To authenticate each requests with a username and password like you want, you should use: Basic Authentication.
To use it, it's pretty simple and it works with all HTTP methods (GET, POST, ...). You just need to add an HTTP header into the request:
Authorization: Basic <...>
The <...>
part is the username:password
encoded in base64.
For example, if your login is foo
and your password is bar
. The HTTP header should have this line:
`Authorization: Basic Zm9vOmJhcg==`
Through your HTTPS connection, it's secure.
EDIT: Using Flask, you can use Flask HTTP auth to achieve this "automatically".