Create a campaign

curl -X POST 'https://www.unitpost.com/api/v1/email/campaigns' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -H 'User-Agent: my-app/1.0' \
  -H 'Content-Type: application/json' \
  -d '{
    "name": "June newsletter",
    "subject": "What's new",
    "from": "you@yourdomain.com",
    "template_id": "tmpl_123",
    "segment_id": "seg_123"
  }'

{
  "object": "campaign",
  "id": "id_123",
  "name": "Example",
  "template_id": "template_123",
  "segment_id": "segment_123",
  "topic_id": "topic_123",
  "from": "you@yourdomain.com",
  "subject": "Welcome to Acme",
  "preview_text": "string",
  "open_tracking": false,
  "click_tracking": false,
  "status": "draft",
  "scheduled_at": "2026-01-01T00:00:00.000Z",
  "variable_fallbacks": {},
  "excluded_contact_ids": [
    "string"
  ],
  "total_recipients": 1,
  "sent_count": 1,
  "failed_count": 1,
  "created_at": "2026-01-01T00:00:00.000Z",
  "updated_at": "2026-01-01T00:00:00.000Z"
}