# Build medOS apps

**Portal version:** 0.1.0  
**Updated:** 2026-08-28  
**Source menu item:** Overview  
**Availability:** Private preview · default-OFF

> The source foundation exists, but no general production activation or public self-service program is claimed.

A medOS partner app is a partner-hosted service with server-held FHIR credentials, verified webhooks, and an optional sandboxed embedded UI.

## What you can use now

- Keep browser, partner server, certifier, hospital admin, and runtime decisions separate.
- Use the Developer Kit as the authoring baseline.

## Current limits

- Third-party JavaScript never runs as native medOS host code.

## 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)