Subscriptions R5 Backport
1.2.0-ballot - ballot

Subscriptions R5 Backport, published by HL7 International / FHIR Infrastructure. This guide is not an authorized publication; it is the continuous build for version 1.2.0-ballot built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/HL7/fhir-subscription-backport-ig/ and changes regularly. See the Directory of published versions

## Actors

Page standards status: Informative

Subscriptions are operations which typically involve two or three actors:

Any FHIR application may support the use of Subscriptions. In this documentation:

### Server

Server refers to the FHIR application or applications acting as the subscription provider. This includes the responsibilities of implementing one or more `SubscriptionTopics`, managing `Subscriptions`, and sending notifications.

Note that when using subscriptions, the FHIR server combines the roles of publisher and information distributer. Some arrangements of the ‘publish and subscribe’ pattern describe separate agents for the two roles. This specification makes no recommendations towards the internal architecture of server implementations.

### Client

Client refers to the FHIR application or applications acting as subscriber. This includes the responsibilities of acting as a FHIR client (to create a Subscription) and receiving notifications on a supported channel.

### Endpoint

Endpoint refers to the portion of the client which is responsible for receiving notifications, if applicable. For example, when using the `rest-hook` channel type the endpoint is the HTTP server listening for notifications.

Note that while part of the client, it is often useful to refer to the endpoint separately for clarity. This specification makes no recommendations towards the internal architecture of client implementations.