Concepts
Three concepts underpin every request to the Huli Public API: the organization boundary (which organization owns the data), cursor-based pagination (how sets are navigated), and the rate-limit and audit system (what the API enforces and records on every authenticated call).
In this section
- Organizations —
organization_idis the security boundary. Every resource belongs to exactly one organization. Cross-organization reads return403. - Pagination — All list endpoints use cursor-based pagination via
_countand_cursor.totalis advisory; do not use it as a loop terminator. - Rate Limiting — Per-key and per-organization request ceilings. Every authenticated request writes an audit record with a 7-year retention obligation.
- Webhooks — Outbound notifications via the FHIR R4
Subscriptionresource. HMAC-signed, id-level, at-least-once deliveries with retries, auto-pause, and$replayfor outage recovery.
FHIR conformance
The public surface is FHIR R4. The normative contract is the live CapabilityStatement at /fhir/R4/metadata. All resources and operations advertised there are what the API actually supports — no divergence between docs and the statement.
Extensions and custom identifiers are documented in the individual resource pages under the API reference.