Batches

Create a Message Batch

client.Messages.Batches.New(ctx, body) (*MessageBatch, error)

POST/v1/messages/batches

Retrieve a Message Batch

client.Messages.Batches.Get(ctx, messageBatchID) (*MessageBatch, error)

GET/v1/messages/batches/{message_batch_id}

List Message Batches

client.Messages.Batches.List(ctx, query) (*Page[MessageBatch], error)

GET/v1/messages/batches

Cancel a Message Batch

client.Messages.Batches.Cancel(ctx, messageBatchID) (*MessageBatch, error)

POST/v1/messages/batches/{message_batch_id}/cancel

Delete a Message Batch

client.Messages.Batches.Delete(ctx, messageBatchID) (*DeletedMessageBatch, error)

DELETE/v1/messages/batches/{message_batch_id}

Retrieve Message Batch results

client.Messages.Batches.Results(ctx, messageBatchID) (*MessageBatchIndividualResponse, error)

GET/v1/messages/batches/{message_batch_id}/results

ModelsExpand Collapse

type DeletedMessageBatch struct{…}

ID string

ID of the Message Batch.

Type MessageBatchDeleted

Deleted object type.

For Message Batches, this is always "message_batch_deleted".

type MessageBatch struct{…}

ID string

Unique object identifier.

The format and length of IDs may change over time.

ArchivedAt Time

RFC 3339 datetime string representing the time at which the Message Batch was archived and its results became unavailable.

CancelInitiatedAt Time

RFC 3339 datetime string representing the time at which cancellation was initiated for the Message Batch. Specified only if cancellation was initiated.

CreatedAt Time

RFC 3339 datetime string representing the time at which the Message Batch was created.

EndedAt Time

RFC 3339 datetime string representing the time at which processing for the Message Batch ended. Specified only once processing ends.

Processing ends when every request in a Message Batch has either succeeded, errored, canceled, or expired.

formatdate-time

ExpiresAt Time

RFC 3339 datetime string representing the time at which the Message Batch will expire and end processing, which is 24 hours after creation.

ProcessingStatus MessageBatchProcessingStatus

Processing status of the Message Batch.

Accepts one of the following:

const MessageBatchProcessingStatusInProgress MessageBatchProcessingStatus = "in_progress"

const MessageBatchProcessingStatusCanceling MessageBatchProcessingStatus = "canceling"

const MessageBatchProcessingStatusEnded MessageBatchProcessingStatus = "ended"

RequestCounts MessageBatchRequestCounts

Tallies requests within the Message Batch, categorized by their status.

Requests start as processing and move to one of the other statuses only once processing of the entire batch ends. The sum of all values always matches the total number of requests in the batch.

Canceled int64

Number of requests in the Message Batch that have been canceled.

This is zero until processing of the entire Message Batch has ended.

Errored int64

Number of requests in the Message Batch that encountered an error.

This is zero until processing of the entire Message Batch has ended.

Expired int64

Number of requests in the Message Batch that have expired.

This is zero until processing of the entire Message Batch has ended.

Processing int64

Number of requests in the Message Batch that are processing.

Succeeded int64

Number of requests in the Message Batch that have completed successfully.

This is zero until processing of the entire Message Batch has ended.

ResultsURL string

URL to a .jsonl file containing the results of the Message Batch requests. Specified only once processing ends.

Results in the file are not guaranteed to be in the same order as requests. Use the custom_id field to match results to requests.

Type MessageBatch

Object type.

For Message Batches, this is always "message_batch".

type MessageBatchCanceledResult struct{…}

Type Canceled

type MessageBatchErroredResult struct{…}

Error ErrorResponse

Error ErrorObjectUnion

Accepts one of the following:

type InvalidRequestError struct{…}

Message string

Type InvalidRequestError

type AuthenticationError struct{…}

Message string

Type AuthenticationError

type BillingError struct{…}

Message string

Type BillingError

type PermissionError struct{…}

Message string

Type PermissionError

type NotFoundError struct{…}

Message string

Type NotFoundError

type RateLimitError struct{…}

Message string

Type RateLimitError

type GatewayTimeoutError struct{…}

Message string

Type TimeoutError

type APIErrorObject struct{…}

Message string

Type APIError

type OverloadedError struct{…}

Message string

Type OverloadedError

RequestID string

Type Error

Type Errored

type MessageBatchExpiredResult struct{…}

Type Expired

type MessageBatchIndividualResponse struct{…}

This is a single line in the response .jsonl file and does not represent the response as a whole.

CustomID string

Developer-provided ID created for each request in a Message Batch. Useful for matching results to requests, as results may be given out of request order.

Must be unique for each request within the Message Batch.

Result MessageBatchResultUnion

Processing result for this request.

Contains a Message output if processing was successful, an error response if processing failed, or the reason why processing was not attempted, such as cancellation or expiration.

Accepts one of the following:

type MessageBatchSucceededResult struct{…}

Message Message

ID string

Unique object identifier.

The format and length of IDs may change over time.

Container Container

Information about the container used in the request (for the code execution tool)

ID string

Identifier for the container used in this request

ExpiresAt Time

The time at which the container will expire.

Content []ContentBlockUnion

Content generated by the model.

This is an array of content blocks, each of which has a type that determines its shape.

Example:

[{"type": "text", "text": "Hi, I'm Claude."}]

If the request input messages ended with an assistant turn, then the response content will continue directly from that last turn. You can use this to constrain the model's output.

For example, if the input messages were:

[
  {"role": "user", "content": "What's the Greek name for Sun? (A) Sol (B) Helios (C) Sun"},
  {"role": "assistant", "content": "The best answer is ("}
]

Then the response content might be:

[{"type": "text", "text": "B)"}]

Accepts one of the following:

type TextBlock struct{…}

Citations []TextCitationUnion

Citations supporting the text block.

The type of citation returned will depend on the type of document being cited. Citing a PDF results in page_location, plain text results in char_location, and content document results in content_block_location.

Accepts one of the following:

type CitationCharLocation struct{…}

CitedText string

DocumentIndex int64

DocumentTitle string

EndCharIndex int64

FileID string

StartCharIndex int64

Type CharLocation

type CitationPageLocation struct{…}

CitedText string

DocumentIndex int64

DocumentTitle string

EndPageNumber int64

FileID string

StartPageNumber int64

Type PageLocation

type CitationContentBlockLocation struct{…}

CitedText string

DocumentIndex int64

DocumentTitle string

EndBlockIndex int64

FileID string

StartBlockIndex int64

Type ContentBlockLocation

type CitationsWebSearchResultLocation struct{…}

CitedText string

EncryptedIndex string

Title string

Type WebSearchResultLocation

URL string

type CitationsSearchResultLocation struct{…}

CitedText string

EndBlockIndex int64

SearchResultIndex int64

Source string

StartBlockIndex int64

Title string

Type SearchResultLocation

Text string

Type Text

type ThinkingBlock struct{…}

Signature string

Thinking string

Type Thinking

type RedactedThinkingBlock struct{…}

Data string

Type RedactedThinking

type ToolUseBlock struct{…}

ID string

Caller ToolUseBlockCallerUnion

Tool invocation directly from the model.

Accepts one of the following:

type DirectCaller struct{…}

Tool invocation directly from the model.

Type Direct

type ServerToolCaller struct{…}

Tool invocation generated by a server-side tool.

ToolID string

Type CodeExecution20250825

type ServerToolCaller20260120 struct{…}

ToolID string

Type CodeExecution20260120

Input map[string, any]

Name string

Type ToolUse

type ServerToolUseBlock struct{…}

ID string

Caller ServerToolUseBlockCallerUnion

Tool invocation directly from the model.

Accepts one of the following:

type DirectCaller struct{…}

Tool invocation directly from the model.

Type Direct

type ServerToolCaller struct{…}

Tool invocation generated by a server-side tool.

ToolID string

Type CodeExecution20250825

type ServerToolCaller20260120 struct{…}

ToolID string

Type CodeExecution20260120

Input map[string, any]

Name ServerToolUseBlockName

Accepts one of the following:

const ServerToolUseBlockNameWebSearch ServerToolUseBlockName = "web_search"

const ServerToolUseBlockNameWebFetch ServerToolUseBlockName = "web_fetch"

const ServerToolUseBlockNameCodeExecution ServerToolUseBlockName = "code_execution"

const ServerToolUseBlockNameBashCodeExecution ServerToolUseBlockName = "bash_code_execution"

const ServerToolUseBlockNameTextEditorCodeExecution ServerToolUseBlockName = "text_editor_code_execution"

const ServerToolUseBlockNameToolSearchToolRegex ServerToolUseBlockName = "tool_search_tool_regex"

const ServerToolUseBlockNameToolSearchToolBm25 ServerToolUseBlockName = "tool_search_tool_bm25"

Type ServerToolUse

type WebSearchToolResultBlock struct{…}

Caller WebSearchToolResultBlockCallerUnion

Tool invocation directly from the model.

Accepts one of the following:

type DirectCaller struct{…}

Tool invocation directly from the model.

Type Direct

type ServerToolCaller struct{…}

Tool invocation generated by a server-side tool.

ToolID string

Type CodeExecution20250825

type ServerToolCaller20260120 struct{…}

ToolID string

Type CodeExecution20260120

Content WebSearchToolResultBlockContentUnion

Accepts one of the following:

type WebSearchToolResultError struct{…}

ErrorCode WebSearchToolResultErrorCode

Accepts one of the following:

const WebSearchToolResultErrorCodeInvalidToolInput WebSearchToolResultErrorCode = "invalid_tool_input"

const WebSearchToolResultErrorCodeUnavailable WebSearchToolResultErrorCode = "unavailable"

const WebSearchToolResultErrorCodeMaxUsesExceeded WebSearchToolResultErrorCode = "max_uses_exceeded"

const WebSearchToolResultErrorCodeTooManyRequests WebSearchToolResultErrorCode = "too_many_requests"

const WebSearchToolResultErrorCodeQueryTooLong WebSearchToolResultErrorCode = "query_too_long"

const WebSearchToolResultErrorCodeRequestTooLarge WebSearchToolResultErrorCode = "request_too_large"

Type WebSearchToolResultError

type WebSearchToolResultBlockContentArray []WebSearchResultBlock

EncryptedContent string

PageAge string

Title string

Type WebSearchResult

URL string

ToolUseID string

Type WebSearchToolResult

type WebFetchToolResultBlock struct{…}

Caller WebFetchToolResultBlockCallerUnion

Tool invocation directly from the model.

Accepts one of the following:

type DirectCaller struct{…}

Tool invocation directly from the model.

Type Direct

type ServerToolCaller struct{…}

Tool invocation generated by a server-side tool.

ToolID string

Type CodeExecution20250825

type ServerToolCaller20260120 struct{…}

ToolID string

Type CodeExecution20260120

Content WebFetchToolResultBlockContentUnion

Accepts one of the following:

type WebFetchToolResultErrorBlock struct{…}

ErrorCode WebFetchToolResultErrorCode

Accepts one of the following:

const WebFetchToolResultErrorCodeInvalidToolInput WebFetchToolResultErrorCode = "invalid_tool_input"

const WebFetchToolResultErrorCodeURLTooLong WebFetchToolResultErrorCode = "url_too_long"

const WebFetchToolResultErrorCodeURLNotAllowed WebFetchToolResultErrorCode = "url_not_allowed"

const WebFetchToolResultErrorCodeURLNotAccessible WebFetchToolResultErrorCode = "url_not_accessible"

const WebFetchToolResultErrorCodeUnsupportedContentType WebFetchToolResultErrorCode = "unsupported_content_type"

const WebFetchToolResultErrorCodeTooManyRequests WebFetchToolResultErrorCode = "too_many_requests"

const WebFetchToolResultErrorCodeMaxUsesExceeded WebFetchToolResultErrorCode = "max_uses_exceeded"

const WebFetchToolResultErrorCodeUnavailable WebFetchToolResultErrorCode = "unavailable"

Type WebFetchToolResultError

type WebFetchBlock struct{…}

Content DocumentBlock

Citations CitationsConfig

Citation configuration for the document

Enabled bool

Source DocumentBlockSourceUnion

Accepts one of the following:

type Base64PDFSource struct{…}

Data string

MediaType ApplicationPDF

Type Base64

type PlainTextSource struct{…}

Data string

MediaType TextPlain

Type Text

Title string

The title of the document

Type Document

RetrievedAt string

ISO 8601 timestamp when the content was retrieved

Type WebFetchResult

URL string

Fetched content URL

ToolUseID string

Type WebFetchToolResult

type CodeExecutionToolResultBlock struct{…}

Content CodeExecutionToolResultBlockContentUnion

Code execution result with encrypted stdout for PFC + web_search results.

Accepts one of the following:

type CodeExecutionToolResultError struct{…}

ErrorCode CodeExecutionToolResultErrorCode

Accepts one of the following:

const CodeExecutionToolResultErrorCodeInvalidToolInput CodeExecutionToolResultErrorCode = "invalid_tool_input"

const CodeExecutionToolResultErrorCodeUnavailable CodeExecutionToolResultErrorCode = "unavailable"

const CodeExecutionToolResultErrorCodeTooManyRequests CodeExecutionToolResultErrorCode = "too_many_requests"

const CodeExecutionToolResultErrorCodeExecutionTimeExceeded CodeExecutionToolResultErrorCode = "execution_time_exceeded"

Type CodeExecutionToolResultError

type CodeExecutionResultBlock struct{…}

Content []CodeExecutionOutputBlock

FileID string

Type CodeExecutionOutput

ReturnCode int64

Stderr string

Stdout string

Type CodeExecutionResult

type EncryptedCodeExecutionResultBlock struct{…}

Code execution result with encrypted stdout for PFC + web_search results.

Content []CodeExecutionOutputBlock

FileID string

Type CodeExecutionOutput

EncryptedStdout string

ReturnCode int64

Stderr string

Type EncryptedCodeExecutionResult

ToolUseID string

Type CodeExecutionToolResult

type BashCodeExecutionToolResultBlock struct{…}

Content BashCodeExecutionToolResultBlockContentUnion

Accepts one of the following:

type BashCodeExecutionToolResultError struct{…}

ErrorCode BashCodeExecutionToolResultErrorCode

Accepts one of the following:

const BashCodeExecutionToolResultErrorCodeInvalidToolInput BashCodeExecutionToolResultErrorCode = "invalid_tool_input"

const BashCodeExecutionToolResultErrorCodeUnavailable BashCodeExecutionToolResultErrorCode = "unavailable"

const BashCodeExecutionToolResultErrorCodeTooManyRequests BashCodeExecutionToolResultErrorCode = "too_many_requests"

const BashCodeExecutionToolResultErrorCodeExecutionTimeExceeded BashCodeExecutionToolResultErrorCode = "execution_time_exceeded"

const BashCodeExecutionToolResultErrorCodeOutputFileTooLarge BashCodeExecutionToolResultErrorCode = "output_file_too_large"

Type BashCodeExecutionToolResultError

type BashCodeExecutionResultBlock struct{…}

Content []BashCodeExecutionOutputBlock

FileID string

Type BashCodeExecutionOutput

ReturnCode int64

Stderr string

Stdout string

Type BashCodeExecutionResult

ToolUseID string

Type BashCodeExecutionToolResult

type TextEditorCodeExecutionToolResultBlock struct{…}

Content TextEditorCodeExecutionToolResultBlockContentUnion

Accepts one of the following:

type TextEditorCodeExecutionToolResultError struct{…}

ErrorCode TextEditorCodeExecutionToolResultErrorCode

Accepts one of the following:

const TextEditorCodeExecutionToolResultErrorCodeInvalidToolInput TextEditorCodeExecutionToolResultErrorCode = "invalid_tool_input"

const TextEditorCodeExecutionToolResultErrorCodeUnavailable TextEditorCodeExecutionToolResultErrorCode = "unavailable"

const TextEditorCodeExecutionToolResultErrorCodeTooManyRequests TextEditorCodeExecutionToolResultErrorCode = "too_many_requests"

const TextEditorCodeExecutionToolResultErrorCodeExecutionTimeExceeded TextEditorCodeExecutionToolResultErrorCode = "execution_time_exceeded"

const TextEditorCodeExecutionToolResultErrorCodeFileNotFound TextEditorCodeExecutionToolResultErrorCode = "file_not_found"

ErrorMessage string

Type TextEditorCodeExecutionToolResultError

type TextEditorCodeExecutionViewResultBlock struct{…}

Content string

FileType TextEditorCodeExecutionViewResultBlockFileType

Accepts one of the following:

const TextEditorCodeExecutionViewResultBlockFileTypeText TextEditorCodeExecutionViewResultBlockFileType = "text"

const TextEditorCodeExecutionViewResultBlockFileTypeImage TextEditorCodeExecutionViewResultBlockFileType = "image"

const TextEditorCodeExecutionViewResultBlockFileTypePDF TextEditorCodeExecutionViewResultBlockFileType = "pdf"

NumLines int64

StartLine int64

TotalLines int64

Type TextEditorCodeExecutionViewResult

type TextEditorCodeExecutionCreateResultBlock struct{…}

IsFileUpdate bool

Type TextEditorCodeExecutionCreateResult

type TextEditorCodeExecutionStrReplaceResultBlock struct{…}

Lines []string

NewLines int64

NewStart int64

OldLines int64

OldStart int64

Type TextEditorCodeExecutionStrReplaceResult

ToolUseID string

Type TextEditorCodeExecutionToolResult

type ToolSearchToolResultBlock struct{…}

Content ToolSearchToolResultBlockContentUnion

Accepts one of the following:

type ToolSearchToolResultError struct{…}

ErrorCode ToolSearchToolResultErrorCode

Accepts one of the following:

const ToolSearchToolResultErrorCodeInvalidToolInput ToolSearchToolResultErrorCode = "invalid_tool_input"

const ToolSearchToolResultErrorCodeUnavailable ToolSearchToolResultErrorCode = "unavailable"

const ToolSearchToolResultErrorCodeTooManyRequests ToolSearchToolResultErrorCode = "too_many_requests"

const ToolSearchToolResultErrorCodeExecutionTimeExceeded ToolSearchToolResultErrorCode = "execution_time_exceeded"

ErrorMessage string

Type ToolSearchToolResultError

type ToolSearchToolSearchResultBlock struct{…}

ToolReferences []ToolReferenceBlock

ToolName string

Type ToolReference

Type ToolSearchToolSearchResult

ToolUseID string

Type ToolSearchToolResult

type ContainerUploadBlock struct{…}

Response model for a file uploaded to the container.

FileID string

Type ContainerUpload

Model Model

The model that will complete your prompt.

See models for additional details and options.

Accepts one of the following:

type Model string

The model that will complete your prompt.

See models for additional details and options.

Accepts one of the following:

const ModelClaudeOpus4_6 Model = "claude-opus-4-6"

Most intelligent model for building agents and coding

const ModelClaudeSonnet4_6 Model = "claude-sonnet-4-6"

Frontier intelligence at scale — built for coding, agents, and enterprise workflows

const ModelClaudeOpus4_5_20251101 Model = "claude-opus-4-5-20251101"

Premium model combining maximum intelligence with practical performance

const ModelClaudeOpus4_5 Model = "claude-opus-4-5"

Premium model combining maximum intelligence with practical performance

const ModelClaude3_7SonnetLatest Model = "claude-3-7-sonnet-latest"

High-performance model with early extended thinking

const ModelClaude3_7Sonnet20250219 Model = "claude-3-7-sonnet-20250219"

High-performance model with early extended thinking

const ModelClaude3_5HaikuLatest Model = "claude-3-5-haiku-latest"

Fastest and most compact model for near-instant responsiveness

const ModelClaude3_5Haiku20241022 Model = "claude-3-5-haiku-20241022"

Our fastest model

const ModelClaudeHaiku4_5 Model = "claude-haiku-4-5"

Hybrid model, capable of near-instant responses and extended thinking

const ModelClaudeHaiku4_5_20251001 Model = "claude-haiku-4-5-20251001"

Hybrid model, capable of near-instant responses and extended thinking

const ModelClaudeSonnet4_20250514 Model = "claude-sonnet-4-20250514"

High-performance model with extended thinking

const ModelClaudeSonnet4_0 Model = "claude-sonnet-4-0"

High-performance model with extended thinking

const ModelClaude4Sonnet20250514 Model = "claude-4-sonnet-20250514"

High-performance model with extended thinking

const ModelClaudeSonnet4_5 Model = "claude-sonnet-4-5"

Our best model for real-world agents and coding

const ModelClaudeSonnet4_5_20250929 Model = "claude-sonnet-4-5-20250929"

Our best model for real-world agents and coding

const ModelClaudeOpus4_0 Model = "claude-opus-4-0"

Our most capable model

const ModelClaudeOpus4_20250514 Model = "claude-opus-4-20250514"

Our most capable model

const ModelClaude4Opus20250514 Model = "claude-4-opus-20250514"

Our most capable model

const ModelClaudeOpus4_1_20250805 Model = "claude-opus-4-1-20250805"

Our most capable model

const ModelClaude3OpusLatest Model = "claude-3-opus-latest"

Excels at writing and complex tasks

const ModelClaude_3_Opus_20240229 Model = "claude-3-opus-20240229"

Excels at writing and complex tasks

const ModelClaude_3_Haiku_20240307 Model = "claude-3-haiku-20240307"

Our previous most fast and cost-effective

string

Role Assistant

Conversational role of the generated message.

This will always be "assistant".

StopReason StopReason

The reason that we stopped.

This may be one the following values:

"end_turn": the model reached a natural stopping point
"max_tokens": we exceeded the requested max_tokens or the model's maximum
"stop_sequence": one of your provided custom stop_sequences was generated
"tool_use": the model invoked one or more tools
"pause_turn": we paused a long-running turn. You may provide the response back as-is in a subsequent request to let the model continue.
"refusal": when streaming classifiers intervene to handle potential policy violations

In non-streaming mode this value is always non-null. In streaming mode, it is null in the message_start event and non-null otherwise.

Accepts one of the following:

const StopReasonEndTurn StopReason = "end_turn"

const StopReasonMaxTokens StopReason = "max_tokens"

const StopReasonStopSequence StopReason = "stop_sequence"

const StopReasonToolUse StopReason = "tool_use"

const StopReasonPauseTurn StopReason = "pause_turn"

const StopReasonRefusal StopReason = "refusal"

StopSequence string

Which custom stop sequence was generated, if any.

This value will be a non-null string if one of your custom stop sequences was generated.

Type Message

Object type.

For Messages, this is always "message".

Usage Usage

Billing and rate-limit usage.

Anthropic's API bills and rate-limits by token counts, as tokens represent the underlying cost to our systems.

Under the hood, the API transforms requests into a format suitable for the model. The model's output then goes through a parsing stage before becoming an API response. As a result, the token counts in usage will not match one-to-one with the exact visible content of an API request or response.

For example, output_tokens will be non-zero, even for an empty string response from Claude.

Total input tokens in a request is the summation of input_tokens, cache_creation_input_tokens, and cache_read_input_tokens.

CacheCreation CacheCreation

Breakdown of cached tokens by TTL

Ephemeral1hInputTokens int64

The number of input tokens used to create the 1 hour cache entry.

Ephemeral5mInputTokens int64

The number of input tokens used to create the 5 minute cache entry.

CacheCreationInputTokens int64

The number of input tokens used to create the cache entry.

CacheReadInputTokens int64

The number of input tokens read from the cache.

InferenceGeo string

The geographic region where inference was performed for this request.

InputTokens int64

The number of input tokens which were used.

OutputTokens int64

The number of output tokens which were used.

ServerToolUse ServerToolUsage

The number of server tool requests.

WebFetchRequests int64

The number of web fetch tool requests.

WebSearchRequests int64

The number of web search tool requests.

ServiceTier UsageServiceTier

If the request used the priority, standard, or batch tier.

Accepts one of the following:

const UsageServiceTierStandard UsageServiceTier = "standard"

const UsageServiceTierPriority UsageServiceTier = "priority"

const UsageServiceTierBatch UsageServiceTier = "batch"

Type Succeeded

type MessageBatchErroredResult struct{…}

Error ErrorResponse

Error ErrorObjectUnion

Accepts one of the following:

type InvalidRequestError struct{…}

Message string

Type InvalidRequestError

type AuthenticationError struct{…}

Message string

Type AuthenticationError

type BillingError struct{…}

Message string

Type BillingError

type PermissionError struct{…}

Message string

Type PermissionError

type NotFoundError struct{…}

Message string

Type NotFoundError

type RateLimitError struct{…}

Message string

Type RateLimitError

type GatewayTimeoutError struct{…}

Message string

Type TimeoutError

type APIErrorObject struct{…}

Message string

Type APIError

type OverloadedError struct{…}

Message string

Type OverloadedError

RequestID string

Type Error

Type Errored

type MessageBatchCanceledResult struct{…}

Type Canceled

type MessageBatchExpiredResult struct{…}

Type Expired

type MessageBatchRequestCounts struct{…}

Canceled int64

Number of requests in the Message Batch that have been canceled.

This is zero until processing of the entire Message Batch has ended.

Errored int64

Number of requests in the Message Batch that encountered an error.

This is zero until processing of the entire Message Batch has ended.

Expired int64

Number of requests in the Message Batch that have expired.

This is zero until processing of the entire Message Batch has ended.

Processing int64

Number of requests in the Message Batch that are processing.

Succeeded int64

Number of requests in the Message Batch that have completed successfully.

This is zero until processing of the entire Message Batch has ended.

type MessageBatchResultUnion interface{…}

Processing result for this request.

Contains a Message output if processing was successful, an error response if processing failed, or the reason why processing was not attempted, such as cancellation or expiration.

Accepts one of the following:

type MessageBatchSucceededResult struct{…}

Message Message

ID string

Unique object identifier.

The format and length of IDs may change over time.

Container Container

Information about the container used in the request (for the code execution tool)

ID string

Identifier for the container used in this request

ExpiresAt Time

The time at which the container will expire.

Content []ContentBlockUnion

Content generated by the model.

This is an array of content blocks, each of which has a type that determines its shape.

Example:

[{"type": "text", "text": "Hi, I'm Claude."}]

If the request input messages ended with an assistant turn, then the response content will continue directly from that last turn. You can use this to constrain the model's output.

For example, if the input messages were:

[
  {"role": "user", "content": "What's the Greek name for Sun? (A) Sol (B) Helios (C) Sun"},
  {"role": "assistant", "content": "The best answer is ("}
]

Then the response content might be:

[{"type": "text", "text": "B)"}]

Accepts one of the following:

type TextBlock struct{…}

Citations []TextCitationUnion

Citations supporting the text block.

Accepts one of the following:

type CitationCharLocation struct{…}

CitedText string

DocumentIndex int64

DocumentTitle string

EndCharIndex int64

FileID string

StartCharIndex int64

Type CharLocation

type CitationPageLocation struct{…}

CitedText string

DocumentIndex int64

DocumentTitle string

EndPageNumber int64

FileID string

StartPageNumber int64

Type PageLocation

type CitationContentBlockLocation struct{…}

CitedText string

DocumentIndex int64

DocumentTitle string

EndBlockIndex int64

FileID string

StartBlockIndex int64

Type ContentBlockLocation

type CitationsWebSearchResultLocation struct{…}

CitedText string

EncryptedIndex string

Title string

Type WebSearchResultLocation

URL string

type CitationsSearchResultLocation struct{…}

CitedText string

EndBlockIndex int64

SearchResultIndex int64

Source string

StartBlockIndex int64

Title string

Type SearchResultLocation

Text string

Type Text

type ThinkingBlock struct{…}

Signature string

Thinking string

Type Thinking

type RedactedThinkingBlock struct{…}

Data string

Type RedactedThinking

type ToolUseBlock struct{…}

ID string

Caller ToolUseBlockCallerUnion

Tool invocation directly from the model.

Accepts one of the following:

type DirectCaller struct{…}

Tool invocation directly from the model.

Type Direct

type ServerToolCaller struct{…}

Tool invocation generated by a server-side tool.

ToolID string

Type CodeExecution20250825

type ServerToolCaller20260120 struct{…}

ToolID string

Type CodeExecution20260120

Input map[string, any]

Name string

Type ToolUse

type ServerToolUseBlock struct{…}

ID string

Caller ServerToolUseBlockCallerUnion

Tool invocation directly from the model.

Accepts one of the following:

type DirectCaller struct{…}

Tool invocation directly from the model.

Type Direct

type ServerToolCaller struct{…}

Tool invocation generated by a server-side tool.

ToolID string

Type CodeExecution20250825

type ServerToolCaller20260120 struct{…}

ToolID string

Type CodeExecution20260120

Input map[string, any]

Name ServerToolUseBlockName

Accepts one of the following:

const ServerToolUseBlockNameWebSearch ServerToolUseBlockName = "web_search"

const ServerToolUseBlockNameWebFetch ServerToolUseBlockName = "web_fetch"

const ServerToolUseBlockNameCodeExecution ServerToolUseBlockName = "code_execution"

const ServerToolUseBlockNameBashCodeExecution ServerToolUseBlockName = "bash_code_execution"

const ServerToolUseBlockNameTextEditorCodeExecution ServerToolUseBlockName = "text_editor_code_execution"

const ServerToolUseBlockNameToolSearchToolRegex ServerToolUseBlockName = "tool_search_tool_regex"

const ServerToolUseBlockNameToolSearchToolBm25 ServerToolUseBlockName = "tool_search_tool_bm25"

Type ServerToolUse

type WebSearchToolResultBlock struct{…}

Caller WebSearchToolResultBlockCallerUnion

Tool invocation directly from the model.

Accepts one of the following:

type DirectCaller struct{…}

Tool invocation directly from the model.

Type Direct

type ServerToolCaller struct{…}

Tool invocation generated by a server-side tool.

ToolID string

Type CodeExecution20250825

type ServerToolCaller20260120 struct{…}

ToolID string

Type CodeExecution20260120

Content WebSearchToolResultBlockContentUnion

Accepts one of the following:

type WebSearchToolResultError struct{…}

ErrorCode WebSearchToolResultErrorCode

Accepts one of the following:

const WebSearchToolResultErrorCodeInvalidToolInput WebSearchToolResultErrorCode = "invalid_tool_input"

const WebSearchToolResultErrorCodeUnavailable WebSearchToolResultErrorCode = "unavailable"

const WebSearchToolResultErrorCodeMaxUsesExceeded WebSearchToolResultErrorCode = "max_uses_exceeded"

const WebSearchToolResultErrorCodeTooManyRequests WebSearchToolResultErrorCode = "too_many_requests"

const WebSearchToolResultErrorCodeQueryTooLong WebSearchToolResultErrorCode = "query_too_long"

const WebSearchToolResultErrorCodeRequestTooLarge WebSearchToolResultErrorCode = "request_too_large"

Type WebSearchToolResultError

type WebSearchToolResultBlockContentArray []WebSearchResultBlock

EncryptedContent string

PageAge string

Title string

Type WebSearchResult

URL string

ToolUseID string

Type WebSearchToolResult

type WebFetchToolResultBlock struct{…}

Caller WebFetchToolResultBlockCallerUnion

Tool invocation directly from the model.

Accepts one of the following:

type DirectCaller struct{…}

Tool invocation directly from the model.

Type Direct

type ServerToolCaller struct{…}

Tool invocation generated by a server-side tool.

ToolID string

Type CodeExecution20250825

type ServerToolCaller20260120 struct{…}

ToolID string

Type CodeExecution20260120

Content WebFetchToolResultBlockContentUnion

Accepts one of the following:

type WebFetchToolResultErrorBlock struct{…}

ErrorCode WebFetchToolResultErrorCode

Accepts one of the following:

const WebFetchToolResultErrorCodeInvalidToolInput WebFetchToolResultErrorCode = "invalid_tool_input"

const WebFetchToolResultErrorCodeURLTooLong WebFetchToolResultErrorCode = "url_too_long"

const WebFetchToolResultErrorCodeURLNotAllowed WebFetchToolResultErrorCode = "url_not_allowed"

const WebFetchToolResultErrorCodeURLNotAccessible WebFetchToolResultErrorCode = "url_not_accessible"

const WebFetchToolResultErrorCodeUnsupportedContentType WebFetchToolResultErrorCode = "unsupported_content_type"

const WebFetchToolResultErrorCodeTooManyRequests WebFetchToolResultErrorCode = "too_many_requests"

const WebFetchToolResultErrorCodeMaxUsesExceeded WebFetchToolResultErrorCode = "max_uses_exceeded"

const WebFetchToolResultErrorCodeUnavailable WebFetchToolResultErrorCode = "unavailable"

Type WebFetchToolResultError

type WebFetchBlock struct{…}

Content DocumentBlock

Citations CitationsConfig

Citation configuration for the document

Enabled bool

Source DocumentBlockSourceUnion

Accepts one of the following:

type Base64PDFSource struct{…}

Data string

MediaType ApplicationPDF

Type Base64

type PlainTextSource struct{…}

Data string

MediaType TextPlain

Type Text

Title string

The title of the document

Type Document

RetrievedAt string

ISO 8601 timestamp when the content was retrieved

Type WebFetchResult

URL string

Fetched content URL

ToolUseID string

Type WebFetchToolResult

type CodeExecutionToolResultBlock struct{…}

Content CodeExecutionToolResultBlockContentUnion

Code execution result with encrypted stdout for PFC + web_search results.

Accepts one of the following:

type CodeExecutionToolResultError struct{…}

ErrorCode CodeExecutionToolResultErrorCode

Accepts one of the following:

const CodeExecutionToolResultErrorCodeInvalidToolInput CodeExecutionToolResultErrorCode = "invalid_tool_input"

const CodeExecutionToolResultErrorCodeUnavailable CodeExecutionToolResultErrorCode = "unavailable"

const CodeExecutionToolResultErrorCodeTooManyRequests CodeExecutionToolResultErrorCode = "too_many_requests"

const CodeExecutionToolResultErrorCodeExecutionTimeExceeded CodeExecutionToolResultErrorCode = "execution_time_exceeded"

Type CodeExecutionToolResultError

type CodeExecutionResultBlock struct{…}

Content []CodeExecutionOutputBlock

FileID string

Type CodeExecutionOutput

ReturnCode int64

Stderr string

Stdout string

Type CodeExecutionResult

type EncryptedCodeExecutionResultBlock struct{…}

Code execution result with encrypted stdout for PFC + web_search results.

Content []CodeExecutionOutputBlock

FileID string

Type CodeExecutionOutput

EncryptedStdout string

ReturnCode int64

Stderr string

Type EncryptedCodeExecutionResult

ToolUseID string

Type CodeExecutionToolResult

type BashCodeExecutionToolResultBlock struct{…}

Content BashCodeExecutionToolResultBlockContentUnion

Accepts one of the following:

type BashCodeExecutionToolResultError struct{…}

ErrorCode BashCodeExecutionToolResultErrorCode

Accepts one of the following:

const BashCodeExecutionToolResultErrorCodeInvalidToolInput BashCodeExecutionToolResultErrorCode = "invalid_tool_input"

const BashCodeExecutionToolResultErrorCodeUnavailable BashCodeExecutionToolResultErrorCode = "unavailable"

const BashCodeExecutionToolResultErrorCodeTooManyRequests BashCodeExecutionToolResultErrorCode = "too_many_requests"

const BashCodeExecutionToolResultErrorCodeExecutionTimeExceeded BashCodeExecutionToolResultErrorCode = "execution_time_exceeded"

const BashCodeExecutionToolResultErrorCodeOutputFileTooLarge BashCodeExecutionToolResultErrorCode = "output_file_too_large"

Type BashCodeExecutionToolResultError

type BashCodeExecutionResultBlock struct{…}

Content []BashCodeExecutionOutputBlock

FileID string

Type BashCodeExecutionOutput

ReturnCode int64

Stderr string

Stdout string

Type BashCodeExecutionResult

ToolUseID string

Type BashCodeExecutionToolResult

type TextEditorCodeExecutionToolResultBlock struct{…}

Content TextEditorCodeExecutionToolResultBlockContentUnion

Accepts one of the following:

type TextEditorCodeExecutionToolResultError struct{…}

ErrorCode TextEditorCodeExecutionToolResultErrorCode

Accepts one of the following:

const TextEditorCodeExecutionToolResultErrorCodeInvalidToolInput TextEditorCodeExecutionToolResultErrorCode = "invalid_tool_input"

const TextEditorCodeExecutionToolResultErrorCodeUnavailable TextEditorCodeExecutionToolResultErrorCode = "unavailable"

const TextEditorCodeExecutionToolResultErrorCodeTooManyRequests TextEditorCodeExecutionToolResultErrorCode = "too_many_requests"

const TextEditorCodeExecutionToolResultErrorCodeExecutionTimeExceeded TextEditorCodeExecutionToolResultErrorCode = "execution_time_exceeded"

const TextEditorCodeExecutionToolResultErrorCodeFileNotFound TextEditorCodeExecutionToolResultErrorCode = "file_not_found"

ErrorMessage string

Type TextEditorCodeExecutionToolResultError

type TextEditorCodeExecutionViewResultBlock struct{…}

Content string

FileType TextEditorCodeExecutionViewResultBlockFileType

Accepts one of the following:

const TextEditorCodeExecutionViewResultBlockFileTypeText TextEditorCodeExecutionViewResultBlockFileType = "text"

const TextEditorCodeExecutionViewResultBlockFileTypeImage TextEditorCodeExecutionViewResultBlockFileType = "image"

const TextEditorCodeExecutionViewResultBlockFileTypePDF TextEditorCodeExecutionViewResultBlockFileType = "pdf"

NumLines int64

StartLine int64

TotalLines int64

Type TextEditorCodeExecutionViewResult

type TextEditorCodeExecutionCreateResultBlock struct{…}

IsFileUpdate bool

Type TextEditorCodeExecutionCreateResult

type TextEditorCodeExecutionStrReplaceResultBlock struct{…}

Lines []string

NewLines int64

NewStart int64

OldLines int64

OldStart int64

Type TextEditorCodeExecutionStrReplaceResult

ToolUseID string

Type TextEditorCodeExecutionToolResult

type ToolSearchToolResultBlock struct{…}

Content ToolSearchToolResultBlockContentUnion

Accepts one of the following:

type ToolSearchToolResultError struct{…}

ErrorCode ToolSearchToolResultErrorCode

Accepts one of the following:

const ToolSearchToolResultErrorCodeInvalidToolInput ToolSearchToolResultErrorCode = "invalid_tool_input"

const ToolSearchToolResultErrorCodeUnavailable ToolSearchToolResultErrorCode = "unavailable"

const ToolSearchToolResultErrorCodeTooManyRequests ToolSearchToolResultErrorCode = "too_many_requests"

const ToolSearchToolResultErrorCodeExecutionTimeExceeded ToolSearchToolResultErrorCode = "execution_time_exceeded"

ErrorMessage string

Type ToolSearchToolResultError

type ToolSearchToolSearchResultBlock struct{…}

ToolReferences []ToolReferenceBlock

ToolName string

Type ToolReference

Type ToolSearchToolSearchResult

ToolUseID string

Type ToolSearchToolResult

type ContainerUploadBlock struct{…}

Response model for a file uploaded to the container.

FileID string

Type ContainerUpload

Model Model

The model that will complete your prompt.

See models for additional details and options.

Accepts one of the following:

type Model string

The model that will complete your prompt.

See models for additional details and options.

Accepts one of the following:

const ModelClaudeOpus4_6 Model = "claude-opus-4-6"

Most intelligent model for building agents and coding

const ModelClaudeSonnet4_6 Model = "claude-sonnet-4-6"

Frontier intelligence at scale — built for coding, agents, and enterprise workflows

const ModelClaudeOpus4_5_20251101 Model = "claude-opus-4-5-20251101"

Premium model combining maximum intelligence with practical performance

const ModelClaudeOpus4_5 Model = "claude-opus-4-5"

Premium model combining maximum intelligence with practical performance

const ModelClaude3_7SonnetLatest Model = "claude-3-7-sonnet-latest"

High-performance model with early extended thinking

const ModelClaude3_7Sonnet20250219 Model = "claude-3-7-sonnet-20250219"

High-performance model with early extended thinking

const ModelClaude3_5HaikuLatest Model = "claude-3-5-haiku-latest"

Fastest and most compact model for near-instant responsiveness

const ModelClaude3_5Haiku20241022 Model = "claude-3-5-haiku-20241022"

Our fastest model

const ModelClaudeHaiku4_5 Model = "claude-haiku-4-5"

Hybrid model, capable of near-instant responses and extended thinking

const ModelClaudeHaiku4_5_20251001 Model = "claude-haiku-4-5-20251001"

Hybrid model, capable of near-instant responses and extended thinking

const ModelClaudeSonnet4_20250514 Model = "claude-sonnet-4-20250514"

High-performance model with extended thinking

const ModelClaudeSonnet4_0 Model = "claude-sonnet-4-0"

High-performance model with extended thinking

const ModelClaude4Sonnet20250514 Model = "claude-4-sonnet-20250514"

High-performance model with extended thinking

const ModelClaudeSonnet4_5 Model = "claude-sonnet-4-5"

Our best model for real-world agents and coding

const ModelClaudeSonnet4_5_20250929 Model = "claude-sonnet-4-5-20250929"

Our best model for real-world agents and coding

const ModelClaudeOpus4_0 Model = "claude-opus-4-0"

Our most capable model

const ModelClaudeOpus4_20250514 Model = "claude-opus-4-20250514"

Our most capable model

const ModelClaude4Opus20250514 Model = "claude-4-opus-20250514"

Our most capable model

const ModelClaudeOpus4_1_20250805 Model = "claude-opus-4-1-20250805"

Our most capable model

const ModelClaude3OpusLatest Model = "claude-3-opus-latest"

Excels at writing and complex tasks

const ModelClaude_3_Opus_20240229 Model = "claude-3-opus-20240229"

Excels at writing and complex tasks

const ModelClaude_3_Haiku_20240307 Model = "claude-3-haiku-20240307"

Our previous most fast and cost-effective

string

Role Assistant

Conversational role of the generated message.

This will always be "assistant".

StopReason StopReason

The reason that we stopped.

This may be one the following values:

"end_turn": the model reached a natural stopping point
"max_tokens": we exceeded the requested max_tokens or the model's maximum
"stop_sequence": one of your provided custom stop_sequences was generated
"tool_use": the model invoked one or more tools
"pause_turn": we paused a long-running turn. You may provide the response back as-is in a subsequent request to let the model continue.
"refusal": when streaming classifiers intervene to handle potential policy violations

In non-streaming mode this value is always non-null. In streaming mode, it is null in the message_start event and non-null otherwise.

Accepts one of the following:

const StopReasonEndTurn StopReason = "end_turn"

const StopReasonMaxTokens StopReason = "max_tokens"

const StopReasonStopSequence StopReason = "stop_sequence"

const StopReasonToolUse StopReason = "tool_use"

const StopReasonPauseTurn StopReason = "pause_turn"

const StopReasonRefusal StopReason = "refusal"

StopSequence string

Which custom stop sequence was generated, if any.

This value will be a non-null string if one of your custom stop sequences was generated.

Type Message

Object type.

For Messages, this is always "message".

Usage Usage

Billing and rate-limit usage.

Anthropic's API bills and rate-limits by token counts, as tokens represent the underlying cost to our systems.

For example, output_tokens will be non-zero, even for an empty string response from Claude.

Total input tokens in a request is the summation of input_tokens, cache_creation_input_tokens, and cache_read_input_tokens.

CacheCreation CacheCreation

Breakdown of cached tokens by TTL

Ephemeral1hInputTokens int64

The number of input tokens used to create the 1 hour cache entry.

Ephemeral5mInputTokens int64

The number of input tokens used to create the 5 minute cache entry.

CacheCreationInputTokens int64

The number of input tokens used to create the cache entry.

CacheReadInputTokens int64

The number of input tokens read from the cache.

InferenceGeo string

The geographic region where inference was performed for this request.

InputTokens int64

The number of input tokens which were used.

OutputTokens int64

The number of output tokens which were used.

ServerToolUse ServerToolUsage

The number of server tool requests.

WebFetchRequests int64

The number of web fetch tool requests.

WebSearchRequests int64

The number of web search tool requests.

ServiceTier UsageServiceTier

If the request used the priority, standard, or batch tier.

Accepts one of the following:

const UsageServiceTierStandard UsageServiceTier = "standard"

const UsageServiceTierPriority UsageServiceTier = "priority"

const UsageServiceTierBatch UsageServiceTier = "batch"

Type Succeeded

type MessageBatchErroredResult struct{…}

Error ErrorResponse

Error ErrorObjectUnion

Accepts one of the following:

type InvalidRequestError struct{…}

Message string

Type InvalidRequestError

type AuthenticationError struct{…}

Message string

Type AuthenticationError

type BillingError struct{…}

Message string

Type BillingError

type PermissionError struct{…}

Message string

Type PermissionError

type NotFoundError struct{…}

Message string

Type NotFoundError

type RateLimitError struct{…}

Message string

Type RateLimitError

type GatewayTimeoutError struct{…}

Message string

Type TimeoutError

type APIErrorObject struct{…}

Message string

Type APIError

type OverloadedError struct{…}

Message string

Type OverloadedError

RequestID string

Type Error

Type Errored

type MessageBatchCanceledResult struct{…}

Type Canceled

type MessageBatchExpiredResult struct{…}

Type Expired

type MessageBatchSucceededResult struct{…}

Message Message

ID string

Unique object identifier.

The format and length of IDs may change over time.

Container Container

Information about the container used in the request (for the code execution tool)

ID string

Identifier for the container used in this request

ExpiresAt Time

The time at which the container will expire.

Content []ContentBlockUnion

Content generated by the model.

This is an array of content blocks, each of which has a type that determines its shape.

Example:

[{"type": "text", "text": "Hi, I'm Claude."}]

If the request input messages ended with an assistant turn, then the response content will continue directly from that last turn. You can use this to constrain the model's output.

For example, if the input messages were:

[
  {"role": "user", "content": "What's the Greek name for Sun? (A) Sol (B) Helios (C) Sun"},
  {"role": "assistant", "content": "The best answer is ("}
]

Then the response content might be:

[{"type": "text", "text": "B)"}]

Accepts one of the following:

type TextBlock struct{…}

Citations []TextCitationUnion

Citations supporting the text block.

Accepts one of the following:

type CitationCharLocation struct{…}

CitedText string

DocumentIndex int64

DocumentTitle string

EndCharIndex int64

FileID string

StartCharIndex int64

Type CharLocation

type CitationPageLocation struct{…}

CitedText string

DocumentIndex int64

DocumentTitle string

EndPageNumber int64

FileID string

StartPageNumber int64

Type PageLocation

type CitationContentBlockLocation struct{…}

CitedText string

DocumentIndex int64

DocumentTitle string

EndBlockIndex int64

FileID string

StartBlockIndex int64

Type ContentBlockLocation

type CitationsWebSearchResultLocation struct{…}

CitedText string

EncryptedIndex string

Title string

Type WebSearchResultLocation

URL string

type CitationsSearchResultLocation struct{…}

CitedText string

EndBlockIndex int64

SearchResultIndex int64

Source string

StartBlockIndex int64

Title string

Type SearchResultLocation

Text string

Type Text

type ThinkingBlock struct{…}

Signature string

Thinking string

Type Thinking

type RedactedThinkingBlock struct{…}

Data string

Type RedactedThinking

type ToolUseBlock struct{…}

ID string

Caller ToolUseBlockCallerUnion

Tool invocation directly from the model.

Accepts one of the following:

type DirectCaller struct{…}

Tool invocation directly from the model.

Type Direct

type ServerToolCaller struct{…}

Tool invocation generated by a server-side tool.

ToolID string

Type CodeExecution20250825

type ServerToolCaller20260120 struct{…}

ToolID string

Type CodeExecution20260120

Input map[string, any]

Name string

Type ToolUse

type ServerToolUseBlock struct{…}

ID string

Caller ServerToolUseBlockCallerUnion

Tool invocation directly from the model.

Accepts one of the following:

type DirectCaller struct{…}

Tool invocation directly from the model.

Type Direct

type ServerToolCaller struct{…}

Tool invocation generated by a server-side tool.

ToolID string

Type CodeExecution20250825

type ServerToolCaller20260120 struct{…}

ToolID string

Type CodeExecution20260120

Input map[string, any]

Name ServerToolUseBlockName

Accepts one of the following:

const ServerToolUseBlockNameWebSearch ServerToolUseBlockName = "web_search"

const ServerToolUseBlockNameWebFetch ServerToolUseBlockName = "web_fetch"

const ServerToolUseBlockNameCodeExecution ServerToolUseBlockName = "code_execution"

const ServerToolUseBlockNameBashCodeExecution ServerToolUseBlockName = "bash_code_execution"

const ServerToolUseBlockNameTextEditorCodeExecution ServerToolUseBlockName = "text_editor_code_execution"

const ServerToolUseBlockNameToolSearchToolRegex ServerToolUseBlockName = "tool_search_tool_regex"

const ServerToolUseBlockNameToolSearchToolBm25 ServerToolUseBlockName = "tool_search_tool_bm25"

Type ServerToolUse

type WebSearchToolResultBlock struct{…}

Caller WebSearchToolResultBlockCallerUnion

Tool invocation directly from the model.

Accepts one of the following:

type DirectCaller struct{…}

Tool invocation directly from the model.

Type Direct

type ServerToolCaller struct{…}

Tool invocation generated by a server-side tool.

ToolID string

Type CodeExecution20250825

type ServerToolCaller20260120 struct{…}

ToolID string

Type CodeExecution20260120

Content WebSearchToolResultBlockContentUnion

Accepts one of the following:

type WebSearchToolResultError struct{…}

ErrorCode WebSearchToolResultErrorCode

Accepts one of the following:

const WebSearchToolResultErrorCodeInvalidToolInput WebSearchToolResultErrorCode = "invalid_tool_input"

const WebSearchToolResultErrorCodeUnavailable WebSearchToolResultErrorCode = "unavailable"

const WebSearchToolResultErrorCodeMaxUsesExceeded WebSearchToolResultErrorCode = "max_uses_exceeded"

const WebSearchToolResultErrorCodeTooManyRequests WebSearchToolResultErrorCode = "too_many_requests"

const WebSearchToolResultErrorCodeQueryTooLong WebSearchToolResultErrorCode = "query_too_long"

const WebSearchToolResultErrorCodeRequestTooLarge WebSearchToolResultErrorCode = "request_too_large"

Type WebSearchToolResultError

type WebSearchToolResultBlockContentArray []WebSearchResultBlock

EncryptedContent string

PageAge string

Title string

Type WebSearchResult

URL string

ToolUseID string

Type WebSearchToolResult

type WebFetchToolResultBlock struct{…}

Caller WebFetchToolResultBlockCallerUnion

Tool invocation directly from the model.

Accepts one of the following:

type DirectCaller struct{…}

Tool invocation directly from the model.

Type Direct

type ServerToolCaller struct{…}

Tool invocation generated by a server-side tool.

ToolID string

Type CodeExecution20250825

type ServerToolCaller20260120 struct{…}

ToolID string

Type CodeExecution20260120

Content WebFetchToolResultBlockContentUnion

Accepts one of the following:

type WebFetchToolResultErrorBlock struct{…}

ErrorCode WebFetchToolResultErrorCode

Accepts one of the following:

const WebFetchToolResultErrorCodeInvalidToolInput WebFetchToolResultErrorCode = "invalid_tool_input"

const WebFetchToolResultErrorCodeURLTooLong WebFetchToolResultErrorCode = "url_too_long"

const WebFetchToolResultErrorCodeURLNotAllowed WebFetchToolResultErrorCode = "url_not_allowed"

const WebFetchToolResultErrorCodeURLNotAccessible WebFetchToolResultErrorCode = "url_not_accessible"

const WebFetchToolResultErrorCodeUnsupportedContentType WebFetchToolResultErrorCode = "unsupported_content_type"

const WebFetchToolResultErrorCodeTooManyRequests WebFetchToolResultErrorCode = "too_many_requests"

const WebFetchToolResultErrorCodeMaxUsesExceeded WebFetchToolResultErrorCode = "max_uses_exceeded"

const WebFetchToolResultErrorCodeUnavailable WebFetchToolResultErrorCode = "unavailable"

Type WebFetchToolResultError

type WebFetchBlock struct{…}

Content DocumentBlock

Citations CitationsConfig

Citation configuration for the document

Enabled bool

Source DocumentBlockSourceUnion

Accepts one of the following:

type Base64PDFSource struct{…}

Data string

MediaType ApplicationPDF

Type Base64

type PlainTextSource struct{…}

Data string

MediaType TextPlain

Type Text

Title string

The title of the document

Type Document

RetrievedAt string

ISO 8601 timestamp when the content was retrieved

Type WebFetchResult

URL string

Fetched content URL

ToolUseID string

Type WebFetchToolResult

type CodeExecutionToolResultBlock struct{…}

Content CodeExecutionToolResultBlockContentUnion

Code execution result with encrypted stdout for PFC + web_search results.

Accepts one of the following:

type CodeExecutionToolResultError struct{…}

ErrorCode CodeExecutionToolResultErrorCode

Accepts one of the following:

const CodeExecutionToolResultErrorCodeInvalidToolInput CodeExecutionToolResultErrorCode = "invalid_tool_input"

const CodeExecutionToolResultErrorCodeUnavailable CodeExecutionToolResultErrorCode = "unavailable"

const CodeExecutionToolResultErrorCodeTooManyRequests CodeExecutionToolResultErrorCode = "too_many_requests"

const CodeExecutionToolResultErrorCodeExecutionTimeExceeded CodeExecutionToolResultErrorCode = "execution_time_exceeded"

Type CodeExecutionToolResultError

type CodeExecutionResultBlock struct{…}

Content []CodeExecutionOutputBlock

FileID string

Type CodeExecutionOutput

ReturnCode int64

Stderr string

Stdout string

Type CodeExecutionResult

type EncryptedCodeExecutionResultBlock struct{…}

Code execution result with encrypted stdout for PFC + web_search results.

Content []CodeExecutionOutputBlock

FileID string

Type CodeExecutionOutput

EncryptedStdout string

ReturnCode int64

Stderr string

Type EncryptedCodeExecutionResult

ToolUseID string

Type CodeExecutionToolResult

type BashCodeExecutionToolResultBlock struct{…}

Content BashCodeExecutionToolResultBlockContentUnion

Accepts one of the following:

type BashCodeExecutionToolResultError struct{…}

ErrorCode BashCodeExecutionToolResultErrorCode

Accepts one of the following:

const BashCodeExecutionToolResultErrorCodeInvalidToolInput BashCodeExecutionToolResultErrorCode = "invalid_tool_input"

const BashCodeExecutionToolResultErrorCodeUnavailable BashCodeExecutionToolResultErrorCode = "unavailable"

const BashCodeExecutionToolResultErrorCodeTooManyRequests BashCodeExecutionToolResultErrorCode = "too_many_requests"

const BashCodeExecutionToolResultErrorCodeExecutionTimeExceeded BashCodeExecutionToolResultErrorCode = "execution_time_exceeded"

const BashCodeExecutionToolResultErrorCodeOutputFileTooLarge BashCodeExecutionToolResultErrorCode = "output_file_too_large"

Type BashCodeExecutionToolResultError

type BashCodeExecutionResultBlock struct{…}

Content []BashCodeExecutionOutputBlock

FileID string

Type BashCodeExecutionOutput

ReturnCode int64

Stderr string

Stdout string

Type BashCodeExecutionResult

ToolUseID string

Type BashCodeExecutionToolResult

type TextEditorCodeExecutionToolResultBlock struct{…}

Content TextEditorCodeExecutionToolResultBlockContentUnion

Accepts one of the following:

type TextEditorCodeExecutionToolResultError struct{…}

ErrorCode TextEditorCodeExecutionToolResultErrorCode

Accepts one of the following:

const TextEditorCodeExecutionToolResultErrorCodeInvalidToolInput TextEditorCodeExecutionToolResultErrorCode = "invalid_tool_input"

const TextEditorCodeExecutionToolResultErrorCodeUnavailable TextEditorCodeExecutionToolResultErrorCode = "unavailable"

const TextEditorCodeExecutionToolResultErrorCodeTooManyRequests TextEditorCodeExecutionToolResultErrorCode = "too_many_requests"

const TextEditorCodeExecutionToolResultErrorCodeExecutionTimeExceeded TextEditorCodeExecutionToolResultErrorCode = "execution_time_exceeded"

const TextEditorCodeExecutionToolResultErrorCodeFileNotFound TextEditorCodeExecutionToolResultErrorCode = "file_not_found"

ErrorMessage string

Type TextEditorCodeExecutionToolResultError

type TextEditorCodeExecutionViewResultBlock struct{…}

Content string

FileType TextEditorCodeExecutionViewResultBlockFileType

Accepts one of the following:

const TextEditorCodeExecutionViewResultBlockFileTypeText TextEditorCodeExecutionViewResultBlockFileType = "text"

const TextEditorCodeExecutionViewResultBlockFileTypeImage TextEditorCodeExecutionViewResultBlockFileType = "image"

const TextEditorCodeExecutionViewResultBlockFileTypePDF TextEditorCodeExecutionViewResultBlockFileType = "pdf"

NumLines int64

StartLine int64

TotalLines int64

Type TextEditorCodeExecutionViewResult

type TextEditorCodeExecutionCreateResultBlock struct{…}

IsFileUpdate bool

Type TextEditorCodeExecutionCreateResult

type TextEditorCodeExecutionStrReplaceResultBlock struct{…}

Lines []string

NewLines int64

NewStart int64

OldLines int64

OldStart int64

Type TextEditorCodeExecutionStrReplaceResult

ToolUseID string

Type TextEditorCodeExecutionToolResult

type ToolSearchToolResultBlock struct{…}

Content ToolSearchToolResultBlockContentUnion

Accepts one of the following:

type ToolSearchToolResultError struct{…}

ErrorCode ToolSearchToolResultErrorCode

Accepts one of the following:

const ToolSearchToolResultErrorCodeInvalidToolInput ToolSearchToolResultErrorCode = "invalid_tool_input"

const ToolSearchToolResultErrorCodeUnavailable ToolSearchToolResultErrorCode = "unavailable"

const ToolSearchToolResultErrorCodeTooManyRequests ToolSearchToolResultErrorCode = "too_many_requests"

const ToolSearchToolResultErrorCodeExecutionTimeExceeded ToolSearchToolResultErrorCode = "execution_time_exceeded"

ErrorMessage string

Type ToolSearchToolResultError

type ToolSearchToolSearchResultBlock struct{…}

ToolReferences []ToolReferenceBlock

ToolName string

Type ToolReference

Type ToolSearchToolSearchResult

ToolUseID string

Type ToolSearchToolResult

type ContainerUploadBlock struct{…}

Response model for a file uploaded to the container.

FileID string

Type ContainerUpload

Model Model

The model that will complete your prompt.

See models for additional details and options.

Accepts one of the following:

type Model string

The model that will complete your prompt.

See models for additional details and options.

Accepts one of the following:

const ModelClaudeOpus4_6 Model = "claude-opus-4-6"

Most intelligent model for building agents and coding

const ModelClaudeSonnet4_6 Model = "claude-sonnet-4-6"

Frontier intelligence at scale — built for coding, agents, and enterprise workflows

const ModelClaudeOpus4_5_20251101 Model = "claude-opus-4-5-20251101"

Premium model combining maximum intelligence with practical performance

const ModelClaudeOpus4_5 Model = "claude-opus-4-5"

Premium model combining maximum intelligence with practical performance

const ModelClaude3_7SonnetLatest Model = "claude-3-7-sonnet-latest"

High-performance model with early extended thinking

const ModelClaude3_7Sonnet20250219 Model = "claude-3-7-sonnet-20250219"

High-performance model with early extended thinking

const ModelClaude3_5HaikuLatest Model = "claude-3-5-haiku-latest"

Fastest and most compact model for near-instant responsiveness

const ModelClaude3_5Haiku20241022 Model = "claude-3-5-haiku-20241022"

Our fastest model

const ModelClaudeHaiku4_5 Model = "claude-haiku-4-5"

Hybrid model, capable of near-instant responses and extended thinking

const ModelClaudeHaiku4_5_20251001 Model = "claude-haiku-4-5-20251001"

Hybrid model, capable of near-instant responses and extended thinking

const ModelClaudeSonnet4_20250514 Model = "claude-sonnet-4-20250514"

High-performance model with extended thinking

const ModelClaudeSonnet4_0 Model = "claude-sonnet-4-0"

High-performance model with extended thinking

const ModelClaude4Sonnet20250514 Model = "claude-4-sonnet-20250514"

High-performance model with extended thinking

const ModelClaudeSonnet4_5 Model = "claude-sonnet-4-5"

Our best model for real-world agents and coding

const ModelClaudeSonnet4_5_20250929 Model = "claude-sonnet-4-5-20250929"

Our best model for real-world agents and coding

const ModelClaudeOpus4_0 Model = "claude-opus-4-0"

Our most capable model

const ModelClaudeOpus4_20250514 Model = "claude-opus-4-20250514"

Our most capable model

const ModelClaude4Opus20250514 Model = "claude-4-opus-20250514"

Our most capable model

const ModelClaudeOpus4_1_20250805 Model = "claude-opus-4-1-20250805"

Our most capable model

const ModelClaude3OpusLatest Model = "claude-3-opus-latest"

Excels at writing and complex tasks

const ModelClaude_3_Opus_20240229 Model = "claude-3-opus-20240229"

Excels at writing and complex tasks

const ModelClaude_3_Haiku_20240307 Model = "claude-3-haiku-20240307"

Our previous most fast and cost-effective

string

Role Assistant

Conversational role of the generated message.

This will always be "assistant".

StopReason StopReason

The reason that we stopped.

This may be one the following values:

"end_turn": the model reached a natural stopping point
"max_tokens": we exceeded the requested max_tokens or the model's maximum
"stop_sequence": one of your provided custom stop_sequences was generated
"tool_use": the model invoked one or more tools
"pause_turn": we paused a long-running turn. You may provide the response back as-is in a subsequent request to let the model continue.
"refusal": when streaming classifiers intervene to handle potential policy violations

In non-streaming mode this value is always non-null. In streaming mode, it is null in the message_start event and non-null otherwise.

Accepts one of the following:

const StopReasonEndTurn StopReason = "end_turn"

const StopReasonMaxTokens StopReason = "max_tokens"

const StopReasonStopSequence StopReason = "stop_sequence"

const StopReasonToolUse StopReason = "tool_use"

const StopReasonPauseTurn StopReason = "pause_turn"

const StopReasonRefusal StopReason = "refusal"

StopSequence string

Which custom stop sequence was generated, if any.

This value will be a non-null string if one of your custom stop sequences was generated.

Type Message

Object type.

For Messages, this is always "message".

Usage Usage

Billing and rate-limit usage.

Anthropic's API bills and rate-limits by token counts, as tokens represent the underlying cost to our systems.

For example, output_tokens will be non-zero, even for an empty string response from Claude.

Total input tokens in a request is the summation of input_tokens, cache_creation_input_tokens, and cache_read_input_tokens.

CacheCreation CacheCreation

Breakdown of cached tokens by TTL

Ephemeral1hInputTokens int64

The number of input tokens used to create the 1 hour cache entry.

Ephemeral5mInputTokens int64

The number of input tokens used to create the 5 minute cache entry.

CacheCreationInputTokens int64

The number of input tokens used to create the cache entry.

CacheReadInputTokens int64

The number of input tokens read from the cache.

InferenceGeo string

The geographic region where inference was performed for this request.

InputTokens int64

The number of input tokens which were used.

OutputTokens int64

The number of output tokens which were used.

ServerToolUse ServerToolUsage

The number of server tool requests.

WebFetchRequests int64

The number of web fetch tool requests.

WebSearchRequests int64

The number of web search tool requests.

ServiceTier UsageServiceTier

If the request used the priority, standard, or batch tier.

Accepts one of the following:

const UsageServiceTierStandard UsageServiceTier = "standard"

const UsageServiceTierPriority UsageServiceTier = "priority"

const UsageServiceTierBatch UsageServiceTier = "batch"

Type Succeeded