Access the Steamworks API from the NW.Js exporter.
What version go's with what SDK? Some more info would be nice. Now when I add the 2 file from the SDK to the package.zip the game will not start. Double click nw.exe to start the game or the steam shortcut for the game and it just wont start. I deleted the steam_api64.dll and now the game runs. So what's the problem with adding that file to package.zip? Fixed. Make sure you do not download newer version of nw.js. Stay at version 30.4
See the notes for each version for which versions you need to match.
Click the version in the list to see release notes. For example, the 0.30.4 release notes are here.