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