Send Next Batch

Send the next batch of a campaign sent in batches

Only for a campaign that finished a batch: status = "paused" with throttle_reason = "batch_complete", or one that ended as completed / failed while recipients were still waiting (it continues its unfinished batch first, if any). Anything else returns HTTP 409 {"code": "campaign_not_awaiting_batch", "message": ...} (also when two requests race: only the first one sends a batch). HTTP 422 send_pacing_unavailable while batch sending is briefly unavailable.

Body (optional): {"batch_size": 500} sends 500 recipients now and saves 500 as the campaign's batch size (1-1,000,000; anything else is HTTP 422 {"code": "send_batch_size_invalid", "message": ...}); {"all_remaining": true} sends everyone who is still waiting. An empty body sends the next batch at the saved batch size. Recipients who opted out, unsubscribed or were blocked since the campaign was prepared are skipped (skipped_ineligible).

Response (200): {batch_number, armed, skipped_ineligible, remaining, campaign}. The batch is sent in the background at the campaign's send speed; the campaign pauses again when the batch is done (or completes when nobody is left).

Required Scopes: campaigns:send