name : initiate-auth.rst **To sign in a user** The following ``initiate-auth`` example signs in a user with the basic username-password flow and no additional challenges. :: aws cognito-idp initiate-auth \ --auth-flow USER_PASSWORD_AUTH \ --client-id 1example23456789 \ --analytics-metadata AnalyticsEndpointId=d70b2ba36a8c4dc5a04a0451aEXAMPLE \ --auth-parameters USERNAME=testuser,PASSWORD=[Password] --user-context-data EncodedData=mycontextdata --client-metadata MyTestKey=MyTestValue Output:: { "AuthenticationResult": { "AccessToken": "eyJra456defEXAMPLE", "ExpiresIn": 3600, "TokenType": "Bearer", "RefreshToken": "eyJra123abcEXAMPLE", "IdToken": "eyJra789ghiEXAMPLE", "NewDeviceMetadata": { "DeviceKey": "us-west-2_a1b2c3d4-5678-90ab-cdef-EXAMPLE11111", "DeviceGroupKey": "-v7w9UcY6" } } } For more information, see `Authentication <https://docs.aws.amazon.com/cognito/latest/developerguide/authentication.html>`__ in the *Amazon Cognito Developer Guide*.