1.2.0:

• Add Thinking type with ThinkingAdaptive and ThinkingEnabled constructors
  • thinking field on CreateMessage
  • ContentBlock_Thinking and ContentBlock_Redacted_Thinking response blocks
  • Content_Thinking and Content_Redacted_Thinking for replaying thinking in multi-turn
  • Delta_Thinking_Delta and Delta_Signature_Delta for streaming
• Add Model_Context_Window_Exceeded constructor to StopReason

1.1.0:

• Replace output_format with output_config on CreateMessage (breaking change)
  • New OutputConfig type with effort and format fields
  • effortConfig helper for effort-only configuration
  • jsonSchemaConfig helper for structured output configuration
• Remove beta header requirement for structured outputs (now GA)

1.0.1:

• Add structured outputs support (beta feature structured-outputs-2025-11-13)
  • OutputFormat type and jsonSchemaFormat helper for JSON outputs
  • output_format field on CreateMessage
  • strict field on Tool and strictFunctionTool helper for strict tool validation
  • additionalProperties field on InputSchema
  • Refusal constructor for StopReason
• Add claude-structured-outputs-example

1.0.0:

• Initial release