# Searching for FHIR Subscriptions with AWS HealthLake
<a name="managing-fhir-subscriptions-searching"></a>

`Subscription` and `SubscriptionTopic` resources are also searchable. HealthLake supports all the common [search parameters](https://docs.aws.amazon.com/healthlake/latest/devguide/reference-fhir-search-parameters.html#search-parameter-types) for Subscription and SubscriptionTopic resources.

Furthermore, we support additional search capabilities through the following parameters:

**Subscription**


| Search parameter | Description | Example | 
| --- | --- | --- | 
| contact | Search on the Subscription.contact field in the R4 core specification | Subscription?contact=phone | 
| criteria | Search on the Subscription.criteria field in the R4 core specification | Subscription?criteria=[baseUrl]/datastore/[datastoreId]/r4/SubscriptionTopic/[topicId] | 
| payload | Search on the Subscription.channel.payload field in the R4 core specification | Subscription?payload=application/fhir\+json | 
| status | Search on the Subscription.status field in the R4 core specification | Subscription?status=error | 
| type | Search on the Subscription.channel.type field in the R4 core specification | Subscription?topic=event-bridge | 
| url | Search on the Subscription.channel.endpoint field in the R4 core specification | Subscription?url=[Subscription.channel.endpoint] | 
| filter-criteria | Search on the criteria extension field with url "http://hl7.org/fhir/uv/subscriptions-backport/StructureDefinition/backport-filter-criteria" as a string | Subscription?filter-criteria=Encounter? | 
| custom-channel | Search on the custom channel type extension field with url "http://hl7.org/fhir/uv/subscriptions-backport/StructureDefinition/backport-channel-type" as Coding<br />[Example Subscription payload](https://build.fhir.org/ig/HL7/fhir-subscription-backport-ig/Subscription-subscription-zulip.json.html) | Subscription?custom-channel=[System]\|[code] | 
| payload-type | Search on the payload type extension field where you specify how the payload is formatted (either id-only or full-resource) | Subscription?payload-type=full-resource | 
| topic | Search on the Subscription.criteria field, where the topic is added | Subscription?topic=[topicId] | 

**SubscriptionTopic**


| Search parameter | Description | Example | 
| --- | --- | --- | 
| date | Search on the date field in the SubscriptionTopic resource | SubscriptionTopic?date=[SubscriptionTopic.date] | 
| derived-or-self | Search on either the url or derivedFrom fields in the SubscriptionTopic resource | SubscriptionTopic?derived-or-self=[SubscriptionTopic.url \| SubscriptionTopic.derivedFrom] | 
| identifier | Search on the SubscriptoinTopic.identifier field | SubscriptionTopic?identifier=[SubscriptionTopic.identifier] | 
| resource | Search on the SubscriptionTopic.resourceTrigger.resource field | SubscriptionTopic?resource=Encounter | 
| status | Search on the status of the SubscriptionTopic | SubscriptionTopic?status=unknown | 
| title | Search on the title for a SubscriptionTopic | SubscriptionTopic?title=admission | 
| trigger-description | Search on SubscriptionTopic.resourceTrigger.description | SubscriptionTopic.trigger-description=resource moving to state 'in-progress' | 
| url | Search on the url for the SubscriptionTopic | SubscriptionTopic?url=[SubscriptionTopic.url] | 
| version | Search on the version for the SubscriptionTopic | SubscriptionTopic?version=1 |