openPASO

open Platform for Agentic Simulation and Optimization

Describe a physics problem in plain words.
An AI model picks a solver, writes its input, runs it, and checks the answer.

_{Click the film to watch it in full quality on the documentation website.}

[!WARNING]
openPASO is under active development, and we invite you to help. It works and is used for
real simulations, but it is young: things change quickly and you will find rough edges. Try it,
tell us what broke, and share what you know about a solver.
See Contribute.

What it does

Simulation programs, called solvers, compute how things physically behave: how a part bends,
how heat spreads, how air flows. They are powerful and hard to use, and each one has its own input
format and its own traps. openPASO puts nine of them behind one door and lets an AI model open
it: you describe what you want in a normal sentence, and the model picks a solver, writes the input,
runs it, and checks that the answer is computed correctly.

Quick start

You need Python 3.10–3.13 and about ten minutes. One solver is enough to begin.

git clone https://github.com/Hereon-InstituteMS/openPASO.git
cd openPASO
python3 -m venv .venv && source .venv/bin/activate
pip install -e . scikit-fem
python check_install.py          # no key, no network: shows which solvers openPASO can use

Then connect an AI model, one of two ways:

• Option A — an AI app you already have (Claude Code, Claude Desktop, Cursor): no extra cost.
  Set it up →
• Option B — your own OpenRouter key: one command per simulation, any model.
  Set it up →

Solvers

Documentation

Everything else is on the documentation website:
installing each solver, both ways of use step by step, all 24 tools the model gets, how openPASO
checks an answer, coupling two solvers on one problem, troubleshooting, and a glossary for every word.

Contribute

Reports of what did not work, solver traps you know, and plain-language fixes to the documentation
are all very welcome. One rule stands above the rest: every improvement must help all simulations,
not one example. See CONTRIBUTING.md and the
Contribute page.

Licence and citation

MIT licence. openPASO was first published as OASiS; the archived releases and the paper use that
name. If you use openPASO in research, please cite:

@software{openpaso2026,
  title  = {openPASO: an open-source multi-physics and multi-code framework
            for verified computer simulations},
  author = {Hermann, Alexander and Shojaei, Arman and Scheider, Ingo and Cyron, Christian},
  year   = {2026},
  doi    = {10.5281/zenodo.20543501},
  url    = {https://github.com/Hereon-InstituteMS/openPASO}
}

_{Helmholtz-Zentrum Hereon · Institute of Materials Mechanics  ·  Hamburg University of Technology}