Node Opcua Modeler MCP Server

node-opcua-modeler-mcp-server

An MCP server that gives AI agents access to the OPC UA companion specification type system — 589 types across 22 industrial namespaces, plus 1,533 engineering units.

Built on node-opcua, the most widely used OPC UA stack for Node.js.

Why?

When an AI agent needs to build an OPC UA information model, it must know:

• What companion spec types exist (DI, Machinery, Robotics, Machine Tools…)
• What components, properties, and methods each type has
• What namespace dependencies are required
• What engineering unit symbols are valid (UNECE Rec. 20)

This MCP server answers all of those questions — offline, for free, in milliseconds.

Quick Start

With Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "opcua-modeler": {
      "command": "npx",
      "args": ["-y", "node-opcua-modeler-mcp-server"]
    }
  }
}

With any MCP client

npx node-opcua-modeler-mcp-server

The server communicates over stdio using the Model Context Protocol.

Tools

list_namespaces

List all 25 OPC UA companion spec namespaces with aliases, URIs, and dependencies.

→ list_namespaces()
← [
    { "alias": "di", "name": "OPC UA for Devices", "uri": "http://opcfoundation.org/UA/DI/", "dependencies": [] },
    { "alias": "robotics", "name": "OPC UA for Robotics", "uri": "http://opcfoundation.org/UA/Robotics/", "dependencies": ["di", "ia"] },
    ...
  ]

resolve_dependencies

Resolve the full dependency chain for companion spec aliases. Returns a topologically sorted list for the YAML namespaces: block.

→ resolve_dependencies({ aliases: ["machineTool"] })
← ["di", "ia", "machinery", "isa95JobControl", "machineryJobs", "machineTool"]

list_types

List all ObjectTypes and VariableTypes defined in a companion spec namespace.

→ list_types({ alias: "robotics" })
← [
    { "browseName": "MotionDeviceType", "kind": "ObjectType", "subtypeOf": "di:ComponentType", ... },
    { "browseName": "AxisType", "kind": "ObjectType", "subtypeOf": "di:ComponentType", ... },
    ...
  ]   // 25 types

get_type_details

Get the full structure of a type — components, properties, methods, interfaces, including inherited members.

→ get_type_details({ alias: "robotics", browseName: "MotionDeviceType" })
← {
    "browseName": "MotionDeviceType",
    "kind": "ObjectType",
    "subtypeOf": "di:ComponentType",
    "interfaces": ["di:IVendorNameplateType", "di:ITagNameplateType"],
    "components": [
      { "browseName": "robotics:Axes", "nodeClass": "Object", "typeDefinition": "FolderType", "modellingRule": "Mandatory" },
      { "browseName": "robotics:PowerTrains", "nodeClass": "Object", "typeDefinition": "FolderType", "modellingRule": "Mandatory" },
      ...
    ],
    "properties": [
      { "browseName": "di:Manufacturer", "dataType": "LocalizedText", "modellingRule": "Mandatory" },
      { "browseName": "robotics:MotionDeviceCategory", "dataType": "MotionDeviceCategoryEnumeration", "modellingRule": "Mandatory" },
      ...
    ]
  }

search_types

Search for types across all companion specs by keyword.

→ search_types({ query: "temperature" })
← [
    { "alias": "glass", "browseName": "MotorTemperatureTooHighEventType", ... },
    { "alias": "padim", "browseName": "TemperatureMeasurementVariableType", ... },
    { "alias": "amb", "browseName": "OverTemperatureConditionClassType", ... }
  ]

find_engineering_unit

Find the official UNECE Rec. 20 engineering unit symbol. Supports fuzzy matching and natural language aliases.

→ find_engineering_unit({ query: "celsius" })
← { "symbol": "°C", "matchType": "alias", "confidence": 1 }

→ find_engineering_unit({ query: "revolutions per minute" })
← { "symbol": "rpm", "matchType": "alias", "confidence": 1 }

→ find_engineering_unit({ query: "bar" })
← { "symbol": "bar", "matchType": "exact", "confidence": 1 }

Coverage

Companion Specifications (25)

Engineering Units

1,533 official UNECE Rec. 20 symbols plus 134 natural language aliases (e.g., "celsius" → °C, "revolutions per minute" → rpm).

How It Works

The server ships with a pre-generated catalog.json containing all type information extracted from OPC Foundation's official NodeSet2.xml files via node-opcua. All queries are answered from this static catalog — no network required, no API key needed.

┌─────────────────────────────────────────┐
│  node-opcua-modeler-mcp-server          │
│                                         │
│  ┌─────────────────────────────────┐    │
│  │ catalog.json (1.7 MB)           │    │
│  │ • 25 companion spec registries  │    │
│  │ • 589 type summaries + details  │    │
│  │ • 1,533 engineering units       │    │
│  └─────────────────────────────────┘    │
│                                         │
│  6 MCP tools → query the catalog        │
│  stdio transport (JSON-RPC)             │
└─────────────────────────────────────────┘

Use Cases

• AI-assisted OPC UA modeling — agents can discover types, resolve dependencies, and validate unit symbols before generating YAML/XML models
• Copilot integration — add OPC UA awareness to coding assistants
• Industrial digital twin design — explore companion spec type hierarchies interactively
• Learning OPC UA — ask an AI to explain types and their relationships

Requirements

• Node.js ≥ 18

Related

• node-opcua — Full OPC UA stack for Node.js
• OPC UA Modeler — Create, validate, and generate OPC UA information models
• Model Context Protocol — Open protocol for AI tool integration

License

MIT © Sterfive