What sysml-rs is (and is not)

sysml-rs is a Rust implementation of the OMG SysML v2 specification: an incremental parser, a semantic model, an execution and physics runtime, and the tooling that sits on top — a CLI, a language server, REST and MCP services, a VS Code extension, and a desktop workbench.

Text goes in and a queryable, executable model comes out. The pipeline is source → tree-sitter CST → semantic graph → name resolution and validation → execution, queries, and diagrams, and every transport (CLI, LSP, HTTP, MCP) dispatches through the same service layer, so the same operation behaves identically everywhere.

What it is not

sysml-rs implements a substantial subset of SysML v2, tracked against the OMG specification. It is not a complete or certified implementation, it has not been through any OMG conformance process, and it makes no conformance claim. Expect constructs that do not parse yet, semantics implemented for the common cases but not every corner, and interfaces that change without a deprecation period while the version stays 0.x.

It is useful today for reading, checking, querying, and executing models you write against the subset it supports. It is not ready to be the system of record for a programme you cannot afford to migrate.

Where it is rough

• Language coverage is partial. The grammar is derived from the OMG Xtext grammars, but not every production is wired through to full semantics. Unsupported syntax surfaces as a parse diagnostic rather than silently doing something else.
• The execution runtime is the youngest part. Continuous dynamics, hybrid models, and verification cases work on the repository examples, which the regression suite locks down. Novel model shapes will find gaps.
• The desktop workbench and diagram surfaces are in active rework. The CLI and LSP are the stable surfaces.
• No stable Rust API yet. Workspace crates are not on crates.io and depend on each other by path.
• The HTTP API is a local development server. It binds loopback only and writes are unauthenticated unless a token is set; widening either is opt-in.

Where to go next

• Learn the language in the SysML v2 Book.
• Build the tool from source using the repository README quick start (a portal installation guide is on its way).
• Contribute via CONTRIBUTING.