SMS API

nexmo · Company

Company No Auth Free & Open API

With the SMS API you can send SMS from your account and lookup messages both messages that you've sent as well as messages sent to your virtual numbers. Numbers are specified in E.164 format. More SMS API documentation is at

Authentication

No authentication requiredFree to use with no key needed.

Sample Requests

POST Send an SMS

Send an outbound SMS from your Vonage account

https://api.apis.guru/v2/specs/nexmo.com/sms/1.2.0/{format}

Hover any highlighted part to learn what it does

curl -X POST "https://api.apis.guru/v2/specs/nexmo.com/sms/1.2.0/{format}"

import requests
response = requests.post(
    "https://api.apis.guru/v2/specs/nexmo.com/sms/1.2.0/{format}",
)
print(response.json())

const url = 'https://api.apis.guru/v2/specs/nexmo.com/sms/1.2.0/{format}';

const response = await fetch(url, {
  method: 'POST',
}); 
const data = await response.json();
console.log(data);

package main

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

func main() {
	targetURL := "https://api.apis.guru/v2/specs/nexmo.com/sms/1.2.0/{format}"
	req, _ := http.NewRequest("POST", targetURL, nil)

	client := &http.Client{}
	resp, _ := client.Do(req)
	defer resp.Body.Close()
	body, _ := io.ReadAll(resp.Body)
	fmt.Println(string(body))
}

require "net/http"
require "json"

uri = URI("https://api.apis.guru/v2/specs/nexmo.com/sms/1.2.0/{format}")

http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = uri.scheme == "https"

req = Net::HTTP::Post.new(uri)

res = http.request(req)
puts JSON.parse(res.body)

<?php
$url = "https://api.apis.guru/v2/specs/nexmo.com/sms/1.2.0/{format}";
$opts = ["http" => [
    "method" => "POST",
]];
$ctx = stream_context_create($opts);
$res = file_get_contents($url, false, $ctx);
print_r(json_decode($res, true));

Postman Setup Guide

Get Postman ↗

See official documentation for authentication and setup.

What can you build with SMS API?

SMS API is a Company API. Developers commonly use company APIs for:

enriching CRM records with company firmographics
building lead-generation and prospecting tools
verifying business identity and registration details
monitoring competitors and market intelligence
powering B2B data enrichment pipelines

No authentication required. This API is open — no signup or key needed. Ideal for quick prototypes and public-facing features. SMS API is free to use, making it a low-risk choice to experiment with.

New to APIs? Read our beginner's guide · Learn about API keys · What is REST?

Open documentation ↗