# Parameter mapping for REST APIs in API Gateway
<a name="rest-api-parameter-mapping"></a>

**Note**  
If you are using an HTTP API, see [Transform API requests and responses for HTTP APIs in API Gateway](http-api-parameter-mapping.md).

In parameter mapping, you map request or response parameters. You can map parameters using parameter mapping expressions or static values. For a list of mapping expressions, see [Parameter mapping source reference for REST APIs in API Gateway](rest-api-parameter-mapping-sources.md). You can use parameter mapping in your integration request for proxy and non-proxy integrations, but to use parameter mapping for an integration response, you need a non-proxy integration.

For example, you can map the method request header parameter `puppies` to the integration request header parameter `DogsAge0`. Then, if a client sends the header `puppies:true` to your API, the integration request sends the request header `DogsAge0:true` to the integration endpoint. The following diagram shows the request lifecycle of this example.

![\[Diagram of API Gateway parameter mapping example for a request\]](http://docs.aws.amazon.com/apigateway/latest/developerguide/images/parameter-mapping-example1.png)


To create this example using API Gateway, see [Example 1: Map a method request parameter to an integration request parameter](request-response-data-mappings.md#request-response-data-mappings-example-1).

 As another example, you can also map the integration response header parameter `kittens` to the method response header parameter `CatsAge0`. Then, if the integration endpoint returns `kittens:false`, the client receives the header `CatsAge0:false`. The following diagram shows the request lifecycle of this example.

![\[Diagram of API Gateway parameter mapping example for a response\]](http://docs.aws.amazon.com/apigateway/latest/developerguide/images/parameter-mapping-example2.png)


**Topics**
+ [Parameter mapping examples for REST APIs in API Gateway](request-response-data-mappings.md)
+ [Parameter mapping source reference for REST APIs in API Gateway](rest-api-parameter-mapping-sources.md)