Prelude Verify

Prelude Verify is an API service that handles SMS and OTP (one-time password) verification for applications. It lets developers send verification codes to users' phones anywhere in the world. The core job is simple: you integrate the API, and when a user needs to verify their identity—like during sign-up or a transaction—Prelude Verify sends them a code via SMS. This is a fundamental building block for secure user onboarding and two-factor authentication.

The service works by connecting to over 30 different SMS providers globally. Its main technical feature is multi-routing: it automatically picks the best provider for each destination based on cost and reliability. If a message fails to send through one provider, the system instantly falls back to another. This aims to achieve high deliverability rates. It also includes fraud detection to identify and block spammy verification attempts before they cost you money.

This tool is built for development teams, particularly at startups and SaaS companies that need a reliable, cost-effective way to verify users. Real-world use includes a dating app confirming new user accounts, a fintech app authorizing a money transfer, or a social platform ensuring a returning user is who they claim to be. If your app needs to send 'Enter the code we just texted you,' Prelude Verify is the engine that sends that text.