Author requirements, architecture, interfaces, calculations, and verification as plain text that lives in Git — readable, diffable, and fast — with a 100% mapping to KerML and the SysML v2 API.
Documentation → deal-lang.org · Get started · Language reference
Digital engineering promises a single source of truth, but today's graphical, binary, GUI-bound MBSE tools fight you for it:
- Sync is fragile — requirements in DOORS, architecture in Cameo, interfaces in spreadsheets, verification in test tools, all drifting apart.
- Versioning is an afterthought — binary model files don't diff, don't merge, and don't fit the workflows software solved decades ago.
- GUIs don't scale — what takes a line of text takes a dozen clicks, and none of it is scriptable.
DEAL treats the system model as code: plain-text .deal / .dealx / .dealview files that compile to SysML v2 JSON and ReqIF, live in Git, diff cleanly, and run through CI. It isn't a replacement for SysML v2 — it's the authoring surface for it.
The compiler and CLI are real and exercised by the test suite:
deal parse tokenize + parse .deal/.dealx → AST JSON
deal check semantic + dimensional analysis (+ --verify against evidence)
deal fmt format in place
deal build generate SysML v2 JSON or a ReqIF archive
deal init scaffold a new project
deal install resolve deal.toml dependencies → deal.lock
deal simulate run simulations registered in deal.sims.toml
deal evidence capture and manage verification evidence
This includes the behavioral surface — actions and state machines (succession flows, decisions, fork/join, loops, send/accept/assign, transitions, entry/do/exit) parse, type-check, format, and emit as OMG-schema-valid SysML v2.
| Repository | What it is | License |
|---|---|---|
| deal | Core compiler — a Zig engine (libdeal.a) with a Rust CLI and LSP server |
Apache-2.0 |
| spec | Language specification, EBNF grammar, and the showcase corpus | MIT |
| deal-stdlib | Standard library — units, base types, and math | — |
| deal-lang.org | Documentation site, deal-lang.org | Apache-2.0 |
The parser, semantic analyzer, formatter, IR, SysML v2 / ReqIF backends, the
calc / constraint surface, project and dependency tooling, and the
simulation-evidence pipeline are implemented and gated by the test suite. The
behavioral surface (actions + state machines) is complete through SysML v2
emission. Next up: the editor-first platform — a desktop editor, import
pipelines, and documentation generation.
DEAL is pre-release and built from source today (Zig 0.16 + Rust). See the installation guide to get going.
Each repository is licensed individually (see the badges above). The core compiler and documentation site are Apache-2.0; the specification is MIT.