before you commit the file.
Rewriting published history
A clean commit history is worth having, but amend, rebase and filter-repo change commit hashes. Only rewrite commits that nobody has pulled; after a rewrite, push with --force-with-lease rather than --force.
Treating a generated file as if it were reviewed
These tools produce a starting point, not a decision. Check the licence text against the canonical source, read the security policy before publishing it, and make sure a CODEOWNERS team actually exists — GitHub silently ignores rules whose owner has no write access.
Putting slow checks in a pre-commit hook
A hook that takes 30 seconds gets bypassed with --no-verify within a week, and then it protects nothing. Keep pre-commit to formatting and linting, move type checks and tests to pre-push or CI.
Frequently asked questions
Which CODEOWNERS file does GitHub use?
The first one it finds, in this order: .github/CODEOWNERS, then CODEOWNERS in the repository root, then docs/CODEOWNERS. Only one is used, so keep a single file rather than splitting rules across locations.
Why is my rule being ignored?
Two usual reasons: the owner does not have write access to the repository (GitHub skips the rule), or a later catch-all pattern matched the same path and overrode it. This tool flags both the absence of a fallback and a misplaced `*`.
Can I request different owners for a file and its directory?
Yes — matching is per path and the most recent match wins, so a specific file rule placed after the directory rule takes effect for that file only.