CodeRabbit Hello World

Overview

Minimal working example demonstrating CodeRabbit AI code review. CodeRabbit reviews PRs automatically via a GitHub/GitLab App -- no SDK or API calls needed. You configure behavior through a .coderabbit.yaml file and interact via PR comments.

Prerequisites

• CodeRabbit GitHub App installed (see coderabbit-install-auth)
• A repository with at least one branch

Instructions

Step 1: Create Minimal Configuration

# .coderabbit.yaml (repository root)
language: "en-US"
reviews:
  profile: "assertive"
  high_level_summary: true
  auto_review:
    enabled: true
    drafts: false
chat:
  auto_reply: true

Step 2: Add Path-Specific Instructions

# .coderabbit.yaml - add review context for better feedback
reviews:
  profile: "assertive"
  high_level_summary: true
  auto_review:
    enabled: true
    drafts: false
  path_instructions:
    - path: "src/**/*.ts"
      instructions: "Check for proper TypeScript types. Flag any use of `any`."
    - path: "**/*.test.*"
      instructions: "Verify edge cases are covered. Check async handling."
chat:
  auto_reply: true

Step 3: Create a PR to Trigger Review

set -euo pipefail
git checkout -b feat/hello-coderabbit

# Add the configuration file
cat > .coderabbit.yaml << 'YAML'
language: "en-US"
reviews:
  profile: "assertive"
  high_level_summary: true
  auto_review:
    enabled: true
    drafts: false
  path_instructions:
    - path: "src/**"
      instructions: "Check for proper error handling and input validation."
chat:
  auto_reply: true
YAML

git add .coderabbit.yaml
git commit -m "feat: add CodeRabbit AI code review configuration"
git push -u origin feat/hello-coderabbit
gh pr create --title "feat: enable CodeRabbit AI code review" \
  --body "Adding .coderabbit.yaml for automated code reviews"

Step 4: Interact with CodeRabbit on the PR

Once CodeRabbit posts its review (typically 2-5 minutes), you can interact:

# In a PR comment, use these commands:
@coderabbitai summary        # Get a walkthrough of all changes
@coderabbitai full review    # Re-run a complete review from scratch
@coderabbitai resolve        # Mark all CodeRabbit comments as resolved
@coderabbitai help           # List all available commands

# Reply to any CodeRabbit comment to have a conversation about the feedback
# CodeRabbit will respond with context-aware explanations

Step 5: Try the CLI for Local Reviews (Optional)

set -euo pipefail
# Review staged changes before committing
git add -A
cr review

# Review with interactive mode for back-and-forth discussion
cr review --interactive

# Review specific files
cr review src/index.ts src/utils.ts

What CodeRabbit Posts on Your PR

1. Walkthrough comment: High-level summary of all changes with a file-by-file breakdown
2. Sequence diagram: Visual control flow of the changes (if enabled)
3. Line-level comments: Specific suggestions on individual code lines
4. Review status: Approved or changes-requested based on severity of findings

Output

• .coderabbit.yaml committed to repository root
• First AI review posted on a test PR within 2-5 minutes
• Interactive review conversation demonstrated

Error Handling

Issue	Cause	Solution
No review appears	App not installed on this repo	Check GitHub App > Repository access
YAML syntax error	Invalid configuration	Validate YAML at yamlchecker.com
Review on wrong branch	Missing base_branches filter	Add base_branches: [main] to config
Bot not responding to commands	Typo in mention	Must use exact @coderabbitai mention

Resources

• YAML Configuration Guide
• Review Commands Reference
• CodeRabbit CLI

Next Steps

Proceed to coderabbit-local-dev-loop for a full development workflow with CodeRabbit.