# Challenge
<a name="API_Challenge"></a>

Describes the type and version of the challenge being used for the Face Liveness session.

## Contents
<a name="API_Challenge_Contents"></a>

 ** Type **   <a name="rekognition-Type-Challenge-Type"></a>
The type of the challenge being used for the Face Liveness session.  
Type: String  
Valid Values: `FaceMovementAndLightChallenge | FaceMovementChallenge`   
Required: Yes

 ** Version **   <a name="rekognition-Type-Challenge-Version"></a>
The version of the challenge being used for the Face Liveness session.  
Type: String  
Length Constraints: Minimum length of 5. Maximum length of 11.  
Pattern: `^(0|[1-9]\d{0,2})\.(0|[1-9]\d{0,2})\.(0|[1-9]\d{0,2})$`   
Required: Yes

## See Also
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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/rekognition-2016-06-27/Challenge) 
+  [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/rekognition-2016-06-27/Challenge) 
+  [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/rekognition-2016-06-27/Challenge)