ml-agents README

The project's README from github.com/Unity-Technologies/ml-agents. As one markdown file: README.md.

Unity ML-Agents Toolkit

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The Unity Machine Learning Agents Toolkit (ML-Agents) is an open-source project that enables games and simulations to serve as environments for training intelligent agents. We provide implementations (based on PyTorch) of state-of-the-art algorithms to enable game developers and hobbyists to easily train intelligent agents for 2D, 3D and VR/AR games. Researchers can also use the provided simple-to-use Python API to train Agents using reinforcement learning, imitation learning, neuroevolution, or any other methods. These trained agents can be used for multiple purposes, including controlling NPC behavior (in a variety of settings such as multi-agent and adversarial), automated testing of game builds and evaluating different game design decisions pre-release. The ML-Agents Toolkit is mutually beneficial for both game developers and AI researchers as it provides a central platform where advances in AI can be evaluated on Unity’s rich environments and then made accessible to the wider research and game developer communities.

Features

Releases & Documentation

⚠️ Documentation Migration Notice We have moved to Unity Package documentation as the primary developer documentation and have deprecated the maintenance of web docs. Please use the Unity Package documentation for the most up-to-date information.

The table below shows our latest release, including our develop branch which is under active development and may be unstable. A few helpful guidelines:

Version Release Date Source Documentation Download Python Package Unity Package
Release 23 August 28, 2025 source docs download 1.1.0 4.0.0
develop (unstable) -- source docs download -- --

If you are a researcher interested in a discussion of Unity as an AI platform, see a pre-print of our reference paper on Unity and the ML-Agents Toolkit.

If you use Unity or the ML-Agents Toolkit to conduct research, we ask that you cite the following paper as a reference:

@article{juliani2020,
  title={Unity: A general platform for intelligent agents},
  author={Juliani, Arthur and Berges, Vincent-Pierre and Teng, Ervin and Cohen, Andrew and Harper, Jonathan and Elion, Chris and Goy, Chris and Gao, Yuan and Henry, Hunter and Mattar, Marwan and Lange, Danny},
  journal={arXiv preprint arXiv:1809.02627},
  url={https://arxiv.org/pdf/1809.02627.pdf},
  year={2020}
}

Additionally, if you use the MA-POCA trainer in your research, we ask that you cite the following paper as a reference:

@article{cohen2022,
  title={On the Use and Misuse of Absorbing States in Multi-agent Reinforcement Learning},
  author={Cohen, Andrew and Teng, Ervin and Berges, Vincent-Pierre and Dong, Ruo-Ping and Henry, Hunter and Mattar, Marwan and Zook, Alexander and Ganguly, Sujoy},
  journal={RL in Games Workshop AAAI 2022},
  url={http://aaai-rlg.mlanctot.info/papers/AAAI22-RLG_paper_32.pdf},
  year={2022}
}

Additional Resources

Community and Feedback

The ML-Agents Toolkit is an open-source project and we encourage and welcome contributions. If you wish to contribute, be sure to review our contribution guidelines and code of conduct.

For problems with the installation and setup of the ML-Agents Toolkit, or discussions about how to best setup or train your agents, please create a new thread on the Unity ML-Agents discussion forum. Be sure to include as many details as possible to help others assist you effectively. If you run into any other problems using the ML-Agents Toolkit or have a specific feature request, please submit a GitHub issue.

Please tell us which samples you would like to see shipped with the ML-Agents Unity package by replying to this discussion thread.

Privacy

In order to improve the developer experience for Unity ML-Agents Toolkit, we have added in-editor analytics. Please refer to "Information that is passively collected by Unity" in the Unity Privacy Policy.

ml-agents (Unity-Technologies/ml-agents)

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19.8K ·GitHub
What is this?Unity ML-Agents Toolkit lets Unity games and simulations act as training environments for AI agents, using deep reinforcement learning and imitation learning. It pairs a Unity SDK with a Python API so game developers and researchers can train NPCs, test builds, or evaluate design decisions.
Is this a Unity package, a Python library, or both?Both - a flexible Unity SDK that gets integrated into your game or custom Unity scene, paired with a Python package that runs the actual RL/IL training and talks to the Unity environment over the Python API.
How do I get it running in my project?Add the com.unity.ml-agents Unity package (verified for Unity 2020.1+) via the Unity Package Manager, then install the matching mlagents Python package to run trainers against your scene, following the current Unity Package documentation for the latest release.
Do I need Python and PyTorch set up separately?Yes - training runs through a separate Python package with PyTorch-based implementations of the algorithms (PPO, SAC, MA-POCA, BC, GAIL), distinct from the C# Unity-side SDK.
Are the old web docs still the way to go?No - the project has deprecated the web docs; the Unity Package documentation is now the primary, up-to-date source, and the develop branch is explicitly called out as unstable.
Is this aimed at game developers, researchers, or both?Both - game devs get tools for NPC behavior, automated build testing, and design evaluation, while researchers get a simple Python API to try RL, imitation learning, neuroevolution, or their own custom algorithms on Unity's environments.
Does the toolkit send any data back to Unity?Yes - the Unity package includes in-editor analytics to improve developer experience, governed by Unity's general privacy policy.
Which RL and imitation learning algorithms come built in?PPO, SAC and MA-POCA for reinforcement learning (including self-play and cooperative/competitive multi-agent setups), plus BC and GAIL for imitation learning from demonstrations.
Can I use the Unity environments outside the native ML-Agents workflow?Yes - you can wrap a Unity learning environment as a Gym environment or as a PettingZoo environment to plug into other RL libraries.
Are there example environments to learn from?Yes - the toolkit ships 17+ example Unity environments covering single-agent, cooperative and competitive multi-agent training scenarios.
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