“It is often said that if something can be described, then it can be automated.
The problem is that describing something is a very complex matter.”

Rhetor

Rhetor is an Integrated Modelling Environment for modelling and solving mixed-integer linear programming problems. Rhetor supports a subset of the Optimisation Programming Language (OPL) syntax and it is built on pyopl, a Python library for parsing and solving OPL-like mathematical programming models using Gurobi or Scipy (Highs). Rhetor integrates GenAI features to support and automate the modelling process.

Installation & start

Install:

pip install rhetor

Start Rhetor:

pyopl

To enable GenAI features, set at least one of the following environment variables before starting Rhetor:

OPENAI_API_KEY — for OpenAI models
GEMINI_API_KEY — for Google Gemini

or install and run ollama locally.

Example (macOS / bash):

export OPENAI_API_KEY="sk-..."

Alternatively, you can use rhetor in Jupyter notebook:

Documentation and examples

Rhetor embeds GenAI features that support the modelling process: features can be explored within the system in a conversational fashion. A complete user guide and examples for PyOPL are available at:

Social media posts

A selection of LinkedIn posts about Rhetor is available below.

License

Rhetor is released under the MIT License.

Citation

Rossi, R. & Prestwich, S. D. (2026).
Grammar-Aware Literate Generative Mathematical Programming with Compiler-in-the-Loop.
arXiv:2601.17670 [cs.PL].

@misc{rossi2026grammarawareliterategenerativemathematical,
            title={Grammar-Aware Literate Generative Mathematical Programming with Compiler-in-the-Loop}, 
            author={Roberto Rossi and Steven D. Prestwich},
            year={2026},
            eprint={2601.17670},
            archivePrefix={arXiv},
            primaryClass={cs.PL},
            url={https://arxiv.org/abs/2601.17670}, 
          }