And once again if you're going through this for a front end course or a backend course then you are going to be using Postman in some very specific ways, and so what I want to do in this section is to have a little bit more of a high-level view of how to work with this tool because you're going to use it for your own specific use case later on and if you're going through a devcamp guide, then we're going to show you how to use it for your specific application.

So right now my goal is to simply give you the ability to become familiar with how to work with Postman but also to show you exactly why you would want to use a tool like this because that I think will help you understand why this is something that can make your entire development process more efficient.

So right here I have the documentation for the DailySmartie API. Now, this is an API that I built so that's the reason why I'm wanting to show it because I have complete control over it and if I was using some other tool like the Google Maps API or Instagram or Facebook, they are constantly changing and so that makes it harder to keep up. So what you're seeing right here on the screen should be exactly what you see when you go to this URL.

I'll include a link to this in the show notes below. So what this is, if you've never worked with an API before, API stands for application programming interface and so that is a big acronym that really just means that it's a way that we can communicate with an application and we can do it without implementing something like a scraper or anything like this.

It gives us a set of commands that we can use and we can actually have our application communicate with another server in another application. So if you scroll down a little bit click on most recent posts what an API gives you is a set of endpoints.

So an endpoint is just a URL. So right here, this URL is https://api.dailysmarty.com/posts so this is just a URL, just like if you were going to go to it in your browser. Now the difference here is that this is going to return JSON data, so it's going to return something that an outside application can actually use.

So if you're building a React, or a Vue, or an Angular app, then you can communicate with this and get the data back in a way that you can parse it and then render it on the screen. So if I copy this and paste it into the browser then you're going to see that we get data right here.

So even though we are not using any kind of outside application or any kind of framework you can go to this endpoint. It's really just a URL But as you can see even though this is a pretty small, basic API this is still pretty confusing to look at and this is pretty much as simple as it gets.

So we're not passing in a username and password and we're not passing in any parameters anything like that. This is as basic as an API request gets and as you can see it is still pretty difficult to work with. So that is where tools like Postman come in and that's what we're going to walk through in this guide is how we can take all of this and then we can use Postman in order to streamline how we can communicate with this type of API.

Let's go and let's pull in Postman, and load it up. So when we open this it's going to give us the ability to set up this type of request. Okay so right here in the load screen and like I mentioned before this may look a little bit different for you but the basic flow is going to be the same no matter what version you have and we want to set up a basic request so if I click on request right here it allows us to give it a name.

So I'm just going to say Daily Smart Production Posts and then it also gives you the ability to create a collection. Now, this is something that's pretty helpful because imagine that you're working with 10 different applications. A collection allows you to create a grouping of those applications so it makes it much easier to look up. So I'm going to do that so I'm just going to say that this should be for the Daily Smarty API.

Then we can save this. So now that we have this saved we have our dashboard where we can communicate with the API. Now if you've never worked with APIs at all then one thing that is very helpful to know is that there are multiple what are called HTTP verbs. So if you click on this dialog box here this is going to give you access to each one of those verbs.

Now the most popular ones are here at the top. Like GET, POST, PUT, PATCH, and DELETE. Now if we go back and look at that documentation you can see that right it even tells us the verb. So we have a GET request and without going into full detail because this isn't an API course, this is a learning how to use an API tool without going into too much detail, what a GET means is it means that you want to get data back.

So any time that you're running a query like this where we're going to this post endpoint then what we're saying is we want to get data back just like we have in this example. So in order to run this in Postman I can just paste this full link.

We do not have any kind of authorization, this is important to know because whenever you start to work with applications that require a username and password which is very common for some larger APIs, like Twitter, Facebook, or anything like that. Then you would click on it and then you would pick whatever type of authentication that you need to use.

So Basic Auth is pretty common, and Digest Auth, and OAuth. Those are also common options as well. Whatever API that you're working with will provide documentation and will tell you which one to pick out. But right now we don't have any authorization or authentication that we need to implement so I can just paste this in.

I have the GET request right here not pasting in any parameters or anything like that, and now if I click send this is going to communicate with that outside API and then whenever it gets data back then it's going to return it and we're going to be able to see it right here on the screen.

And there we go. So right here you can see this is coming in from a live application. So this is as I'm recording this. This is the set of content that's currently on Daily Smarty so you can see the last one that I did was actually, of course, I'm working on which is a flask one says 'Steps for building a flask API application with Python 3', It has all the HTML content from when it was created, the topics and then the links associated with that.

So if we were to come here and go to dailysmarty.com you'll be able to see exactly that post. I'm no longer in the API right now, I'm just looking at the regular app, and in this case, it's a Rails application, and you can see that post is here.

It says steps for building a flask API with Python 3 and it has all of the data, and if you scroll all the way down to the bottom it has some resource links and those are also included.

Now if you look back at what this API document there are not really documentation this API response looks like. Imagine that you wanted to work with a very large and convoluted type of API and many of them are. Whenever you're working with the large API you're typically going to get multiple levels of nesting and the JSON data can be very difficult to parse and that's a reason why you don't want to just use it in the browser.

But notice in Postman how much easier this is to read. I can look and see that I'm going to work with this post type of structure and it's an array of items. Then inside of there, I can see that each one of the items has an ID title content each and just going down all the way down to post links, and then I can see that post links has an array.

So what this gives me the ability to do is to know what type of data that I'm going to be working with so that whatever application I'm building allows me to just visualize it all because that's a much much easier than trying to do it manually.

I remember when I originally started working with API and this was years ago. This was really the only way that you could read the data and another very popular way is using a tool called curl, And you've seen curl a few times as we've set up the development environment.

So you would run a curl command in the terminal and you'd paste in an endpoint, and then you'd get data that pretty much look like our JSON and those are very difficult to parse and then every time that you wanted to make a change then you'd have to go through creating the command from scratch and it really just wasn't a fun way of working with APIs

But with Postman, I can make any kind of adjustments on the fly here that I need to. So for example, if I go back to the documentation and you can see on the bottom here, you can actually search for posts and right there if I click on search for posts and then pull that up. Now you can see that this is a slightly different endpoint.

https://api.dailysmarty.com/search?q=rails

So instead of it being slash posts, it's slash search and so I'm going to copy that. Come back to Postman and put in that exact query here and now if I run this once again with a get request and I'm not passing in anything else because I can hit this endpoint directly.

Now if I hit send, it's going to go out, and there you go. You can see we have a search that returns to the key of rails so each one of the rails post is going to be returned from the API so that is something that is much easier to do than either going to the URL or having to do it in the terminal.

Now the last thing I'm going to leave you with is one last tool that is also something that you're going to be doing quite a bit. You may have noticed that we've been working with a live API this entire time but if you're building out an API for somebody else so say that you're building out a flask API then you want to be able to test that but you don't want to have to push it up and deploy it every time that you test it out.

You may want to just test it with your server as it's running on your local machine. So before the video started, I started a very basic type of Rails application and it has an endpoint so it has the ability to communicate. So what I can come here and do is in Postman I'm going to create another request here and I'm just going to type a localhost. This will give me 3000. And then I have an endpoint called guides.

Now unless you have this on your local machine then you're not going to be able to type this exact command. I'm just doing this to show you that it is something that's possible so if you have a server that is running say a flask or rails API, it is going to be running on localhost out on some port and then it's going to have an endpoint.

I just want to show you that you can run this exact same command and it'll pick up your local server. So I say localhost:3000/guides and I hit send. Then it's going out and it is grabbing these data points, so each one of these is a post.

So you can communicate with it here. Now, this isn't returning JSON, as you can see this returns HTML because this particular API isn't set up to communicate and send JSON back. But what you can do is you can perform this so I can say localhost 3000 and communicate with any endpoint that you're working with on your local machine.

Because I know if you're going through this guide there's a very good chance you're going through it in order to learn how to build out your own API for others. And so one of the big things you're going to need to do our a very common thing is to be able to work with your local machine. So now you know how to work with outside services along with ones on your local system and now you're ready to start building out your own API as.

Resources

• DailySmarty API Documentation