Trigger Claude Automatically on Every PR with GitHub Actions

The default Claude GitHub Actions setup responds to @claude mentions. But you can configure it to run automatically on every PR — no manual trigger needed.

After running /install-github-app, edit the workflow file in .github/workflows/ to add an automatic trigger with a prompt parameter:

name: Claude PR Review

on:
  pull_request:
    types: [opened, synchronize]

jobs:
  claude-review:
    runs-on: ubuntu-latest
    steps:
      - uses: anthropics/claude-code-action@v1
        with:
          anthropic_api_key: ${{ secrets.ANTHROPIC_API_KEY }}
          prompt: |
            Review this pull request. Check for:
            - Logic errors or unintended side effects
            - Missing error handling
            - Security issues (injection, auth bypasses, hardcoded secrets)
            - Tests that should exist but don't
            Post a summary comment with findings grouped by severity.

Claude reads your CLAUDE.md when it runs in CI, so it already knows your project conventions, coding standards, and patterns to avoid — no need to repeat them in the prompt.

You can also scope reviews to specific file paths so Claude only triggers when relevant code changes:

on:
  pull_request:
    paths:
      - 'src/**'
      - 'packages/api/**'

For scheduled audits — weekly security scans, dependency checks — use schedule instead:

on:
  schedule:
    - cron: '0 9 * * 1'  # Every Monday at 9am

Automatic reviews mean every PR gets a second pair of eyes — not just the ones where someone remembered to ask.