API testing is integration testing of API's which checks the functionality , performance & security aspects of API's.

As GUI test is difficult to maintain and requires a considerable amount of period, API has evolved as primary testing of application logic.

API to be tested are those which are developed by development team or third party API's which we would consume in our project.

API testing involves:

• Calling the API with different parameter values

• API boundary value conditions

• Actions performed by API i.e. updating database, calling other API

• Validating Response

Popular API which are used are REST implement in JSON format, which we will be looking during the course. Rest has become  most popular because it is light and easy to maintain.

Rest-assured is library developed by Jaway which is best open source library specially designed to automated Rest API. It also supports XML and JSON Request/Responses.

No need of any tool when you need to automate API, simple coding skills will let you perfect automation of API, will be taught during the course.

Advantage

• Request can be easily prepared and send over internet
• Assertions in Response data
• Clean code which is easy to be maintained