Integration Request — AXPERT VM IV-4000 TWIN (Wi-Fi or Solar of Thing App)

Third party integrations
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Hello everyone,
I would like to request an integration (or guidance on an existing one) for my Axpert VM IV-4000 TWIN inverter to work natively with Home Assistant.

:battery: Inverter details:
• Model: Axpert VM IV-4000 TWIN (Voltronic Power platform)
• Connection options: built-in Wi-Fi module + RS232/USB port
• Mobile app: Solar of Thing

:brain: Goal:
I’d like to read inverter data (PV, battery, load, grid input, etc.) and ideally send control commands (like output priority) directly to Home Assistant, either through:
• Local Wi-Fi (if possible to bypass the cloud)
• Or through the “Solar of Thing” API (if accessible)
• Or any other available integration / protocol (Modbus, MQTT bridge, etc.)

:test_tube: What I tried so far:

  1. Tried the built-in Wi-Fi module
    o I can access data in the Solar of Thing mobile app, but the inverter does not expose a local Modbus or MQTT port.
    o Port scanning (nmap) shows no open port on 8899 (so not a Solarman-compatible stick).
    o Access to http://<inverter_ip> shows nothing usable (proprietary cloud tunnel).
  2. Checked HACS integrations:
    o Solarman Local → not compatible (Wi-Fi stick not Solarman-based)
    o mpp-solar → requires USB/RS232 connection
    o Inverter Charger Integration → didn’t recognize the device over Wi-Fi
  3. Tried docker-voltronic-homeassistant (GitHub - ned-kelly/docker-voltronic-homeassistant: Programmatically read data from your Voltronic, Axpert, Mppsolar PIP, Voltacon, Effekta etc Inverter and send it to Home Assistant via MQTT - Works with RS232 & USB!)
    o Works only via USB/RS232, not over Wi-Fi.
    o I haven’t tested it physically yet (planning to connect via USB soon), but I prefer a wireless solution if possible.

:mag: What I’m looking for:
• Any way to communicate locally over Wi-Fi (not via cloud)
• Or any open API / protocol documentation for Solar of Thing app
• Or help building a custom integration / MQTT bridge to pull data from the inverter
If anyone has managed to integrate an Axpert VM IV series (especially the Twin variant) — please share how you did it.

:gear: Home Assistant setup:
• Home Assistant OS on Raspberry Pi 5
• MQTT broker + Node-RED already configured
• Other energy sensors integrated successfully (Shelly, Frigate, etc.)

:pray: Appreciation:
Thanks in advance to anyone who can help!
I’d be happy to test beta code, share logs, or provide diagnostic info from the inverter or the Solar of Thing app to make this integration possible.

Would you like me to:
• make it shorter and more direct (for quick community replies),
or
• keep it in this detailed structured format (for developers and technical responses)?

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