How to authenticate and access Google APIs using OAuth 2.0

Google offers a wide array of over 200 APIs, including popular ones like YouTube, Google Calendar, and Gmail, which require authentication through OAuth 2.0 to access. This guide demonstrates how to authenticate with these APIs using TypeScript, specifically focusing on the Google Calendar API as an example. It involves creating an OAuth 2.0 client ID on the Google Cloud Platform, completing an OAuth consent screen, and obtaining a refresh token through a multistage process involving both command-line and browser interactions. The tutorial details setting up a TypeScript Node project to automate API interactions by acquiring and securely storing a refresh token, which can be used to access various Google APIs repeatedly. Additionally, it highlights that the same authentication process can be applied to integrate with any other Google API, such as YouTube or Gmail, by adjusting the scope to fit the specific API requirements.