HomeGuidesAPI Reference
Submit Documentation FeedbackJoin Developer CommunityOptimizely GitHubOptimizely NuGetLog In

Event delivery


When you receive an event, acknowledge the delivery by returning an HTTP 200 or 202 status code. Anything other than 200 or 202 will be considered as delivery failure.


It is expected that the callback endpoint will respond within 10 seconds of receiving the webhook event. If it takes more then 10 seconds, the connection will be terminated and will be considered as delivery failure.


In case of delivery failure, Welcome will retry to deliver the event for up to three days with an exponential back off.

Duplicate events

In rare cases, callback endpoints might receive the same event more than once. Please make your event processing idempotent to guard against duplicated events.

Delivery sequence

Welcome does not guarantee the delivery of events in the sequence in which they are generated. You can always use the Welcome Open API to fetch the latest data.

Did this page help you?