MuleSoft Integration Architect Practice Test

Black-box integration testing focuses on validating how components work together through their public interfaces, without looking at internal code. In this approach, you test the API by sending requests and checking the responses.

REST-assured provides a code-based DSL for testing REST endpoints within your Java tests, making it easy to validate status codes, headers, and payloads in CI pipelines. Restlet Client is a GUI-based tool (often as a browser extension) that lets you compose and send HTTP requests and inspect responses interactively. SOAPUI is a mature, feature-rich testing tool for SOAP and REST services that supports assertions, test suites, and data-driven tests.

Since all three enable exercising an API from the outside and verifying the results, they are all suitable for black-box integration testing. So, all of these tools are popular options for this purpose.