Send individual (personalized bulk)

Send a personalized bulk of SMS in a single request: every recipient gets its own message text and its own sender ID. This is the difference from /sms/send, which fans one message out to many recipients.

POST /api/v1/sms/send-individual · Permission: sms.send

Each accepted recipient is queued, billed and tracked exactly like a normal send, and gets its own message_id in the response — so you can correlate delivery by message_id or by phone number via GET /sms/messages. A blocked_country recipient is returned in results[] without a message_id and is not queued. Missing local pricing does not reject a valid live recipient: it is accepted and queued with a provisional local cost.

Request

cURL

curl -X POST https://restlink23telecom.com/api/v1/sms/send-individual \
  -H "X-API-Key: $API_KEY" \
  -H "Idempotency-Key: send-20260627-batch-001" \
  -H "Content-Type: application/json" \
  -d '{
  "messages": [
    {
      "to": "+14155551234",
      "message": "Hi John, your code is 847291",
      "sender_id": "MyApp"
    },
    {
      "to": "+447911123456",
      "message": "Hi Anna, your code is 113355",
      "sender_id": "MyApp"
    }
  ]
}'

Node.js

const res = await fetch('https://restlink23telecom.com/api/v1/sms/send-individual', {
  method: 'POST',
  headers: { 'X-API-Key': process.env.API_KEY, 'Idempotency-Key': 'send-20260627-batch-001', 'Content-Type': 'application/json' },
  body: JSON.stringify({
    "messages": [
      {
        "to": "+14155551234",
        "message": "Hi John, your code is 847291",
        "sender_id": "MyApp"
      },
      {
        "to": "+447911123456",
        "message": "Hi Anna, your code is 113355",
        "sender_id": "MyApp"
      }
    ]
  }),
});

if (!res.ok) {
  const err = await res.json();
  throw new Error(`${err.error_code}: ${err.description}`);
}
const data = await res.json();
console.log(data);

Python

import os
import requests

res = requests.post(
    "https://restlink23telecom.com/api/v1/sms/send-individual",
    headers={"X-API-Key": os.environ["API_KEY"], "Idempotency-Key": "send-20260627-batch-001"},
    json={
        "messages": [{
            "to": "+14155551234",
            "message": "Hi John, your code is 847291",
            "sender_id": "MyApp"
        }, {
            "to": "+447911123456",
            "message": "Hi Anna, your code is 113355",
            "sender_id": "MyApp"
        }]
    },
)
res.raise_for_status()
print(res.json())

PHP

<?php
$ch = curl_init('https://restlink23telecom.com/api/v1/sms/send-individual');
curl_setopt_array($ch, [
    CURLOPT_CUSTOMREQUEST  => 'POST',
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER     => ['X-API-Key: ' . getenv('API_KEY'), 'Idempotency-Key: send-20260627-batch-001', 'Content-Type: application/json'],
    CURLOPT_POSTFIELDS     => json_encode([
        'messages' => [[
            'to' => '+14155551234',
            'message' => 'Hi John, your code is 847291',
            'sender_id' => 'MyApp'
        ], [
            'to' => '+447911123456',
            'message' => 'Hi Anna, your code is 113355',
            'sender_id' => 'MyApp'
        ]]
    ]),
]);

$response = curl_exec($ch);
$status   = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);

if ($status !== 200) {
    throw new Exception("HTTP $status: $response");
}
$data = json_decode($response, true);
print_r($data);

Ruby

require "net/http"
require "json"

uri = URI("https://restlink23telecom.com/api/v1/sms/send-individual")
req = Net::HTTP::Post.new(uri)
req["X-API-Key"] = ENV.fetch("API_KEY")
req["Idempotency-Key"] = "send-20260627-batch-001"
req["Content-Type"] = "application/json"
req.body = {
  messages: [{
    to: "+14155551234",
    message: "Hi John, your code is 847291",
    sender_id: "MyApp"
  }, {
    to: "+447911123456",
    message: "Hi Anna, your code is 113355",
    sender_id: "MyApp"
  }]
}.to_json

res = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) { |http| http.request(req) }
raise "HTTP #{res.code}: #{res.body}" unless res.is_a?(Net::HTTPSuccess)

puts JSON.parse(res.body)

Java

import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;

HttpClient client = HttpClient.newHttpClient();

HttpRequest request = HttpRequest.newBuilder()
    .uri(URI.create("https://restlink23telecom.com/api/v1/sms/send-individual"))
    .header("X-API-Key", System.getenv("API_KEY"))
    .header("Idempotency-Key", "send-20260627-batch-001")
    .header("Content-Type", "application/json")
    .POST(HttpRequest.BodyPublishers.ofString("""
        {
          "messages": [
            {
              "to": "+14155551234",
              "message": "Hi John, your code is 847291",
              "sender_id": "MyApp"
            },
            {
              "to": "+447911123456",
              "message": "Hi Anna, your code is 113355",
              "sender_id": "MyApp"
            }
          ]
        }"""))
    .build();

HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
System.out.println(response.body());

Go

package main

import (
  "fmt"
  "io"
  "net/http"
  "os"
  "strings"
)

func main() {
  payload := strings.NewReader(`{
  "messages": [
    {
      "to": "+14155551234",
      "message": "Hi John, your code is 847291",
      "sender_id": "MyApp"
    },
    {
      "to": "+447911123456",
      "message": "Hi Anna, your code is 113355",
      "sender_id": "MyApp"
    }
  ]
}`)

  req, err := http.NewRequest("POST", "https://restlink23telecom.com/api/v1/sms/send-individual", payload)
  if err != nil {
    panic(err)
  }
  req.Header.Set("X-API-Key", os.Getenv("API_KEY"))
  req.Header.Set("Idempotency-Key", "send-20260627-batch-001")
  req.Header.Set("Content-Type", "application/json")

  res, err := http.DefaultClient.Do(req)
  if err != nil {
    panic(err)
  }
  defer res.Body.Close()

  data, _ := io.ReadAll(res.Body)
  fmt.Println(string(data))
}

.NET

using System.Text;

using var client = new HttpClient();
client.DefaultRequestHeaders.Add("X-API-Key",
    Environment.GetEnvironmentVariable("API_KEY"));
client.DefaultRequestHeaders.Add("Idempotency-Key", "send-20260627-batch-001");

var json = """
{
  "messages": [
    {
      "to": "+14155551234",
      "message": "Hi John, your code is 847291",
      "sender_id": "MyApp"
    },
    {
      "to": "+447911123456",
      "message": "Hi Anna, your code is 113355",
      "sender_id": "MyApp"
    }
  ]
}
""";
var content = new StringContent(json, Encoding.UTF8, "application/json");
var response = await client.PostAsync("https://restlink23telecom.com/api/v1/sms/send-individual", content);

response.EnsureSuccessStatusCode();
Console.WriteLine(await response.Content.ReadAsStringAsync());

Field	Type	Required	Description
Idempotency-Key header	string	Yes	Stable key for this logical batch. Reuse it after a timeout or 5xx. Completed responses are retained for 24 hours and replayed byte-for-byte with Idempotent-Replayed: true; a replay is not a new send. A key used with a different body returns 409 IDEMPOTENCY_KEY_REUSED
messages	object[]	Yes	1 to 1000 messages
messages[].to	string	Yes	Recipient phone number in E.164 format (+ optional, 6-15 digits)
messages[].message	string	Yes	Message text for this recipient — encoding is detected automatically; max 10 SMS segments
messages[].sender_id	string	Yes	Sender ID for this recipient: 3-11 ASCII alphanumeric characters, first character cannot be a number

The API trims leading and trailing whitespace from each to, message and sender_id before validation. Values that are blank after trimming, malformed phone numbers, over-10-segment messages, and invalid senders return 400.

Response

The response shape is identical to /sms/send: each accepted recipient appears in both messages and results with its own message_id. When a completed request is retried with the same Idempotency-Key, the API returns the stored response, does not consume batch tokens again, and includes Idempotent-Replayed: true.

200 OK

{
  "status": true,
  "messages": [
    {"dnis": "+14155551234", "message_id": "api_42_1743667200123456789_a3f8b2c1d9e45f67", "segment_num": 1},
    {"dnis": "+447911123456", "message_id": "api_42_1743667200123456789_b7c4e8f1a2d3690b", "segment_num": 1}
  ],
  "results": [
    {"dnis": "+14155551234", "message_id": "api_42_1743667200123456789_a3f8b2c1d9e45f67", "segments": 1, "status": "accepted"},
    {"dnis": "+447911123456", "message_id": "api_42_1743667200123456789_b7c4e8f1a2d3690b", "segments": 1, "status": "accepted"}
  ],
  "summary": {
    "total_recipients": 2,
    "total_segments": 2,
    "total_cost": 0.02,
    "encoding": "GSM-7",
    "accepted_count": 2,
    "blocked_count": 0,
    "unpriced_count": 0,
    "queue_error_count": 0,
    "config_error_count": 0,
    "db_error_count": 0
  }
}

Field	Description
messages	Accepted messages only (one entry per recipient)
results	All recipients with their individual status
summary	Totals: accepted, blocked, errors, cost and batch encoding. encoding is GSM-7 or UCS-2 when at least one recipient is accepted, and can be empty when no recipient is accepted

Per-recipient statuses

results[].status	Meaning
accepted	Queued for delivery
blocked_country	Recipient’s country is in your blocked list
unpriced	Legacy/sandbox non-acceptance status retained for compatibility. Current live pricing misses are accepted and queued with a provisional local cost
queue_error	Sandbox simulator storage failure (sk_test_ only); live Redis enqueue failures stay accepted and are recovered from the durable outbox
config_error	SMS sending not configured on the account
db_error	The recipient’s outbox row could not be written

Atomic validation

Field validation is atomic: a single malformed entry (missing to, message or sender_id) rejects the whole batch with a 400 that names the offending index (e.g. messages[42].message is required) — nothing is sent. Fix the entry and resubmit with a fresh Idempotency-Key. Persistence is atomic for recipients that pass business checks: either all accepted recipients are queued, or none are. blocked_country recipients are not sent; valid live recipients remain accepted when local pricing is missing.

Errors

HTTP	Code	Description
400	INVALID_BODY	Cannot parse request body
400	INVALID_MESSAGES	Missing or empty messages array
400	IDEMPOTENCY_KEY_REQUIRED / INVALID_IDEMPOTENCY_KEY	Missing or invalid Idempotency-Key header
400	TOO_MANY_MESSAGES	Over 1000 messages
400	INVALID_TO	A messages[i].to is missing or not E.164-style
400	INVALID_MESSAGE	A messages[i].message is missing or exceeds 10 SMS segments
400	INVALID_SENDER	A messages[i].sender_id is missing or not 3-11 ASCII alphanumeric characters
403	NO_SMS_ACCESS	SMS not enabled on your account
403	CONFIG_ERROR	SMS credentials incomplete — contact support
403	WORKSPACE_NOT_AVAILABLE	Target workspace was deleted — use a live workspace
409	IDEMPOTENCY_KEY_REUSED	Same key was already used with a different request body
409	IDEMPOTENCY_REQUEST_IN_PROGRESS	Same key is still processing; retry later with the same key
429	RATE_LIMIT_EXCEEDED	The batch exceeds your per-second message budget — see the note below
500	DB_ERROR	Could not queue (atomic rollback) — retry the whole request
503	SANDBOX_UNAVAILABLE / RATE_LIMIT_UNAVAILABLE / QUEUE_UNAVAILABLE	Sandbox simulator not enabled (sk_test_), rate limiter unavailable, or SMS queue unavailable — retry shortly with the same Idempotency-Key

Pricing and balance are fail-open for direct API sends

New live processing does not create PRICING_UNAVAILABLE or a send-time 402 when Portal’s local pricing or balance data is missing. A valid recipient is accepted with a message_id; the local cost can be provisional until the delivery report arrives. Never retry an accepted message_id solely because its immediate cost is 0.

Batch size & rate limit

Each message in the batch counts against your per-second message budget, so a single request consumes messages.length rate-limit tokens. The hard request cap is 1000 messages, but the effective max for your account is min(1000, burst_limit). A batch larger than your account’s burst limit is rejected with 429 — split it into smaller requests or ask support to raise your limit.

Sandbox behavior

Sandbox keys (sk_test_) validate the same request shape and return the same response fields, but they simulate delivery without live pricing, balance or blocked-country enforcement. Live keys can return blocked_country; missing Portal pricing or balance data does not reject a valid live recipient.

Delivery tracking

The send response confirms acceptance, not delivery. Because every recipient gets a distinct message_id, you can track each one precisely:

• Webhooks (recommended): receive a delivery report per recipient the moment the carrier reports it.
• Per message: call GET /sms/status/:message_id for any message_id returned above.
• By phone: call GET /sms/messages with phone=, from= and to= to pull every message to a number over a date range and match results by recipient.