Guides and tutorials for building with messaging APIs — WhatsApp Business API, SMS OTP, and transactional email.
March 15, 2026 · 10 min read
A developer-focused comparison of the best messaging APIs for WhatsApp, SMS, and email in 2026. Covers SendAPI, Twilio, Vonage, Sinch, Plivo, and Infobip — with pricing, features, and honest recommendations.
March 15, 2026 · 9 min read
A unified messaging API lets you send WhatsApp, SMS, and email from a single integration. This guide explains what it is, how it works, and how to evaluate providers — with code examples.
March 12, 2026 · 8 min read
A complete guide to integrating the WhatsApp Business API. Learn how to send template messages, notifications, and OTP codes programmatically using SendAPI.
March 12, 2026 · 6 min read
Step-by-step guide to implementing SMS OTP verification in a Node.js app using SendAPI. Covers sending codes, verifying input, expiry, and rate limiting.
March 12, 2026 · 5 min read
Understand the key differences between transactional and marketing email — different rules, different infrastructure, and why mixing them will hurt your deliverability.
March 12, 2026 · 5 min read
Not sure whether you need the WhatsApp Business API or the free WhatsApp Business app? This guide breaks down the differences by use case, volume, and technical capability.
March 12, 2026 · 6 min read
Learn how to send bulk SMS messages programmatically — batching, rate limits, personalization, delivery tracking, and handling failures at scale.