https://www.ecobee.com/developers/Developers need to own an ecobee product in order to register as developers. Nest allows developers to register and test using virtual products. That is why we were able to provide users with some Nest commands.
It is not possible to develop for products without access to them. The ecobee 3 costs hundreds of dollars.
If you own the product, you can register the product and sign up for your own developer account. Register an app in order to get an app key. If you then want to PM me all that info, including how to sign in to your developer's account, I will see if I can figure something out with it -- but I can't guarantee anything.