A GitHub code review bot that automatically analyzes pull requests using Claude AI and posts review comments.

• Responds to GitHub pull request webhooks
• Analyzes code changes using Anthropic's Claude
• Posts detailed review comments on PRs
• Secure webhook signature verification

GitHub Token: Create a fine-grained personal access token at https://github.com/settings/personal-access-tokens/new with:

• Repository access: Select the specific repository you want to review
• Permissions > Repository permissions:
  • Metadata: Read-only (required)
  • Contents: Read-only (required to fetch file contents)
  • Pull requests: Read and write (required to post review comments)

Anthropic API Key: Get your API key from Anthropic Console

In Val Town, set these environment variables:

• GITHUB_TOKEN: Your GitHub personal access token
• ANTHROPIC_API_KEY: Your Anthropic API key
• WEBHOOK_SECRET: A random secret string (generate with: openssl rand -hex 32)

Your webhook URL will be: https://[your-username]--[val-id].web.val.run/webhook

You can find this URL by clicking on your index.ts val in Val Town.

In your GitHub repository:

1. Go to Settings > Webhooks > Add webhook
2. Set Payload URL: Your Val Town webhook URL (from step 3)
3. Set Content type: application/json
4. Set Secret: Same value as your WEBHOOK_SECRET environment variable
5. Select Let me select individual events → Check Pull requests
6. Ensure Active is checked
7. Click Add webhook

Create a test pull request in your repository. The bot should:

1. Post an initial "review in progress" comment
2. Analyze the changed files
3. Post a detailed review comment within 30-60 seconds

The bot automatically reviews pull requests when they are opened or reopened. It will:

1. Fetch the changed files from the PR
2. Analyze the code using Claude
3. Post a review comment with findings

• index.ts - Main webhook handler and review logic
• github.ts - GitHub API integration
• claude.ts - Claude AI integration
• utils.ts - Utility functions for webhook verification
• test.ts - Test utilities for debugging

1. Check that your webhook URL is correct in GitHub settings
2. Verify all environment variables are set in Val Town
3. Check the webhook delivery logs in GitHub (Settings > Webhooks > Recent Deliveries)
4. Look at the Val Town logs for error messages

• Ensure your GitHub token has the correct permissions
• Verify the token hasn't expired
• Check that the repository is accessible with your token

• The bot analyzes up to 10 files per PR to stay within API limits
• Only code files are reviewed (JS, TS, Python, etc.)
• Very large files are truncated to prevent token limit issues

• Ensure the WEBHOOK_SECRET in Val Town matches the secret in GitHub
• Check that the webhook is configured to send JSON payloads

• Reviews up to 10 files per PR
• File content is truncated to 2000 characters for analysis
• Only reviews code files (filters out documentation, images, etc.)
• Requires internet access to GitHub and Anthropic APIs