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.

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

or you can use the Rhetor Skills and PyOPL MCP to integrate Rhetor with your favorite agentic workflow (e.g. Github Copilot).

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:

• User guide
• Gallery of examples
• Sample PyOPL models

A selection of LinkedIn posts about Rhetor is available below.

Rhetor is released under the MIT License.

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}, 
          }