Helianthus is an open-source energy interoperability platform. It connects equipment that speaks different protocols, preserves the facts reported by each protocol, and exposes qualified energy data through consistent APIs and tools.

The goal is practical: make heating, solar, storage, EV charging, and other energy systems easier to inspect and integrate without pretending that every device or protocol behaves the same way.

• Protocol integrations for eBUS, EEBUS, MODBUS/SunSpec, CAN-based energy devices, and GREE VRF.
• A protocol-neutral semantic registry for qualified power, energy, storage, EVSE, thermal, and infrastructure data.
• A gateway with MCP, GraphQL, Portal, and Prometheus surfaces.
• Home Assistant packaging and integration work.
• Public protocol documentation, replay fixtures, qualification rules, and contributor tools.
• Matter and EEBUS interface work that advances only where the available protocol and mapping evidence supports it.

eBUS is the most mature end-to-end path today. Other protocol families range from implemented and offline-tested foundations to evidence-blocked candidates. Exact device support, packaging, and physical validation vary by capability; the software maturity matrix records those distinctions.

protocol transport and raw evidence
  -> protocol and profile registries
  -> shared energy semantics
  -> gateway APIs and operator tools
  -> Home Assistant and other consumers

Native protocol repositories own framing, identity, qualification, and raw observations. helianthus-semreg owns promoted protocol-neutral energy state. The helianthus-ebusgateway composes those layers and serves the public interfaces. This keeps source evidence available and makes any loss in projection visible.

• Run and explore: Curious user guide
• Make a first contribution: Follow one read-only profile
• Reproduce the public build: Anonymous reproducibility record
• Work with protocol evidence: Protocol hacker guide
• Contribute across repositories: Developer guide and contribution policy
• Check exact maturity: Software maturity matrix

Each repository carries its own setup, tests, contribution boundaries, and license. Start with an issue in the repository that owns the behavior you want to change. For licensing and third-party sources, see LICENSING.md and THIRD_PARTY.md.