[joshstrange]

Here: https://passwordless.net/ (It's for Express + NodeJS)

Open source, you can use whatever you want to get the code to the user. It's from Mozilla.

[michaelmior]

Unfortunately I think the biggest advertised feature is the ability to authenticate users by phone number which this doesn't do.

[thesumofall]

It does and it's designed for it. Found this example online: https://github.com/rbudiharso/smsauth-example Basically you can use any delivery mechanism with it you'd like

[michaelmior]

My apologies. This wasn't obvious from the main project page.