This is a Spring Boot starter library that deeply integrates Square's Retrofit HTTP client with Spring Boot's auto-configuration, allowing developers to declare typed HTTP APIs via Java interfaces annotated with `@RetrofitClient`. The library provides a comprehensive set of features: automatic OkHttpClient management, a pluggable interceptor chain (global, network, path-match), configurable retry with exponential backoff and jitter, circuit breaking (via Sentinel or Resilience4j), logging strategies, Micrometer metrics, custom error decoding, and connection pooling. It also supports Spring Boot Actuator for runtime introspection, GraalVM native image/AOT compilation, and reactive call adapters (RxJava 2/3, Reactor). The architecture is modular with clear SPIs for extensibility (e.g., `SourceOkHttpClientRegistrar`, `GlobalInterceptor`, `RetrofitDegrade`, `ErrorDecoder`), and the configuration is annotation-driven with global defaults overridable per-client. The codebase is well-tested with integration tests using MockWebServer, and documentation is provided in multiple languages. However, the tight coupling to specific versions of Retrofit, OkHttp, and Spring Boot introduces moderate technical drift, as some optional dependencies (e.g., Sentinel 1.8.6, Resilience4j 1.7.1) are older. The library is primarily a framework integration rather than a standalone application, but its design patterns serve as a reference for building Spring Boot auto-configuration with complex SPI chains.