And so if we were then to take a look at what happens when we sign in, this process is going to be really simple as well. All right, so we're just going to sign in. And I'm back into my account. And that was coming from the sessions controller right here. And I'm basically displaying the form. And then I'm grabbing a user. And then if the user is authenticated with the passwords, this is where Rails is checking. It basically takes the password I put through the form, runs it through the same algorithm that it used to generate the hash passwords that are being stored in the database. And if that works well, then it sets the session variable and it redirects to a different account. Otherwise, we just display an error message and we send them back to that page. And just to drag this home one more time when we click the sign out button, all we're doing is setting that session variable back to now. Okay. Does that make sense so far? Moral of the story, session periods. All right. Okay, so now let's take a look at how do we inject a second step into the sign-in process. So how do we take, how do we make it so that when somebody types in an email, and then when they type in their password, that they're going to get an SMS from offing. And they're going to have to punch in that code into our Rails app in order to have access to the page. So the first thing that I had to do is go to offing, sign up for a free account. If you, so what is it? I think an authentication is two cents and if you are under $3 in any given month, they don't send you a bill. So basically it is free for development. And unless you're running, once you get into production, you'll probably have a bill, you know, depending on what you're using it, but it's going to be pretty low. And so I need to grab my API key. And then my API key, I'm going to drop here into my secrets.yaml. Let's call this an offing key, or we'll call it offing API key. All right. And then I'm going to create a new file here on Kilmer Rails Server. 
### Language ###
English

### Assessment ###
We could ask about the pricing information of the authentication service mentioned (Authy)

### Query ###
Looking for a budget-friendly authentication service - what's the monthly cost threshold before billing starts?
Looking for a budget-friendly authentication service - what's the monthly cost threshold before billing starts?