I believe you still have to use a third-party package (https://github.com/meteorhacks/npm), but it's quite easy to use and I've never had any problems with it.
As someone who has been building on Meteor for a while and using many npm modules, I've never actually heard of "meteorhacks:npm", and to be honest I'm confused what it's for...
I just don't understand why Meteor decided to be incompatible with the vast majority of server-side JavaScript in the wild.
https://github.com/sandstorm-io/sandstorm/blob/master/shell/...