v49

latestOpenAPI 3.1.0raw.githubusercontent.com2026-07-261319281.7 MB

Retrieve a Message Batch

This endpoint is idempotent and can be used to poll for Message Batch completion. To access the results of a Message Batch, make a request to the results_url field in the response.

Learn more about the Message Batches API in our user guide

get/v1/messages/batches/{message_batch_id}

Path parameters

message_batch_idstring required

ID of the Message Batch.

Headers

anthropic-versionstring

The version of the Claude API you want to use.

Read more about versioning and our version history here.

The version of the Claude API you want to use.

Read more about versioning and our version history here.

x-api-keystring

Your unique API key for authentication.

This key is required in the header of all API requests, to authenticate your account and access Anthropic's services. Get your API key through the Console. Each key is scoped to a Workspace.

Your unique API key for authentication.

This key is required in the header of all API requests, to authenticate your account and access Anthropic's services. Get your API key through the Console. Each key is scoped to a Workspace.

Response

Successful Response

archived_atstring date-time nullable required

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

cancel_initiated_atstring date-time nullable required

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

created_atstring date-time required

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

ended_atstring date-time nullable required

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.

expires_atstring date-time required

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

idstring required

Unique object identifier.

The format and length of IDs may change over time.

processing_status'in_progress' | 'canceling' | 'ended' required

Processing status of the Message Batch.

results_urlstring nullable required

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'message_batch' required

Object type.

For Message Batches, this is always "message_batch".

Example response

{
  "archived_at": "2024-08-20T18:37:24.100435Z",
  "cancel_initiated_at": "2024-08-20T18:37:24.100435Z",
  "created_at": "2024-08-20T18:37:24.100435Z",
  "ended_at": "2024-08-20T18:37:24.100435Z",
  "expires_at": "2024-08-20T18:37:24.100435Z",
  "id": "msgbatch_013Zva2CMHLNnXjNJJKqJ2EF",
  "processing_status": "in_progress",
  "request_counts": {
    "canceled": 10,
    "errored": 30,
    "expired": 10,
    "processing": 100,
    "succeeded": 50
  },
  "results_url": "https://api.anthropic.com/v1/messages/batches/msgbatch_013Zva2CMHLNnXjNJJKqJ2EF/results"
}