The Checkbox API requires an authentication token (AuthToken) in order to make API calls. In order to obtain an AuthToken you can access the AuthenticationService.Login method using your username and password. AuthTokens are on a rolling 20 minute expiration timer. This means that your token will last for 20 minutes after the last API call was made utilizing it.
AuthTokens inherit the permissions of the user that they were obtained for. This means that you will be able to access all data using this token that you would if you were logged into the application as them.
Authentication Endpoint: https://[yourdomain]/services/authenticationservice.svc