# Event destinations

**Portal version:** 0.1.0  
**Updated:** 2026-08-28  
**Source menu item:** Event destinations  
**Availability:** Documented and testable

> The source contract and local workflow exist. Access still depends on the target hospital deployment and its policy gates.

FHIR subscriptions and HMAC-signed webhook delivery are the partner event destination contract.

## What you can use now

- Verify raw bodies, timestamp windows, delivery IDs, event types, and HMAC signatures before parsing.
- Persist delivery IDs transactionally with side effects to prevent replay.

## Current limits

- Queue-row transition topics are not a supported external event family.

## Next step

Start with the [medOS Developer overview](/developers/platform/overview) and confirm the target hospital’s enabled contracts before production work.

## Canonical references

- [FHIR R4 integration](/integrations/fhir)
- [Public API](/backend/public-api)
- [Security and compliance](/architecture/security-and-compliance)
- [Developer portal status and coverage](/developers/platform/changelog)