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Learn Swagger and the OpenAPI Specification
Highest Rated
Rating: 4.5 out of 5(6,000 ratings)
33,066 students

Learn Swagger and the OpenAPI Specification

API Definition Files, Tools, and Documentation (OAS 2.0)
Created byPeter Gruenbaum
Last updated 1/2026
English

What you'll learn

  • Read and write Open API Specification (Swagger) files to define and document APIs
  • Use Swagger tools to edit files, create documentation, and create SDKs
  • Understand alternatives to Swagger and OAS.

Course content

3 sections13 lectures1h 5m total length
  • Introduction7:13

    Covers:

    • API Definitions
    • What is a REST API?
    • Prerequisites
    • Swagger
    • The Open API Initiative
    • Course Overview
  • API Definition5:33

    Covers:

    • What’s an API Definition File?
    • Anatomy of an API Request
    • What’s in an API Definition File?
    • Getting Information to create an API Definition File
  • YAML6:32
    Covers:
    • How YAML is used with the Open API Specification
    • What is YAML?
    • Rules of YAML
  • YAML
  • YAML

Requirements

  • You should understand how REST APIs work
  • You should be able to read and understand JSON
  • If you need these skills, take my courses on JSON/XML and REST

Description

The OpenAPI Specification (often called "Swagger") is currently the most popular way to create definitions of RESTful APIs. With these definitions, you can create sophisticated, autogenerated documentation, generate SDKs in several languages, and do automated testing. Swagger is a set of open source tools that use these Open API Specification definition files.

This class is for people in the software industry who are fairly technical, but are not software developers: for example, project managers, API product managers, and technical writers. It assumes that you understand REST and JSON, but that's about all. It is meant to be for people who are new to the Open API Specification and Swagger, rather than for experts. It covers:

  • What you can do with OpenAPI Specification (OAS) files

  • The YAML file format

  • How to create an OAS file

  • How to specify security

  • How to add documentation

  • How to write an OAS file in JSON

  • Alternatives to Swagger and OAS

This class does not cover:

  • How to set up Swagger on your own server

  • How to modify Swagger open source code

In addition to videos, this course contains 8 hands-on exercises that lead you step-by-step in creating an API definition file, including a final project where you create a file from scratch using documentation from an actual commercial API. It also contains a document with resources on learning more about OAS, Swagger, and alternatives.

In addition to the video lectures, expect to spend at least 4 hours doing the exercises. These exercises are key to understanding Swagger and OAS.

Important: The course uses OAS 2. A newer version, OAS 3, is starting to be used more, but  many companies are still using OAS 2. There is a lecture that points you to the differences between OAS 2 and OAS 3.

Who this course is for:

  • Anyone who wants to be able to read or write Open API Specification (Swagger) files
  • Project managers
  • Technical writers
  • Technical sales staff
  • Technically-skilled managers