Web Services API Testing

Overview Learning objectives What you'll learn Key facts FAQs What our customers say Get in touch

Course overview

Build your confidence in REST API and web services testing during this course, with a focus on understanding API behaviour, checking responses and validating how connected systems exchange data. The course develops practical skills that you can apply in functional API testing, helping you identify defects earlier, assess integrations more effectively and support more reliable software delivery in complex technical environments.

Practical REST API testing skills

This interactive three-day course is designed for software testers, QA professionals and technical team members who are new to API testing. You’ll learn how RESTful web services work, how to build and inspect requests, and how to check responses using tools such as cURL and Postman. The course also introduces Open API files and RESTSharp, helping you develop practical skills for testing service behaviour and adding API checks into existing automation frameworks.

Learning objectives

Understand API and web service architecture
Explain RESTful web services
Build API requests
Analyse API responses
Use cURL and Postman
Work with Open API files
Create Postman checks
Run data-driven requests
Apply RESTSharp basics
Support automation frameworks

What you'll learn

Learn how to test RESTful web services with greater precision, from understanding API structures to checking responses, managing test data and using tools such as cURL, Postman and RESTSharp. You will practice techniques that help reveal issues earlier, strengthen functional coverage and extend testing beyond the user interface into the services that power modern applications.

API foundations

APIs allow applications to share data and functionality without relying on the user interface. You will build a clear understanding of API types, RESTful web services, clients, requests, responses, response codes, XML and JSON, giving you the technical grounding to plan API tests with confidence and discuss service behaviour more effectively with developers.

Functional API testing

Learn what to test in RESTful web services and how to check whether an API behaves as expected over this three-day course. By focusing on functional and non-functional considerations, you can assess service behaviour directly, find defects that may be missed through UI testing alone and provide faster feedback to teams on critical application logic.

Test data and dependencies

You will explore how to capture values from one API response, reuse them in later requests and run data-driven checks using CSV files in Postman. This helps you test realistic service flows, reduce repeated manual effort and expose defects that only appear when an API handles different inputs, IDs or data conditions.

Automation framework integration

This course builds your understanding of how REST testing can be added to an existing automation framework, including introductory work with BDD, Gherkin, SpecFlow and RESTSharp. This helps you understand how API checks can sit alongside wider automated testing activity and strengthen coverage below the user interface.

Tool-based testing

The course equips you with practical experience of the cURL and Postman tools, including sending requests, analysing responses, checking values, checking response times and running collections. These skills help you progress from manual exploration to more consistent, repeatable API checks that support day-to-day testing activity.

What's included

Three days of instructor-led training
Online or on-site study options
Practical API exercises
Demo REST API practice
cURL and Postman activities
RESTSharp introduction
Automation framework examples

Key facts

Certification

No certification is specified for this course.

Who it’s for

This course is for anyone new to API testing who wants practical RESTful web services testing skills.

Prerequisites

No formal pre-requisites are specified for this course.

Exam information

No exam is specified for this course.

Optional extras

No optional extras are included.

Pre-course

No separate pre-course activity is required.

FAQs

This course helps delegates understand how RESTful web services work and how to test them using practical tools and techniques. It covers API concepts, functional testing approaches, cURL, Postman, test dependencies, data-driven requests and introductory RESTSharp use within an automation framework.

What is API testing?

API testing checks how services behave when they receive requests and return responses. Instead of testing through the user interface, testers work directly with the service layer to verify data, response codes, behaviour and outputs, helping teams find issues earlier in connected applications.

Who should attend this course?

This course is suitable for anyone new to API testing who wants to understand RESTful web services and how to test them in practice. It is especially relevant for testers and technical team members who need to extend their testing beyond the user interface.

Do I need API testing experience?

No previous API testing experience is specified for this course. Delegates should be ready to work with technical concepts such as requests, responses, response codes, XML and JSON, as these are covered as part of the course content.

What tools are covered?

The course includes a practical introduction to cURL, Postman and RESTSharp. Learners use these tools to send requests, analyse responses, write checks, work with collections and understand how REST testing can fit into an existing automation framework.

Does the course include practical exercises?

Yes. Practical examples are demonstrated throughout the course, and delegates practice what they have learned in each chapter against a demo REST API service. This helps translate the technical concepts into skills that can be applied in real testing work.

Does the course cover Postman?

Yes. The course covers the basics of using Postman, writing tests in Postman, checking values, checking response times, using the collection runner, running data-driven requests with CSV files and executing Postman collections from the command line.

Will I learn API automation?

The course introduces how REST testing can be integrated into an existing automation framework, including BDD, Gherkin, SpecFlow and RESTSharp. It gives delegates a practical starting point for understanding how API checks can support wider automated testing activity.

What our customers say

"Communications were prompt, from querying the course up to actually doing the course."

Jessica Eslava – TSG learner

"Great training! Quick and easy communication."

Veronica Wessels – TSG learner

Why study with TSG?

25+ years' experience

Trusted by individuals, businesses and public sector organisations for over 25 years.

20,000+ learners trained

Join a network of learners focused on developing their software testing skills

98% customer satisfaction

TSG trainers are frequently rated as ‘good’ or ‘excellent’ by our learners

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Guidance from experienced advisors

If you’re unsure which course aligns with your technical requirements or career direction, we’ll help you assess your options and choose with confidence.

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Develop skills that support real delivery outcomes

From software testing to broader digital skills, we work with you to design learning that strengthens capability, improves performance, and supports long-term business goals.

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