Gen3 MAIN 40 support — new integration using gRPC

[Griswoldlabs]

Hi everyone,

I wanted to share that I've built a separate Home Assistant integration for the Span MAIN 40 (Gen3) panel, since the Gen3 hardware replaced the REST API with gRPC and this project doesn't currently support it.

The new integration reverse-engineers the gRPC trait system on port 50065 to provide:

• Real-time power/voltage/current streaming for all circuits
• Breaker state detection (ON/OFF binary sensors)
• Dual-phase (120V/240V) support
• Config flow setup — just enter the panel IP
• Fully local, no cloud or authentication needed

GitHub: https://github.com/Griswoldlabs/span-panel-ha
Install: Available as a HACS custom repository (HACS default listing pending)

This is specifically for the Gen3 MAIN 40. If you have a MAIN 32 or earlier, this repo (SpanPanel/span) is still the right choice.

I'm looking for other Gen3 owners to test, and I'm especially curious if anyone has an MLO 48 — it may use the same gRPC protocol.

Happy to collaborate or share findings about the Gen3 gRPC protocol if it would help add Gen3 support to this project.

[cayossarian]

Impressive. If you want to integrate into the single repo which is already the default, you can create a PR and once we test it works against both panels we can add you as an admin in the org. The 32 uses a package span-panel-api for connectivity so doing similar for yours would allow a pluggable approach for the connectivity depending on panel type

[Griswoldlabs]

PR submitted: #169

This implements the Gen3 gRPC support as discussed — additive, non-breaking change with all Gen3 code isolated in a gen3/ subdirectory. Gen2 code is completely untouched.

What's in the PR:

• Auto-detection in config flow (REST → gRPC fallback)
• SpanGrpcClient with raw protobuf parsing on port 50065 (no auth needed)
• Push-based streaming wrapped in DataUpdateCoordinator
• Per-circuit power/voltage/current sensors + breaker binary sensors + main feed sensors
• Only 96 lines added to existing files (early-return routing branches)

Tested on our MAIN 40 with 25 circuits — all readings match the Span app. Happy to iterate on any feedback.