Review Panel

The Review panel loads a GitHub pull request into a local git worktree, runs an agent review pass against the diff, and lets the user push the resulting inline comments back to the PR — either one at a time or all at once.

Enabling

The panel is gated behind review.enabled (default false). Set it in ~/.loop/config.json (or a project override) to opt in:

"review": {
  "enabled": true
}

When disabled, the FE hides the Review tab from the panel picker and the backend returns 403 for /review/* requests. The flag is layered per-global / per-project / per-worktree the same way as github.gh_user.

Lifecycle

Load — the FE fetches open PRs (GET /review/prs → gh pr list) and renders them as a clickable list; the user picks one. The backend:
- Looks the PR up via gh pr view <number> for metadata and base/head refs.
- Resolves the head SHA via gh pr view --json headRefOid.
- Creates a worktree off the PR head branch under the channel’s dir_path.
- Fetches the base ref into the parent repo (git fetch origin <base>) so origin/<base> resolves locally for the Run step.
Run — the user clicks Run. The backend launches a single agent run inside the worktree using the configured review prompt (review.prompt or review.prompt_path in ~/.loop/config.json; falls back to a built-in default). The prompt tells the agent to compute the diff itself with git diff origin/<base>...HEAD from the worktree — keeps the container argv small and lets the agent read individual files for context. The agent emits <review-comment path="..." line="N" side="RIGHT|LEFT">...body...</review-comment> blocks, which are parsed and streamed to the FE as they arrive.
Push — each comment ships with Push (single) and a Push all (N) affordance in the header (when at least one comment is unpushed). The backend uses gh api ... /pulls/N/comments against the captured head SHA so comments anchor to the right commit even if the PR is force-pushed later.
Close — closing the session deletes the in-memory session record and removes the worktree on disk. Pushed comments remain on GitHub.

Concurrency

A second POST /review/run while the first is still in flight returns 202 {"status":"in_progress"} without restarting the agent. Comments keep streaming through the existing run.

Status transitions

Status is broadcast over the WebSocket as review.status events so multiple panes / browser tabs stay in sync without polling.

idle ──load──▶ loading ──ok──▶ ready ──run──▶ reviewing ──ok──▶ ready
                  │                            │
                  └──err──▶ error              └──err──▶ error

Configuration

{
  "review": {
    "prompt": "Review the diff between <diff> tags and emit one <review-comment> block per actionable issue. Skip style nits."
  }
}

Or, to keep the prompt out of the JSON file:

{ "review": { "prompt_path": "review.md" } }

The latter is read from ~/.loop/review/review.md. Setting both is an error; setting neither uses the daemon’s built-in default prompt.

Required output format

The parser anchors comments by the tag attributes, so an override prompt must instruct the agent to emit blocks shaped exactly like:

<review-comment path="path/to/file" line="N" side="RIGHT">
One paragraph describing the issue.
</review-comment>

path is repo-relative.
line is the line on the indicated side of the diff.
side is "RIGHT" for added/modified lines (the common case) or "LEFT" for lines removed from the base. This matches GitHub’s pulls/{N}/comments API, so the value is forwarded as-is on push.

Blocks that fail to parse are silently dropped, and the parser deduplicates by content hash so re-emitting the same block during streaming is safe.