clientMetadata

One or more key-value pairs that you can provide as custom input to the Lambda function that you specify for the post authentication trigger.

Cognito.swift:127
let clientMetadata: [String : String]?

To pass this data to your Lambda function, you can use the ClientMetadata parameter in the AdminRespondToAuthChallenge and RespondToAuthChallenge API actions. Amazon Cognito doesn’t include data from the ClientMetadata parameter in AdminInitiateAuth and InitiateAuth API operations in the request that it passes to the post authentication function.