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 — and lets agents validate, generate, and reverse-engineer OPC UA information models.
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"],
"env": {
"OPCUA_MODELER_API_KEY": "stfv_your_api_key_here"
}
}
}
}
Note: The API key is optional for discovery tools (offline) and
opcua_model_validate(5 free calls/day). It is required foropcua_model_generateandopcua_model_reverse. Get a free key at opcua-modeler.sterfive.com.
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 }
opcua_model_validate ☁️
Validate an OPC UA YAML model for correctness. Returns diagnostics with severity, codes, messages, and line numbers. Works without an API key (limited to 5 calls/day).
→ opcua_model_validate({ yaml: "namespaces:\n di:\n..." })
← {
"valid": true,
"diagnostics": [
{ "severity": "warning", "code": "W001", "message": "...", "line": 42 }
]
}
opcua_model_generate ☁️
Generate OPC UA NodeSet2.xml and Symbols.CSV from a validated YAML model. Returns base64-encoded artifacts. Requires an API key.
→ opcua_model_generate({ yaml: "namespaces:\n di:\n...", include_docs: false })
← {
"valid": true,
"artifacts": {
"nodeset2_xml": "PD94bWwg...",
"symbols_csv": "bmFtZSxu..."
},
"diagnostics": []
}
opcua_model_reverse ☁️
Reverse-engineer a NodeSet2.xml file back into the YAML DSL format. Requires an API key.
→ opcua_model_reverse({ xml: "<?xml version=..." })
← {
"yaml": "namespaces:\n di:\n...",
"diagnostics": []
}
Coverage
Companion Specifications (25)
| Alias | Specification | Types |
|---|---|---|
padim | OPC UA for PA-DIM | 101 |
ijtBase | OPC UA for IJT Base | 65 |
machineTool | OPC UA for Machine Tools | 63 |
di | OPC UA for Devices | 44 |
glass | OPC UA for Glass Manufacturing | 36 |
machineVision | OPC UA for Machine Vision | 36 |
adi | OPC UA for Analyzer Devices | 35 |
commercialKitchenEquipment | OPC UA for Commercial Kitchen Equipment | 35 |
robotics | OPC UA for Robotics | 25 |
ia | OPC UA for Industrial Automation | 20 |
amb | OPC UA for AMB | 18 |
autoId | OPC UA for AutoID | 18 |
metalForming | OPC UA for Metal Forming | 16 |
machinery | OPC UA for Machinery | 15 |
gds | OPC UA GDS | 14 |
woodworking | OPC UA for Woodworking | 13 |
cnc | OPC UA for CNC Systems | 12 |
| …and 5 more | ||
| Total | 22 namespaces | 589 types |
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 │
│ │
│ LOCAL TOOLS (offline, free) │
│ ┌────────────────────────────────────────┐ │
│ │ catalog.json (1.7 MB) │ │
│ │ • 25 companion spec registries │ │
│ │ • 589 type summaries + details │ │
│ │ • 1,533 engineering units │ │
│ └────────────────────────────────────────┘ │
│ 6 tools → query the catalog │
│ │
│ CLOUD TOOLS (via api.opcua-modeler.sterfive.io) │
│ 3 tools → validate / generate / reverse │
│ │
│ 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