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I’ve been looking for a way to keep updated a list of entitlements for the subscriptions, but it seems there’s no webhook or event triggered when an entitlement is added/modified for a subscription. Is there a way to do that?

Summary

The subscription changed events do not have the entitlements data, so you may question how to keep a track of the updated list of entitlements at the subscription level. 

Solution 

Currently, we could not include entitlements in the subscription object because the object was getting bloated and was raising scaling concerns on our end. Right now, the best way to implement this is to hit the List Subscription Entitlements endpoint as soon as you receive the entitlement_overrides_updated webhook and retrieve the updated entitlements. 

The endpoint is listed here.

The entitlement_overrides_updated will help us in identifying when an entitlement has been updated at the subscription level.