MarcandCopilot
cd1ba90295
Nine review comments; two were answered by the previous commit (the generic extension seam and the file named after it are both gone). The rest: Sample layout and a second sample The data channel samples now live under samples/Core, and a new ConsoleDataChannelAudio joins the throughput benchmark. It stands up a Server and a Client in one process, synthesises a short melody as 16-bit PCM once at startup and streams it on repeat over a data channel while the Client plays it back. Nothing binary enters the repository. The source writes in real time rather than as fast as the channel will take it, because a media source is paced by its own clock and writing faster only adds latency; the progress line reports frames, bytes and credit stalls so a consumer that cannot keep up is visible rather than silently buffered. Measured over 31 seconds: 1582 frames, 2725 KiB, zero credit stalls, which is exactly real time for 20 ms frames. Playback uses NAudio 2.3.0 (MIT), referenced only by that sample - nothing under src/ gains a dependency. NAudio's output devices are Windows interfaces and 2.x has no ALSA or CoreAudio backend, so on Linux and macOS the sample writes the received stream to a WAV instead and says which it is doing on startup. The Windows-only paths sit behind OperatingSystem.IsWindows() rather than a CA1416 suppression. Documentation "Where the code lives" describes where the code is rather than where it moved from, and the same edit removes "rather than in ...", "remains" and the rest of the change narration. Two sections that were a development diary - the tables of defects found while writing tests and while running the sample - are gone entirely: they recorded history rather than the state of the implementation. Logging The response-dispatched callback logged through a message that reads "Failed to send fault response to client", which is not what happened, and on the HTTPS listener it invented a requestId of 0 to fit that signature. All three listeners now have a named message that says what actually failed. net8.0 for the QUIC binding Rather than excluding net8.0, the binding targets it and enables preview features, so a net8.0 consumer opts in the same way for System.Net.Quic. The three file-wide NET9_0_OR_GREATER guards are gone; only QuicServerConnectionOptions.HandshakeTimeout stays guarded because it is genuinely .NET 9+, and the listener's own admission expiry still bounds a stalled handshake there. Removing the #if around [Experimental] ExperimentalAttribute is a .NET 8 type, and the repo's rule is to polyfill rather than fork with #if, so it joins the existing polyfills in Opc.Ua.Types. Verified that this is a real opt-in and not just something that compiles: with the suppression removed, a net48 caller of a data channel Service fails the build with "error DataChannels", which is the same behaviour as net10.0. Validated with the matrix CI runs: all seven pinned UA.slnx builds (net10.0, net9.0, net8.0, net48, net472, netstandard2.0, netstandard2.1), 316 data channel tests on net10.0 and 242 on net48, Opc.Ua.Server.Tests 4072, Opc.Ua.Client.Tests 2126, Opc.Ua.Redundancy.Client.Tests 123, and the reference server Docker image end to end. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 5d026b47-265d-4c97-8715-26e207dfa03c
OPC UA .NET Standard Stack
🆕 This is version 2.0 of the OPC UA .NET Standard Stack (current
master).Looking for the supported 1.x release? It lives on the
master378branch (last release:1.5.378). All new feature work happens here onmaster;master378continues to receive security and critical-bug fixes for the 1.x line.
The official OPC Foundation reference implementation of OPC UA for .NET — a certified, cross-platform stack with client, server, PubSub, GDS, complex types, and source-generated tooling. Used in production across industrial control, manufacturing, energy, and IoT systems.
📦 What it is
- A full-stack OPC UA implementation — Core / Client / Server / PubSub / GDS / LDS / Complex Types / Device Integration / Positioning libraries built on .NET, with UA-TCP and HTTPS transports.
- Cross-platform — runs on .NET 10, .NET 9, .NET 8 (LTS), .NET Framework 4.8, and .NET Standard 2.1; ships Native-AOT-friendly assemblies.
- Certified for compliance — the reference server has been certified through an OPC Foundation Certification Test Lab and is continuously verified against the latest Compliance Test Tool (CTT).
- Companion-spec coverage — Part 9 (Alarms & Conditions), Part 11 (Historical Access), Part 13 (Aggregates), Part 16 (State Machines), Part 17 (Alias Names), Part 18 (Role Management), Part 20 (File Transfer), Part 100 (Device Integration), Parts 210/211 (Relative Spatial Location and Global Positioning), OPC-10030 (ISA-95 Common Model) with OPC-10031-4 Job Control V1/V2, OPC 10100-1 (WoT Connectivity), OPC 40001-1 (Industrial Automation), OPC 40010-1 (Robotics).
- Modern developer surface — first-class
Microsoft.Extensions.DependencyInjectionhosting (services.AddOpcUa()), fluent server + client builders, source-generated NodeManagers and DataTypes, and an MCP server so LLMs / Copilot can drive an OPC UA client.
For the full feature breakdown see OPC UA Profiles and Facets and the What's New in 2.0 tour.
🚀 Getting started
You need the .NET 10 SDK to build the repo. From the repository root:
dotnet restore UA.slnx
dotnet build UA.slnx
For the supported target frameworks and platform notes see
the Developer Guide. The official NuGet packages
are published to nuget.org under the OPCFoundation.NetStandard
prefix — the meta package
OPCFoundation.NetStandard.Opc.Ua
pulls in everything, or pick the split
OPCFoundation.NetStandard.Opc.Ua.Core / .Client / .Server /
.Bindings.Https packages directly. Preview builds for every successful
master build are available in the
Azure DevOps opcua-preview feed.
Sample applications
Each sample has its own README.md with build and run instructions.
Reference applications
- Console Reference Server — the certified reference server (with Quickstarts, CTT, and Mono configs). Also ships as a Docker container.
- Console Reference Client — cross-platform reference client demonstrating sessions, subscriptions, browsing, and method calls.
- Console LDS Server — a standalone
Local Discovery Server built on
Opc.Ua.Lds.Server.
PubSub samples
- Console Reference PubSub Client —
one executable with
publisher,subscriber, andexternal(external-server adapter) modes across the supported transport profiles.
Minimal / Device-Integration samples
- Minimal Calc Server — minimal server built on the source-generated NodeManager pipeline (Calc model).
- Minimal Boiler Server — minimal Boiler-model server with the fluent state-machine builder; Native-AOT publishable.
- Pump Device Integration Server —
minimal Device Integration (Part 100) server using
Opc.Ua.Di.Server's fluent builder. - Minimal Robot Server — OPC 40010 Robotics with independently configurable RSL/GPOS motion and live OpenUSD transforms.
- Intent Enabled Robot — one collaborative arm exposing the draft Robot Intent command surface: task-level motion verbs tracked on a Part 10 program lifecycle, with missions, command authority and safety-aware refusal.
- Intent Viewer Client — click a target in an OpenUSD viewport and watch the arm execute the resulting intent; also runs headless.
- Minimal ISA-95 Server — minimal server hosting the OPC-10030 ISA-95 Common Model together with OPC-10031-4 Job Control V1 and V2, using the typed common-model builder and the in-memory Job Control provider.
More sample projects are maintained in the companion OPC UA .NET Samples repository.
Developer tools
- OPC UA MCP Server — installable .NET tool and container that exposes OPC UA client operations as MCP tools for LLMs and Copilot. The tools also ship as libraries (
…Opc.Ua.Mcp.Core,.PubSub,.Diagnostics,.PubSub.Diagnostics) so an application can embed them next to its own MCP tools.
🔧 Migrating from 1.5.378 to 2.0
The 2.0 release introduces breaking API changes, and comes with a full prescriptive migration guide that links to per-area documentation covering telemetry, packages, source generation, types, encoders, node states, identity, certificates, configuration, sessions / subscriptions, alarms / model change, and TimeProvider.
Most of the mechanical migration work is automated:
OPCFoundation.NetStandard.Opc.Ua.MigrationAnalyzerNuGet — install it in your project to get analyzer warnings (UA0001–UA0022)- one-click code fixes for the patterns in the guide. Setup steps are in the package's NugetREADME.md.
- Migration agent skill — the
opcua-v20-migrationskill walks Copilot / Claude / any coding agent through installing the NuGet, runningdotnet format analyzersto apply auto-fixes, and handling the small residual manual patterns. The skill knows which sub-doc to load for each symptom so it stays context-efficient.
If you are still on 1.x and not ready to upgrade, stay on the
master378
branch — it continues to receive security and critical-bug fixes.
🤝 Contributing and license
Community contributions are welcome. Fork the repository, make your changes on a branch, and open a pull request; see CONTRIBUTING.md for the contribution workflow.
Contributors must sign the OPC Foundation Contributor License Agreement (CLA). The CLA "I AGREE" gate is presented automatically on your first PR.
The project is licensed under the OPC Foundation MIT License. Report security vulnerabilities via the process documented in SECURITY.md.
📚 Further reading
- Documentation index — every per-feature doc with a one-line description.
- What's New in 2.0 — narrative tour of the 1.5.378 → 2.0 changes grouped by theme and layer.
- OPC UA Profiles and Facets — facets / transports / security policies the stack implements.
- Migration Guide — prescriptive
per-version migration reference (links to
docs/migrate/2.0.x/). - OPC UA Online Reference — the official OPC 10000 series specification index.
- OPC UA .NET Samples — companion repository with more sample applications.
- Preview NuGet feed — prerelease builds from Azure DevOps.