curl -X PUT "https://api.usegately.com/api/v1/campaigns/CAMPAIGN_ID" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "X-Project-ID: YOUR_PROJECT_ID" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "June Newsletter (revised)",
    "subject": "What we shipped this month — updated",
    "content": "<h1>June Update</h1><p>Updated content here.</p>"
  }'

import { GatelyCampaigns } from '@gately/sdk'

const campaigns = new GatelyCampaigns({ projectId: 'YOUR_PROJECT_ID' })

const updated = await campaigns.update('CAMPAIGN_ID', {
  name: 'June Newsletter (revised)',
  subject: 'What we shipped this month — updated',
  content: '<h1>June Update</h1><p>Updated content here.</p>',
})

{
  "success": true,
  "message": "Campaign updated successfully",
  "campaign": {
    "id": "a1b2c3d4-e5f6-4789-abcd-ef1234567890",
    "name": "June Newsletter (revised)",
    "subject": "What we shipped this month — updated",
    "status": "scheduled",
    "updated_at": "2025-06-15T11:30:00.000Z"
  }
}

{
  "error": "Cannot update campaign that is sending or already sent"
}

{
  "error": "Missing required fields: name, subject, content"
}