Calling this API causes a message to be sent to the end user with a confirmation code that is required to change the user's password. For the Username parameter, you can use the username or user alias. The method used to send the confirmation code is sent according to the specified AccountRecoverySetting. For more information, see Recovering User Accounts in the Amazon Cognito Developer Guide . If neither a verified phone number nor a verified email exists, an InvalidParameterException is thrown. To use the confirmation code for resetting the password, call ConfirmForgotPassword.


This action might generate an SMS text message. Starting June 1, 2021, US telecom carriers require you to register an origination phone number before you can send SMS messages to US phone numbers. If you use SMS text messages in Amazon Cognito, you must register a phone number with Amazon Pinpoint. Amazon Cognito uses the registered number automatically. Otherwise, Amazon Cognito users who must receive SMS messages might not be able to sign up, activate their accounts, or sign in.

If you have never used SMS text messages with Amazon Cognito or any other Amazon Web Service, Amazon Simple Notification Service might place your account in the SMS sandbox. In sandbox mode , you can send messages only to verified phone numbers. After you test your app while in the sandbox environment, you can move out of the sandbox and into production. For more information, see SMS message settings for Amazon Cognito user pools in the Amazon Cognito Developer Guide .

See also: AWS API Documentation

Request Syntax

response = client.forgot_password(
        'IpAddress': 'string',
        'EncodedData': 'string'
        'AnalyticsEndpointId': 'string'
        'string': 'string'
  • ClientId (string) --


    The ID of the client associated with the user pool.

  • SecretHash (string) -- A keyed-hash message authentication code (HMAC) calculated using the secret key of a user pool client and username plus the client ID in the message.
  • UserContextData (dict) --

    Contextual data about your user session, such as the device fingerprint, IP address, or location. Amazon Cognito advanced security evaluates the risk of an authentication event based on the context that your app generates and passes to Amazon Cognito when it makes API requests.

    • IpAddress (string) --

      The source IP address of your user's device.

    • EncodedData (string) --

      Encoded device-fingerprint details that your app collected with the Amazon Cognito context data collection library. For more information, see Adding user device and session data to API requests.

  • Username (string) --


    The user name of the user for whom you want to enter a code to reset a forgotten password.

  • AnalyticsMetadata (dict) --

    The Amazon Pinpoint analytics metadata that contributes to your metrics for ForgotPassword calls.

    • AnalyticsEndpointId (string) --

      The endpoint ID.

  • ClientMetadata (dict) --

    A map of custom key-value pairs that you can provide as input for any custom workflows that this action triggers.

    You create custom workflows by assigning Lambda functions to user pool triggers. When you use the ForgotPassword API action, Amazon Cognito invokes any functions that are assigned to the following triggers: pre sign-up , custom message , and user migration . When Amazon Cognito invokes any of these functions, 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 parameter in your ForgotPassword request. In your function code in 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 .


    When you use the ClientMetadata parameter, remember that Amazon Cognito won't do the following:

    • 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.
    • Validate the ClientMetadata value.
    • Encrypt the ClientMetadata value. Don't use Amazon Cognito to provide sensitive information.
    • (string) --
      • (string) --
Return type



Response Syntax

    'CodeDeliveryDetails': {
        'Destination': 'string',
        'DeliveryMedium': 'SMS'|'EMAIL',
        'AttributeName': 'string'

Response Structure

  • (dict) --

    The response from Amazon Cognito to a request to reset a password.

    • CodeDeliveryDetails (dict) --

      The code delivery details returned by the server in response to the request to reset a password.

      • Destination (string) --

        The email address or phone number destination where Amazon Cognito sent the code.

      • DeliveryMedium (string) --

        The method that Amazon Cognito used to send the code.

      • AttributeName (string) --

        The name of the attribute that Amazon Cognito verifies with the code.


  • CognitoIdentityProvider.Client.exceptions.ResourceNotFoundException
  • CognitoIdentityProvider.Client.exceptions.InvalidParameterException
  • CognitoIdentityProvider.Client.exceptions.UnexpectedLambdaException
  • CognitoIdentityProvider.Client.exceptions.UserLambdaValidationException
  • CognitoIdentityProvider.Client.exceptions.NotAuthorizedException
  • CognitoIdentityProvider.Client.exceptions.InvalidLambdaResponseException
  • CognitoIdentityProvider.Client.exceptions.TooManyRequestsException
  • CognitoIdentityProvider.Client.exceptions.LimitExceededException
  • CognitoIdentityProvider.Client.exceptions.InvalidSmsRoleAccessPolicyException
  • CognitoIdentityProvider.Client.exceptions.InvalidSmsRoleTrustRelationshipException
  • CognitoIdentityProvider.Client.exceptions.InvalidEmailRoleAccessPolicyException
  • CognitoIdentityProvider.Client.exceptions.CodeDeliveryFailureException
  • CognitoIdentityProvider.Client.exceptions.UserNotFoundException
  • CognitoIdentityProvider.Client.exceptions.InternalErrorException
  • CognitoIdentityProvider.Client.exceptions.ForbiddenException