when I'm using the API I need to authenticate with a key and a secret, which I obtain from swagger ui (Swagger UI). Since the token expires, how can I refresh it automatically? I need to run a cron job script which fetches data daily without the need to manually update the secrets every day.
To get started with Analytics 2.0 APIs you must first decide whether your application will need an OAuth client or a JWT client.
A JWT client is best if you are creating an application that needs to programmatically authenticate calls to the Adobe Analytics APIs. A new JWT token can be generated whenever the old one is about to expire so your application can continue to make API calls.