AWS Smithy Java client framework reaches general availability

Smithy provides a model-driven approach to defining services and generating code, using declarative formats to capture API structure, constraints, and protocol bindings. This ensures clients, services, and documentation remain aligned with API evolution from a single source of truth.

Generated Smithy Java clients are protocol-agnostic and include built-in support for HTTP transport, various AWS protocols (AWS JSON 1.0/1.1, restJson1, restXml, Query), and Smithy RPCv2 CBOR. Protocols can be swapped at runtime without rebuilding the client.

A dynamic client is available that loads Smithy models at runtime, allowing interaction with any service API without a code generation step. This is useful for tools, aggregators, or systems needing to interact with unknown services at build time with a small deployment footprint.

Smithy Java can generate type-safe Java classes from Smithy shapes without service context. This allows for code reuse and consistency across projects sharing common types, extending the model-first approach beyond service calls.

Smithy Java is built around Java 21's virtual threads, offering a blocking-style interface that is easy to read, write, and debug. This approach avoids complex async APIs, allowing developers to focus on business logic while the JVM handles task scheduling and synchronization.

The Smithy Java client code generation is now generally available, meaning its public APIs are stable and committed to backward compatibility for production use. Developers can use it to build type-safe, protocol-agnostic Java clients directly from Smithy models, automating serialization, protocol handling, and request/response lifecycles.