Create a broadcast

Saves a draft email to send to everyone in an audience. Use {{{FIRST_NAME|there}}}, {{{LAST_NAME}}}, {{{EMAIL}}} or any contact property; text after | is used when a contact has no value. Every message gets an unsubscribe link and the one-click unsubscribe headers, and a footer link is added if you leave out {{{UNSUBSCRIBE_URL}}}. Instead of html you can send a design: a list of blocks (heading, text, button, image, divider, spacer, footer) with an accent color, background and font. We turn it into email-safe HTML and a plain-text version, and the dashboard can open it in the visual editor. Pass segment_id to send to a segment of the audience instead of everyone in it. Pass ab_test to split test it: your subject and content are version A, each entry in ab_test.variants is another version (B, C, D) that replaces whatever it sets, test_percent of the audience (5 to 50) is divided between the versions, and after wait_hours (1 to 72) the version with the best winner_by (opens or clicks) is sent to everyone else. A split test needs open (or click) tracking on the sending domain. Nothing is sent until you call send.

Required scope: broadcasts:manage

Request body

Unknown fields are rejected, so a typo never silently does nothing.

Example

curl -X POST 'https://api.sendsend.email/v1/broadcasts' \
  -H "Authorization: Bearer $SENDSEND_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{
  "audience_id": "aud_7Qe2…",
  "from": "Acme <news@mail.acme.com>",
  "subject": "What’s new, {{{FIRST_NAME|there}}}",
  "html": "<p>Hi {{{FIRST_NAME|there}}}, here is what shipped.</p><p><a href=\"{{{UNSUBSCRIBE_URL}}}\">Unsubscribe</a></p>"
}'

Response 201

{
  "id": "bcast_Tz8…",
  "object": "broadcast",
  "name": "October update",
  "audience_id": "aud_7Qe2…",
  "topic_id": null,
  "from": "Acme <news@mail.acme.com>",
  "subject": "What’s new, {{{FIRST_NAME|there}}}",
  "status": "draft",
  "status_reason": null,
  "scheduled_at": null,
  "sent": 0,
  "skipped": 0,
  "failed": 0,
  "created_at": "2026-10-06T15:00:00.000Z"
}

Errors

Every error has the same shape. See Errors.