sim

sim reads existing CAE files and turns them into structured text an agent can use — without launching the solver.

Python 3.10+ · Apache-2.0 · alpha

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Scan existing simulation assets

Point sim scan at a folder of .mph / .inp / .cas.h5 / .aedt files and get back structured JSON an agent can reason over — model inventory, materials, boundary conditions, mesh counts, solve settings. No solver, no license, and nothing else to install:

uv init                  # only if this is not already a uv project
uv add sim-cli-core
uv run sim --json scan ./historical-cases

$ uv run sim --json scan ./cases/beam.inp --full
{
  "schema_version": "sim.scan/v1",
  "assets": [{
    "file_name": "beam.inp",
    "format": "abaqus-inp",
    "summary": {"data": {
      "title": "Cantilever beam thermal-stress",
      "node_count": 3,
      "element_count": 1,
      "materials": ["STEEL"],
      "sections": ["SOLID SECTION:STEEL"],
      "steps": ["STATIC"],
      "boundary_keywords": ["BOUNDARY"],
      "load_keywords": ["CLOAD"],
      "output_keywords": ["NODE PRINT"]
    }}
  }]
}

(abridged — the real envelope also carries ok, engine, request, and a roll-up summary block.)

Solver	Files	--format id
COMSOL	.mph	comsol-mph
Abaqus	.inp, .inc	abaqus-inp
Fluent	.cas.h5, .msh.h5	fluent-hdf5
Ansys Electronics Desktop (HFSS / Icepak)	.aedt, .aedtz	hfss-aedt
Ansys Mechanical	.mechdb, .mechdat	ansys-mechanical
Icepak Classic	.tzr	icepak-tzr
Simcenter FloTHERM	.pack, .xml, .floxml	flotherm-pack, flotherm-floxml
Simulink	.slx, .mdl	simulink-slx, simulink-mdl
MATLAB data	.mat	matlab-mat

The default view is bounded — lists come back as {total, sample, truncated} so a large scan cannot blow up an agent's context — and absolute paths are redacted unless --include-paths is set. Use --full for the complete parser result on a small input set, --limit and --no-recursive to bound a directory walk, and --format to force a format for an explicitly named file.

Every command takes --json and returns a stable envelope with a closed error-code enum — see docs/agent-readability.md. Run uv run sim --json describe for a machine-readable command manifest.

Example: what's in this folder?

Scan ./legacy-cases and tell me which models are package-level thermal
studies, which already have solved results, and what total power each one
assumes. Use `uv run sim --json scan`.

Optional: working with a local solver

Scanning never needs a solver. If an agent also has to detect solver installs, lint a script before running it, or keep a solver session open, add that solver's package (for example sim-plugin-comsol) and its agent skill:

uv add sim-plugin-comsol
uv run sim plugin sync-skills --target .agents/skills --copy   # .claude/skills for Claude Code
uv run sim check comsol

The supported solvers, install commands, live-session commands, and the sim.toml manifest are covered in docs/plugin-install.md. Running the solver on another host is covered in docs/remote-solvers.md.

Solver ownership

sim-cli does not bundle or redistribute simulation solvers or vendor SDKs. Install and operate each underlying solver according to its vendor terms. See NOTICE for optional SDK dependency notes.

sim-cli is an independent open-source project and is not affiliated with, endorsed by, or sponsored by any solver vendor. Product, solver, and company names remain the property of their respective owners.

Docs

• docs/agent-readability.md — --json envelope, error-code enum, exit codes. Read this first if you are an agent.
• docs/plugin-install.md — optional solver packages, live sessions, and the sim.toml reference
• docs/remote-solvers.md — running the solver on another host, and the security constraints that apply
• docs/DEVELOPMENT.md — project setup, layout, driver protocol, and architecture notes
• docs/why-cli-first.md — why a CLI rather than MCP
• CONTRIBUTING.md — branch, test, and PR workflow

License

Apache-2.0 — see LICENSE.