Reference

Specification

The normative contract: what a client and a server MUST, SHOULD and MAY do. Generated from SPEC.md in the protocol repository, so this page and the specification never disagree.

Version 2026-09-12 (0.9)Wire format JSON-RPC 2.0Transports stdio · HTTP + SSEReference impl openmhp (Python)

Contents

  1. 1Why MHP
  2. 2Architecture
  3. 3Scale: one device among thousands
  4. 4The device package
  5. 5Primitives
  6. 6Lifecycle
  7. 7Safety model
  8. 8Notifications
  9. 9Transports and discovery
  10. 10Three control surfaces
  11. 11Authoring descriptors
  12. 12Error codes
  13. 13Device classes (initial vocabulary)
  14. 14Bridging existing ecosystems
  15. 15Conformance
  16. 16Not yet specified
  17. Areference implementation