Systems and methods provide logic that validates a code generated by a user, and that executes a function of a programmatic interface after the user code is validated. In one implementation, a computer-implemented method performs a multifactor authentication of a user prior to executing a function of a programmatic interface. The method includes receiving, at a server, a user code through a programmatic interface. The server computes a server code in response to the user code, and compares the user code to the server code to determine that the user code corresponds to the server code. The server validates the user code and executes a function of the programmatic interface, after the user code is validated.