Generate Rendered Preview of a Transactional Template

This new endpoint allows developers to generate a rendered HTML preview of a transactional email template using dynamic parameters or a contacts attributes.

Use Cases:

• Preview how a transactional template will render with real or test data.
• Validate personalization variables before sending emails.
• Automate template rendering in backend systems.

curl --request POST \
  --url https://api.brevo.com/v3/smtp/template/preview \
  --header 'api-key: YOUR_API_KEY' \
  --header 'Content-Type: application/json' \
  --data '{
    "templateId": 22,
    "params": {
      "Firstname": "John",
      "Lastname": "Doe"
    }
  }'

Route: Generate the rendered preview of transactional template