[ aws . cognito-idp ]



Initiates the authentication flow, as an administrator.

Calling this action requires developer credentials.

See also: AWS API Documentation

See ‘aws help’ for descriptions of global parameters.


--user-pool-id <value>
--client-id <value>
--auth-flow <value>
[--auth-parameters <value>]
[--client-metadata <value>]
[--analytics-metadata <value>]
[--context-data <value>]
[--cli-input-json | --cli-input-yaml]
[--generate-cli-skeleton <value>]
[--cli-auto-prompt <value>]


--user-pool-id (string)

The ID of the Amazon Cognito user pool.

--client-id (string)

The app client ID.

--auth-flow (string)

The authentication flow for this call to execute. The API action will depend on this value. For example:

  • REFRESH_TOKEN_AUTH will take in a valid refresh token and return new tokens.

  • USER_SRP_AUTH will take in USERNAME and SRP_A and return the SRP variables to be used for next challenge execution.

  • USER_PASSWORD_AUTH will take in USERNAME and PASSWORD and return the next challenge or tokens.

Valid values include:

  • USER_SRP_AUTH : Authentication flow for the Secure Remote Password (SRP) protocol.

  • REFRESH_TOKEN_AUTH /REFRESH_TOKEN : Authentication flow for refreshing the access token and ID token by supplying a valid refresh token.

  • CUSTOM_AUTH : Custom authentication flow.

  • ADMIN_NO_SRP_AUTH : Non-SRP authentication flow; you can pass in the USERNAME and PASSWORD directly if the flow is enabled for calling the app client.

  • USER_PASSWORD_AUTH : Non-SRP authentication flow; USERNAME and PASSWORD are passed directly. If a user migration Lambda trigger is set, this flow will invoke the user migration Lambda if the USERNAME is not found in the user pool.

  • ADMIN_USER_PASSWORD_AUTH : Admin-based user password authentication. This replaces the ADMIN_NO_SRP_AUTH authentication flow. In this flow, Cognito receives the password in the request instead of using the SRP process to verify passwords.

Possible values:








--auth-parameters (map)

The authentication parameters. These are inputs corresponding to the AuthFlow that you are invoking. The required values depend on the value of AuthFlow :

  • For USER_SRP_AUTH : USERNAME (required), SRP_A (required), SECRET_HASH (required if the app client is configured with a client secret), DEVICE_KEY

  • For REFRESH_TOKEN_AUTH/REFRESH_TOKEN : REFRESH_TOKEN (required), SECRET_HASH (required if the app client is configured with a client secret), DEVICE_KEY

  • For ADMIN_NO_SRP_AUTH : USERNAME (required), SECRET_HASH (if app client is configured with client secret), PASSWORD (required), DEVICE_KEY

  • For CUSTOM_AUTH : USERNAME (required), SECRET_HASH (if app client is configured with client secret), DEVICE_KEY

key -> (string)

value -> (string)

Shorthand Syntax:


JSON Syntax:

{"string": "string"

--client-metadata (map)

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

You create custom workflows by assigning AWS Lambda functions to user pool triggers. When you use the AdminInitiateAuth API action, Amazon Cognito invokes the AWS Lambda functions that are specified for various triggers. The ClientMetadata value is passed as input to the functions for only the following triggers:

  • Pre signup

  • Pre authentication

  • User migration

When Amazon Cognito invokes the functions for these triggers, it passes a JSON payload, which the function receives as input. This payload contains a validationData attribute, which provides the data that you assigned to the ClientMetadata parameter in your AdminInitiateAuth request. In your function code in AWS Lambda, you can process the validationData value to enhance your workflow for your specific needs.

When you use the AdminInitiateAuth API action, Amazon Cognito also invokes the functions for the following triggers, but it does not provide the ClientMetadata value as input:

  • Post authentication

  • Custom message

  • Pre token generation

  • Create auth challenge

  • Define auth challenge

  • Verify auth challenge

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.

key -> (string)

value -> (string)

Shorthand Syntax:


JSON Syntax:

{"string": "string"

--analytics-metadata (structure)

The analytics metadata for collecting Amazon Pinpoint metrics for AdminInitiateAuth calls.

AnalyticsEndpointId -> (string)

The endpoint ID.

Shorthand Syntax:


JSON Syntax:

  "AnalyticsEndpointId": "string"

--context-data (structure)

Contextual data such as the user’s device fingerprint, IP address, or location used for evaluating the risk of an unexpected event by Amazon Cognito advanced security.

IpAddress -> (string)

Source IP address of your user.

ServerName -> (string)

Your server endpoint where this API is invoked.

ServerPath -> (string)

Your server path where this API is invoked.

HttpHeaders -> (list)

HttpHeaders received on your server in same order.


The HTTP header.

headerName -> (string)

The header name

headerValue -> (string)

The header value.

EncodedData -> (string)

Encoded data containing device fingerprinting details, collected using the Amazon Cognito context data collection library.

Shorthand Syntax:


JSON Syntax:

  "IpAddress": "string",
  "ServerName": "string",
  "ServerPath": "string",
  "HttpHeaders": [
      "headerName": "string",
      "headerValue": "string"
  "EncodedData": "string"

--cli-input-json | --cli-input-yaml (string) Reads arguments from the JSON string provided. The JSON string follows the format provided by --generate-cli-skeleton. If other arguments are provided on the command line, those values will override the JSON-provided values. It is not possible to pass arbitrary binary values using a JSON-provided value as the string will be taken literally. This may not be specified along with --cli-input-yaml.

--generate-cli-skeleton (string) Prints a JSON skeleton to standard output without sending an API request. If provided with no value or the value input, prints a sample input JSON that can be used as an argument for --cli-input-json. Similarly, if provided yaml-input it will print a sample input YAML that can be used with --cli-input-yaml. If provided with the value output, it validates the command inputs and returns a sample output JSON for that command.

--cli-auto-prompt (boolean) Automatically prompt for CLI input parameters.

See ‘aws help’ for descriptions of global parameters.


To initiate authorization

This example initiates authorization using the ADMIN_NO_SRP_AUTH flow for username jane@example.com

The client must have sign-in API for server-based authentication (ADMIN_NO_SRP_AUTH) enabled.

Use the session information in the return value to call admin-respond-to-auth-challenge.


aws cognito-idp admin-initiate-auth --user-pool-id us-west-2_aaaaaaaaa --client-id 3n4b5urk1ft4fl3mg5e62d9ado --auth-flow ADMIN_NO_SRP_AUTH --auth-parameters USERNAME=jane@example.com,PASSWORD=password


  "ChallengeName": "NEW_PASSWORD_REQUIRED",
  "Session": "SESSION",
  "ChallengeParameters": {
      "USER_ID_FOR_SRP": "84514837-dcbc-4af1-abff-f3c109334894",
      "requiredAttributes": "[]",
      "userAttributes": "{\"email_verified\":\"true\",\"phone_number_verified\":\"true\",\"phone_number\":\"+01xxx5550100\",\"email\":\"jane@example.com\"}"


ChallengeName -> (string)

The name of the challenge which you are responding to with this call. This is returned to you in the AdminInitiateAuth response if you need to pass another challenge.

  • MFA_SETUP : If MFA is required, users who do not have at least one of the MFA methods set up are presented with an MFA_SETUP challenge. The user must set up at least one MFA type to continue to authenticate.

  • SELECT_MFA_TYPE : Selects the MFA type. Valid MFA options are SMS_MFA for text SMS MFA, and SOFTWARE_TOKEN_MFA for TOTP software token MFA.

  • SMS_MFA : Next challenge is to supply an SMS_MFA_CODE , delivered via SMS.

  • PASSWORD_VERIFIER : Next challenge is to supply PASSWORD_CLAIM_SIGNATURE , PASSWORD_CLAIM_SECRET_BLOCK , and TIMESTAMP after the client-side SRP calculations.

  • CUSTOM_CHALLENGE : This is returned if your custom authentication flow determines that the user should pass another challenge before tokens are issued.

  • DEVICE_SRP_AUTH : If device tracking was enabled on your user pool and the previous challenges were passed, this challenge is returned so that Amazon Cognito can start tracking this device.

  • DEVICE_PASSWORD_VERIFIER : Similar to PASSWORD_VERIFIER , but for devices only.

  • ADMIN_NO_SRP_AUTH : This is returned if you need to authenticate with USERNAME and PASSWORD directly. An app client must be enabled to use this flow.

  • NEW_PASSWORD_REQUIRED : For users which are required to change their passwords after successful first login. This challenge should be passed with NEW_PASSWORD and any other required attributes.

Session -> (string)

The session which should be passed both ways in challenge-response calls to the service. If AdminInitiateAuth or AdminRespondToAuthChallenge API call determines that the caller needs to go through another challenge, they return a session with other challenge parameters. This session should be passed as it is to the next AdminRespondToAuthChallenge API call.

ChallengeParameters -> (map)

The challenge parameters. These are returned to you in the AdminInitiateAuth response if you need to pass another challenge. The responses in this parameter should be used to compute inputs to the next call (AdminRespondToAuthChallenge ).

All challenges require USERNAME and SECRET_HASH (if applicable).

The value of the USER_ID_FOR_SRP attribute will be the user’s actual username, not an alias (such as email address or phone number), even if you specified an alias in your call to AdminInitiateAuth . This is because, in the AdminRespondToAuthChallenge API ChallengeResponses , the USERNAME attribute cannot be an alias.

key -> (string)

value -> (string)

AuthenticationResult -> (structure)

The result of the authentication response. This is only returned if the caller does not need to pass another challenge. If the caller does need to pass another challenge before it gets tokens, ChallengeName , ChallengeParameters , and Session are returned.

AccessToken -> (string)

The access token.

ExpiresIn -> (integer)

The expiration period of the authentication result in seconds.

TokenType -> (string)

The token type.

RefreshToken -> (string)

The refresh token.

IdToken -> (string)

The ID token.

NewDeviceMetadata -> (structure)

The new device metadata from an authentication result.

DeviceKey -> (string)

The device key.

DeviceGroupKey -> (string)

The device group key.