How to create a no-password authentication system

I’m learning Meteor and it’s great so far! But I’m a bit stuck on creating an authentication system that fits my needs.

Basically creating an account with your email and then signing in by entering your email, then getting an email sent to you with a sign in link.

I’ve been searching the web for examples of custom authentications but most use the great accounts packages.

How could this be done? What can/should I use of what already exists (adapt accounts package)?