Audience

Bulk create contacts

Create up to 1000 contacts in a single request. Send contacts to give each row its own properties, lists and topics, or the legacy emails array when the whole batch shares one property map. Emails are normalized and deduplicated; addresses that already exist are reported in already_existed, are always attached to the requested lists and topics and always have a row-level opt_out applied, and have their properties merged only when update_existing is set. Rows that fail validation are skipped and returned in errors — the request only fails with 422 when nothing could be written. The response carries the contact ids, so a follow-up call to the bulk list or topic endpoints needs no lookup. Requires the audience:write scope and is blocked for sandbox API keys.

post/audience/contacts/bulk

Request

  • Base URL: https://app.lettr.com/api
  • URL: https://app.lettr.com/api/audience/contacts/bulk
  • Auth: HTTP bearer

Request body

OR

Example request

{
  "emails": [
    "jane@example.com",
    "joe@example.com"
  ],
  "contacts": [
    {
      "email": "jane@example.com",
      "properties": {
        "first_name": "Jane"
      }
    }
  ]
}

Response

Contacts created

messagestring required

Example response

{
  "message": "Contacts created successfully.",
  "data": {
    "created": 2
  }
}

Changes

No recorded changes to this operation across all 1 revision of this API.