Clinic partitions

Ava EMR is multi-tenant at the clinic level, and the FHIR API makes that explicit in the URL:

{issuer}/fhir/r4/{partition_id}

Every clinic — including your synthetic sandbox — is its own partition with its own FHIR base URL. There is no cross-partition endpoint: a token is issued for one partition and resource ids are only meaningful within it.

What this means for your code

• Never hardcode a base URL. Take iss from the launch parameters (and the token response's context) each time — an app installed at ten clinics sees ten different base URLs.
• Scope your caches and stored ids by partition. Patient/abc in one clinic is unrelated to Patient/abc in another.
• Discovery is per-issuer. Fetch .well-known/smart-configuration and metadata from the issuer that launched you, not from a cached copy for a different clinic.

Your sandbox behaves exactly like a production clinic in this respect, so an integration that works there generalizes: the only thing that changes at each installation is the pair of issuer and partition id the launch hands you.