Build SMS Features
in Minutes

Simple REST APIs with comprehensive documentation. Free API access, real-time webhooks, 99.9% uptime, and SDKs for PHP, Python, Node.js, Java, and Go.

Explore APIs View Guides
FREE API Access
<100ms Response Time
99.9% Uptime SLA
Quick Links: SMS API OTP API Contacts API WhatsApp API Voice API MMS API HTTP API

Available APIs

Choose the API that fits your needs

SMS API

Send SMS messages to any phone number in Kenya. Perfect for notifications, alerts, and marketing campaigns.

REST API HTTP API
OTP API

Generate and verify one-time passwords for two-factor authentication and secure verification.

REST API HTTP API
Contacts API

Manage contacts and groups programmatically. Create, update, delete, and organize your contact database.

REST API HTTP API
WhatsApp API

Send messages via WhatsApp Business API. Reach customers on their preferred messaging platform.

REST API HTTP API
Voice API

Make voice calls and send voice messages. Automate voice communications for your business.

REST API HTTP API
MMS API

Send multimedia messages with images, videos, and audio. Enhance your messaging with rich media.

REST API HTTP API
Viber API

Send messages via Viber. Communicate with users on the Viber messaging platform.

REST API HTTP API
Contact Groups API

Organize contacts into groups. Send targeted messages to specific groups of recipients.

REST API HTTP API
Profile API

Manage your account profile and settings. Update account information programmatically.

REST API HTTP API

Documentation Guides

Everything you need to integrate OpenSMS APIs

Quick Start

Get your first API call working in 5 minutes with step-by-step instructions and code examples.

View Guide →
Authentication

Learn how to authenticate your API requests and manage API keys securely with best practices.

View Guide →
Webhooks

Receive real-time delivery reports and SMS status updates via webhooks for instant notifications.

View Guide →
Code Examples

Ready-to-use code snippets in PHP, Python, Node.js, Java, C#, and more languages.

View Examples →
Rate Limiting

Understand rate limits, quotas, and how to handle rate limit responses from the API.

View Guide →
Error Codes

Complete reference of error codes, their meanings, and how to handle them in your application.

View Reference →

Frequently Asked Questions

Find answers to common questions

Yes! API access is completely free. You only pay for the messages you send. Sign up for free and get instant API access.

Rate limits depend on your plan. Check the Rate Limiting documentation for specific limits and how to handle them.

You can get delivery reports via webhooks or by polling the API. Check the Webhooks documentation for more information.

We support any language that can make HTTP requests. Check our Code Examples for PHP, Python, Node.js, Java, and more.

Yes! We use industry-standard security practices including API key authentication, HTTPS encryption, and OAuth support. Learn more in our Authentication Guide.