# Payload


Information needed to configure the payload.

By default, AWS IoT Events generates a standard payload in JSON for any action. This action payload contains all attribute-value pairs that have the information about the detector model instance and the event triggered the action. To configure the action payload, you can use `contentExpression`.

## Contents


 ** contentExpression **   <a name="iotevents-Type-Payload-contentExpression"></a>
The content of the payload. You can use a string expression that includes quoted strings (`'<string>'`), variables (`$variable.<variable-name>`), input values (`$input.<input-name>.<path-to-datum>`), string concatenations, and quoted strings that contain `${}` as the content. The recommended maximum size of a content expression is 1 KB.  
Type: String  
Length Constraints: Minimum length of 1.  
Required: Yes

 ** type **   <a name="iotevents-Type-Payload-type"></a>
The value of the payload type can be either `STRING` or `JSON`.  
Type: String  
Valid Values: `STRING | JSON`   
Required: Yes

## See Also


For more information about using this API in one of the language-specific AWS SDKs, see the following:
+  [AWS SDK for C\$1\$1](https://docs.aws.amazon.com/goto/SdkForCpp/iotevents-2018-07-27/Payload) 
+  [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/iotevents-2018-07-27/Payload) 
+  [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/iotevents-2018-07-27/Payload)