GitHub PR Review

Review a PR, draft findings by severity, post as a batched pending review after per-comment approval.

Phase 1 — Validate & gather

Parse $ARGUMENTS for the PR number and optional -parallel flag. If missing/invalid, ask via AskUserQuestion: "Which PR number would you like me to review?"

bash "${CLAUDE_SKILL_DIR}/scripts/gather-pr-context.sh" $ARGUMENTS

Returns {repo, pr_number, metadata, commit_sha, diff, project_rules, eligibility, primary_language, parallel_requested}. On error, stop.

Eligibility checks via AskUserQuestion (options: Yes / Skip):

• eligibility.is_draft: "This PR is a draft. Review anyway?"
• eligibility.state != OPEN: "This PR is [closed/merged]. Review anyway?"
• eligibility.already_reviewed: "You've already reviewed this PR. Review again?"

If eligibility.branch_matches is false, warn: "You're on branch {current_branch} but the PR is on {head_ref}. Git blame results for pre-existing issue detection may be inaccurate."

Select mode:

• -parallel flag → parallel
• diff.lines > 3000 → ask: Parallel (faster, more tokens) / Single (slower, fewer tokens)
• Otherwise → single

Phase 2 — Analyze

Load ${CLAUDE_SKILL_DIR}/templates/review-categories.md for the 5 categories and severity rules. If project_rules.claude_md or project_rules.review_md is present, incorporate them as additional criteria — project rules take precedence on conflict.

Single mode

Read the full diff. Evaluate all 5 categories sequentially. For each genuine issue, draft a finding: {path, line, body, severity} (Critical / Warning / Nit), with optional suggestion block in body.

Parallel mode

Launch 6 Agent calls in a single message (all in parallel). You MUST use the fully-qualified subagent_type — the bix-github:pr-review: prefix is required, otherwise the call falls back to general-purpose and ignores the agent's model: frontmatter.

#	subagent_type	Scope
1	bix-github:pr-review:correctness	Logic errors, null safety, data integrity, edge cases, regression risk
2	bix-github:pr-review:conventions	Naming, code organization, error handling, consistency
3	bix-github:pr-review:performance	Hot-path allocations, complexity, redundant computation
4	bix-github:pr-review:security	Input validation, injection, data exposure, access control
5	bix-github:pr-review:tests	Missing tests, untested edges, stale tests, weak assertions
6	bix-github:pr-review:docs	Missing/stale docs on public API. Also pass primary_language. Skip entirely if primary_language is null or unsupported.

Each agent gets: diff content, PR metadata, and project rules if present. Each returns a JSON array of findings. After all complete, merge and deduplicate: if multiple agents flag the same path:line, keep the higher-severity one.

Pre-existing issue detection (both modes)

For each finding, run git blame -L <line>,<line> -- <path>. If the blamed commit predates the PR branch, tag the finding [Pre-existing].

Sort

New first, pre-existing last. Within each group: Critical > Warning > Nit.

Phase 3 — Docs review (single mode only)

Skip in parallel mode — handled by the pr-review-docs agent in Phase 2.

If primary_language is null or unsupported, skip with a note. Otherwise load ${CLAUDE_SKILL_DIR}/templates/doc-review-guide.md and apply language rules to the diff. Add findings: Nit for missing, Warning for stale.

Phase 4 — Per-comment approval

Load ${CLAUDE_SKILL_DIR}/templates/review-comment-format.md for line number rules and formatting.

Present each finding via AskUserQuestion:

[Severity] Comment N — `path/file` line L: brief summary

{Full comment body with optional suggestion block}

Options: Post / Skip / Modify. On Modify, ask what to change, apply, re-present.

After all comments, show summary:

Posted:  Comment 1 (src/auth.ts:20) [Critical], Comment 3 (src/utils.ts:45) [Nit]
Skipped: Comment 2 (src/config.ts:8) [Nit]
Event type: REQUEST_CHANGES

Then ask: "Ready to submit the review with N comments?" — Submit / Cancel.

Phase 5 — Post review

Build a JSON payload with approved comments, using commit_sha from the gather output:

cat <<'JSONEOF' | gh api repos/:owner/:repo/pulls/{PR_NUMBER}/reviews -X POST --input -
{
  "commit_id": "{commit_sha}",
  "comments": [ ... ]
}
JSONEOF

Submit with event type:

• Any [Critical] posted → REQUEST_CHANGES
• Only [Warning]/[Nit] → COMMENT
• Zero comments → user picks APPROVE or COMMENT

gh api repos/:owner/:repo/pulls/{PR_NUMBER}/reviews/{REVIEW_ID}/events \
  -X POST -f event="{EVENT}" -f body="{SUMMARY}"

Phase 6 — Summary

Display posted count, skipped count, event type, and the PR URL from metadata.url.

Rules

• Always a pending review, even for one comment. Batch all comments into one review.
• Always per-comment approval — never post without explicit user approval of each comment and the final submission.
• Always verify line numbers — count from diff hunk headers, verify against actual file content.
• Always JSON input — never -f 'comments[][...]' (causes 422).
• Never fabricate — only flag issues actually in the diff.
• Never expand scope — note issues outside the diff but don't include them in the review.