AWS Cognito Identity authenticate using cURL

auth.json

{
   "AuthParameters" : {
      "USERNAME" : "alice@example.com",
      "PASSWORD" : "mysecret"
   },
   "AuthFlow" : "USER_PASSWORD_AUTH",
   "ClientId" : "9..............."
}

auth.sh

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

notes.txt

Dashboard -> "App Clients" -> "Show Details" -> check "Enable username-password (non-SRP) flow for app-based authentication (USER_PASSWORD_AUTH)"