Changes to Create a Message

the error response's property type changed from no type to object for status 404

added the optional property error/details to the response with the 404 status

added ThreadAlreadyContinuedErrorDetails ThreadContinueInFlightErrorDetails ThreadFingerprintMismatchErrorDetails ThreadUnsupportedRequestErrorDetails to the error/details response property anyOf list for the response status 400

removed discriminator from error response property for the response status 404

removed InvalidRequestError AuthenticationError BillingError PermissionError NotFoundError RateLimitError GatewayTimeoutError APIError OverloadedError from the error response property oneOf list for the response status 404

added the required property error/message to the response with the 404 status

added the required property error/type to the response with the 404 status

the messages/items request property type changed from object to no type

removed the request property messages/items/content

removed the request property messages/items/role

removed the request property temperature

removed the request property top_k

removed the request property top_p

added assistant system user discriminator mapping keys to the messages/items request property

added UserInputMessage AssistantInputMessage SystemInputMessage to the messages/items request property oneOf list

the error response's property type changed from no type to object for status 503

added the optional property error/details to the response with the 503 status

removed discriminator from error response property for the response status 503

removed InvalidRequestError AuthenticationError BillingError PermissionError NotFoundError RateLimitError GatewayTimeoutError APIError OverloadedError from the error response property oneOf list for the response status 503

added the required property error/message to the response with the 503 status

added the required property error/type to the response with the 503 status

added the new optional request property speed

added the required property usage/speed to the response with the 200 status

removed subschema #15 subschema #16 from the model request property anyOf list

added subschema #15 subschema #16 to the model request property anyOf list

added subschema #15 subschema #16 to the model response property anyOf list for the response status 200

removed subschema #15 subschema #16 from the model response property anyOf list for the response status 200

the error response's property type changed from no type to object for status 400

the error response's property type changed from no type to object for status 409

the error response's property type changed from no type to object for status 413

the error response's property type changed from no type to object for status 429

the error response's property type changed from no type to object for status 529

added the optional property error/details to the response with the 400 status

added the optional property error/details to the response with the 409 status

added the optional property error/details to the response with the 413 status

added the optional property error/details to the response with the 429 status

added the optional property error/details to the response with the 529 status

removed discriminator from error response property for the response status 400

removed discriminator from error response property for the response status 409

removed discriminator from error response property for the response status 413

removed discriminator from error response property for the response status 429

removed discriminator from error response property for the response status 529

removed InvalidRequestError AuthenticationError BillingError PermissionError NotFoundError RateLimitError GatewayTimeoutError APIError OverloadedError from the error response property oneOf list for the response status 400

removed InvalidRequestError AuthenticationError BillingError PermissionError NotFoundError RateLimitError GatewayTimeoutError APIError OverloadedError from the error response property oneOf list for the response status 409

removed InvalidRequestError AuthenticationError BillingError PermissionError NotFoundError RateLimitError GatewayTimeoutError APIError OverloadedError from the error response property oneOf list for the response status 413

removed InvalidRequestError AuthenticationError BillingError PermissionError NotFoundError RateLimitError GatewayTimeoutError APIError OverloadedError from the error response property oneOf list for the response status 429

removed InvalidRequestError AuthenticationError BillingError PermissionError NotFoundError RateLimitError GatewayTimeoutError APIError OverloadedError from the error response property oneOf list for the response status 529

added the required property error/message to the response with the 400 status

added the required property error/message to the response with the 409 status

added the required property error/message to the response with the 413 status

added the required property error/message to the response with the 429 status

added the required property error/message to the response with the 529 status

added the required property error/type to the response with the 400 status

added the required property error/type to the response with the 409 status

added the required property error/type to the response with the 413 status

added the required property error/type to the response with the 429 status

added the required property error/type to the response with the 529 status

added subschema #1 to the model request property anyOf list

added subschema #1 to the model response property anyOf list for the response status 200

removed subschema #18 subschema #19 from the model request property anyOf list

added subschema #18 subschema #19 to the model request property anyOf list

added subschema #18 subschema #19 to the model response property anyOf list for the response status 200

removed subschema #18 subschema #19 from the model response property anyOf list for the response status 200

removed subschema #4 from the model request property anyOf list

added subschema #1 subschema #5 to the model request property anyOf list

added subschema #1 subschema #5 to the model response property anyOf list for the response status 200

removed subschema #4 from the model response property anyOf list for the response status 200

added between_tools discriminator mapping keys to the thinking request property

added ThinkingConfigBetweenTools to the thinking request property oneOf list

added the new optional request property diagnostics

added the required property diagnostics to the response with the 200 status

the stop_details/anyOf[subschema #1: RefusalStopDetails]/category/anyOf[subschema #1: RefusalCategory] response's property type changed from string to no type for status 200

added subschema #1 subschema #2 subschema #3 subschema #4 subschema #5 to the stop_details/anyOf[subschema #1: RefusalStopDetails]/category/anyOf[subschema #1: RefusalCategory] response property anyOf list for the response status 200

removed the bio enum value from the stop_details/anyOf[subschema #1: RefusalStopDetails]/category/anyOf[subschema #1: RefusalCategory] response property for the response status 200

removed the cyber enum value from the stop_details/anyOf[subschema #1: RefusalStopDetails]/category/anyOf[subschema #1: RefusalCategory] response property for the response status 200

removed the frontier_llm enum value from the stop_details/anyOf[subschema #1: RefusalStopDetails]/category/anyOf[subschema #1: RefusalCategory] response property for the response status 200

removed the general_harms enum value from the stop_details/anyOf[subschema #1: RefusalStopDetails]/category/anyOf[subschema #1: RefusalCategory] response property for the response status 200

removed the reasoning_extraction enum value from the stop_details/anyOf[subschema #1: RefusalStopDetails]/category/anyOf[subschema #1: RefusalCategory] response property for the response status 200

added subschema #3 to the model request property anyOf list

added subschema #3 to the model response property anyOf list for the response status 200

added the new optional request property tools/items/oneOf[subschema #14: WebFetchTool_20250910]/url_sources

added the new optional request property tools/items/oneOf[subschema #16: WebFetchTool_20260209]/url_sources

added the new optional request property tools/items/oneOf[subschema #17: WebFetchTool_20260309]/url_sources

added the new optional request property tools/items/oneOf[subschema #19: WebFetchTool_20260318]/url_sources

added the new content_too_large enum value to the content/items/oneOf[subschema #7: ResponseWebFetchToolResultBlock]/content/anyOf[subschema #1: ResponseWebFetchToolResultError]/error_code response property for the response status 200

added the new content_too_large enum value to the request property messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #11: RequestWebFetchToolResultBlock]/content/anyOf[subschema #1: RequestWebFetchToolResultError]/error_code

the content/items/oneOf[subschema #1: ResponseTextBlock]/text response property's maxLength was unset from 5000000 for the response status 200

added the new optional header request parameter anthropic-workspace-id

added the non-success response with the status 400

added the non-success response with the status 401

added the non-success response with the status 403

added the non-success response with the status 404

added the non-success response with the status 408

added the non-success response with the status 409

added the non-success response with the status 412

added the non-success response with the status 413

added the non-success response with the status 429

added the non-success response with the status 431

added the non-success response with the status 499

added the non-success response with the status 500

added the non-success response with the status 501

added the non-success response with the status 503

added the non-success response with the status 504

added the non-success response with the status 529

removed the request property tools/items/oneOf[subschema #7: BrowserToolset_20260801]/allowed_callers

removed the request property tools/items/oneOf[subschema #9: ComputerToolset_20260801]/allowed_callers

added subschema #2 subschema #3 to the model request property anyOf list

added subschema #2 subschema #3 to the model response property anyOf list for the response status 200

added the new optional request property messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #11: RequestWebFetchToolResultBlock]/content/anyOf[subschema #2: RequestWebFetchResultBlock]/content/source/oneOf[subschema #3: ContentBlockSource]/content/anyOf[subschema #2: content_block_source_content]/items/oneOf[subschema #2: RequestImageBlock]/transformations

added the new optional request property messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #2: RequestImageBlock]/transformations

added the new optional request property messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #3: RequestDocumentBlock]/source/oneOf[subschema #3: ContentBlockSource]/content/anyOf[subschema #2: content_block_source_content]/items/oneOf[subschema #2: RequestImageBlock]/transformations

added the new optional request property messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #7: RequestToolUseBlock]/toolset_name

added the new optional request property messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #8: RequestToolResultBlock]/content/anyOf[subschema #2]/items/oneOf[subschema #2: RequestImageBlock]/transformations

added the new optional request property messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #8: RequestToolResultBlock]/content/anyOf[subschema #2]/items/oneOf[subschema #4: RequestDocumentBlock]/source/oneOf[subschema #3: ContentBlockSource]/content/anyOf[subschema #2: content_block_source_content]/items/oneOf[subschema #2: RequestImageBlock]/transformations

added the new optional request property messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #8: RequestToolResultBlock]/toolset_name

added ContainerParams to the container request property anyOf list

added browser_state discriminator mapping keys to the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #8: RequestToolResultBlock]/content/anyOf[subschema #2]/items request property

added file discriminator mapping keys to the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #11: RequestWebFetchToolResultBlock]/content/anyOf[subschema #2: RequestWebFetchResultBlock]/content/source request property

added file discriminator mapping keys to the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #11: RequestWebFetchToolResultBlock]/content/anyOf[subschema #2: RequestWebFetchResultBlock]/content/source/oneOf[subschema #3: ContentBlockSource]/content/anyOf[subschema #2: content_block_source_content]/items/oneOf[subschema #2: RequestImageBlock]/source request property

added file discriminator mapping keys to the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #2: RequestImageBlock]/source request property

added file discriminator mapping keys to the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #3: RequestDocumentBlock]/source request property

added file discriminator mapping keys to the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #3: RequestDocumentBlock]/source/oneOf[subschema #3: ContentBlockSource]/content/anyOf[subschema #2: content_block_source_content]/items/oneOf[subschema #2: RequestImageBlock]/source request property

added file discriminator mapping keys to the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #8: RequestToolResultBlock]/content/anyOf[subschema #2]/items/oneOf[subschema #2: RequestImageBlock]/source request property

added file discriminator mapping keys to the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #8: RequestToolResultBlock]/content/anyOf[subschema #2]/items/oneOf[subschema #4: RequestDocumentBlock]/source request property

added file discriminator mapping keys to the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #8: RequestToolResultBlock]/content/anyOf[subschema #2]/items/oneOf[subschema #4: RequestDocumentBlock]/source/oneOf[subschema #3: ContentBlockSource]/content/anyOf[subschema #2: content_block_source_content]/items/oneOf[subschema #2: RequestImageBlock]/source request property

added BrowserToolset_20260801 ComputerToolset_20260801 to the tools/items request property oneOf list

added FileDocumentSource to the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #11: RequestWebFetchToolResultBlock]/content/anyOf[subschema #2: RequestWebFetchResultBlock]/content/source request property oneOf list

added FileDocumentSource to the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #3: RequestDocumentBlock]/source request property oneOf list

added FileDocumentSource to the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #8: RequestToolResultBlock]/content/anyOf[subschema #2]/items/oneOf[subschema #4: RequestDocumentBlock]/source request property oneOf list

added FileImageSource to the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #11: RequestWebFetchToolResultBlock]/content/anyOf[subschema #2: RequestWebFetchResultBlock]/content/source/oneOf[subschema #3: ContentBlockSource]/content/anyOf[subschema #2: content_block_source_content]/items/oneOf[subschema #2: RequestImageBlock]/source request property oneOf list

added FileImageSource to the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #2: RequestImageBlock]/source request property oneOf list

added FileImageSource to the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #3: RequestDocumentBlock]/source/oneOf[subschema #3: ContentBlockSource]/content/anyOf[subschema #2: content_block_source_content]/items/oneOf[subschema #2: RequestImageBlock]/source request property oneOf list

added FileImageSource to the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #8: RequestToolResultBlock]/content/anyOf[subschema #2]/items/oneOf[subschema #2: RequestImageBlock]/source request property oneOf list

added FileImageSource to the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #8: RequestToolResultBlock]/content/anyOf[subschema #2]/items/oneOf[subschema #4: RequestDocumentBlock]/source/oneOf[subschema #3: ContentBlockSource]/content/anyOf[subschema #2: content_block_source_content]/items/oneOf[subschema #2: RequestImageBlock]/source request property oneOf list

added RequestBrowserStateBlock to the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #8: RequestToolResultBlock]/content/anyOf[subschema #2]/items request property oneOf list

added the optional property content/items/oneOf[subschema #4: ResponseToolUseBlock]/toolset_name to the response with the 200 status

added the required property container/anyOf[subschema #1: Container]/skills to the response with the 200 status

removed RequestMidConvSystemBlock from the messages/items/content/anyOf[subschema #2]/items request property oneOf list

removed mid_conv_system discriminator mapping keys from the messages/items/content/anyOf[subschema #2]/items request property

the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #11: RequestWebFetchToolResultBlock]/content/anyOf[subschema #2: RequestWebFetchResultBlock]/content/source/oneOf[subschema #3: ContentBlockSource]/content/anyOf[subschema #2: content_block_source_content]/items/oneOf[subschema #1: RequestTextBlock]/citations/anyOf[subschema #1]/items/oneOf[subschema #1: RequestCharLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #11: RequestWebFetchToolResultBlock]/content/anyOf[subschema #2: RequestWebFetchResultBlock]/content/source/oneOf[subschema #3: ContentBlockSource]/content/anyOf[subschema #2: content_block_source_content]/items/oneOf[subschema #1: RequestTextBlock]/citations/anyOf[subschema #1]/items/oneOf[subschema #2: RequestPageLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #11: RequestWebFetchToolResultBlock]/content/anyOf[subschema #2: RequestWebFetchResultBlock]/content/source/oneOf[subschema #3: ContentBlockSource]/content/anyOf[subschema #2: content_block_source_content]/items/oneOf[subschema #1: RequestTextBlock]/citations/anyOf[subschema #1]/items/oneOf[subschema #3: RequestContentBlockLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #17: RequestMidConvSystemBlock]/content/items/oneOf[subschema #1: RequestTextBlock]/citations/anyOf[subschema #1]/items/oneOf[subschema #1: RequestCharLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #17: RequestMidConvSystemBlock]/content/items/oneOf[subschema #1: RequestTextBlock]/citations/anyOf[subschema #1]/items/oneOf[subschema #2: RequestPageLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #17: RequestMidConvSystemBlock]/content/items/oneOf[subschema #1: RequestTextBlock]/citations/anyOf[subschema #1]/items/oneOf[subschema #3: RequestContentBlockLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #1: RequestTextBlock]/citations/anyOf[subschema #1]/items/oneOf[subschema #1: RequestCharLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #1: RequestTextBlock]/citations/anyOf[subschema #1]/items/oneOf[subschema #2: RequestPageLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #1: RequestTextBlock]/citations/anyOf[subschema #1]/items/oneOf[subschema #3: RequestContentBlockLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #3: RequestDocumentBlock]/source/oneOf[subschema #3: ContentBlockSource]/content/anyOf[subschema #2: content_block_source_content]/items/oneOf[subschema #1: RequestTextBlock]/citations/anyOf[subschema #1]/items/oneOf[subschema #1: RequestCharLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #3: RequestDocumentBlock]/source/oneOf[subschema #3: ContentBlockSource]/content/anyOf[subschema #2: content_block_source_content]/items/oneOf[subschema #1: RequestTextBlock]/citations/anyOf[subschema #1]/items/oneOf[subschema #2: RequestPageLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #3: RequestDocumentBlock]/source/oneOf[subschema #3: ContentBlockSource]/content/anyOf[subschema #2: content_block_source_content]/items/oneOf[subschema #1: RequestTextBlock]/citations/anyOf[subschema #1]/items/oneOf[subschema #3: RequestContentBlockLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #4: RequestSearchResultBlock]/content/items/citations/anyOf[subschema #1]/items/oneOf[subschema #1: RequestCharLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #4: RequestSearchResultBlock]/content/items/citations/anyOf[subschema #1]/items/oneOf[subschema #2: RequestPageLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #4: RequestSearchResultBlock]/content/items/citations/anyOf[subschema #1]/items/oneOf[subschema #3: RequestContentBlockLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #8: RequestToolResultBlock]/content/anyOf[subschema #2]/items/oneOf[subschema #1: RequestTextBlock]/citations/anyOf[subschema #1]/items/oneOf[subschema #1: RequestCharLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #8: RequestToolResultBlock]/content/anyOf[subschema #2]/items/oneOf[subschema #1: RequestTextBlock]/citations/anyOf[subschema #1]/items/oneOf[subschema #2: RequestPageLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #8: RequestToolResultBlock]/content/anyOf[subschema #2]/items/oneOf[subschema #1: RequestTextBlock]/citations/anyOf[subschema #1]/items/oneOf[subschema #3: RequestContentBlockLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #8: RequestToolResultBlock]/content/anyOf[subschema #2]/items/oneOf[subschema #3: RequestSearchResultBlock]/content/items/citations/anyOf[subschema #1]/items/oneOf[subschema #1: RequestCharLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #8: RequestToolResultBlock]/content/anyOf[subschema #2]/items/oneOf[subschema #3: RequestSearchResultBlock]/content/items/citations/anyOf[subschema #1]/items/oneOf[subschema #2: RequestPageLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #8: RequestToolResultBlock]/content/anyOf[subschema #2]/items/oneOf[subschema #3: RequestSearchResultBlock]/content/items/citations/anyOf[subschema #1]/items/oneOf[subschema #3: RequestContentBlockLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #8: RequestToolResultBlock]/content/anyOf[subschema #2]/items/oneOf[subschema #4: RequestDocumentBlock]/source/oneOf[subschema #3: ContentBlockSource]/content/anyOf[subschema #2: content_block_source_content]/items/oneOf[subschema #1: RequestTextBlock]/citations/anyOf[subschema #1]/items/oneOf[subschema #1: RequestCharLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #8: RequestToolResultBlock]/content/anyOf[subschema #2]/items/oneOf[subschema #4: RequestDocumentBlock]/source/oneOf[subschema #3: ContentBlockSource]/content/anyOf[subschema #2: content_block_source_content]/items/oneOf[subschema #1: RequestTextBlock]/citations/anyOf[subschema #1]/items/oneOf[subschema #2: RequestPageLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #8: RequestToolResultBlock]/content/anyOf[subschema #2]/items/oneOf[subschema #4: RequestDocumentBlock]/source/oneOf[subschema #3: ContentBlockSource]/content/anyOf[subschema #2: content_block_source_content]/items/oneOf[subschema #1: RequestTextBlock]/citations/anyOf[subschema #1]/items/oneOf[subschema #3: RequestContentBlockLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the system/anyOf[subschema #2]/items/citations/anyOf[subschema #1]/items/oneOf[subschema #1: RequestCharLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the system/anyOf[subschema #2]/items/citations/anyOf[subschema #1]/items/oneOf[subschema #2: RequestPageLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

the system/anyOf[subschema #2]/items/citations/anyOf[subschema #1]/items/oneOf[subschema #3: RequestContentBlockLocationCitation]/document_title/anyOf[subschema #1] request property's maxLength was increased from 255 to 500

removed subschema #17 subschema #18 from the model request property anyOf list

removed subschema #17 subschema #18 from the model response property anyOf list for the response status 200

removed subschema #5 subschema #6 subschema #8 subschema #12 subschema #13 subschema #16 subschema #17 from the model request property anyOf list

added subschema #5 subschema #6 subschema #7 subschema #9 subschema #13 subschema #14 subschema #17 subschema #18 to the model request property anyOf list

added subschema #5 subschema #6 subschema #7 subschema #9 subschema #13 subschema #14 subschema #17 subschema #18 to the model response property anyOf list for the response status 200

removed subschema #5 subschema #6 subschema #8 subschema #12 subschema #13 subschema #16 subschema #17 from the model response property anyOf list for the response status 200

added the new model_context_window_exceeded enum value to the stop_reason/anyOf[#/components/schemas/StopReason] response property for the response status 200

added the new general_harms enum value to the stop_details/anyOf[subschema #1: RefusalStopDetails]/category/anyOf[subschema #1: RefusalCategory] response property for the response status 200

removed the military_weapons enum value from the stop_details/anyOf[subschema #1: RefusalStopDetails]/category/anyOf[subschema #1: RefusalCategory] response property for the response status 200

added subschema #2 to the model request property anyOf list

added subschema #2 to the model response property anyOf list for the response status 200

added WebSearchTool_20260318 WebFetchTool_20260318 to the tools/items request property oneOf list

added the new military_weapons enum value to the stop_details/anyOf[subschema #1: RefusalStopDetails]/category/anyOf[subschema #1: RefusalCategory] response property for the response status 200

added the new optional header request parameter anthropic-user-profile-id

removed subschema #17 subschema #18 subschema #19 subschema #20 subschema #21 from the model request property anyOf list

added the new code_execution_20260521 enum value to the request property tools/items/oneOf[subschema #10: WebSearchTool_20250305 -> subschema #11: WebSearchTool_20250305]/allowed_callers/items

added the new code_execution_20260521 enum value to the request property tools/items/oneOf[subschema #11: WebFetchTool_20250910 -> subschema #12: WebFetchTool_20250910]/allowed_callers/items

added the new code_execution_20260521 enum value to the request property tools/items/oneOf[subschema #12: WebSearchTool_20260209 -> subschema #13: WebSearchTool_20260209]/allowed_callers/items

added the new code_execution_20260521 enum value to the request property tools/items/oneOf[subschema #13: WebFetchTool_20260209 -> subschema #14: WebFetchTool_20260209]/allowed_callers/items

added the new code_execution_20260521 enum value to the request property tools/items/oneOf[subschema #14: WebFetchTool_20260309 -> subschema #15: WebFetchTool_20260309]/allowed_callers/items

added the new code_execution_20260521 enum value to the request property tools/items/oneOf[subschema #15: ToolSearchToolBM25_20251119 -> subschema #16: ToolSearchToolBM25_20251119]/allowed_callers/items

added the new code_execution_20260521 enum value to the request property tools/items/oneOf[subschema #16: ToolSearchToolRegex_20251119 -> subschema #17: ToolSearchToolRegex_20251119]/allowed_callers/items

added the new code_execution_20260521 enum value to the request property tools/items/oneOf[subschema #1: Tool]/allowed_callers/items

added the new code_execution_20260521 enum value to the request property tools/items/oneOf[subschema #2: BashTool_20250124]/allowed_callers/items

added the new code_execution_20260521 enum value to the request property tools/items/oneOf[subschema #3: CodeExecutionTool_20250522]/allowed_callers/items

added the new code_execution_20260521 enum value to the request property tools/items/oneOf[subschema #4: CodeExecutionTool_20250825]/allowed_callers/items

added the new code_execution_20260521 enum value to the request property tools/items/oneOf[subschema #5: CodeExecutionTool_20260120]/allowed_callers/items

added the new code_execution_20260521 enum value to the request property tools/items/oneOf[subschema #6: MemoryTool_20250818 -> subschema #7: MemoryTool_20250818]/allowed_callers/items

added the new code_execution_20260521 enum value to the request property tools/items/oneOf[subschema #7: TextEditor_20250124 -> subschema #8: TextEditor_20250124]/allowed_callers/items

added the new code_execution_20260521 enum value to the request property tools/items/oneOf[subschema #8: TextEditor_20250429 -> subschema #9: TextEditor_20250429]/allowed_callers/items

added the new code_execution_20260521 enum value to the request property tools/items/oneOf[subschema #9: TextEditor_20250728 -> subschema #10: TextEditor_20250728]/allowed_callers/items

added CodeExecutionTool_20260521 to the tools/items request property oneOf list

removed subschema #17 subschema #18 subschema #19 subschema #20 subschema #21 from the model response property anyOf list for the response status 200

added the new frontier_llm enum value to the stop_details/anyOf[subschema #1: RefusalStopDetails]/category/anyOf[subschema #1] response property for the response status 200

removed subschema #4 from the model request property anyOf list

added the new reasoning_extraction enum value to the stop_details/anyOf[subschema #1: RefusalStopDetails]/category/anyOf[subschema #1] response property for the response status 200

added subschema #2 subschema #3 subschema #6 to the model request property anyOf list

added subschema #2 subschema #3 subschema #6 to the model response property anyOf list for the response status 200

removed subschema #4 from the model response property anyOf list for the response status 200

removed subschema #13 subschema #14 from the model request property anyOf list

added the new optional request property messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #15: RequestToolSearchToolResultBlock]/content/anyOf[subschema #1: RequestToolSearchToolResultError]/error_message

added subschema #13 subschema #14 to the model request property anyOf list

added subschema #13 subschema #14 to the model response property anyOf list for the response status 200

removed subschema #13 subschema #14 from the model response property anyOf list for the response status 200

added the new url_not_in_prior_context enum value to the content/items/oneOf[subschema #7: ResponseWebFetchToolResultBlock]/content/anyOf[subschema #1: ResponseWebFetchToolResultError]/error_code response property for the response status 200

added subschema #2 to the model request property anyOf list

added mid_conv_system discriminator mapping keys to the messages/items/content/anyOf[subschema #2]/items request property

added the new system enum value to the request property messages/items/role

added the new url_not_in_prior_context enum value to the request property messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #11: RequestWebFetchToolResultBlock]/content/anyOf[subschema #1: RequestWebFetchToolResultError]/error_code

added RequestMidConvSystemBlock to the messages/items/content/anyOf[subschema #2]/items request property oneOf list

added subschema #2 to the model response property anyOf list for the response status 200

added the required property usage/output_tokens_details to the response with the 200 status

the tools/items/oneOf[subschema #9: TextEditor_20250728]/input_examples/items/additionalProperties request property type changed from unknown to no type

the tools/items/oneOf[subschema #9: TextEditor_20250728]/input_examples/items/additionalProperties request property type changed from no type to unknown

the max_tokens request property's min was decreased from 1.00 to 0.00

removed subschema #13 subschema #14 subschema #15 subschema #16 from the model request property anyOf list

added subschema #2 subschema #14 subschema #15 subschema #16 subschema #17 to the model request property anyOf list

added the new xhigh enum value to the request property output_config/effort/anyOf[subschema #1: EffortLevel]

added subschema #2 subschema #14 subschema #15 subschema #16 subschema #17 to the model response property anyOf list for the response status 200

removed subschema #13 subschema #14 subschema #15 subschema #16 from the model response property anyOf list for the response status 200

removed subschema #2 from the model request property anyOf list

added subschema #2 subschema #3 to the model request property anyOf list

request property temperature deprecated

request property top_k deprecated

request property top_p deprecated

added subschema #2 subschema #3 to the model response property anyOf list for the response status 200

removed subschema #2 from the model response property anyOf list for the response status 200

added the required property stop_details to the response with the 200 status

the metadata/user_id/anyOf[subschema #1] request property's maxLength was increased from 256 to 512

removed subschema #3 subschema #6 subschema #7 subschema #8 subschema #9 subschema #10 subschema #11 subschema #14 subschema #15 subschema #16 subschema #17 subschema #18 subschema #19 subschema #20 subschema #21 subschema #22 subschema #23 from the model request property anyOf list

added the new optional request property thinking/oneOf[subschema #1: ThinkingConfigEnabled]/display

added the new optional request property thinking/oneOf[subschema #3: ThinkingConfigAdaptive]/display

added subschema #3 subschema #4 subschema #5 subschema #8 subschema #9 subschema #10 subschema #11 subschema #12 subschema #13 subschema #16 to the model request property anyOf list

added WebFetchTool_20260309 to the tools/items request property oneOf list

added subschema #3 subschema #4 subschema #5 subschema #8 subschema #9 subschema #10 subschema #11 subschema #12 subschema #13 subschema #16 to the model response property anyOf list for the response status 200

removed subschema #3 subschema #6 subschema #7 subschema #8 subschema #9 subschema #10 subschema #11 subschema #14 subschema #15 subschema #16 subschema #17 subschema #18 subschema #19 subschema #20 subschema #21 subschema #22 subschema #23 from the model response property anyOf list for the response status 200

added the new optional request property cache_control

added the new code_execution_20260120 enum value to the request property tools/items/oneOf[subschema #10: WebSearchTool_20250305]/allowed_callers/items

added the new code_execution_20260120 enum value to the request property tools/items/oneOf[subschema #11: WebFetchTool_20250910]/allowed_callers/items

added the new code_execution_20260120 enum value to the request property tools/items/oneOf[subschema #12: WebSearchTool_20260209]/allowed_callers/items

added the new code_execution_20260120 enum value to the request property tools/items/oneOf[subschema #13: WebFetchTool_20260209]/allowed_callers/items

added the new code_execution_20260120 enum value to the request property tools/items/oneOf[subschema #14: ToolSearchToolBM25_20251119]/allowed_callers/items

added the new code_execution_20260120 enum value to the request property tools/items/oneOf[subschema #15: ToolSearchToolRegex_20251119]/allowed_callers/items

added the new code_execution_20260120 enum value to the request property tools/items/oneOf[subschema #1: Tool]/allowed_callers/items

added the new code_execution_20260120 enum value to the request property tools/items/oneOf[subschema #2: BashTool_20250124]/allowed_callers/items

added the new code_execution_20260120 enum value to the request property tools/items/oneOf[subschema #3: CodeExecutionTool_20250522]/allowed_callers/items

added the new code_execution_20260120 enum value to the request property tools/items/oneOf[subschema #4: CodeExecutionTool_20250825]/allowed_callers/items

added the new code_execution_20260120 enum value to the request property tools/items/oneOf[subschema #5: CodeExecutionTool_20260120]/allowed_callers/items

added the new code_execution_20260120 enum value to the request property tools/items/oneOf[subschema #6: MemoryTool_20250818]/allowed_callers/items

added the new code_execution_20260120 enum value to the request property tools/items/oneOf[subschema #7: TextEditor_20250124]/allowed_callers/items

added the new code_execution_20260120 enum value to the request property tools/items/oneOf[subschema #8: TextEditor_20250429]/allowed_callers/items

added the new code_execution_20260120 enum value to the request property tools/items/oneOf[subschema #9: TextEditor_20250728]/allowed_callers/items

removed the required property usage/speed from the response with the 200 status

removed the request property speed

request property messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #9: RequestServerToolUseBlock]/name was restricted to a list of enum values

the name response property const value web_search was removed for the status 200

added ResponseWebFetchToolResultBlock ResponseCodeExecutionToolResultBlock ResponseBashCodeExecutionToolResultBlock ResponseTextEditorCodeExecutionToolResultBlock ResponseToolSearchToolResultBlock ResponseContainerUploadBlock to the content/items response property oneOf list for the response status 200

added the new bash_code_execution enum value to the content/items/oneOf[subschema #5: ResponseServerToolUseBlock]/name response property for the response status 200

added the new code_execution enum value to the content/items/oneOf[subschema #5: ResponseServerToolUseBlock]/name response property for the response status 200

added the new text_editor_code_execution enum value to the content/items/oneOf[subschema #5: ResponseServerToolUseBlock]/name response property for the response status 200

added the new tool_search_tool_bm25 enum value to the content/items/oneOf[subschema #5: ResponseServerToolUseBlock]/name response property for the response status 200

added the new tool_search_tool_regex enum value to the content/items/oneOf[subschema #5: ResponseServerToolUseBlock]/name response property for the response status 200

added the new web_fetch enum value to the content/items/oneOf[subschema #5: ResponseServerToolUseBlock]/name response property for the response status 200

added the new web_search enum value to the content/items/oneOf[subschema #5: ResponseServerToolUseBlock]/name response property for the response status 200

added the new optional request property container

added the new optional request property messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #10: RequestWebSearchToolResultBlock]/caller

added the new optional request property messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #7: RequestToolUseBlock]/caller

added the new optional request property messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #9: RequestServerToolUseBlock]/caller

added the new optional request property speed

added the new optional request property tools/items/oneOf[subschema #1: Tool]/allowed_callers

added the new optional request property tools/items/oneOf[subschema #1: Tool]/defer_loading

added the new optional request property tools/items/oneOf[subschema #1: Tool]/input_examples

added the new optional request property tools/items/oneOf[subschema #2: BashTool_20250124]/allowed_callers

added the new optional request property tools/items/oneOf[subschema #2: BashTool_20250124]/defer_loading

added the new optional request property tools/items/oneOf[subschema #2: BashTool_20250124]/input_examples

added the new optional request property tools/items/oneOf[subschema #3: TextEditor_20250124 -> subschema #7: TextEditor_20250124]/allowed_callers

added the new optional request property tools/items/oneOf[subschema #3: TextEditor_20250124 -> subschema #7: TextEditor_20250124]/defer_loading

added the new optional request property tools/items/oneOf[subschema #3: TextEditor_20250124 -> subschema #7: TextEditor_20250124]/input_examples

added the new optional request property tools/items/oneOf[subschema #4: TextEditor_20250429 -> subschema #8: TextEditor_20250429]/allowed_callers

added the new optional request property tools/items/oneOf[subschema #4: TextEditor_20250429 -> subschema #8: TextEditor_20250429]/defer_loading

added the new optional request property tools/items/oneOf[subschema #4: TextEditor_20250429 -> subschema #8: TextEditor_20250429]/input_examples

added the new optional request property tools/items/oneOf[subschema #5: TextEditor_20250728 -> subschema #9: TextEditor_20250728]/allowed_callers

added the new optional request property tools/items/oneOf[subschema #5: TextEditor_20250728 -> subschema #9: TextEditor_20250728]/defer_loading

added the new optional request property tools/items/oneOf[subschema #5: TextEditor_20250728 -> subschema #9: TextEditor_20250728]/input_examples

added the new optional request property tools/items/oneOf[subschema #6: WebSearchTool_20250305 -> subschema #10: WebSearchTool_20250305]/allowed_callers

added the new optional request property tools/items/oneOf[subschema #6: WebSearchTool_20250305 -> subschema #10: WebSearchTool_20250305]/defer_loading

added subschema #3 to the model request property anyOf list

the name request property const value web_search was removed

added bash_code_execution_tool_result code_execution_tool_result container_upload text_editor_code_execution_tool_result tool_search_tool_result web_fetch_tool_result discriminator mapping keys to the messages/items/content/anyOf[subschema #2]/items request property

added tool_reference discriminator mapping keys to the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #8: RequestToolResultBlock]/content/anyOf[subschema #2]/items request property

added the new bash_code_execution enum value to the request property messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #9: RequestServerToolUseBlock]/name

added the new code_execution enum value to the request property messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #9: RequestServerToolUseBlock]/name

added the new text_editor_code_execution enum value to the request property messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #9: RequestServerToolUseBlock]/name

added the new tool_search_tool_bm25 enum value to the request property messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #9: RequestServerToolUseBlock]/name

added the new tool_search_tool_regex enum value to the request property messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #9: RequestServerToolUseBlock]/name

added the new web_fetch enum value to the request property messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #9: RequestServerToolUseBlock]/name

added the new web_search enum value to the request property messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #9: RequestServerToolUseBlock]/name

added CodeExecutionTool_20250522 CodeExecutionTool_20250825 CodeExecutionTool_20260120 MemoryTool_20250818 WebFetchTool_20250910 WebSearchTool_20260209 WebFetchTool_20260209 ToolSearchToolBM25_20251119 ToolSearchToolRegex_20251119 to the tools/items request property oneOf list

added RequestToolReferenceBlock to the messages/items/content/anyOf[subschema #2]/items/oneOf[subschema #8: RequestToolResultBlock]/content/anyOf[subschema #2]/items request property oneOf list

added RequestWebFetchToolResultBlock RequestCodeExecutionToolResultBlock RequestBashCodeExecutionToolResultBlock RequestTextEditorCodeExecutionToolResultBlock RequestToolSearchToolResultBlock RequestContainerUploadBlock to the messages/items/content/anyOf[subschema #2]/items request property oneOf list