# Testing and debugging

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This page was generated from content adapted from the [AWS Developer Guide](https://github.com/awsdocs/aws-sam-developer-guide.git)
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## Invoking functions locally

* **Note**\
  The sam local invoke command corresponds to the AWS Command Line Interface (AWS CLI) command <https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/invoke.html>. You can use either command to invoke a Lambda function.

## Running API Gateway locally

* **Note**\
  \&#xNAN;*Hot reloading* is when only the files that changed are refreshed, and the state of the application remains the same. In contrast, *live reloading* is when the entire application is refreshed, and the state of the application is lost.

## Step-through debugging Lambda functions locally

* **Note**\
  If you're using `sam local start-api`, the local API Gateway instance exposes all of your Lambda functions. However, because you can specify a single debug port, you can only debug one function at a time. You need to call your API before the AWS SAM CLI binds to the port, which allows the debugger to connect.