Send SMS

POST /v1/sms/send

Dispatches a standard text message (SMS) to a mobile phone number anywhere in the world. Our global routing engine will automatically select the optimum tier-1 telecom carrier for the destination country to maximize deliverability and minimize latency.

Authentication

All requests to this endpoint must include your API key in the Authorization header as a Bearer token.

Header	Type	Required	Description
Authorization	string	Yes	Bearer sk_live_YOUR_API_KEY
Idempotency-Key	string	No	A unique UUIDv4 to prevent duplicate deliveries on network retries.

Request Body

Send an application/json payload with the following parameters:

Parameter	Type	Required	Description
to	string	Yes	The destination phone number in E.164 format (e.g., +14155552671).
message	string	Yes	The text content of the SMS. Maximum length is 1600 characters.
sender_id	string	No	Optional custom alphanumeric Sender ID (up to 11 characters) to display instead of a generic shortcode. Note: Requires pre-registration in certain countries.
callback_url	string	No	A specific webhook URL where delivery status updates for this specific message should be pushed.

Example Request

cURL

curl -X POST https://api.sendapi.co/v1/sms/send \
  -H "Authorization: Bearer sk_live_123456789" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "+447700900000",
    "message": "Your package has been dispatched. Track it at https://example.com",
    "sender_id": "AcmeCorp"
  }'

Node.js

import { SendAPI } from '@sendapi/node';

const client = new SendAPI('sk_live_123456789');

const response = await client.sms.send({
  to: '+447700900000',
  message: 'Your package has been dispatched. Track it at https://example.com',
  sender_id: 'AcmeCorp'
});

console.log(response.id);

Response

Returns a Message object indicating that the SMS has been successfully submitted to the carrier network.

{
  "id": "sms_01H8BKF...Z2T",
  "object": "sms.message",
  "status": "queued",
  "to": "+447700900000",
  "parts": 1,
  "cost": "0.014",
  "currency": "USD",
  "created_at": "2026-03-09T14:30:00Z"
}

Rate Limits

This endpoint is limited to 100 requests per second (RPS) on the Team plan, and standard throughput limits apply depending on the destination country's carrier regulations. For high-volume marketing blasts, use the Bulk SMS endpoint.