We’ve had a lot of requests from app partners for a settings storage exposed through the REST API. This feature is now exposed at /app-settings and is ready for production purposes. So now you have a place to store user preferences and default settings for your integration.
The /app-settings endpoint allows apps to save settings specific to the app through the API as custom key/value pairs. The settings are naturally specific to the individual apps and are not accessible for any other integrations.
Settings can be saved for both the agreement as a whole and for specific users. This allows for integration-wide default settings while offering flexibility for user-centric preferences as well.
The settings endpoint is not intended as an unlimited blob storage. For this reason the settings endpoints are limited to 200 key/value pairs each.
Read the documentation here.