Claude Platform Docs

Retrieve Message Batch results

$ ant messages:batches 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

Parameters
--message-batch-id: string

ID of the Message Batch.

Returns
message_batch_individual_response: 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: MessageBatchSucceededResult { message, type } or MessageBatchErroredResult { error, type } or MessageBatchCanceledResult { type } or MessageBatchExpiredResult { type }

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.

One of the following:
message_batch_succeeded_result: object{ message, type }
message: object{ id, container, content, 7 more }
id: string

Unique object identifier.

The format and length of IDs may change over time.

container: object{ id, expires_at, skills }

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.

formatdate-time
skills: array of ContainerSkill { skill_id, type, version }

Skills loaded in the container

skill_id: string

Skill ID

maxLength64
minLength1
type: "anthropic" or "custom"

Type of skill - either 'anthropic' (built-in) or 'custom' (user-defined)

One of the following:
"anthropic"
"custom"
version: string

The resolved version: a skill version ID for custom skills.

maxLength64
minLength1
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)"}]
One of the following:
text_block: 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.

One of the following:
citation_char_location: object{ cited_text, document_index, document_title, 4 more }
cited_text: string
document_index: number
minimum0
document_title: string
end_char_index: number
file_id: string
start_char_index: number
minimum0
type: "char_location"
citation_page_location: object{ cited_text, document_index, document_title, 4 more }
cited_text: string
document_index: number
minimum0
document_title: string
end_page_number: number
file_id: string
start_page_number: number
minimum1
type: "page_location"
citation_content_block_location: object{ cited_text, document_index, document_title, 4 more }
cited_text: string

The full text of the cited block range, concatenated.

Always equals the contents of content[start_block_index:end_block_index] joined together. The text block is the minimal citable unit; this field is never a substring of a single block. Not counted toward output tokens, and not counted toward input tokens when sent back in subsequent turns.

document_index: number
minimum0
document_title: string
end_block_index: number

Exclusive 0-based end index of the cited block range in the source's content array.

Always greater than start_block_index; a single-block citation has end_block_index = start_block_index + 1.

file_id: string
start_block_index: number

0-based index of the first cited block in the source's content array.

minimum0
type: "content_block_location"
citations_web_search_result_location: object{ cited_text, encrypted_index, title, 2 more }
cited_text: string
encrypted_index: string
title: string
maxLength512
type: "web_search_result_location"
url: string
citations_search_result_location: object{ cited_text, end_block_index, search_result_index, 4 more }
cited_text: string

The full text of the cited block range, concatenated.

Always equals the contents of content[start_block_index:end_block_index] joined together. The text block is the minimal citable unit; this field is never a substring of a single block. Not counted toward output tokens, and not counted toward input tokens when sent back in subsequent turns.

end_block_index: number

Exclusive 0-based end index of the cited block range in the source's content array.

Always greater than start_block_index; a single-block citation has end_block_index = start_block_index + 1.

search_result_index: number

0-based index of the cited search result among all search_result content blocks in the request, in the order they appear across messages and tool results.

Counted separately from document_index; server-side web search results are not included in this count.

minimum0
source: string
start_block_index: number

0-based index of the first cited block in the source's content array.

minimum0
title: string
type: "search_result_location"
text: string
maxLength5000000
minLength0
type: "text"
thinking_block: object{ signature, thinking, type }
signature: string

A value used to verify that this thinking block was generated by Claude when it is passed back to the API.

This is an opaque field and should not be interpreted or parsed. When passing thinking blocks back to the API (required when using tools with extended thinking), pass them back exactly as received, with this field intact.

See extended thinking for details.

thinking: string

The text of Claude's thinking process for this block.

type: "thinking"
redacted_thinking_block: object{ data, type }
data: string

The contents of this redacted thinking block, returned when portions of the model's thinking were safety-redacted. This field is opaque and encrypted, with no readable content.

Pass redacted_thinking blocks back to the API unchanged when continuing a multi-turn conversation.

See extended thinking for details.

type: "redacted_thinking"
tool_use_block: object{ id, caller, input, 3 more }
id: string
pattern^[a-zA-Z0-9_-]+$
caller: DirectCaller { type } or ServerToolCaller { tool_id, type } or ServerToolCaller20260120 { tool_id, type }

Tool invocation directly from the model.

One of the following:
direct_caller: object{ type }

Tool invocation directly from the model.

type: "direct"
server_tool_caller: object{ tool_id, type }

Tool invocation generated by a server-side tool.

tool_id: string
pattern^srvtoolu_[a-zA-Z0-9_]+$
type: "code_execution_20250825"
server_tool_caller_20260120: object{ tool_id, type }
tool_id: string
pattern^srvtoolu_[a-zA-Z0-9_]+$
type: "code_execution_20260120"
input: map[unknown]
name: string
minLength1
type: "tool_use"
toolset_name: optional string

For a toolset member tool_use, the toolset family.

maxLength64
minLength1
pattern^[a-zA-Z0-9_-]+$
server_tool_use_block: object{ id, caller, input, 2 more }
id: string
pattern^srvtoolu_[a-zA-Z0-9_]+$
caller: DirectCaller { type } or ServerToolCaller { tool_id, type } or ServerToolCaller20260120 { tool_id, type }

Tool invocation directly from the model.

One of the following:
direct_caller: object{ type }

Tool invocation directly from the model.

type: "direct"
server_tool_caller: object{ tool_id, type }

Tool invocation generated by a server-side tool.

tool_id: string
pattern^srvtoolu_[a-zA-Z0-9_]+$
type: "code_execution_20250825"
server_tool_caller_20260120: object{ tool_id, type }
tool_id: string
pattern^srvtoolu_[a-zA-Z0-9_]+$
type: "code_execution_20260120"
input: map[unknown]
name: "web_search" or "web_fetch" or "code_execution" or 4 more
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"
web_search_tool_result_block: 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.

One of the following:
direct_caller: object{ type }

Tool invocation directly from the model.

type: "direct"
server_tool_caller: object{ tool_id, type }

Tool invocation generated by a server-side tool.

tool_id: string
pattern^srvtoolu_[a-zA-Z0-9_]+$
type: "code_execution_20250825"
server_tool_caller_20260120: object{ tool_id, type }
tool_id: string
pattern^srvtoolu_[a-zA-Z0-9_]+$
type: "code_execution_20260120"
content: WebSearchToolResultError { error_code, type } or array of WebSearchResultBlock { encrypted_content, page_age, title, 2 more }
One of the following:
web_search_tool_result_error: object{ error_code, type }
error_code: "invalid_tool_input" or "unavailable" or "max_uses_exceeded" or 3 more
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"
union_member_1: 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
pattern^srvtoolu_[a-zA-Z0-9_]+$
type: "web_search_tool_result"
web_fetch_tool_result_block: 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.

One of the following:
direct_caller: object{ type }

Tool invocation directly from the model.

type: "direct"
server_tool_caller: object{ tool_id, type }

Tool invocation generated by a server-side tool.

tool_id: string
pattern^srvtoolu_[a-zA-Z0-9_]+$
type: "code_execution_20250825"
server_tool_caller_20260120: object{ tool_id, type }
tool_id: string
pattern^srvtoolu_[a-zA-Z0-9_]+$
type: "code_execution_20260120"
content: WebFetchToolResultErrorBlock { error_code, type } or WebFetchBlock { content, retrieved_at, type, url }
One of the following:
web_fetch_tool_result_error_block: object{ error_code, type }
error_code: "invalid_tool_input" or "url_too_long" or "url_not_allowed" or 6 more
One of the following:
"invalid_tool_input"
"url_too_long"
"url_not_allowed"
"url_not_in_prior_context"
"url_not_accessible"
"unsupported_content_type"
"too_many_requests"
"max_uses_exceeded"
"unavailable"
type: "web_fetch_tool_result_error"
web_fetch_block: object{ content, retrieved_at, type, url }
tool_use_id: string
pattern^srvtoolu_[a-zA-Z0-9_]+$
type: "web_fetch_tool_result"
code_execution_tool_result_block: object{ content, tool_use_id, type }
content: CodeExecutionToolResultError { error_code, type } or CodeExecutionResultBlock { content, return_code, stderr, 2 more } or EncryptedCodeExecutionResultBlock { content, encrypted_stdout, return_code, 2 more }

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

One of the following:
code_execution_tool_result_error: object{ error_code, type }
error_code: "invalid_tool_input" or "unavailable" or "too_many_requests" or "execution_time_exceeded"
One of the following:
"invalid_tool_input"
"unavailable"
"too_many_requests"
"execution_time_exceeded"
type: "code_execution_tool_result_error"
code_execution_result_block: 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"
encrypted_code_execution_result_block: 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
pattern^srvtoolu_[a-zA-Z0-9_]+$
type: "code_execution_tool_result"
bash_code_execution_tool_result_block: object{ content, tool_use_id, type }
content: BashCodeExecutionToolResultError { error_code, type } or BashCodeExecutionResultBlock { content, return_code, stderr, 2 more }
One of the following:
bash_code_execution_tool_result_error: object{ error_code, type }
error_code: "invalid_tool_input" or "unavailable" or "too_many_requests" or 2 more
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"
bash_code_execution_result_block: 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
pattern^srvtoolu_[a-zA-Z0-9_]+$
type: "bash_code_execution_tool_result"
text_editor_code_execution_tool_result_block: 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 }
One of the following:
text_editor_code_execution_tool_result_error: object{ error_code, error_message, type }
error_code: "invalid_tool_input" or "unavailable" or "too_many_requests" or 2 more
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"
text_editor_code_execution_view_result_block: object{ content, file_type, num_lines, 3 more }
content: string
file_type: "text" or "image" or "pdf"
One of the following:
"text"
"image"
"pdf"
num_lines: number
start_line: number
total_lines: number
type: "text_editor_code_execution_view_result"
text_editor_code_execution_create_result_block: object{ is_file_update, type }
is_file_update: boolean
type: "text_editor_code_execution_create_result"
text_editor_code_execution_str_replace_result_block: 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
pattern^srvtoolu_[a-zA-Z0-9_]+$
type: "text_editor_code_execution_tool_result"
tool_search_tool_result_block: object{ content, tool_use_id, type }
content: ToolSearchToolResultError { error_code, error_message, type } or ToolSearchToolSearchResultBlock { tool_references, type }
One of the following:
tool_search_tool_result_error: object{ error_code, error_message, type }
error_code: "invalid_tool_input" or "unavailable" or "too_many_requests" or "execution_time_exceeded"
One of the following:
"invalid_tool_input"
"unavailable"
"too_many_requests"
"execution_time_exceeded"
error_message: string
type: "tool_search_tool_result_error"
tool_search_tool_search_result_block: object{ tool_references, type }
tool_references: array of ToolReferenceBlock { tool_name, type }
tool_name: string
maxLength256
minLength1
pattern^[a-zA-Z0-9_-]{1,256}$
type: "tool_reference"
type: "tool_search_tool_search_result"
tool_use_id: string
pattern^srvtoolu_[a-zA-Z0-9_]+$
type: "tool_search_tool_result"
container_upload_block: object{ file_id, type }

Response model for a file uploaded to the container.

file_id: string
type: "container_upload"
model: "claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more or string

The model that will complete your prompt.

See models for additional details and options.

One of the following:
"claude-sonnet-5"

High-performance model for coding and agents

"claude-fable-5"

Next generation of intelligence for the hardest knowledge work and coding problems

"claude-mythos-5"

Most capable model for cybersecurity and biology research

"claude-opus-5"

Powerful intelligence for long-running agents and coding

"claude-opus-4-8"

Powerful intelligence for long-running agents and coding

"claude-opus-4-7"

Powerful intelligence for long-running agents and coding

"claude-mythos-preview"

New class of intelligence, strongest in coding and cybersecurity

"claude-opus-4-6"

Powerful intelligence for long-running 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"

Powerful intelligence for long-running agents and coding

"claude-opus-4-5-20251101"

Powerful intelligence for long-running agents and coding

"claude-sonnet-4-5"

High-performance model for agents and coding

"claude-sonnet-4-5-20250929"

High-performance model for agents and coding

role: "assistant"

Conversational role of the generated message.

This will always be "assistant".

stop_details: object{ category, explanation, type }

Structured information about a refusal.

category: "cyber" or "bio" or "frontier_llm" or 2 more

The policy category that triggered a refusal.

One of the following:
"cyber"

The request could enable cyber harm, such as malware or exploit development. Benign cybersecurity work can also trigger this category.

"bio"

The request could enable biological harm, such as dangerous lab methods. Beneficial life sciences work can also trigger this category.

"frontier_llm"

The request could assist the development of competing AI models, which is restricted under Anthropic's commercial terms. Benign machine learning work can also trigger this category.

"reasoning_extraction"

The request asks the model to reproduce its internal reasoning in the response text. To get reasoning in a structured form instead, use adaptive thinking.

"general_harms"

The request could be related to an area that was determined as harmful. Benign work might sometimes trigger this category.

explanation: string

Human-readable explanation of the refusal.

This text is not guaranteed to be stable. null when no explanation is available for the category.

type: "refusal"
stop_reason: "end_turn" or "max_tokens" or "stop_sequence" or 4 more

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
  • "model_context_window_exceeded": we exceeded the model's context window

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.

One of the following:
"end_turn"
"max_tokens"
"stop_sequence"
"tool_use"
"pause_turn"
"refusal"
"model_context_window_exceeded"
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: object{ cache_creation, cache_creation_input_tokens, cache_read_input_tokens, 6 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: object{ 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.

minimum0
ephemeral_5m_input_tokens: number

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

minimum0
cache_creation_input_tokens: number

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

minimum0
cache_read_input_tokens: number

The number of input tokens read from the cache.

minimum0
inference_geo: string

The geographic region where inference was performed for this request.

input_tokens: number

The number of input tokens which were used.

minimum0
output_tokens: number

The number of output tokens which were used.

minimum0
output_tokens_details: object{ thinking_tokens }

Breakdown of output tokens by category.

output_tokens remains the inclusive, authoritative total used for billing. This object provides a read-only decomposition for observability — for example, how many of the billed output tokens were spent on internal reasoning that may have been summarized before being returned to you.

thinking_tokens: number

Number of output tokens the model generated as internal reasoning, including the thinking-block delimiter tokens.

Reflects the raw reasoning the model produced, not the (possibly shorter) summarized thinking text returned in the response body. Computed by re-tokenizing the raw reasoning text, so it may differ from the model's exact generation count by a small number of tokens. Always ≤ output_tokens; output_tokens - thinking_tokens approximates the non-reasoning output.

minimum0
server_tool_use: object{ web_fetch_requests, web_search_requests }

The number of server tool requests.

web_fetch_requests: number

The number of web fetch tool requests.

minimum0
web_search_requests: number

The number of web search tool requests.

minimum0
service_tier: "standard" or "priority" or "batch"

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

One of the following:
"standard"
"priority"
"batch"
type: "succeeded"
message_batch_errored_result: object{ error, type }
error: object{ error, request_id, type }
error: InvalidRequestError { message, type } or AuthenticationError { message, type } or BillingError { message, type } or 6 more
One of the following:
invalid_request_error: object{ message, type }
message: string
type: "invalid_request_error"
authentication_error: object{ message, type }
message: string
type: "authentication_error"
billing_error: object{ message, type }
message: string
type: "billing_error"
permission_error: object{ message, type }
message: string
type: "permission_error"
not_found_error: object{ message, type }
message: string
type: "not_found_error"
rate_limit_error: object{ message, type }
message: string
type: "rate_limit_error"
gateway_timeout_error: object{ message, type }
message: string
type: "timeout_error"
api_error_object: object{ message, type }
message: string
type: "api_error"
overloaded_error: object{ message, type }
message: string
type: "overloaded_error"
request_id: string
type: "error"
type: "errored"
message_batch_canceled_result: object{ type }
type: "canceled"
message_batch_expired_result: object{ type }
type: "expired"

Retrieve Message Batch results

ant messages:batches results \
  --api-key my-anthropic-api-key \
  --message-batch-id message_batch_id