Medplum vs Zus Health

Medplum

Graded on the hosted FHIR API at api.medplum.com. Rate limits, a RateLimit header and a 99.99 per cent SLA are published, AccessPolicy resources allow read-only clients, and an official MCP server sits in the registry. Its main tool can delete records with no annotation, the status page could not be read, and the privacy policy dates from 2022.

Zus Health

FHIR R4 over an aggregated patient profile drawn from CommonWell, Carequality, Surescripts, Quest and ADT networks, with published rate limits, a 99.5 per cent SLA and a dated changelog. Accounts and sandboxes are provisioned by Zus on request, with no public prices, no named security certification and no SDK.

Medplum

1. Use a ClientApplication with an AccessPolicy limited to the resources the task needs, and set readonly where no writes are needed
2. Read the RateLimit header and wait for the reset time after a 429. Writes cost 100 quota points, searches 20 and reads 1
3. Create patients with conditional create (If-None-Exist) or upsert on an identifier so a retry doesn't make a duplicate
4. Pass paths to fhir-request relative to the FHIR R4 base, with no leading slash or /fhir/R4 prefix
5. Use Prefer: respond-async for large bundles. Operations inside the background job don't count against the quota

Zus Health

1. Cache the access token for its hour. More than 200 token requests an hour per App Client returns 429
2. Request Patient History at most once per patient per 24 hours, and poll the job status endpoint
3. Use conditional create by identifier so a retried write doesn't duplicate a resource
4. Send Zus-If-Match with the resource's ETag on PUT and PATCH
5. Set _count up to 500 on searches, since the default page is 10