<p>A map of custom key-value pairs that you can provide as input for any custom workflows that this action triggers.</p> <p>You create custom workflows by assigning Lambda functions to user pool triggers. When you use the ConfirmSignUp API action, Amazon Cognito invokes the function that is assigned to the <i>post confirmation</i> trigger. When Amazon Cognito invokes this function, it passes a JSON payload, which the function receives as input. This payload contains a <code>clientMetadata</code> attribute, which provides the data that you assigned to the ClientMetadata parameter in your ConfirmSignUp request. In your function code in Lambda, you can process the <code>clientMetadata</code> value to enhance your workflow for your specific needs.</p> <p>For more information, see <a href="https://docs.aws.amazon.com/cognito/latest/developerguide/cognito-user-identity-pools-working-with-aws-lambda-triggers.html"> Customizing user pool Workflows with Lambda Triggers</a> in the <i>Amazon Cognito Developer Guide</i>.</p> <note> <p>When you use the ClientMetadata parameter, remember that Amazon Cognito won't do the following:</p> <ul> <li> <p>Store the ClientMetadata value. This data is available only to Lambda triggers that are assigned to a user pool to support custom workflows. If your user pool configuration doesn't include triggers, the ClientMetadata parameter serves no purpose.</p> </li> <li> <p>Validate the ClientMetadata value.</p> </li> <li> <p>Encrypt the ClientMetadata value. Don't use Amazon Cognito to provide sensitive information.</p> </li> </ul> </note>