# Versioning and deprecation

> How the FHIR R4 and REST v1 interfaces, webhook payloads and SDKs change, and how breaking changes are announced.

Source: https://developers.anpheros.com/guides/versioning

- **FHIR R4** at `/fhir/R4` and **REST v1** at `/v1` are stable interfaces. Additive changes (new fields, new resource types, new endpoints, new event types) ship without notice; the SDKs and `docs/openapi.json` are regenerated in the same commit and a test fails otherwise.
- **Breaking changes** get a new prefix (`/v2`) and at least **6 months** of parallel operation; the old prefix answers with a `Deprecation` and `Sunset` header during that period.
- **Webhook payloads** carry a `type`; new types are additive. A subscriber to `*` must ignore unknown types.
- **SDKs** follow semver; a major SDK version may drop a sunset API prefix.
- **Security fixes** may tighten validation (for example value sets) without a version bump; such tightening is announced in the changelog with 30 days' notice unless it closes an active vulnerability.

## Conformance enforcement (announced 23 September 2026)

Writes that miss IPS / HL7 Europe laboratory requirements currently return `201`/`200` with an
`Anpheros-Conformance` header. After an observation period (planned: 60–90 days from this notice) the
platform switches to **block** mode: such writes answer `422` with an `OperationOutcome` listing every
gap. Integrators that need more time can be exempted per project during the transition. Resource types
added 23 September 2026: `Procedure`, `DiagnosticReport`, `CarePlan`, `FamilyMemberHistory`,
`ServiceRequest`, `Goal` (additive).