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<h1 align="center">openPASO</h1>
<p align="center"><b>open Platform for Agentic Simulation and Optimization</b></p>
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<a href="https://hereon-institutems.github.io/openPASO/"><img src="https://img.shields.io/badge/docs-website-FF6B4A?style=flat-square" alt="Documentation"></a>
<a href="LICENSE"><img src="https://img.shields.io/badge/license-MIT-64748B?style=flat-square" alt="MIT licence"></a>
<a href="https://www.python.org/"><img src="https://img.shields.io/badge/python-3.10--3.13-64748B?style=flat-square" alt="Python 3.10 to 3.13"></a>
<a href="https://doi.org/10.5281/zenodo.20543501"><img src="https://img.shields.io/badge/DOI-10.5281%2Fzenodo.20543501-64748B?style=flat-square" alt="DOI"></a>
<a href="https://hereon-institutems.github.io/openPASO/solvers/"><img src="https://img.shields.io/badge/solvers-9-FF6B4A?style=flat-square" alt="9 solvers"></a>
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<i>Describe a physics problem in plain words.<br>
An AI model picks a solver, writes its input, runs it, and checks the answer.</i>
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<a href="https://hereon-institutems.github.io/openPASO/">
<img src="docs/assets/openPASO_film.gif" alt="openPASO in 29 seconds: describe the physics, openPASO picks the solver, runs it, and checks the result against the literature" width="800">
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<br><sub>Click the film to watch it in full quality on the documentation website.</sub>
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> [!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](https://hereon-institutems.github.io/openPASO/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.
```bash
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 →](https://hereon-institutems.github.io/openPASO/use/ai-app/)
- **Option B — your own OpenRouter key**: one command per simulation, any model.
[Set it up →](https://hereon-institutems.github.io/openPASO/use/api-key/)
## Solvers
| | | |
|---|---|---|
| [scikit-fem](https://hereon-institutems.github.io/openPASO/solvers/skfem/) | [NGSolve](https://hereon-institutems.github.io/openPASO/solvers/ngsolve/) | [Kratos Multiphysics](https://hereon-institutems.github.io/openPASO/solvers/kratos/) |
| [DUNE-fem](https://hereon-institutems.github.io/openPASO/solvers/dune/) | [FEniCSx](https://hereon-institutems.github.io/openPASO/solvers/fenics/) | [deal.II](https://hereon-institutems.github.io/openPASO/solvers/dealii/) |
| [FEBio](https://hereon-institutems.github.io/openPASO/solvers/febio/) | [4C Multiphysics](https://hereon-institutems.github.io/openPASO/solvers/fourc/) | [SPARTA](https://hereon-institutems.github.io/openPASO/solvers/sparta/) |
## Documentation
Everything else is on the **[documentation website](https://hereon-institutems.github.io/openPASO/)**:
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](CONTRIBUTING.md) and the
[Contribute page](https://hereon-institutems.github.io/openPASO/contribute/).
## 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:
```bibtex
@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}
}
```
<p align="center">
<sub>Helmholtz-Zentrum Hereon · Institute of Materials Mechanics ·
Hamburg University of Technology</sub>
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