Introduction to APIs - REST API, GraphQL, SOAP Web Services

Understand how HTTP works. Use tools like Postman and learn about JSON, XML.
Rating: 4.4 out of 5 (207 ratings)
10,645 students
Introduction to APIs - REST API, GraphQL, SOAP Web Services
Rating: 4.4 out of 5 (207 ratings)
10,645 students
Create GET, POST, PUT, DELETE requests
Understand HTTP messages
Understand GET vs POST request method
Work with real-world APIs


  • The possibility of installing new tools on your computer.

API is a very generic term. In this course you will learn what an API actually is and learn how to work with different web APIs: REST, SOAP and GraphQL.

RESTful APIs (or simply REST API) are everywhere nowadays but at the same time they are getting more complex to get started with: different HTTP methods, headers, cookies, dealing with file uploads or authentication with api keys, tokens, OAuth and so much more.

To work with APIs we will use the Postman app! Postman allows you very quickly create a request with the required HTTP method and parameters, submit the request and easily inspect the results.

Postman can help if you are developing APIs as well! I have created this course for testing engineers and well as for software developers.  Postman can help you during the development of your API as well as after the API is completed, by running tests that make sure your API is still working as intended.

So let’s look at what you are going to learn:

  • Understand what an API really is

  • Get the basics right: understand the structure of HTTP messages

  • Start with simple requests and advance towards more complex scenarios

  • Learn to deal with authentication / authorization mechanisms like Basic Auth, API Keys, or OAuth.

Excited to learn about APIs? Sign-up up today!

Who this course is for:
  • Anyone who want to get started with APIs
  • Beginner developers who want to use APIs in their projects
  • QA engineers who want to learn how to use APIs
Course content
6 sections • 23 lectures • 1h 59m total length
  • What is an API?
  • How to use an API?
  • APIs vs web services
  • Brief history of APIs
  • APIs vs Web services
  • Why do we need HTTP?
  • HTTP message structure
  • HTTP request method (GET, POST, PUT, DELETE, ...)
  • Introduction to Postman (tool for working with APIs)
  • What are query parameters? ...
  • Query parameters assignment
    5 questions
  • What are path parameters? ...
  • Query parameters and path parameters
    1 question
  • HTTP headers
  • HTTP headers: Content-Type header
  • HTTP headers: Authorization header
  • HTTP headers: Cookie header (Cookies)
  • HTTP body
  • HTTP status code (200, 301, 401, 403, 404, ...)
  • Your first SOAP request
  • Assignment - SOAP web service
    6 questions
  • Introduction to GraphQL
  • OAuth 2.0 authorization flow using the Dropbox API and Postman
  • OAuth 1.0 authorization flow using the Flickr API and Postman
  • Not the end
  • Bonus

​Agile Software Developer
Valentin Despa
  • 4.5 Instructor Rating
  • 17,581 Reviews
  • 127,128 Students
  • 9 Courses

Agile Enterprise software developer with a strong background in computer science. I believe there is a better way of developing software by using Agile and Scrum.

I have been involved in many open-source projects, including being a member of the Joomla! CMS Bug Squad, Joomla! Stack Exchange moderator and TYPO3 CMS Security Team. As you can guess, I am a dedicated software developer and open source lover.

I decided to join Udemy because of my desire to share my know-how in specific areas.