What is the REST (or CLI) API for logging in to Amazon Cognito user pools

Question

How do i make logins happen via Amazon Cognito REST APIs (for user pools) on platforms for which there is no official SDK? - Note that i am asking

Answer 1

This curl command works for me:

curl -X POST --data @aws-auth-data.json \
-H 'X-Amz-Target: AWSCognitoIdentityProviderService.InitiateAuth' \
-H 'Content-Type: application/x-amz-json-1.1' \
https://cognito-idp.us-east-1.amazonaws.com/

Where aws-auth-data.json is:

{
   "AuthParameters" : {
      "USERNAME" : "yourusername@example.com",
      "PASSWORD" : "yourpassword"
   },
   "AuthFlow" : "USER_PASSWORD_AUTH",
   "ClientId" : "75........................"
}

The user pool client must allow USER_PASSWORD_AUTH for this to work - that's an AWS-side setting.