Authors Tavern API tests as YAML files (`test_*.tavern.yaml`) with `test_name` + `stages` + `request` + `response` blocks, runs them through the Tavern pytest plugin (auto-discovered), and gates CI on the resulting JUnit XML. Covers RESTful, MQTT, and gRPC variants. Use when the project runs on pytest and prefers YAML over a Python- or Java-DSL; on the JVM use karate-testing or restassured-testing instead, and for schema-driven property-based fuzzing on the same pytest stack use schemathesis-fuzzing.