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1---2title: Retrieve a Message Batch3url: https://platform.claude.com/docs/en/api/beta/messages/batches/retrieve4---56# Retrieve a Message Batch78**GET** `/v1/messages/batches/{message_batch_id}`910This 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.1112Learn more about the Message Batches API in our [user guide](https://platform.claude.com/docs/en/build-with-claude/batch-processing)1314## Path parameters1516- `message_batch_id: string`1718 ID of the Message Batch.1920## Headers2122- `"anthropic-beta": optional array of AnthropicBeta`2324 Optional header to specify the beta version(s) you want to use.2526 - `string`2728 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 43 more`2930 - `"message-batches-2024-09-24"`3132 - `"prompt-caching-2024-07-31"`3334 - `"computer-use-2024-10-22"`3536 - `"computer-use-2025-01-24"`3738 - `"pdfs-2024-09-25"`3940 - `"token-counting-2024-11-01"`4142 - `"token-efficient-tools-2025-02-19"`4344 - `"output-128k-2025-02-19"`4546 - `"files-api-2025-04-14"`4748 - `"mcp-client-2025-04-04"`4950 - `"mcp-client-2025-11-20"`5152 - `"dev-full-thinking-2025-05-14"`5354 - `"interleaved-thinking-2025-05-14"`5556 - `"code-execution-2025-05-22"`5758 - `"extended-cache-ttl-2025-04-11"`5960 - `"context-1m-2025-08-07"`6162 - `"context-management-2025-06-27"`6364 - `"model-context-window-exceeded-2025-08-26"`6566 - `"skills-2025-10-02"`6768 - `"fast-mode-2026-02-01"`6970 - `"output-300k-2026-03-24"`7172 - `"user-profiles-2026-03-24"`7374 - `"user-profiles-2026-08-18"`7576 - `"user-profiles-2026-09-04"`7778 - `"advisor-tool-2026-03-01"`7980 - `"managed-agents-2026-04-01"`8182 - `"cache-diagnosis-2026-04-07"`8384 - `"dreaming-2026-04-21"`8586 - `"thinking-token-count-2026-05-13"`8788 - `"server-side-fallback-2026-06-01"`8990 - `"server-side-fallback-2026-07-01"`9192 - `"fallback-credit-2026-06-01"`9394 - `"fallback-credit-2026-07-01"`9596 - `"agent-memory-2026-07-22"`9798 - `"mid-conversation-tool-changes-2026-07-01"`99100 - `"compact-2026-01-12"`101102 - `"computer-use-2025-11-24"`103104 - `"mcp-tunnels-2026-06-22"`105106 - `"structured-outputs-2025-11-13"`107108 - `"task-budgets-2026-03-13"`109110 - `"thinking-display-updates-2026-08-18"`111112 - `"ce-user-management-2026-07-13"`113114 - `"mid-conversation-output-config-2026-07-01"`115116 - `"thinking-binding-controls-2026-08-01"`117118 - `"mid-conversation-system-clear-at-2026-08-21"`119120 - `"compact-2026-09-04"`121122- `"anthropic-workspace-id": optional string`123124## Returns125126- `BetaMessageBatch object`127128 - `type: "message_batch"`129130 Object type.131132 For Message Batches, this is always `"message_batch"`.133134 default: message_batch135136 - `id: string`137138 Unique object identifier.139140 The format and length of IDs may change over time.141142 - `archived_at: string or null`143144 RFC 3339 datetime string representing the time at which the Message Batch was archived and its results became unavailable.145146 format: date-time147148 - `cancel_initiated_at: string or null`149150 RFC 3339 datetime string representing the time at which cancellation was initiated for the Message Batch. Specified only if cancellation was initiated.151152 format: date-time153154 - `created_at: string`155156 RFC 3339 datetime string representing the time at which the Message Batch was created.157158 format: date-time159160 - `ended_at: string or null`161162 RFC 3339 datetime string representing the time at which processing for the Message Batch ended. Specified only once processing ends.163164 Processing ends when every request in a Message Batch has either succeeded, errored, canceled, or expired.165166 format: date-time167168 - `expires_at: string`169170 RFC 3339 datetime string representing the time at which the Message Batch will expire and end processing, which is 24 hours after creation.171172 format: date-time173174 - `processing_status: "in_progress" or "canceling" or "ended"`175176 Processing status of the Message Batch.177178 - `"in_progress"`179180 - `"canceling"`181182 - `"ended"`183184 - `request_counts: BetaMessageBatchRequestCounts`185186 Tallies requests within the Message Batch, categorized by their status.187188 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.189190 - `canceled: number`191192 Number of requests in the Message Batch that have been canceled.193194 This is zero until processing of the entire Message Batch has ended.195196 default: 0197198 - `errored: number`199200 Number of requests in the Message Batch that encountered an error.201202 This is zero until processing of the entire Message Batch has ended.203204 default: 0205206 - `expired: number`207208 Number of requests in the Message Batch that have expired.209210 This is zero until processing of the entire Message Batch has ended.211212 default: 0213214 - `processing: number`215216 Number of requests in the Message Batch that are processing.217218 default: 0219220 - `succeeded: number`221222 Number of requests in the Message Batch that have completed successfully.223224 This is zero until processing of the entire Message Batch has ended.225226 default: 0227228 - `results_url: string or null`229230 URL to a `.jsonl` file containing the results of the Message Batch requests. Specified only once processing ends.231232 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.233234## Example235236```bash237curl https://api.anthropic.com/v1/messages/batches/$MESSAGE_BATCH_ID \238 -H 'anthropic-version: 2023-06-01' \239 -H 'anthropic-beta: message-batches-2024-09-24' \240 -H "X-Api-Key: $ANTHROPIC_API_KEY"241```242243### Response (200)244245```json246{247 "id": "msgbatch_013Zva2CMHLNnXjNJJKqJ2EF",248 "archived_at": "2024-08-20T18:37:24.100435Z",249 "cancel_initiated_at": "2024-08-20T18:37:24.100435Z",250 "created_at": "2024-08-20T18:37:24.100435Z",251 "ended_at": "2024-08-20T18:37:24.100435Z",252 "expires_at": "2024-08-20T18:37:24.100435Z",253 "processing_status": "in_progress",254 "request_counts": {255 "canceled": 10,256 "errored": 30,257 "expired": 10,258 "processing": 100,259 "succeeded": 50260 },261 "results_url": "https://api.anthropic.com/v1/messages/batches/msgbatch_013Zva2CMHLNnXjNJJKqJ2EF/results",262 "type": "message_batch"263}264```265