Smile CDR Subscriptions
FHIR Subscription (R4) and Subscription / SubscriptionTopic (R4B/R5 backport) support for push notifications on resource change, with REST hook, websocket, email, and message-queue channels.
Smile CDR Subscriptions is one of 11 APIs that Smile Digital Health publishes on the APIs.io network.
Tagged areas include Subscriptions, Webhooks, Event Driven, and Notifications. The published artifact set on APIs.io includes API documentation.