Send Emails via API (Transactional Email Guide)

Send transactional emails like OTPs, welcome messages, alerts, and custom emails using Voyant Email API with secure signature-based authentication.

Base URL: https://api.voyantnetworks.com
Endpoint:
• /v1/email/send

Official SDKs & Libraries

Use official SDKs for faster integration across platforms.

Node.js

Backend / Server-side

npm →

JavaScript (Browser)

Frontend / Web

js script →

Flutter

Mobile / Web Apps

pub.dev →

Python

Backend / ML / Scripts

coming soon

Field Values (Enums)

language → en | hi | es | fr | de | pt | ru | ja

button.type → filled | outlined | text

Three Step Request Flow

Use any template below as emailData , sign the payload, then send a REST API request.

Step 1: Create Payload

{
  "accountId":"...",
  "projectId":"...",
  "apiKey":"...",
  "emailData": { ... }
}

Step 2: Generate Signature

signature =
HMAC_SHA256(
  JSON.stringify(payload),
  API_SECRET
)

Header:
x-signature: signature

Step 3: Send Request

POST /v1/email/send
Content-Type: application/json

Template Examples (Full)

All fields shown. Optional fields marked clearly.

{
  "to": "user@email.com",
  "language": "en",
  "detectLocation": true,
  "requestId": "req_123",
  "fromType": "verify",
  "replyTo": "support@example.com",

  "templateName": "email_verification",
  "templateData": {
    "username": "John",
    "otp": "123456",
    "expiryMinutes": 10,
    "deviceText": "Chrome on Windows"
  }
}

{
  "to": "user@email.com",
  "language": "en",
  "detectLocation": false,
  "requestId": "req_456",
  "fromType": "updates",
  "replyTo": "hello@example.com",

  "templateName": "welcome",
  "templateData": {
    "username": "John",
    "appName": "Voyant",

    "button": {
      "type": "filled",
      "text": "Get Started",
      "url": "https://example.com",
      "color": "#4f46e5"
    }
  }
}

{
  "to": "user@email.com",
  "language": "en",
  "detectLocation": true,
  "requestId": "req_789",
  "fromType": "support",
  "replyTo": "support@example.com",

  "templateName": "custom",
  "templateData": {
    "greeting": "Hello John",
    "title": "Important Update",
    "subtitle": "Please review this information",
    "message": "Your account settings have been updated successfully.",
    "subject": "Account Update",

    "button": {
      "type": "outlined",
      "text": "View Details",
      "url": "https://example.com",
      "color": "#22c55e"
    }
  }
}

• nonce must be exactly 10 characters
• OTP auto-generated if not provided
• Rate limits apply
• Invalid signature → request fails
• Signature must be sent in body (not header)

Next Steps

Manage and optimize your email API usage:

📧 Create Email API → 📊 Manage Email API → ⚠️ View Error Codes →