Machine-readable code

A method to associate a user account associated with a first device with a second device, the method comprising:

• providing, on the second device, an optical code having an identifier of the second device;
• capturing, using the first device, the optical code provided by the second device;
• extracting, using the first device, the identifier from the optical code;
• sending, using the first device, the identifier to a server computing device;
• receiving, at the second device, a token for the user account from the server computing device;
• and
• at the second device, accessing one or more services associated with the user account using the token.

A system comprising:

• a server computing device that is associated with an audio streaming service;
• a mobile computing device with a camera, wherein the mobile computing device is associated with a user account for the audio streaming service;
• a smart speaker device unassociated with the user account, wherein to associate the smart speaker device with the user account includes:
• displaying, on the smart speaker device, an optical code having an identifier of the smart speaker device;
• capturing, using the mobile computing device, the optical code displayed by the smart speaker device;
• extracting, using the mobile computing device, the identifier from the optical code;
• sending the identifier from the mobile computing device to the server computing device;
• receiving, at the smart speaker device, from the server computing device, an authorization token for the user account;
• using the authorization token, associating the smart speaker device to the user account;
• and
• accessing the audio streaming service from the smart speaker device.