VS Code Extension

The OPC UA Modeler VS Code extension gives you full IDE intelligence when authoring .model.yaml files — completions, real-time diagnostics, hover hints, and quick fixes — powered by the bundled LSP server.

Installation

Option A — Using the CLI (recommended)

If you already have opcua-modeler installed, run:

opcua-modeler install-extension

This installs two extensions in one step:

1. The OPC UA Modeler extension — from the Marketplace (or the bundled .vsix as offline fallback)
2. The RedHat YAML extension (redhat.vscode-yaml) — installed automatically as a companion, providing the YAML Language Server that powers schema validation. Skipped gracefully in --offline mode (you can install it manually in that case).

It also auto-configures opcuaModeler.serverPath in your VS Code settings.json so the extension finds the CLI without any manual setup.

Available flags: --offline (skip Marketplace, use bundled .vsix), --force (re-install even if already installed), --editor <code|cursor|codium|code-insiders>.

Option B — VS Code Marketplace

1. Open VS Code
2. Go to the Extensions panel (Ctrl+Shift+X)
3. Search for "OPC UA Modeler" (publisher: Sterfive)
4. Click Install

Note: With this method you will need to install the RedHat YAML extension separately.

Option C — Manual .vsix install

code --install-extension opcua-modeler-<version>.vsix

Note: With this method you will also need to install the RedHat YAML extension manually.

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Activated file types

The extension activates automatically on any of these file patterns:

Pattern	Description
*.nodeset.yaml	Recommended extension for NodeSet YAML files
*.nodeset.yml	Alternate short extension
*.model.yaml	Legacy convention
*.model.yml	Legacy short extension
model.yaml	Bare filename convention
model.yml	Bare short filename

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What you get

Once activated, the extension provides:

✅ Real-time diagnostics

Errors and warnings appear inline as you type — no need to run the CLI manually.

• Structural errors (wrong keys, missing required fields, invalid types) appear almost instantly via JSON Schema validation.
• Semantic errors (invalid type references, broken browse paths, duplicate anchors, illegal optionals) appear ~500 ms after you stop typing.

✅ Context-aware completions

Press Space, :, - or / to trigger completions. The server understands the OPC UA address space and offers relevant suggestions for every field:

Field	What you get
typeDefinition:	All non-abstract ObjectTypes and VariableTypes in the address space
subtypeOf:	Types filtered by the enclosing section kind (objectTypes, variableTypes, etc.)
dataType:	All 23 OPC UA scalar primitives + your custom structure types
optionals: / promotedToMandatory:	Optional members of the enclosing type
organizedBy: / componentOf: / propertyOf:	Valid browse paths in the virtual node tree
initializers: variable:	Initializable variable paths with data types and enum values
interfaces:	All available InterfaceTypes

Local document types always appear first in completion lists (sorted with a ! prefix).

✅ Hover documentation

Hover over an initializers: variable: path to see:

• The DataType of that variable
• For enumerations: the list of valid enum values with their numeric codes

✅ Quick-fix code actions

When a organizedBy: (or similar placement) path is invalid, a 💡 lightbulb appears. Click it to get:

• Replace with <best-match> — automatically substitutes the closest valid path (Levenshtein distance ≤ 3)
• Remove invalid path — deletes the entry

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Extension settings

Open VS Code settings (Ctrl+,) and search for opcuaModeler:

Setting	Default	Description
opcuaModeler.useCli	true	When true, uses opcua-modeler lsp --stdio as the server process. When false, uses the bundled Node IPC server.
opcuaModeler.serverPath	(auto)	Full path to the opcua-modeler CLI binary. Leave empty to use the binary found in PATH.
opcuaModeler.trace.server	"off"	LSP trace level: "off" / "messages" / "verbose". Use "verbose" for debugging.

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Status bar

The extension adds a small indicator to the VS Code status bar (bottom-left):

State	Indicator
Starting…	⟳ OPC UA Modeler
Ready	✓ OPC UA Modeler
Error	✗ OPC UA Modeler (click for details)

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Commands

Open the Command Palette (Ctrl+Shift+P) and search for:

Command	Description
OPC UA Modeler: Restart Language Server	Force-restarts the LSP server process. Useful after updating opcua-modeler.

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Troubleshooting

Completions / diagnostics not working?

1. Check the status bar indicator — if it shows ✗, click it to open the Output panel.
2. Make sure opcua-modeler is installed and accessible in your PATH:

   opcua-modeler version

3. If using a custom binary path, verify opcuaModeler.serverPath is correct.
4. Try OPC UA Modeler: Restart Language Server from the Command Palette.
5. Set opcuaModeler.trace.server to "verbose" and inspect the Output → OPC UA Modeler channel.