This is what I get for Stack Apps:
{ "display_name": "user", "email_hash": "11aa11...22bb22...", "reputation": 101, "user_id": 0000, "user_type": "registered" } And this is what I get from other sites:
{ "display_name": "user", "email_hash": "11aa11...22bb22...", "on_site": { "api_endpoint": "http://api.meta.stackoverflow.com", "description": "Q&A about Stack Overflow, Server Fault, and Super User", "icon_url": "http://sstatic.net/mso/apple-touch-icon.png", "logo_url": "http://sstatic.net/mso/img/logo.png", "name": "Stack Overflow Meta", "site_url": "http://meta.stackoverflow.com" }, "reputation": 101, "user_id": 0000, "user_type": "registered" } As you can see, the whole on_site portion is missing.