MarcandCopilot
33b691be6e
CI fix Opc.Ua.Bindings.Quic hardcoded TargetFrameworks net9.0;net10.0 and so did not take part in the repo's per-TFM pin. A UA.slnx build pinned with CustomTestTarget builds the rest of the stack for that one TFM, which broke this project three different ways: * pinned net10.0 - the project's net9.0 leg referenced a stack built only for net10.0, so restore failed with NU1201. This is what failed the ubuntu Core.DataChannels job in 32 seconds. * pinned net472/net48 - the net9.0 leg resolved the net472 assets of Opc.Ua.Core and failed with CS0012 on IAsyncDisposable. * pinned net8.0 - System.Net.Quic is behind RequiresPreviewFeatures there, so the project cannot take part at all. The project now follows the pin when the pin can host it, and otherwise opts into the existing RestrictForLegacyTfm no-op shape that samples/ConsoleDataChannelStreaming already uses. That mechanism only knew about the .NET Framework and netstandard pins - the right floor for a .NET 8+ project - so it gains RestrictForLegacyTfmAdditionalTargets for a project whose floor is higher. The shipped package shape is unchanged: an unpinned build still produces net9.0;net10.0. Verified by running the same matrix the CI legs run. All seven pinned UA.slnx builds succeed: net10.0, net9.0, net8.0, net48, net472, netstandard2.0, netstandard2.1. That matrix also caught a break the earlier per-project validation missed: SampleDataChannelAuthorizer was never updated for the direction-aware IDataChannelAuthorizer signature, so the sample did not compile. It now grants only the SourceToSink direction it actually publishes, which is the point of the Part 4 errata 7.2 rule it demonstrates. Seam simplification The Stack/Tcp change was carrying weight it did not need. Three removals, no behaviour change: * SecureChannelMessage is gone. It crossed the boundary with exactly one producer and one consumer, was never stored or compared, and carried IEquatable, ==, != and GetHashCode purely to satisfy CA1815 - about sixty lines of ceremony. OnMessageReceived now takes the three values directly. * The onSecuring callback is gone, and with it the SequenceBudget member of the host interface. It was the subtlest part of the contract - a callback that runs inside the send serialization and may veto atomically - and its only implementation consumed the budget. Core already owns SequenceNumberBudget and is the code doing the securing, so it now claims the number itself under the same lock. The guarantee is identical and the extension no longer has to reason about the serialization at all. * GlobalChannelId is gone. It had no reader. The host interface drops from nine members to six, and Stack/Tcp from 1358 added lines to 1270. Moving the engine back into Opc.Ua.Core was considered and rejected: it would remove about 330 of those lines, none of them the hard parts - the FIFO send gate exists because there is a second writer on one sequence counter, not because of an assembly boundary - while moving 7241 lines of engine into Core on every TFM for an experimental feature. 316 tests pass on net10.0 and 242 on net48. Opc.Ua.Server.Tests (4072) and Opc.Ua.Sessions.Tests (777) are unchanged, which is the check that matters because the seam sits on the send and receive path of all Service traffic. 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.