API ReferenceAWSCognitoIdentityICognitoIdentityMergeDeveloperIdentitiesResponseOn this pageICognitoIdentityMergeDeveloperIdentitiesResponseInterface in AWS.CognitoIdentity Interface for MergeDeveloperIdentities responses. Ancestors ICognitoIdentityResponse Properties IdentityId property IdentityId: string The unique identifier for the identity in the format REGION:GUID.