UA-ModelCompiler

What you actually use it for

• Compiling a model design file into a NodeSet2 XML file plus an identifier CSV, reproducibly, from a script.
• Compiling a directory of nodesets for a specific namespace URI so that dependencies resolve consistently.
• Putting model generation into CI, so the nodeset in your repository is always the one your build produced.
• Producing the generated identifiers that server code needs alongside the nodeset, rather than transcribing NodeIds by hand.
• Working with structures that permit subtypes, where the compiler has an explicit switch rather than degrading fields to plain ExtensionObjects.

Walkthrough

1. Install it as a .NET global toolRun dotnet tool install --global OPCFoundation.Opc.Ua.ModelCompiler.Tool. You then invoke it as Opc.Ua.ModelCompiler. Because it is a global tool, the same install works on a Linux build agent as on a developer laptop.
2. Compile a model design fileOpc.Ua.ModelCompiler compile -d2 ./MyModel.xml -cg ./MyModel.csv -o2 ./output takes your design and produces the NodeSet2 output plus the identifier CSV. Keep both under version control; the CSV is what stops NodeIds drifting between builds.
3. Compile a nodeset directory for one namespaceOpc.Ua.ModelCompiler compile-nodesets -input ./NodeSets -o2 ./output -uri http://opcfoundation.org/UA/DI/ compiles a whole nodeset tree for a named namespace URI. Use this when your model depends on companion specifications and you need the dependency closure handled properly.
4. Pin the nodeset versions you compile againstCheck the companion nodesets into your repository at a known revision rather than pulling latest at build time. Companion specifications are republished, and a silently newer dependency is a silently different model.
5. Wire it into the buildMake nodeset compilation a build step and fail the build on compiler errors. A model that only compiles on one engineer's machine is the same class of problem as code that only builds there.
6. Load the output into a server and browse itCompilation success is not conformance. Load the produced NodeSet2 into your server stack, browse it with an independent client and confirm HasTypeDefinition and mandatory components resolve as intended.

What it will not do

• Command-line only. There is no graphical editor, so authoring the design XML is on you or on another tool.
• Requires a .NET SDK on the build machine, which some constrained build environments will not have.
• It validates and compiles; it does not test behaviour, conformance or client interoperability.
• Options and switch names change between releases, so a command line copied from older documentation may not run.
• It will not tell you that you chose the wrong companion specification or the wrong base type.

Alternatives

Last verified 7 September 2026 against OPC UA 1.05.07. OPC UA Connect is an educational resource and is not affiliated with the OPC Foundation.