CodeRabbit Performance Tuning
Overview
Optimize CodeRabbit review speed, relevance, and developer experience. Review time is primarily a function of PR size. Comment quality is controlled by profile selection, path instructions, and learnings. This skill covers all the levers for tuning CodeRabbit to your team's needs.
Prerequisites
- CodeRabbit installed and producing reviews
.coderabbit.yaml in repository root- Several PRs worth of review history to evaluate
Performance Factors
| Factor | Impact | You Control? |
|---|
| PR size (lines changed) | Review speed (2-15 min) | Yes -- keep PRs small |
| Profile (chill/assertive) | Comment volume | Yes -- .coderabbit.yaml |
| Path instructions | Comment relevance | Yes -- .coderabbit.yaml |
| Path filters | Files reviewed | Yes -- .coderabbit.yaml |
| Learnings | Long-term quality | Yes -- via PR comment feedback |
| CodeRabbit service load | Review latency | No -- check status page |
Instructions
Step 1: Optimize PR Size for Faster Reviews
# PR size directly impacts review speed and quality
| PR Size | Review Time | Review Quality |
|---------|------------|----------------|
| < 200 lines | 2-3 min | Excellent -- focused, actionable |
| 200-500 lines | 3-7 min | Good -- catches most issues |
| 500-1000 lines | 7-12 min | Moderate -- may miss nuanced issues |
| 1000+ lines | 12-15+ min | Low -- too much context |
# Enforce PR size limits with CI:
name: PR Size Check
on: [pull_request]
jobs:
check:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v4
with:
fetch-depth: 0
- name: Check PR size
run: |
TOTAL=$(git diff --stat origin/${{ github.base_ref }}...HEAD | tail -1 | \
grep -oP '\d+ insertion|d+ deletion' | grep -oP '\d+' | \
awk '{sum+=$1} END {print sum+0}')
echo "Lines changed: $TOTAL"
if [ "$TOTAL" -gt 500 ]; then
echo "::warning::Large PR ($TOTAL lines). Consider splitting for better CodeRabbit review quality."
fi
Step 2: Choose the Right Review Profile
reviews:
profile: "assertive"
Step 3: Add Path Instructions for Relevance
reviews:
path_instructions:
- path: "src/api/**"
instructions: |
Review for: input validation, proper HTTP status codes, auth middleware.
Ignore: import order, logging format.
- path: "src/components/**"
instructions: |
Review for: accessibility (aria labels), performance (memo/useMemo).
Ignore: CSS naming, component file structure.
- path: "**/*.test.*"
instructions: |
Review for: assertion completeness, edge cases, async handling.
Do NOT comment on: test naming conventions, import order.
- path: "src/legacy/**"
instructions: |
Legacy code being incrementally migrated.
ONLY flag: security vulnerabilities, data loss risks, crashes.
Do NOT suggest: refactoring, naming changes, style improvements.
- path: "scripts/**"
instructions: |
One-off scripts. Only flag: security issues, destructive operations
without confirmation, missing error handling on file/network ops.
Step 4: Exclude Low-Value Files
reviews:
path_filters:
- "!**/*.lock"
- "!**/package-lock.json"
- "!**/pnpm-lock.yaml"
- "!**/*.generated.*"
- "!**/generated/**"
- "!dist/**"
- "!build/**"
- "!**/*.min.js"
- "!**/*.min.css"
- "!**/*.snap"
- "!**/__mocks__/**"
- "!**/fixtures/**"
- "!**/testdata/**"
- "!vendor/**"
- "!node_modules/**"
- "!**/*.csv"
- "!**/*.sql"
auto_review:
ignore_title_keywords:
- "WIP"
- "DO NOT MERGE"
- "chore: bump"
Step 5: Train CodeRabbit with Learnings
# CodeRabbit learns from your feedback on PR comments.
# This improves relevance over time.
# When CodeRabbit gives feedback you disagree with, reply:
"We intentionally use default exports in this project for Next.js pages.
Please don't flag default exports in files under src/pages/."
# When CodeRabbit catches something valuable, reinforce it:
"Good catch! Always flag missing error boundaries in React components."
# View and manage learnings:
# app.coderabbit.ai > Organization > Learnings
# Learnings persist across PRs and repos within the organization.
# They are the most effective long-term tuning mechanism.
Step 6: Measure Improvement
set -euo pipefail
ORG="${1:-your-org}"
REPO="${2:-your-repo}"
echo "=== Review Quality Metrics ==="
TOTAL_PRS=0
TOTAL_COMMENTS=0
for PR_NUM in $(gh api "repos/$ORG/$REPO/pulls?state=closed&per_page=20" --jq '.[].number'); do
COMMENTS=$(gh api "repos/$ORG/$REPO/pulls/$PR_NUM/comments" \
--jq '[.[] | select(.user.login=="coderabbitai[bot]")] | length' 2>/dev/null || echo "0")
if [ "$COMMENTS" -gt 0 ]; then
TOTAL_PRS=$((TOTAL_PRS + 1))
TOTAL_COMMENTS=$((TOTAL_COMMENTS + COMMENTS))
echo "PR #$PR_NUM: $COMMENTS comments"
fi
done
if [ "$TOTAL_PRS" -gt 0 ]; then
AVG=$(( TOTAL_COMMENTS / TOTAL_PRS ))
echo ""
echo "Average: $AVG comments/PR"
echo ""
if [ "$AVG" -gt 10 ]; then
echo "Recommendation: Switch to 'chill' profile or add path_instructions"
elif [ -lt 2 ];
Output
- PR size guidelines documented and enforced via CI
- Review profile selected based on team needs
- Path instructions configured for relevant feedback
- Low-value files excluded from review
- Learnings trained from team feedback
- Review quality measured with metrics
Error Handling
| Issue | Cause | Solution |
|---|
| Review takes 15+ min | PR too large (1000+ lines) | Split into smaller PRs |
| Too many irrelevant comments | No path_instructions | Add context for key directories |
| Team ignoring reviews | Review fatigue from noise | Switch to chill, add exclusions |
| Same issue flagged repeatedly | Learning not created | Reply to comment stating the preference |
| Reviews on generated code | Missing path_filters | Add !**/generated/** to exclusions |
Resources
Next Steps
For learnings and advanced tuning, see coderabbit-core-workflow-b.
