You give the code in a .js file that you include in a browser plugin but, you don't state clearly whether this is or is not an open source project. The .js file has no license in it either.

File: https://www.inboxsdk.com/build/inboxsdk.js

Then I see the github page: https://github.com/InboxSDK/

There is no InboxSDK project but, just two example chrome plugins using the inboxSDK.

All the trappings and mechanics of open source without the actual source and an actual open source license. Are you guys just testing this to see if you can productize it? Or are you going to go all the way and open source this?