SysML v2 Editor

Spec42: SysML v2 Language Support

This extension adds SysML v2 (and KerML) language support to VS Code, powered by Spec42 (spec42).

If you work with MBSE and want fast feedback while editing models, this extension provides IDE features like diagnostics, navigation, and completions across your workspace and (optionally) your library sources.

Highlights

Language Server Protocol (LSP) features for .sysml and .kerml
Workspace-aware: features work across your whole workspace, not just the active file
Library indexing: point the extension to library roots (for example the SysML v2 release repo) for richer navigation and completion
Bundled server binary in published builds (with a safe fallback to spec42 on your PATH)
Syntax highlighting for SysML v2 / KerML

Features

Diagnostics: syntax/validation feedback as you type
Hover: quick info on symbols
Completion: suggestions while editing
Navigation: go to definition, find references, rename
Symbols: document symbols and workspace symbol search
Code actions & formatting: where supported by the server

Getting started

Install the extension.
Open any .sysml or .kerml file.
(Optional) Configure library roots for better cross-file navigation and completion.

Configuration

This extension contributes the following settings:

spec42.serverPath
- Path to the spec42 binary.
- Default: "spec42"
- Notes:
  - In published builds, the extension will try to use a bundled server when serverPath is left at the default.
  - Set an absolute path (or workspace-relative path) if you want to use a custom build.
spec42.libraryPaths
- An array of paths to library roots (absolute or workspace-relative).
- Files under these paths are indexed for hover, go-to-definition, and completion.

Example settings.json:

{
  "spec42.libraryPaths": [
    "../SysML-v2-Release",
    "./my-company-sysml-library"
  ]
}

Troubleshooting

The server can’t be started
- If the bundled server isn’t available for your platform/arch (or you’re using a dev build), install spec42 separately and ensure it’s on your PATH, or set spec42.serverPath to the binary location.
Libraries don’t resolve
- Make sure each entry in spec42.libraryPaths points to the root folder(s) that contain the library sources (and that the paths are correct relative to the opened workspace).

Elan8