New Features and Improvements

Enhanced AWS SDK Integration

• New AWS authentication schemes: Added support for multiple authentication methods including SigV4, SigV4A, and bearer token authentication
• Improved credential providers:
• Added HTTP credential provider for containerized environments (ECS/EKS)
• Enhanced SSO credential provider with automatic token refresh
• Added support for environment variable-based credentials with account ID and credential scope
• New authentication configuration: Users can now specify authentication scheme preferences via:
• Environment variable: AWS_AUTH_SCHEME_PREFERENCE
• Config file setting: auth_scheme_preference
• Bearer tokens: AWS_BEARER_TOKEN_<SERVICE_NAME>

Protocol and Serialization Enhancements

• Added comprehensive protocol support:
• AWS JSON RPC (1.0 and 1.1)
• AWS Query protocol
• AWS EC2 Query protocol
• AWS REST JSON
• AWS REST XML
• New serialization/deserialization infrastructure: Added schema-based serialization with support for complex data types including big integers, big decimals, and timestamps

Improved Error Handling

• Service exceptions: New base ServiceException class with better error metadata
• Protocol-specific error handling: Each AWS protocol now has specialized error deserialization
• Enhanced error messages: More descriptive error messages with request IDs and extended metadata

Performance and Reliability

• Request retry enhancements: Improved retry strategies with configurable retry modes
• Connection timeout configuration: Different timeout settings based on deployment mode (standard, in-region, cross-region, mobile)
• Middleware improvements: Added recursion detection for Lambda environments to prevent infinite loops

Developer Experience

• Command builder pattern: New fluent API for building commands:

  Command.classBuilder()
    .n("ServiceClient", "OperationCommand")
    .f(inputFilter, outputFilter)
    .ser(serializer)
    .de(deserializer)
    .build()

• Aggregated client support: Automatically generate convenience methods for all service operations
• Improved logging: Better structured logging with sensitive data filtering