GitHub Actions Tutorial — GitHub Apps

GitHub Apps

The default GITHUB_TOKEN has limitations — it can’t trigger other workflows, has limited rate limits, and its permissions are scoped to the current repository. GitHub Apps solve these problems.

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When to Use a GitHub App

Scenario	GITHUB_TOKEN	GitHub App
Checkout code	✅	✅
Comment on PRs	✅	✅
Trigger other workflows	❌	✅
Cross-repo operations	❌	✅
Higher API rate limits	1,000/hr	5,000/hr
Fine-grained permissions	✅	✅

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Creating a GitHub App

1. Organization Settings → Developer settings → GitHub Apps → New GitHub App
2. Set required permissions (e.g., contents: write, pull-requests: write)
3. Install the app on your organization or specific repositories
4. Note the App ID and generate a private key

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Using a GitHub App in Workflows

Use the actions/create-github-app-token action to generate a token:

jobs:
  automation:
    runs-on: ubuntu-latest
    steps:
      - name: Generate App Token
        id: app-token
        uses: actions/create-github-app-token@v1
        with:
          app-id: ${{ secrets.APP_ID }}
          private-key: ${{ secrets.APP_PRIVATE_KEY }}

      - uses: actions/checkout@v4
        with:
          token: ${{ steps.app-token.outputs.token }}

      - name: Create PR (will trigger other workflows)
        run: |
          git checkout -b automated-update
          echo "update" >> file.txt
          git add . && git commit -m "Automated update"
          git push origin automated-update
        env:
          GH_TOKEN: ${{ steps.app-token.outputs.token }}

      - name: Open PR
        run: gh pr create --title "Automated Update" --body "Bot PR"
        env:
          GH_TOKEN: ${{ steps.app-token.outputs.token }}

PRs created with App tokens will trigger CI workflows (unlike GITHUB_TOKEN).

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Common Use Cases

Use Case	Why App Token
Automated dependency updates	PRs trigger CI
Cross-repo releases	Access other repos
Bot PRs and comments	Higher rate limits
Repository management	Admin-level operations

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Quick Reference

Concept	Detail
Create	Org Settings → Developer → GitHub Apps
Secrets	APP_ID + APP_PRIVATE_KEY
Token action	actions/create-github-app-token@v1
Rate limit	5,000 requests/hour per installation
Key benefit	Tokens trigger other workflows

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