Review your agent's diff
in a real git client

Two tools, one gap

A desktop git client reads a diff beautifully and can't tell your agent anything. A browser review tool can talk to your agent and tends to read badly. This is both halves.

The commit graph, and a merge shown against its first parent — what it brought in.

The review loop

An agent run leaves you fifty changed files. The loop is v to mark a file reviewed and jump to the next unviewed one, c when something looks wrong, repeat. The header tracks how far you've got.

What your agent receives

The CLI blocks until you submit. Whatever it prints on stdout becomes your agent's next input — so a slash command is the whole integration.

# Code review feedback

Reviewed `checkout` — origin/main...HEAD. 1 comment.

> **1 blocking comment** — these must be resolved.

## `src/checkout/pricing.ts`

### src/checkout/pricing.ts:23 — issue (blocking)

*L23*

```ts
  return roundMinor(subtotal + tax - orderDiscount);
```

Order discount is applied after tax here, but the doc comment says the
authority treats it as a post-tax adjustment — pin that with a test.

Or let it fire on its own

diffotator hook --install adds a Stop hook, so a review opens whenever a turn leaves real changes. Blocking comments return {"decision":"block","reason":…} — the agent is sent back to work with your review as the reason. It stays silent on a clean tree, on small turns, and on a tree you already reviewed.

Fast because it doesn't ship the review to you

Browser diff viewers usually inline the entire review into one HTML document — we measured one session at 17 MB. diffotator sends nothing up front and fetches one file at a time.

How

• Nothing is inlined. Git data is fetched per file as you open it.
• Rows are windowed. Commit list and diff render only the visible slice.
• Heights are derived, never measured. Uniform code rows plus a computed height for inline comment cards, so a prefix-sum index stays exact and scrolling never jumps.
• Highlighting runs on visible rows only, from a small regex tokenizer instead of a grammar bundle.
• Full context up front. One git diff -U1000000 per file, so expanding folded context costs nothing.

Git shapes that bite

Most diff viewers are written against a straight line of ordinary commits. Each of these was a real bug during development, and each one has a test.

Commits resolve to an explicit two-dot pair against the first parent, or the repo's empty tree at a root. That's also what makes a merge show what it merged in.

Where it fits

It's a reviewer, not a git client replacement. Keep using Fork for the things Fork is for.

Try it on your current branch

One command in any git repository.