Homie 5 MCP server

[Tieske]

An MCP server for Homie 5 devices 🎉

https://github.com/Tieske/homie5-mcp-server

[Tieske]

The main problem is the lack of metadata/context. It requires specific instruction on devices etc to control them. There is no way to say; "turn off the lights in the livingroom", since that metadata is not available via Homie.

This leads me to believe we should define an extension for meta-data.

[dcj]

An MCP server for Homie 5 devices

I have been extremely anxious for exactly this to happen/exist, but I haven't had time to work on it, which might be understandable given the other announcments I've made recently :-)

I am very excited that I (and others) should be able to use this to interact with a SPAN smart-panel

This leads me to believe we should define an extension for meta-data.

Yes, "heck yes" !

[schaze]

There is a v4 meta extension https://github.com/homieiot/convention/blob/develop/extensions/documents/homie_meta_extension.md - which should more or less work for v5. Although it is a bit overcomplicated at some parts.
But this is a completely generic meta extension, it makes no assumptions about rooms or anything else - it is more like annotations and tags for kubernetes ressources.
That beeing set a LLM would most likely not care what convention is used to define room=livingroom or location=livingroom or whatever - it would most likely be able to cope.

I have been toying around in my head with a new meta extension also for usage with LLMs or with my automation and (coming soon) dashboard which could leverage this information to simply configuration or rules...

My main concern with the metadata extension so far was that for the most part it would be information "about" the device not information "from" the device. Meaning my zigbee lightbulb in Hue or Deconz or my relais in Homematic does not know which room it belongs to, it is assigned to it "externally". (This is my main headache as all my devices are published via x to homie bridges, and there I can only publish data that I get from the hubs/ccus/...).
So I am looking for a way to add metadata externally to device on the mqtt bus as well. (Manually most likely). My current idea was to build up the information in parallel to the devices in a separate topic.

Not sure if I am the only one with that problem - but I thought I'd share.

Long story short, I would be interested in a meta extension as well. In fact I have a rough spec (disclosure: AI assisted) done which I could provide if you are interested.

[dcj]

Suggestion: Let's start a seperate metadata thread. And that thread/effort should start with defining the problem, and/or enumerating use-cases. To be clear, I am 100% in favor of that activity.

[schaze]

I started a discussion with what I have currently as "something to hate" - I am looking forward to comments/contributions/opinions:
#342

[jacoscaz]

Really cool @Tieske !

I've been doing some work on a custom agentic harness and MCP servers recently. In fact, MCP servers and LLMs are the reason why I still haven't published any progress with my Homie projects. AI is happening, whether with us or to us, and I had some catching up to do not to fall in the latter camp.

I'm going to test this with it over the weekend and report back!

This leads me to believe we should define an extension for meta-data.

Yes, I think this would be a good idea. Also, profiles would definitely help.

There is no way to say; "turn off the lights in the livingroom", since that metadata is not available via Homie.

(Emphasis mine). I've been doing a lot of thinking on this front in the past months. I've come to the conclusion that, at least for my own personal projects, location information is better handled as being orthogonal to devices. That is to say, I have found it easier to have a service that tells me where everything in the house is located, both devices and humans (tracked through said devices).

This has nothing to do with the metadata issue but thought I'd mention it anyway as I, too, had originally started out looking for ways to add location metadata to Homie. Happy to exchange notes if you're interested.

[Tieske]

thx for all the kudos, but I must say; it was an evenings work using Claude.

I'm still fighting claude to accept an unauthenticated MCP server on a local network, but haven't found a way yet.

[dcj]

it was an evenings work using Claude.

It is a new world with the advent of AI-assisted coding. I developed the span-hass SPAN panel Home Assistant integration over the weekend, and if hadn't shot myself in the foot previously in unreleated way, but which got triggered by the high volume of metering data it wouldn't have taken the whole weekend....

I'm still fighting claude to accept an unauthenticated MCP server on a local network, but haven't found a way yet.

As I write this, I am using Claude to configure itself to talk to my 3 SPAN panels via your MCP server.
AFAICT, your server uses MQTT.js, which IIRC is unable to talk the MQTT protocol natively, it requires websocket (WS) access to the broker, fortunately Mosquitto supports WS (and WSS) access, and the SPAN panel's eBus/Homie MQTT broker already enabled them (because the SPAN Home On-premise browser-based JavaScript app uses MQTT.js, and we had EXACTLY the same issue there)

I am having a suprising amount of trouble getting Claude to find and start these MCP servers, I'll update this thread when/if I get that working!

[dcj]

It's alive!!!

Panel Core — SPAN HW 1.2, firmware spanos2/r202603/05
  - Serial: nt-xxxx-xxxxx
  - L1: 122.0V, L2: 122.2V, 200A main breaker
  - Main relay: CLOSED, dominant power source: GRID
  - Grid-islandable: true (has battery backup)

  Lugs

  ┌────────────┬──────────────┬─────────────────┬─────────────────┐
  │            │ Active Power │ Imported Energy │ Exported Energy │
  ├────────────┼──────────────┼─────────────────┼─────────────────┤
  │ Upstream   │ 805.9 W      │ 19.4 MWh        │ 2.7 MWh         │
  ├────────────┼──────────────┼─────────────────┼─────────────────┤
  │ Downstream │ 1727.5 W     │ 12.7 MWh        │ 5.6 MWh         │
  └────────────┴──────────────┴─────────────────┴─────────────────┘

  Aggregate Power Flows

  ┌─────────┬──────────────────────┐
  │ Source  │        Power         │
  ├─────────┼──────────────────────┤
  │ PV      │ -1954 W (generating) │
  ├─────────┼──────────────────────┤
  │ Battery │ 0 W (idle)           │
  ├─────────┼──────────────────────┤
  │ Grid    │ -819 W (importing)   │
  ├─────────┼──────────────────────┤
  │ Site    │ 2773 W (consuming)   │
  └─────────┴──────────────────────┘

  Battery (BESS) — Tesla Powerwall 2 AC
  - Serial: TGxxxxxxxxxxxx, FW 26.2.0
  - 81 kWh capacity, SoC: 100%, SoE: 81.0 kWh
  - Connected, ON_GRID, positioned UPSTREAM

  Solar PV — Enphase IQ7PLUS, 4640 W nameplate, positioned IN_PANEL
  - Currently generating ~1905 W

  Power Control System (PCS) — mostly unconfigured, 200A requested import limit

  Circuits (16 total, all relays CLOSED)

  ┌───────────────────────────────┬───────┬───────────┬───────────────┐
  │            Circuit            │ Space │   Power   │ Shed Priority │
  ├───────────────────────────────┼───────┼───────────┼───────────────┤
  │ Kitchen-Outlets-1 & Outlets-2 │ 1     │ -4.6 W    │ NEVER         │
  ├───────────────────────────────┼───────┼───────────┼───────────────┤
  │ Clothes-Dryer                 │ 2     │ 0.0 W     │ OFF_GRID      │
  ├───────────────────────────────┼───────┼───────────┼───────────────┤
  │ Attic-Back-Outlet             │ 5     │ 0.0 W     │ SOC_THRESHOLD │
  ├───────────────────────────────┼───────┼───────────┼───────────────┤
  │ HVAC-Heating-Coil             │ 6     │ 0.0 W     │ OFF_GRID      │
  ├───────────────────────────────┼───────┼───────────┼───────────────┤
  │ Wine Refrigerator             │ 7     │ -6.7 W    │ SOC_THRESHOLD │
  ├───────────────────────────────┼───────┼───────────┼───────────────┤
  │ Water-Heater                  │ 9     │ 0.0 W     │ NEVER         │
  ├───────────────────────────────┼───────┼───────────┼───────────────┤
  │ HVAC-Heat-Pump                │ 10    │ -5.8 W    │ OFF_GRID      │
  ├───────────────────────────────┼───────┼───────────┼───────────────┤
  │ HVAC-Air-Handler              │ 13    │ -61.5 W   │ OFF_GRID      │
  ├───────────────────────────────┼───────┼───────────┼───────────────┤
  │ Ovens                         │ 14    │ -7.4 W    │ OFF_GRID      │
  ├───────────────────────────────┼───────┼───────────┼───────────────┤
  │ Studio-HVAC                   │ 17    │ -10.2 W   │ OFF_GRID      │
  ├───────────────────────────────┼───────┼───────────┼───────────────┤
  │ Cooktop/Stove                 │ 18    │ -6.1 W    │ SOC_THRESHOLD │
  ├───────────────────────────────┼───────┼───────────┼───────────────┤
  │ Future-240VAC-1               │ 21    │ 0.0 W     │ OFF_GRID      │
  ├───────────────────────────────┼───────┼───────────┼───────────────┤
  │ Espresso-Machine              │ 22    │ -6.0 W    │ SOC_THRESHOLD │
  ├───────────────────────────────┼───────┼───────────┼───────────────┤
  │ Future-240VAC-2               │ 25    │ 0.0 W     │ OFF_GRID      │
  ├───────────────────────────────┼───────┼───────────┼───────────────┤
  │ Shed-240VAC-Outlet            │ 26    │ 0.0 W     │ OFF_GRID      │
  ├───────────────────────────────┼───────┼───────────┼───────────────┤
  │ Commissioned PV System        │ 29    │ +1904.6 W │ OFF_GRID      │
  └───────────────────────────────┴───────┴───────────┴───────────────┘

  Settable properties: relay and shed-priority on each circuit, dominant-power-source on the core node.

[jacoscaz]

Woaaah! Awesome!

[dcj]

Here is how I configured this MCP for use with SPAN API -> eBus -> Homie:

Tieske/homie5-mcp-server#2

[jacoscaz]

I'm still fighting claude to accept an unauthenticated MCP server on a local network, but haven't found a way yet.

Off-topic: this is almost half the reason why I started working on my own harness, that is, to have a super-simple, in-process transport for MCP.