# OPC UA Modeler (remote · api.opcua-modeler.sterfive.io)

OPC UA companion spec types, namespace dependencies, and engineering units for AI agents

- Trust score: 79/100 (medium)
- Change this week: +4
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-09-20

## Components

- remote · `api.opcua-modeler.sterfive.io`: 79/100 (this document), [markdown](https://verifymcp.io/servers/node-opcua-node-opcua-modeler-mcp-server/api-mcp.md), [page](https://verifymcp.io/servers/node-opcua-node-opcua-modeler-mcp-server/api-mcp)
- npm · `node-opcua-modeler-mcp-server`: 94/100, [markdown](https://verifymcp.io/servers/node-opcua-node-opcua-modeler-mcp-server/node-opcua-modeler-mcp-server.md), [page](https://verifymcp.io/servers/node-opcua-node-opcua-modeler-mcp-server/node-opcua-modeler-mcp-server)

## Channel facts

- Endpoint: `https://api.opcua-modeler.sterfive.io/api/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `1.6.1`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-09-20.

- **Endpoint Security**: 60/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - Authorisation not fully verified: no authorisation is required to call this server, and 12 tool(s) never declared a destructiveHint. The MCP spec treats an absent hint as destructive by default, so we cannot call this surface safe.
  - HTTPS is enforced; there's no plaintext access path.
  - HSTS check failed: the Strict-Transport-Security header is absent.
  - DNSSEC is configured correctly; the domain's records validate against the full chain to the root.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 85/100
  - AI-judged instruction clarity (excellent).
  - Tool/resource definitions use about 987 tokens (~82/item across 12 items; 12 tools + 0 resources), lean.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 80/100
  - Stability observed for 24 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% of tool parameters carry a description.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 12 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 12 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.

## Install

### How do I install the OPC UA Modeler MCP server?

OPC UA Modeler is a hosted endpoint at https://api.opcua-modeler.sterfive.io/api/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add --transport http node-opcua-node-opcua-modeler-mcp-server 'https://api.opcua-modeler.sterfive.io/api/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "node-opcua-node-opcua-modeler-mcp-server": {
      "url": "https://api.opcua-modeler.sterfive.io/api/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "node-opcua-node-opcua-modeler-mcp-server": {
      "type": "http",
      "url": "https://api.opcua-modeler.sterfive.io/api/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.node-opcua-node-opcua-modeler-mcp-server]
url = "https://api.opcua-modeler.sterfive.io/api/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "node-opcua-node-opcua-modeler-mcp-server": {
      "type": "remote",
      "url": "https://api.opcua-modeler.sterfive.io/api/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add node-opcua-node-opcua-modeler-mcp-server --url 'https://api.opcua-modeler.sterfive.io/api/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  node-opcua-node-opcua-modeler-mcp-server:
    url: "https://api.opcua-modeler.sterfive.io/api/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "node-opcua-node-opcua-modeler-mcp-server": {
      "Transport": "http",
      "Url": "https://api.opcua-modeler.sterfive.io/api/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add node-opcua-node-opcua-modeler-mcp-server -t streamable-http -u 'https://api.opcua-modeler.sterfive.io/api/mcp'
```

### Other

```json
{
  "mcpServers": {
    "node-opcua-node-opcua-modeler-mcp-server": {
      "type": "http",
      "url": "https://api.opcua-modeler.sterfive.io/api/mcp"
    }
  }
}
```

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-09-20 (score 79, +1)

No change was recorded against any check on this day. Stability & Change Management went from 77 to 80. That category is still filling its 30-day observation window: 23 days of observed history at the previous scan, 24 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-18 (score 78, +1)

No change was recorded against any check on this day. Stability & Change Management went from 70 to 73. That category is still filling its 30-day observation window: 21 days of observed history at the previous scan, 22 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-16 (score 77, +1)

No change was recorded against any check on this day. Stability & Change Management went from 63 to 67. That category is still filling its 30-day observation window: 19 days of observed history at the previous scan, 20 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-14 (score 76, +1)

No change was recorded against any check on this day. Stability & Change Management went from 57 to 60. That category is still filling its 30-day observation window: 17 days of observed history at the previous scan, 18 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-12 (score 75, +1)

No change was recorded against any check on this day. Stability & Change Management went from 50 to 53. That category is still filling its 30-day observation window: 15 days of observed history at the previous scan, 16 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-11 (score 74, 0)

- [cosmetic] “opcua_model_reverse” added an optional parameter “self_contained”

### 2026-09-09 (score 74, +1)

No change was recorded against any check on this day. Stability & Change Management went from 40 to 43. That category is still filling its 30-day observation window: 12 days of observed history at the previous scan, 13 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-09-07 (score 73, +1)

No change was recorded against any check on this day. Stability & Change Management went from 33 to 37. That category is still filling its 30-day observation window: 10 days of observed history at the previous scan, 11 at this one. The score rises as the window fills, whether or not the server changes.

## MCP tools (12)

### `resolve_dependencies` (~67 tokens)

Resolve namespace dependencies

Given one or more companion spec namespace aliases, returns the full resolved dependency list that MUST go in the YAML `namespaces:` section. Always call this before generating the namespaces block.

Input parameters:

- `aliases` (array, required): Companion spec aliases to resolve (e.g. ["machineTool", "robotics"])

### `list_namespaces` (~39 tokens)

List companion specifications

List all well-known OPC UA companion spec namespace aliases with their full names, URIs, and dependencies. Use this to discover what namespaces are available.

### `list_types` (~67 tokens)

List types in a namespace

List ALL ObjectTypes, VariableTypes, and InterfaceTypes defined in a specific companion spec namespace. ALWAYS call this before using any type from a namespace — NEVER guess type names.

Input parameters:

- `alias` (string, required): Companion spec alias (e.g. "machinery", "di", "robotics")

### `get_type_details` (~89 tokens)

Get type details

Get detailed information about a specific type: its components, properties, methods, interfaces, and optional members. Use this to understand a type's structure before creating instances or subtypes.

Input parameters:

- `alias` (string, required): Companion spec alias where the type is defined (e.g. "machinery")
- `browseName` (string, required): The type browse name (e.g. "MachineryItemIdentificationType")

### `search_types` (~60 tokens)

Search types across specs

Search for types across ALL companion specs by keyword. Use this when you don't know which namespace defines a type. Returns matching types with their namespace alias.

Input parameters:

- `query` (string, required): Search keyword (e.g. "identification", "temperature", "motion")

### `find_reusable_block` (~137 tokens)

Find a reusable interface or AddIn

Find reusable Interfaces / AddIns by capability — pass a member name or keyword (e.g. "SerialNumber", "DeviceHealth", "Location") and get the standard blocks that already expose it. PREFER applying/composing an existing block over redefining its members inline. Interfaces are applied with `interfaces:`; addins (types with a DefaultInstanceBrowseName) are composed with `addIns:`. A single property → use the Interface; a whole named sub-object → use the AddIn.

Input parameters:

- `query` (string, required): Member name or capability keyword (e.g. "SerialNumber", "health", "calibration")

### `find_engineering_unit` (~73 tokens)

Find an engineering unit

Find the official UNECE Rec. 20 engineering unit symbol for a given description. ALWAYS call this before using any engineering unit — NEVER guess unit symbols.

Input parameters:

- `query` (string, required): Description or common name of the unit (e.g. "revolutions per minute", "celsius", "pressure bar")

### `get_dsl_reference` (~58 tokens)

Get the DSL grammar reference

Get the grammar reference for the OPC UA modeler YAML DSL: file header, top-level sections, name-prefix conventions, minimal examples, and common mistakes. Call this FIRST before writing any YAML model by hand. Works without an API key.

### `opcua_model_validate` (~69 tokens)

Validate an OPC UA model

Validate an OPC UA YAML model for correctness. Returns diagnostics with severity (error/warning/info), codes, messages, and line numbers. Works without an API key (limited to 50 calls/day). ALWAYS validate before generating.

Input parameters:

- `yaml` (string, required): The full YAML model source to validate

### `opcua_model_generate` (~104 tokens)

Generate NodeSet2 XML

Generate OPC UA NodeSet2.xml and Symbols.CSV from a YAML model. Requires an API key (set OPCUA_MODELER_API_KEY env var). Returns base64-encoded artifacts if the model is valid, or diagnostics if validation fails. Optionally set include_docs=true to also generate markdown documentation.

Input parameters:

- `include_docs` (boolean): Set to true to include markdown documentation (slower)
- `yaml` (string, required): The full YAML model source to generate from

### `opcua_model_reverse` (~122 tokens)

Reverse-engineer NodeSet2 XML

Reverse-engineer a NodeSet2.xml file back into the YAML DSL format. Requires an API key (set OPCUA_MODELER_API_KEY env var). Optionally specify the target namespace URI to extract.

Input parameters:

- `namespace_uri` (string): Target namespace URI to extract (auto-detected if omitted)
- `self_contained` (boolean): Return one self-contained .opcua.yaml stream: the model, its NodeId symbol table and dependency declarations (default: bare YAML)
- `xml` (string, required): The NodeSet2.xml content to reverse-engineer

### `opcua_model_create` (~102 tokens)

Create a model from a description

Generate an OPC UA YAML model from a natural language description using AI. Requires an API key (set OPCUA_MODELER_API_KEY env var). The AI will auto-detect relevant companion specs, generate a validated model with documentation, and auto-correct validation errors.

Input parameters:

- `forceSpecs` (array): Companion spec aliases to force (e.g. ["di", "ia"])
- `prompt` (string, required): Natural language description of the OPC UA model to generate

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/node-opcua-node-opcua-modeler-mcp-server/api-mcp#diagnostics

## Score history

- 2026-09-20: 79
- 2026-09-19: 78
- 2026-09-18: 78
- 2026-09-17: 77
- 2026-09-16: 77
- 2026-09-15: 76
- 2026-09-14: 76
- 2026-09-13: 75
- 2026-09-12: 75
- 2026-09-11: 74
- 2026-09-10: 74
- 2026-09-09: 74
- 2026-09-08: 73
- 2026-09-07: 73
- 2026-09-06: 72
- 2026-09-05: 72
- 2026-09-04: 71
- 2026-09-03: 71
- 2026-09-02: 70
- 2026-09-01: 70
- 2026-08-31: 69
- 2026-08-30: 69
- 2026-08-29: 68
- 2026-08-28: 68
- 2026-08-27: 67

## Common questions

### What is the OPC UA Modeler MCP server?

OPC UA Modeler is an MCP server listed in the public MCP registry as io.github.node-opcua/node-opcua-modeler-mcp-server. OPC UA companion spec types, namespace dependencies, and engineering units for AI agents. This page covers its hosted endpoint (https://api.opcua-modeler.sterfive.io/api/mcp).

### Is the OPC UA Modeler MCP server safe to use?

OPC UA Modeler scores 79 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the OPC UA Modeler MCP server expose?

OPC UA Modeler exposes 12 tools: resolve_dependencies, list_namespaces, list_types, get_type_details, search_types, and 7 more. Their descriptions and schemas cost roughly 987 tokens of context every time the server is loaded.

### Does the OPC UA Modeler MCP server require authentication?

No. We connected to OPC UA Modeler without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

### Is the OPC UA Modeler MCP server still maintained?

OPC UA Modeler is still listed as active in the MCP registry. We last reached this channel on 20 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

## Links

- Remote endpoint: https://api.opcua-modeler.sterfive.io/api/mcp
- Repository: https://github.com/node-opcua/node-opcua-modeler-mcp-server
- Website: https://opcua-modeler.sterfive.io/
- Changelog RSS feed: https://verifymcp.io/servers/node-opcua-node-opcua-modeler-mcp-server/api-mcp.xml
- Changelog JSON feed: https://verifymcp.io/servers/node-opcua-node-opcua-modeler-mcp-server/api-mcp.json
- HTML version of this page: https://verifymcp.io/servers/node-opcua-node-opcua-modeler-mcp-server/api-mcp