openplc-mcp

An MCP server for OpenPLC workflows: inspect ladder projects, control the runtime, debug variables, and generate helpful project documentation.

openplc-mcp connects MCP-compatible clients to an OpenPLC project and runtime.

It is designed to help you:

• understand an OpenPLC project quickly
• validate ladder logic before deployment
• upload and control programs on the runtime
• inspect runtime/debug information safely
• generate a project report and an operator guide

The goal is to make common OpenPLC tasks easier without forcing you to work directly with raw runtime endpoints or low-level project files.

git clone git@github.com:ardzz/openplc-mcp.git
cd openplc-mcp
npm ci
cp .env.example .env
npm run build
npm start

Once the server is running, point your MCP client to dist/index.js.

Most MCP clients support a server entry similar to this:

{
  "mcpServers": {
    "openplc-mcp": {
      "command": "node",
      "args": ["/absolute/path/to/openplc-mcp/dist/index.js"],
      "env": {
        "OPENPLC_PROJECT_ROOT": "/absolute/path/to/your/openplc-project",
        "OPENPLC_RUNTIME_URL": "https://localhost:8443",
        "OPENPLC_RUNTIME_USERNAME": "openplc",
        "OPENPLC_RUNTIME_PASSWORD": "openplc"
      }
    }
  }
}

After the server is connected to your MCP client, you can use it for practical workflows such as:

• Project understanding
• summarize the OpenPLC project
• list available POUs
• read and validate a ladder program

• Runtime operations
• check runtime status and logs
• upload a compiled program package
• wait for compilation and start or stop the PLC