I am using PHPStorm 8.0.2
Adding server:
Tools > Task & Context > Configure server.
Based on https://asana.com/developers/documentation/getting-started/authentication#sts=API%20Keys .
Always getting 403, does anyone tried to connect this from PHPStorm?
Edit 15.06.2017: The Url's have changed, so if you get a "Bad Request" with seamingly correct settings, check the Task-list urls from this answer
Here´s what worked for me based on https://youtrack.jetbrains.com/issue/WI-19852 from LazyOne´s comment
1) get a API key Personal Access Token and use that as your Username in the Servers configuration in PHPStorm
2) Project ID comes from the URL if your within the Project (the first long number)
3) Password is your Account Password
Edit 15.07.2016: Asana deprecates the API keys in favor of the personal Access tokens. But with that it works the same way.