# Perform custom processing on CloudFormation templates with template macros
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With macros, you can perform custom processing on templates, from simple actions like find-and-replace operations to extensive transformations of entire templates.

To get an idea of the breadth of possibilities, consider the `AWS::Include` and `AWS::Serverless` transforms, which are macros hosted by CloudFormation:
+ [AWS::Include transform](https://docs.amazonaws.cn/AWSCloudFormation/latest/TemplateReference/transform-aws-include.html) enables you to insert boilerplate template snippets into your templates.
+ [AWS::Serverless transform](https://docs.amazonaws.cn/AWSCloudFormation/latest/TemplateReference/transform-aws-serverless.html) takes an entire template written in the Amazon Serverless Application Model (Amazon SAM) syntax and transforms and expands it into a compliant CloudFormation template. For more information about serverless applications and Amazon SAM, see [Amazon Serverless Application Model Developer Guide](https://docs.amazonaws.cn/serverless-application-model/latest/developerguide/what-is-sam.html).

**Topics**
+ [Billing](#template-macros-billing)
+ [Macro examples](#template-macros-examples-list)
+ [Related resources](#template-macros-related-resources)
+ [Overview of CloudFormation macros](template-macros-overview.md)
+ [Create a CloudFormation macro definition](template-macros-author.md)
+ [Example simple string replacement macro](macros-example.md)
+ [Troubleshoot the processed template](template-macros-troubleshoot-processed-template.md)

## Billing
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When a macro runs, the owner of the Lambda function is billed for any charges related to the execution of that function.

The `AWS::Include` and `AWS::Serverless` transforms are macros hosted by CloudFormation. There is no charge for using them.

## Macro examples
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In addition to the examples in this section, you can find example macros, including source code and templates, in our [GitHub repository](https://github.com/aws-cloudformation/aws-cloudformation-templates/tree/main/CloudFormation/MacrosExamples). These examples are provided 'as-is' for instructional purposes.

## Related resources
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+ [https://docs.amazonaws.cn/AWSCloudFormation/latest/TemplateReference/aws-resource-cloudformation-macro.html](https://docs.amazonaws.cn/AWSCloudFormation/latest/TemplateReference/aws-resource-cloudformation-macro.html)
+ [CloudFormation template Transform section](transform-section-structure.md)
+ [https://docs.amazonaws.cn/AWSCloudFormation/latest/TemplateReference/intrinsic-function-reference-transform.html](https://docs.amazonaws.cn/AWSCloudFormation/latest/TemplateReference/intrinsic-function-reference-transform.html)
+ [AWS::Serverless transform](https://docs.amazonaws.cn/AWSCloudFormation/latest/TemplateReference/transform-aws-serverless.html)
+ [AWS::Include transform](https://docs.amazonaws.cn/AWSCloudFormation/latest/TemplateReference/transform-aws-include.html)