io.github.flowiesner/fronius-mcp

fronius-mcp

Real-time solar data from your Fronius inverter, directly in Claude.

Ask things like:

"How much solar power am I generating right now?"

"What's my battery charge level?"

"Am I currently importing or exporting to the grid?"

"How much energy did I produce this year?"

"What can you do with my solar system?"

"Analyse my photovoltaics for me."

Connects to the Fronius Solar API v1 directly on your local network — no cloud account, no subscription, no data leaving your home.

How it works

fronius-mcp is a Model Context Protocol (MCP) server. MCP is an open standard that lets AI assistants like Claude connect to external tools and data sources. Once configured, Claude can call your inverter's local API in real time — whenever you ask a question about your solar system, Claude fetches live data and answers based on what's actually happening right now.

Requirements

• A Fronius inverter on your local network with the Solar API (JSON API) enabled
• Claude Desktop
• uv — a fast Python package manager (one-line install)

Setup

1. Install uv

uv is a fast Python package manager used to run fronius-mcp without a permanent install.

macOS / Linux:

curl -LsSf https://astral.sh/uv/install.sh | sh

Windows (PowerShell):

irm https://astral.sh/uv/install.ps1 | iex

Restart your terminal after installing.

2. Add to Claude Desktop

Open your claude_desktop_config.json and add the fronius block inside mcpServers:

{
  "mcpServers": {
    "fronius": {
      "command": "uvx",
      "args": ["fronius-mcp"]
    }
  }
}

Config file location:

Tip: If the mcpServers key already exists, just add the fronius block inside it — don't create a second mcpServers.

3. Restart Claude Desktop

Close and reopen Claude Desktop so it picks up the new server config.

4. Configure your inverter

In a new Claude conversation, say:

"Configure my Fronius inverter at 192.168.178.35"

Claude will save your inverter's IP and confirm the connection. This is a one-time step — the address is stored in ~/.fronius-mcp.json and persists across restarts.

Don't know your inverter's IP? Tell Claude: "I want to configure my Fronius inverter but I don't know the IP." Claude will walk you through finding it via your router, Fronius Solar.web, or the inverter's touch display — and how to enable the Solar API in the inverter's web interface if you haven't done that yet.

What you can ask

Once set up, just talk to Claude naturally. Some examples:

• "What's my current solar output?" — live PV generation in watts
• "How self-sufficient am I right now?" — autonomy and self-consumption percentages
• "Is my battery charging or discharging?" — battery power flow and state of charge
• "How much have I fed into the grid today?" — energy totals from the smart meter
• "What devices are connected to my inverter?" — full system topology
• "Give me a full overview of my solar system." — Claude combines all data sources into a summary

Tools

Compatible Hardware

Developed and tested on:

• Fronius Symo GEN24 10.0 Plus
• BYD Battery-Box Premium HV (13.824 kWh)
• Fronius Smart Meter (grid feed-in point, 3-phase)

Other Fronius inverters with Solar API v1 support should work. Some API endpoints behave differently across models — if something doesn't work on your hardware, open an issue.

License

Apache 2.0 — see LICENSE.