AWS::Cognito::UserPoolUser - AWS CloudFormation


The AWS::Cognito::UserPoolUser resource creates an Amazon Cognito user pool user.


To declare this entity in your AWS CloudFormation template, use the following syntax:


{ "Type" : "AWS::Cognito::UserPoolUser", "Properties" : { "ClientMetadata" : Map, "DesiredDeliveryMediums" : List, "ForceAliasCreation" : Boolean, "MessageAction" : String, "UserAttributes" : List, "Username" : String, "UserPoolId" : String, "ValidationData" : List } }


Type: AWS::Cognito::UserPoolUser Properties: ClientMetadata: Map DesiredDeliveryMediums: List ForceAliasCreation: Boolean MessageAction: String UserAttributes: List Username: String UserPoolId: String ValidationData: List



A map of custom key-value pairs that you can provide as input for the custom workflow that is invoked by the pre sign-up trigger.

You create custom workflows by assigning AWS Lambda functions to user pool triggers. When you create a UserPoolUser resource and include the ClientMetadata property, Amazon Cognito invokes the function that is assigned to the pre sign-up trigger. When Amazon Cognito invokes this function, it passes a JSON payload, which the function receives as input. This payload contains a clientMetadata attribute, which provides the data that you assigned to the ClientMetadata property. In your function code in AWS Lambda, you can process the clientMetadata value to enhance your workflow for your specific needs.

For more information, see Customizing User Pool Workflows with Lambda Triggers in the Amazon Cognito Developer Guide.


Take the following limitations into consideration when you use the ClientMetadata parameter:

  • Amazon Cognito does not store the ClientMetadata value. This data is available only to AWS Lambda triggers that are assigned to a user pool to support custom workflows. If your user pool configuration does not include triggers, the ClientMetadata parameter serves no purpose.

  • Amazon Cognito does not validate the ClientMetadata value.

  • Amazon Cognito does not encrypt the the ClientMetadata value, so don't use it to provide sensitive information.

Required: No

Type: Map of String

Update requires: Replacement


Specify "EMAIL" if email will be used to send the welcome message. Specify "SMS" if the phone number will be used. The default value is "SMS". You can specify more than one value.

Required: No

Type: List of String

Update requires: Replacement


This parameter is used only if the phone_number_verified or email_verified attribute is set to True. Otherwise, it is ignored.

If this parameter is set to True and the phone number or email address specified in the UserAttributes parameter already exists as an alias with a different user, the API call will migrate the alias from the previous user to the newly created user. The previous user will no longer be able to log in using that alias.

If this parameter is set to False, the API throws an AliasExistsException error if the alias already exists. The default value is False.

Required: No

Type: Boolean

Update requires: Replacement


Set to RESEND to resend the invitation message to a user that already exists and reset the expiration limit on the user's account. Set to SUPPRESS to suppress sending the message. You can specify only one value.

Required: No

Type: String

Allowed values: RESEND | SUPPRESS

Update requires: Replacement


The user attributes and attribute values to be set for the user to be created. These are name-value pairs You can create a user without specifying any attributes other than Username. However, any attributes that you specify as required (in or in the Attributes tab of the console) must be supplied either by you (in your call to AdminCreateUser) or by the user (when they sign up in response to your welcome message).

For custom attributes, you must prepend the custom: prefix to the attribute name.

To send a message inviting the user to sign up, you must specify the user's email address or phone number. This can be done in your call to AdminCreateUser or in the Users tab of the Amazon Cognito console for managing your user pools.

In your call to AdminCreateUser, you can set the email_verified attribute to True, and you can set the phone_number_verified attribute to True. (You can also do this by calling

  • email: The email address of the user to whom the message that contains the code and user name will be sent. Required if the email_verified attribute is set to True, or if "EMAIL" is specified in the DesiredDeliveryMediums parameter.

  • phone_number: The phone number of the user to whom the message that contains the code and user name will be sent. Required if the phone_number_verified attribute is set to True, or if "SMS" is specified in the DesiredDeliveryMediums parameter.

Required: No

Type: List of AttributeType

Update requires: Replacement


The value that you want to set as the username sign-in attribute. The following conditions apply to the username parameter.

  • The username can't be a duplicate of another username in the same user pool.

  • You can't change the value of a username after you create it.

  • You can only provide a value if usernames are a valid sign-in attribute for your user pool. If your user pool only supports phone numbers or email addresses as sign-in attributes, Amazon Cognito automatically generates a username value. For more information, see Customizing sign-in attributes.

Required: No

Type: String

Update requires: Replacement


The user pool ID for the user pool where the user will be created.

Required: Yes

Type: String

Minimum: 1

Maximum: 55

Pattern: [\w-]+_[0-9a-zA-Z]+

Update requires: Replacement


Temporary user attributes that contribute to the outcomes of your pre sign-up Lambda trigger. This set of key-value pairs are for custom validation of information that you collect from your users but don't need to retain.

Your Lambda function can analyze this additional data and act on it. Your function might perform external API operations like logging user attributes and validation data to Amazon CloudWatch Logs. Validation data might also affect the response that your function returns to Amazon Cognito, like automatically confirming the user if they sign up from within your network.

For more information about the pre sign-up Lambda trigger, see Pre sign-up Lambda trigger.

Required: No

Type: List of AttributeType

Update requires: Replacement

Return values


When you pass the logical ID of this resource to the intrinsic Ref function, Ref returns the name of the user. For example: admin.

For more information about using the Ref function, see Ref.