# About ML-Agents Extensions package (`com.unity.ml-agents.extensions`) The Unity ML-Agents Extensions package contains optional add-ons to the C# SDK for the [Unity ML-Agents Toolkit](https://github.com/Unity-Technologies/ml-agents). These extensions are all considered experimental, and their API or behavior may change between versions. ## Package contents The following table describes the package folder structure: | **Location** | **Description** | | ---------------- | ---------------------------------------------------------------------- | | _Documentation~_ | Contains the documentation for the Unity package. | | _Editor_ | Contains utilities for Editor windows and drawers. | | _Runtime_ | Contains core C# APIs for integrating ML-Agents into your Unity scene. | | _Tests_ | Contains the unit tests for the package. | The Runtime directory currently contains three features: * [Match-3 sensor and actuator](Match3.md) * [Grid-based sensor](Grid-Sensor.md) * Physics-based sensors * [Input System Package Integration](InputActuatorComponent.md) ## Installation The ML-Agents Extensions package is not currently available in the Package Manager. There are two recommended ways to install the package: ### Local Installation [Clone the repository](https://github.com/Unity-Technologies/ml-agents/tree/release_16_docs/docs/Installation.md#clone-the-ml-agents-toolkit-repository-optional) and follow the [Local Installation for Development](https://github.com/Unity-Technologies/ml-agents/tree/release_16_docs/docs/Installation.md#advanced-local-installation-for-development-1) directions (substituting `com.unity.ml-agents.extensions` for the package name). ### Github via Package Manager In Unity 2019.4 or later, open the Package Manager, hit the "+" button, and select "Add package from git URL". ![Package Manager git URL](https://github.com/Unity-Technologies/ml-agents/blob/release_16_docs/docs/images/unity_package_manager_git_url.png) In the dialog that appears, enter ``` git+https://github.com/Unity-Technologies/ml-agents.git?path=com.unity.ml-agents.extensions#release_16 ``` You can also edit your project's `manifest.json` directly and add the following line to the `dependencies` section: ``` "com.unity.ml-agents.extensions": "git+https://github.com/Unity-Technologies/ml-agents.git?path=com.unity.ml-agents.extensions#release_16", ``` See [Git dependencies](https://docs.unity3d.com/Manual/upm-git.html#subfolder) for more information. Note that this may take several minutes to resolve the packages the first time that you add it. ## Requirements This version of the Unity ML-Agents package is compatible with the following versions of the Unity Editor: - 2019.4 and later If using the `InputActuatorComponent` - install the `com.unity.inputsystem` package version `1.1.0-preview.3` or later. ## Known Limitations - For the `InputActuatorComponent` - Limited implementation of `InputControls` - No way to customize the action space of the `InputActuatorComponent` ## Need Help? The main [README](https://github.com/Unity-Technologies/ml-agents/tree/release_16_docs/README.md) contains links for contacting the team or getting support.