Structured output support for Anthropic Claude models on Amazon Bedrock

Amazon Web Services (AWS) has announced that all Anthropic Claude models on Amazon Bedrock will now support structured outputs at the bedrock-runtime and bedrock-mantle endpoints.

Thanks to structured output support, developers can invoke Claude using Boto3 and bedrock-runtime APIs, or via the Messages API at the bedrock-mantle endpoint, to receive JSON responses that directly conform to a defined schema. This innovation eliminates the need for custom parsing, retry logic, or post-processing workflows.

The system uses constrained decoding, which enforces the JSON schema during token generation. This shifts output formatting from probabilistic to deterministic.