## SubscriptionRequest type [​](/content/docs/sdk/core.subscriptionrequest#subscriptionrequest-type "Direct link to SubscriptionRequest type"/index.html)

A `FHIRcast` subscription request.

Can be passed to `MedplumClient.fhircastConnect` or `MedplumClient.fhircastUnsubscribe` to either open a `FHIRcast` connection, or unsubscribe from the subscription.

**Signature:**

```typescript
export type SubscriptionRequest = {

channelType: 'websocket';

mode: 'subscribe' | 'unsubscribe';

events: FhircastEventName[];

topic: string;

endpoint: string;

};
```

**References:** [FhircastEventName](/content/docs/sdk/core.fhircasteventname)

- [SubscriptionRequest type](/content/docs/sdk/core.subscriptionrequest#subscriptionrequest-type/index.html)