Future Pandora partners request access to the developer portal by completing the partnership request access form. Request partnership access here.
Once partner access is granted, a Pandora partner can sign into the developer portal and create applications through which API usage is authorized and requests managed. Partners can invite their developers to access portal documentation and a realtime API Explorer in order to get familiar with the Pandora API services and try out some tutorials based on the sample web application provided by Pandora.
See also Becoming a Pandora Partner.