# Creating custom rules using the Debugger client library
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You can create custom rules to monitor your training job using the Debugger rule APIs and the open source [`smdebug` Python library](https://github.com/awslabs/sagemaker-debugger/) that provide tools to build your own rule containers.

## Prerequisites for creating a custom rule
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To create Debugger custom rules, you need the following prerequisites.
+ [SageMaker Debugger Rule.custom API](https://sagemaker.readthedocs.io/en/stable/api/training/debugger.html#sagemaker.debugger.Rule.custom)
+ [The open source smdebug Python library](https://github.com/awslabs/sagemaker-debugger/)
+ Your own custom rule python script
+ [Amazon SageMaker Debugger image URIs for custom rule evaluators](debugger-reference.md#debuger-custom-rule-registry-ids)

**Topics**
+ [Prerequisites for creating a custom rule](#debugger-custom-rules-prerequisite)
+ [Use the `smdebug` client library to create a custom rule as a Python script](debugger-custom-rules-python-script.md)
+ [Use the Debugger APIs to run your own custom rules](debugger-custom-rules-python-sdk.md)