OMLT: Optimization & Machine Learning Toolkit readers may be interested in the OMLT (Optimization & Machine Learning Toolkit) open-source python package. Please see the below message sent from the team:

Dear colleagues,

We are writing to introduce the OMLT (Optimization & Machine Learning Toolkit) open-source python package, available at and on pypi (pip install omlt).

OMLT incorporates trained machine learning models (dense/convolutional neural networks and gradient-boosted trees) into pyomo optimization problems. Models can be input using ONNX, thereby implicitly supporting PyTorch, TensorFlow, etc. Moreover, many formulations are provided: reduced-space vs full-space, big-M vs other mixed-integer encodings, etc.

Our example jupyter notebooks include neural network verification, autothermal reformer optimization, and Bayesian optimization.

A preprint describing the package is available at Please do not hesitate to contact us with any questions!

Best regards,
The OMLT Team
(Francesco Ceccon, Jordan Jalving, Joshua Haddad, Alexander Thebelt, Calvin Tsay, Carl Laird, Ruth Misener)