[BUG]: subscription.started webhook payload is missing entitlements

[kikihakiem]

Describe the bug
When a customer’s plan is upgraded or downgraded, current subscription is terminated, a new one is started and subscription.started webhook is sent for the new subscription. But the payload does not include the entitlements array, unlike the subscription.updated webhook, which does include it. Downstream apps that sync entitlements from webhooks cannot do so without an extra API call to fetch the subscription.

To Reproduce
Steps to reproduce the behavior:

1. Create two plans (e.g. Basic and Premium) with an entitlement (e.g. max_transactions).
2. Create a customer and a subscription to the Basic plan.
3. Configure a webhook endpoint for the organization and ensure it receives webhooks.
4. In the Lago UI, upgrade the subscription from Basic to Premium.
5. Inspect the subscription.started webhook request body sent to your endpoint.

Expected behavior
The subscription.started webhook payload should include the entitlements array on the subscription object (resolved for the new plan), in the same way as the subscription.updated webhook.

Screenshots
N/A

Support

• Self-hosted Lago v1.41.0

Additional context
N/A

[Aryan-Shrivastva]

Hey, quick question, when including entitlements in subscription.started, should they strictly come from the plan definition, or should we also account for potential overrides / custom values on the subscription?