Using the GitHub API in your app→
Learn how to set up your app to listen for events and use the Octokit library to perform REST API operations.
Using content attachments→
Content attachments allow a GitHub App to provide more information in GitHub for URLs that link to registered domains. GitHub renders the information provided by the app under the URL in the body or comment of an issue or pull request.
Creating CI tests with the Checks API→
Build a continuous integration server to run tests using a GitHub App and the Checks API.