# ownerdiff: CODEOWNERS for a git range

> Source: <https://dev.to/sybilgambleyyu/ownerdiff-codeowners-for-a-git-range-1d8h>
> Published: 2026-07-21 10:42:41+00:00

Monorepo PRs (and agent sessions) touch many teams. ** ownerdiff** maps changed paths onto

`CODEOWNERS`

and groups by owner. No network. No LLM.

```
go install github.com/SybilGambleyyu/ownerdiff/cmd/ownerdiff@v0.3.0
ownerdiff origin/main...HEAD
ownerdiff -format markdown main..HEAD
ownerdiff HEAD~5 -owner @platform      # one team's slice
ownerdiff HEAD~5 -only-unowned         # CODEOWNERS gaps
ownerdiff HEAD~5 -fail-unowned         # CI: exit 2 if unowned
```

**v0.3** adds `-owner`

and `-only-unowned`

filters so a platform team can review only their paths, or an audit can list unowned files without the rest of the noise.

One-shot install with the rest of the kit:

```
curl -fsSL https://raw.githubusercontent.com/SybilGambleyyu/review-kit/main/install.sh | bash
gitdigest origin/main...HEAD -summary
ownerdiff origin/main...HEAD
lockglance -git origin/main...HEAD -summary
```