Webhooks now carry the same data as the API

Objects in webhook payloads could contain empty {} or [] values where the real data belonged - for example a customer’s payer_uuid, custom_fields and mrr_by_currency, or a plan’s renewal_intervals and tiers. That is fixed.

Every object in a webhook now has exactly the same fields and values as the API returns for it: customer as GET /customers/{uuid}, subscription as an item of GET /subscriptions, plan as GET /plans/{uuid} and invoice as GET /invoices/{uuid}. A field the API leaves out - such as the tier fields on a plan that is not tiered - is left out of the webhook too.

If your integration worked around the empty values, for example by fetching the customer from the API after each webhook, you can now read the values directly from the webhook. Customers also gain the next_billing_date field, as in the API.