This is a simple OAuth2 client for iOS and macOS. It handles OAuth2 authorization, fetching access token or refresh token on expiration. The whole package is written with up to date async/await functions. The API has 3 functions to use:
This function returns the access_token if its still valid, if not, a refresh token is fetched. If this is invalid as well, the authorization process (login) will be triggered by ASWebAuthenticationSession.