# Custom models in Neptune ML
<a name="machine-learning-custom-models"></a>

**Note**  
Neptune ML custom model support relies on an older version of Python 3. To create and run custom GNN models with up-to-date dependencies use [GraphStorm on SageMaker](https://graphstorm.readthedocs.io/en/v0.3.1/cli/model-training-inference/distributed/sagemaker.html).  
[Real-time inductive inference](machine-learning-overview-evolving-data.md#inductive-vs-transductive-inference) is not currently supported for custom models.

Neptune ML lets you define your own custom model implementations using Python. You can train and deploy custom models using Neptune ML infrastructure very much as you do for the built-in models, and use them to obtain predictions through graph queries.

You can start implementing a custom model of your own in Python by following the [Neptune ML toolkit examples](https://github.com/awslabs/neptuneml-toolkit/tree/main/examples/custom-models/), and by using the model components provided in the Neptune ML toolkit. The following sections provide more details.

**Contents**
+ [Overview of custom models in Neptune ML](machine-learning-custom-model-overview.md)
  + [When to use a custom model in Neptune ML](machine-learning-custom-model-overview.md#machine-learning-custom-models-when-to-use)
  + [Workflow for developing and using a custom model in Neptune ML](machine-learning-custom-model-overview.md#machine-learning-custom-model-workflow)
+ [Custom model development in Neptune ML](machine-learning-custom-model-development.md)
  + [Custom model training script development in Neptune ML](machine-learning-custom-model-development.md#machine-learning-custom-model-training-script)
  + [Custom model transform script development in Neptune ML](machine-learning-custom-model-development.md#machine-learning-custom-model-transform-script)
  + [Custom `model-hpo-configuration.json` file in Neptune ML](machine-learning-custom-model-development.md#machine-learning-custom-model-hpo-configuration-file)
  + [Local testing of your custom model implementation in Neptune ML](machine-learning-custom-model-development.md#machine-learning-custom-model-testing)