Retrieve Message Batch results

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

Streams the results of a Message Batch as a .jsonl file.

Each line in the file is a JSON object containing the result of a single request in the Message Batch. Results are not guaranteed to be in the same order as requests. Use the custom_id field to match results to requests.

Learn more about the Message Batches API in our user guide

Path ParametersExpand Collapse

message_batch_id: string

ID of the Message Batch.

ReturnsExpand Collapse

MessageBatchIndividualResponse = object { custom_id, result }

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

custom_id: 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: MessageBatchResult

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:

MessageBatchSucceededResult = object { message, type }

message: Message { id, container, content, 6 more }

id: string

Unique object identifier.

The format and length of IDs may change over time.

container: Container { id, expires_at }

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

id: string

Identifier for the container used in this request

expires_at: string

The time at which the container will expire.

content: array of ContentBlock

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:

TextBlock = object { citations, text, type }

citations: array of TextCitation

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:

CitationCharLocation = object { cited_text, document_index, document_title, 4 more }

cited_text: string

document_index: number

document_title: string

end_char_index: number

file_id: string

start_char_index: number

type: "char_location"

CitationPageLocation = object { cited_text, document_index, document_title, 4 more }

cited_text: string

document_index: number

document_title: string

end_page_number: number

file_id: string

start_page_number: number

type: "page_location"

CitationContentBlockLocation = object { cited_text, document_index, document_title, 4 more }

cited_text: string

document_index: number

document_title: string

end_block_index: number

file_id: string

start_block_index: number

type: "content_block_location"

CitationsWebSearchResultLocation = object { cited_text, encrypted_index, title, 2 more }

cited_text: string

encrypted_index: string

title: string

type: "web_search_result_location"

url: string

CitationsSearchResultLocation = object { cited_text, end_block_index, search_result_index, 4 more }

cited_text: string

end_block_index: number

search_result_index: number

source: string

start_block_index: number

title: string

type: "search_result_location"

text: string

type: "text"

ThinkingBlock = object { signature, thinking, type }

signature: string

thinking: string

type: "thinking"

RedactedThinkingBlock = object { data, type }

data: string

type: "redacted_thinking"

ToolUseBlock = object { id, caller, input, 2 more }

id: string

caller: DirectCaller { type } or ServerToolCaller { tool_id, type } or ServerToolCaller20260120 { tool_id, type }

Tool invocation directly from the model.

Accepts one of the following:

DirectCaller = object { type }

Tool invocation directly from the model.

type: "direct"

ServerToolCaller = object { tool_id, type }

Tool invocation generated by a server-side tool.

tool_id: string

type: "code_execution_20250825"

ServerToolCaller20260120 = object { tool_id, type }

tool_id: string

type: "code_execution_20260120"

input: map[unknown]

name: string

type: "tool_use"

ServerToolUseBlock = object { id, caller, input, 2 more }

id: string

caller: DirectCaller { type } or ServerToolCaller { tool_id, type } or ServerToolCaller20260120 { tool_id, type }

Tool invocation directly from the model.

Accepts one of the following:

DirectCaller = object { type }

Tool invocation directly from the model.

type: "direct"

ServerToolCaller = object { tool_id, type }

Tool invocation generated by a server-side tool.

tool_id: string

type: "code_execution_20250825"

ServerToolCaller20260120 = object { tool_id, type }

tool_id: string

type: "code_execution_20260120"

input: map[unknown]

name: "web_search" or "web_fetch" or "code_execution" or 4 more

Accepts one of the following:

"web_search"

"web_fetch"

"code_execution"

"bash_code_execution"

"text_editor_code_execution"

"tool_search_tool_regex"

"tool_search_tool_bm25"

type: "server_tool_use"

WebSearchToolResultBlock = object { caller, content, tool_use_id, type }

caller: DirectCaller { type } or ServerToolCaller { tool_id, type } or ServerToolCaller20260120 { tool_id, type }

Tool invocation directly from the model.

Accepts one of the following:

DirectCaller = object { type }

Tool invocation directly from the model.

type: "direct"

ServerToolCaller = object { tool_id, type }

Tool invocation generated by a server-side tool.

tool_id: string

type: "code_execution_20250825"

ServerToolCaller20260120 = object { tool_id, type }

tool_id: string

type: "code_execution_20260120"

content: WebSearchToolResultBlockContent

Accepts one of the following:

WebSearchToolResultError = object { error_code, type }

error_code: WebSearchToolResultErrorCode

Accepts one of the following:

"invalid_tool_input"

"unavailable"

"max_uses_exceeded"

"too_many_requests"

"query_too_long"

"request_too_large"

type: "web_search_tool_result_error"

UnionMember1 = array of WebSearchResultBlock { encrypted_content, page_age, title, 2 more }

encrypted_content: string

page_age: string

title: string

type: "web_search_result"

url: string

tool_use_id: string

type: "web_search_tool_result"

WebFetchToolResultBlock = object { caller, content, tool_use_id, type }

caller: DirectCaller { type } or ServerToolCaller { tool_id, type } or ServerToolCaller20260120 { tool_id, type }

Tool invocation directly from the model.

Accepts one of the following:

DirectCaller = object { type }

Tool invocation directly from the model.

type: "direct"

ServerToolCaller = object { tool_id, type }

Tool invocation generated by a server-side tool.

tool_id: string

type: "code_execution_20250825"

ServerToolCaller20260120 = object { tool_id, type }

tool_id: string

type: "code_execution_20260120"

content: WebFetchToolResultErrorBlock { error_code, type } or WebFetchBlock { content, retrieved_at, type, url }

Accepts one of the following:

WebFetchToolResultErrorBlock = object { error_code, type }

error_code: WebFetchToolResultErrorCode

Accepts one of the following:

"invalid_tool_input"

"url_too_long"

"url_not_allowed"

"url_not_accessible"

"unsupported_content_type"

"too_many_requests"

"max_uses_exceeded"

"unavailable"

type: "web_fetch_tool_result_error"

WebFetchBlock = object { content, retrieved_at, type, url }

content: DocumentBlock { citations, source, title, type }

citations: CitationsConfig { enabled }

Citation configuration for the document

enabled: boolean

source: Base64PDFSource { data, media_type, type } or PlainTextSource { data, media_type, type }

Accepts one of the following:

Base64PDFSource = object { data, media_type, type }

data: string

media_type: "application/pdf"

type: "base64"

PlainTextSource = object { data, media_type, type }

data: string

media_type: "text/plain"

type: "text"

title: string

The title of the document

type: "document"

retrieved_at: string

ISO 8601 timestamp when the content was retrieved

type: "web_fetch_result"

url: string

Fetched content URL

tool_use_id: string

type: "web_fetch_tool_result"

CodeExecutionToolResultBlock = object { content, tool_use_id, type }

content: CodeExecutionToolResultBlockContent

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

Accepts one of the following:

CodeExecutionToolResultError = object { error_code, type }

error_code: CodeExecutionToolResultErrorCode

Accepts one of the following:

"invalid_tool_input"

"unavailable"

"too_many_requests"

"execution_time_exceeded"

type: "code_execution_tool_result_error"

CodeExecutionResultBlock = object { content, return_code, stderr, 2 more }

content: array of CodeExecutionOutputBlock { file_id, type }

file_id: string

type: "code_execution_output"

return_code: number

stderr: string

stdout: string

type: "code_execution_result"

EncryptedCodeExecutionResultBlock = object { content, encrypted_stdout, return_code, 2 more }

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

content: array of CodeExecutionOutputBlock { file_id, type }

file_id: string

type: "code_execution_output"

encrypted_stdout: string

return_code: number

stderr: string

type: "encrypted_code_execution_result"

tool_use_id: string

type: "code_execution_tool_result"

BashCodeExecutionToolResultBlock = object { content, tool_use_id, type }

content: BashCodeExecutionToolResultError { error_code, type } or BashCodeExecutionResultBlock { content, return_code, stderr, 2 more }

Accepts one of the following:

BashCodeExecutionToolResultError = object { error_code, type }

error_code: BashCodeExecutionToolResultErrorCode

Accepts one of the following:

"invalid_tool_input"

"unavailable"

"too_many_requests"

"execution_time_exceeded"

"output_file_too_large"

type: "bash_code_execution_tool_result_error"

BashCodeExecutionResultBlock = object { content, return_code, stderr, 2 more }

content: array of BashCodeExecutionOutputBlock { file_id, type }

file_id: string

type: "bash_code_execution_output"

return_code: number

stderr: string

stdout: string

type: "bash_code_execution_result"

tool_use_id: string

type: "bash_code_execution_tool_result"

TextEditorCodeExecutionToolResultBlock = object { content, tool_use_id, type }

content: TextEditorCodeExecutionToolResultError { error_code, error_message, type } or TextEditorCodeExecutionViewResultBlock { content, file_type, num_lines, 3 more } or TextEditorCodeExecutionCreateResultBlock { is_file_update, type } or TextEditorCodeExecutionStrReplaceResultBlock { lines, new_lines, new_start, 3 more }

Accepts one of the following:

TextEditorCodeExecutionToolResultError = object { error_code, error_message, type }

error_code: TextEditorCodeExecutionToolResultErrorCode

Accepts one of the following:

"invalid_tool_input"

"unavailable"

"too_many_requests"

"execution_time_exceeded"

"file_not_found"

error_message: string

type: "text_editor_code_execution_tool_result_error"

TextEditorCodeExecutionViewResultBlock = object { content, file_type, num_lines, 3 more }

content: string

file_type: "text" or "image" or "pdf"

Accepts one of the following:

"text"

"image"

"pdf"

num_lines: number

start_line: number

total_lines: number

type: "text_editor_code_execution_view_result"

TextEditorCodeExecutionCreateResultBlock = object { is_file_update, type }

is_file_update: boolean

type: "text_editor_code_execution_create_result"

TextEditorCodeExecutionStrReplaceResultBlock = object { lines, new_lines, new_start, 3 more }

lines: array of string

new_lines: number

new_start: number

old_lines: number

old_start: number

type: "text_editor_code_execution_str_replace_result"

tool_use_id: string

type: "text_editor_code_execution_tool_result"

ToolSearchToolResultBlock = object { content, tool_use_id, type }

content: ToolSearchToolResultError { error_code, error_message, type } or ToolSearchToolSearchResultBlock { tool_references, type }

Accepts one of the following:

ToolSearchToolResultError = object { error_code, error_message, type }

error_code: ToolSearchToolResultErrorCode

Accepts one of the following:

"invalid_tool_input"

"unavailable"

"too_many_requests"

"execution_time_exceeded"

error_message: string

type: "tool_search_tool_result_error"

ToolSearchToolSearchResultBlock = object { tool_references, type }

tool_references: array of ToolReferenceBlock { tool_name, type }

tool_name: string

type: "tool_reference"

type: "tool_search_tool_search_result"

tool_use_id: string

type: "tool_search_tool_result"

ContainerUploadBlock = object { file_id, type }

Response model for a file uploaded to the container.

file_id: string

type: "container_upload"

model: Model

The model that will complete your prompt.

See models for additional details and options.

Accepts one of the following:

UnionMember0 = "claude-opus-4-6" or "claude-sonnet-4-6" or "claude-haiku-4-5" or 12 more

The model that will complete your prompt.

See models for additional details and options.

Accepts one of the following:

"claude-opus-4-6"

Most intelligent model for building agents and coding

"claude-sonnet-4-6"

Best combination of speed and intelligence

"claude-haiku-4-5"

Fastest model with near-frontier intelligence

"claude-haiku-4-5-20251001"

Fastest model with near-frontier intelligence

"claude-opus-4-5"

Premium model combining maximum intelligence with practical performance

"claude-opus-4-5-20251101"

Premium model combining maximum intelligence with practical performance

"claude-sonnet-4-5"

High-performance model for agents and coding

"claude-sonnet-4-5-20250929"

High-performance model for agents and coding

"claude-opus-4-1"

Exceptional model for specialized complex tasks

"claude-opus-4-1-20250805"

Exceptional model for specialized complex tasks

"claude-opus-4-0"

Powerful model for complex tasks

"claude-opus-4-20250514"

Powerful model for complex tasks

"claude-sonnet-4-0"

High-performance model with extended thinking

"claude-sonnet-4-20250514"

High-performance model with extended thinking

"claude-3-haiku-20240307"

Fast and cost-effective model

UnionMember1 = string

role: "assistant"

Conversational role of the generated message.

This will always be "assistant".

stop_reason: 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:

"end_turn"

"max_tokens"

"stop_sequence"

"tool_use"

"pause_turn"

"refusal"

stop_sequence: 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 { cache_creation, cache_creation_input_tokens, cache_read_input_tokens, 5 more }

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.

cache_creation: CacheCreation { ephemeral_1h_input_tokens, ephemeral_5m_input_tokens }

Breakdown of cached tokens by TTL

ephemeral_1h_input_tokens: number

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

ephemeral_5m_input_tokens: number

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

cache_creation_input_tokens: number

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

cache_read_input_tokens: number

The number of input tokens read from the cache.

inference_geo: string

The geographic region where inference was performed for this request.

input_tokens: number

The number of input tokens which were used.

output_tokens: number

The number of output tokens which were used.

server_tool_use: ServerToolUsage { web_fetch_requests, web_search_requests }

The number of server tool requests.

web_fetch_requests: number

The number of web fetch tool requests.

web_search_requests: number

The number of web search tool requests.

service_tier: "standard" or "priority" or "batch"

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

Accepts one of the following:

"standard"

"priority"

"batch"

type: "succeeded"

MessageBatchErroredResult = object { error, type }

error: ErrorResponse { error, request_id, type }

error: ErrorObject

Accepts one of the following:

InvalidRequestError = object { message, type }

message: string

type: "invalid_request_error"

AuthenticationError = object { message, type }

message: string

type: "authentication_error"

BillingError = object { message, type }

message: string

type: "billing_error"

PermissionError = object { message, type }

message: string

type: "permission_error"

NotFoundError = object { message, type }

message: string

type: "not_found_error"

RateLimitError = object { message, type }

message: string

type: "rate_limit_error"

GatewayTimeoutError = object { message, type }

message: string

type: "timeout_error"

APIErrorObject = object { message, type }

message: string

type: "api_error"

OverloadedError = object { message, type }

message: string

type: "overloaded_error"

request_id: string

type: "error"

type: "errored"

MessageBatchCanceledResult = object { type }

type: "canceled"

MessageBatchExpiredResult = object { type }

type: "expired"

Retrieve Message Batch results

curl https://api.anthropic.com/v1/messages/batches/$MESSAGE_BATCH_ID/results \
    -H 'anthropic-version: 2023-06-01' \
    -H "X-Api-Key: $ANTHROPIC_API_KEY"

Retrieve Message Batch results

Path ParametersExpand Collapse

ReturnsExpand Collapse

Returns Examples