Validic Inform vs Zus Health

Validic Inform

Graded on the Inform REST and Streaming APIs. An agent can create a free developer account through a sign-up API, with only an emailed code needing a person's inbox, and llms.txt plus agent guides document every step. The organisation token travels in the URL query string, the free tier holds synthetic data only, and production access needs an Enterprise contract.

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.

Validic Inform

1. Show the developer the free-tier terms and wait for acceptance before calling POST /auth/register
2. Send Authorization: <id_token> to sign-up calls, but pass the organisation token as ?token= on Inform calls
3. Use the customer uid in URLs, never Validic's internal id, which returns a silent 404
4. Keep date ranges to 30 days or less and page month by month for backfills
5. Unwrap data on list responses and treat an empty array as normal on a new account

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