An API is a set of routines, protocols, and tools that allow software applications to communicate with each other. It defines the functionality that is independent of implementation. An API expresses the operations, inputs, outputs, and types of a software component. It allows creation of applications that can access features or data from an operating system, application, or other service. An API acts as an intermediary that allows two applications to communicate, delivering requests from one app to a provider and returning the response.

1. What is an API
Elliott Richmond

2. What is an API?
•An API defines functionalities that are
independent of their respective
implementations

4. …
•an application programming interface
(API) is a set of routines, protocols,
and tools for building software
applications.

6. …
•An API expresses a software
component in terms of its operations,
inputs, outputs, and underlying types.

8. …
•a set of functions and procedures
that allow the creation of applications
which access the features or data of
an operating system, application, or
other service.

10. What we know
•Application Programming Interface.
•An API is a software intermediary
that allows two applications to talk to
each other.

11. API

12. In other words…
•an API is the messenger that delivers
your request to the provider that
you're requesting it from and then
delivers the response back to you.

17. JSON
JavaScript Object Notation

18. json
json

19. Request
ProviderAPI
Response

20. API Providers

21. API Glossary
•Endpoint Requests
GET / POST / PATCH / DELETE / …

22. API Endpoints
https://api.domain.com/oauth2/token
https://api.domain.com?access_token=xxxxxxx
https://api.domain.com/rest/?api_key=xxx&name=bob

23. API Request Code
•HTTP
•cURL
•Javascript (AJAX, XMLHttpRequest)
•PHP cURL

24. API Request Code
$curl = curl_init();
curl_setopt_array($curl, array(
CURLOPT_URL => “https://api.domain.com/?param&param&param…..“,
CURLOPT_RETURNTRANSFER => true,
CURLOPT_CUSTOMREQUEST => "POST",
CURLOPT_POSTFIELDS => "grant_type=client_credentials",
CURLOPT_HTTPHEADER => array(
"Authorization: Basic xxxxxxxxxxxxxxxx",
"cache-control: no-cache"
),
));
$response = curl_exec($curl);
$err = curl_error($curl);
curl_close($curl)
if ($err) {
echo "cURL Error #:" . $err;
} else {
echo $response;
}

25. API Request Code
var settings = {
"async": true,
"crossDomain": true,
"url": "https://api.domain.com/?param&param&param…..",
"method": "POST",
"headers": {
"Authorization": "Basic xxxxxxxxxxxxxxxxxx",
"cache-control": "no-cache"
},
"data": {
"grant_type": “client_credentials"
}
}
$.ajax(settings).done(function (response) {
console.log(response);
});

26. API Testing Tools
Paw Postman Swagger
paw.cloud getpostman.com swagger.io

27. API Types
•Public
•Authenticated
client_key / client_secret
•Public / Authenticated

28. API Providers

29. WordPress Rest API
domain.com/wp-json/wp/v2/posts

30. WordPress Rest API

31. WordPress Rest API
https://developer.wordpress.org/rest-api/reference/
https://chrome.google.com/webstore/detail/json-viewer/gbmdgpbipfallnflgajpaliibnhdgobh

32. Why use the
WordPress API
Headless CMS
Data Migrations
Mobile APP services