Practice API Apps for REST API Testing Exercises
Categories: Change Log, Practice Sites, API Testing
The 2025-02-16 update added pages for Best Buy API Playground, FX Trade Hub, and Tracks. It also removed a sample TODO API that did not work reliably during Docker testing.
The main benefit of this update was variety. A single small TODO API is useful for learning request syntax, but API testers also need practice with bigger data sets, business-style domains, UI plus API workflows, authentication, OpenAPI documentation, and realistic setup constraints. Adding these practice apps made the Practice Sites area more useful for learners who want to move beyond isolated endpoint examples.
Why Add Full Practice Applications?
Small APIs are useful for learning request syntax. Larger practice applications help testers think about workflows, state, data relationships, and business rules.
Full applications also help testers practise the messy middle of API testing. You can ask whether the UI and API show the same data, whether data created through the API appears in the application, whether setup instructions are complete, and whether the API documentation matches the running service.
Best Buy API Playground
The Best Buy API Playground was added because it gives testers a richer data set than a beginner sample API. It is useful when you want to practise filtering, searching, reading larger responses, and working with multiple resource types instead of a single collection.
It is also useful for CRUD workflow practice because the API supports create, read, update, and delete style operations. That means learners can practise setting up data, changing it, checking the changed state, and cleaning up after the test. Those steps matter in real projects because API tests can easily become unreliable when data setup and teardown are treated as an afterthought.
Use this API when you want to practise exploratory testing against a domain with more data and more opportunity for variation.
FX Trade Hub
FX Trade Hub was added as a smaller business-flavoured API with default data and Swagger UI support. It is useful for practising with a domain that feels more realistic than todos or generic items, while still being approachable enough for learners.
The default data is the main benefit. Testers can start by reading existing records, then create new examples, amend them, and compare expected values with actual responses. That supports practice around status codes, request bodies, validation, duplicate data, and whether the API responds consistently when data already exists.
Use FX Trade Hub when you want a manageable API that still encourages business-rule thinking.
Tracks
Tracks was added because it includes both a web application and a REST API. That makes it especially useful for testers who want to connect API testing with user workflows.
Tracks was also the case study application used in the book Automating and Testing a REST API, so it gives learners a route from manual exploration into automation thinking. You can observe a workflow in the UI, identify the API calls that support it, then design API tests that check the same behaviour more directly.
Use Tracks when you want to practise API testing as part of application testing, not as a separate technical exercise.
Why Remove the TODO API Sample?
The update also removed a sample TODO API that failed during Docker testing. That was a quality decision. A practice API should help learners focus on testing ideas, not spend their time debugging an unreliable setup.
Unreliable practice targets are sometimes useful for advanced troubleshooting, but they are poor teaching tools when the goal is to learn API testing fundamentals. Removing that link made the practice-site list more trustworthy.
What to Practise
When using these apps, avoid only sending happy path requests. Try to explore:
- Valid and invalid CRUD flows.
- Missing or inconsistent data.
- UI workflows backed by API calls.
- How OpenAPI documentation matches the running API.
- What happens when requests are repeated or sent out of order.
Use the Practice Sites page to choose an application based on the type of API testing practice you want. If you are still learning the basics, start with a smaller API. If you are ready to think about workflows, data relationships, and documentation accuracy, these full practice apps are a better next step.