AWS announces general availability of Smithy-Java client framework

AWS today announced the general availability of Smithy-Java, an open-source Java framework for generating type-safe clients and standalone classes from Smithy models. Smithy-Java addresses one of the most consistently requested capabilities from enterprise Smithy users: production-grade Java SDK generation. The framework allows you to generate clients from models and async patterns that increase cognitive load and maintenance burden for developers building modern Java applications.

Built on Java 21's virtual threads, Smithy-Java provides a blocking-style API that is both simpler to use and competitive in performance with complex async alternatives. Key benefits include auto-generated type-safe clients from Smithy, protocol flexibility with runtime protocol swapping for gradual migration paths. The GA release includes the Java client code generator, support for AWS SigV4 and all major AWS protocols (AWS JSON, REST-JSON, REST-XML, AWS Query, and Smithy RPCv2-CBOR), standalone type code generation for sharing types across multiple services or data modeling, and a dynamic client that can call Smithy services without a codegen step.

The framework pioneers two architectural innovations: schema-driven serialization that reduces SDK size while improving performance, and binary decision diagrams (BDD) for endpoint rules resolution delivering significant latency improvements. Internal Amazon teams have already built complete services in weeks rather than months using Smithy-Java, with service teams depending on it internally. The framework is ideal for organizations invested in the Smithy ecosystem, teams requiring protocol-agnostic development, and developers building new services with generated server stubs.

To learn more, visit our blog post and follow the Smithy Java Quickstart guide.