OPCFoundation.NetStandard.Opc.Ua.Mcp.Core

OPCFoundation.NetStandard.Opc.Ua.Mcp.Core

OPC UA Model Context Protocol (MCP) tools for the Part 4 services, packaged so they can be embedded in any MCP server host rather than only run as the shipped opcua-mcp tool.

Use this package when an application wants to offer OPC UA tools to an LLM and add tools of its own.

Tools

Connect and session management, browse and view services, read and write attributes, method calls, subscriptions and monitored items, node management, NodeSet2 export, and PKI/certificate administration.

Usage

builder.Services.AddOpcUaMcpCore();

builder.Services.AddMcpServer()
    .WithStdioServerTransport()
    .WithOpcUaMcpFilters()
    .WithOpcUaCoreTools(McpToolProfile.Services)
    .WithTools<MyApplicationTools>();

WithOpcUaMcpFilters registers the request and schema filters that make tool errors actionable and tool schemas explicit; call it once per server even when several OPC UA tool packages are composed.

Trimming and Native AOT

The assembly is marked IsAotCompatible on net10.0: its own IL is free of trim and AOT warnings, and tool results are written with Utf8JsonWriter rather than the reflection-based JsonSerializer.

That is not yet the same as working in an ahead-of-time published host. Registering the tools still requires JSON reflection, because the MCP SDK builds each tool's input schema by asking JsonSchemaExporter for a JsonTypeInfo of every parameter type; without a source-generated context covering the tool signatures this throws NotSupportedException. Opc.Ua.Aot.Tests.McpAotTests pins that limitation so it is stated rather than discovered at run time.

OPCFoundation.NetStandard.Opc.Ua.Mcp.Diagnostics is deliberately not marked AOT-compatible: it depends on SharpPcap and on reflective service-call dissection.

Related packages

License

OPC Foundation MIT License 1.00 — http://opcfoundation.org/License/MIT/1.00/