Reusable JVM client core for the DoQA Autotest API: configuration resolution (system properties over environment over properties file), model builders serializing to the API contract, an HTTP client with token auth, retries and timeouts, run-selection modes, and an Allure-compatible file sink. No runtime dependencies: HTTP via java.net.http (JDK 11+), JSON via a small built-in codec, so any test-framework adapter can build on top of it.