ReOTP.
Fast-Track Integration 🚀

Zero-Delay
Authentication

Goodbye loading spinners. ReOTP is natively designed to provide a 0-second login experience by pre-fetching verification links in the background.

1. Predictive Init

While the user types their number, a silent request fetches the links without deducting balance.

2. Instant Redirect

When the user clicks login, they are redirected to WhatsApp instantly without waiting for a server response.

3. Real-time Status Check (Polling / SSE)

In the frontend, the code polls for verification success instantly until complete.

Optimized for AI Agents

Copy this prompt, and Cursor or Claude will generate the complete Zero-Delay Authentication code for you in seconds.

Comprehensive Documentation Index

Getting Started

Introduction to ReOTP

Learn how to integrate WhatsApp and Telegram OTP verification into your app.

Integration Models

Zero-Type Auth

The newest and fastest system: One-click login without entering any number.

Standard 2FA

How to program classic two-factor authentication with high security for sensitive operations.

Passwordless Lite

How to integrate the fastest login method for Super Apps.

Security

Rate Limiting & Anti-Spam

Understand the security protocols that protect your project.

API Reference

1. Pre-fetch Links in Background (Zero-Delay)

Secretly pre-fetch verification links with zero delay before the user clicks login.

2. Check Status

Query the status of the ongoing verification session.

Advanced Features

Webhooks Reference

Receive instant updates on verification events directly on your backend.

Channel Setup

Custom WhatsApp Linking

Send OTP verification messages from your own custom brand number.

SDKs & Libraries

ReOTP Node.js SDK

A ready-to-use library to simplify using ReOTP in Node.js/Next.js applications.

Security & Sync

Webhooks & HMAC Security

Learn how to receive secure, real-time notifications when a phone number is verified.

JWT Authentication

Using signed JWTs to securely authenticate the client.

Pricing & Billing

Smart Token Billing

How credits are automatically deducted based on the verification method.

Use Cases

Zero-Type Login (No Number Required)

One-click login — no typing required

Standard 2FA After Password

Maximum security for sensitive operations with ReOTP

New Account Registration by Phone

Instant phone-only registration — no email or password

Money Transfer Confirmation

Verify user identity before executing any money transfer

Order Checkout Confirmation

Prevent fake orders with ReOTP confirmation before payment

Change Linked Phone Number

Confirm ownership of new number before linking to account

Change Password or Email

Extra confirmation to protect sensitive data

Delete Account Confirmation

Final ReOTP confirmation before permanent deletion

Delivery & Logistics Hand-off

Confirm package receipt directly on phone

New Device Login Verification

Alert user when logging in from an unknown device

Wallet Withdrawal Confirmation

Protect customer funds with ReOTP confirmation for every withdrawal

Booking & Appointment Confirmation

Prevent fake bookings with ReOTP confirmation for every appointment

Subscription Renewal Confirmation

ReOTP confirmation before auto-renewal charges

Tips

Pro Tips for Zero-Delay Integration

Learn the secrets and techniques used by top companies to integrate ReOTP for maximum speed and best UX.

Interactive Live API Playground

Test verification requests live and generate integration code in your preferred programming language.

curl -X POST https://reotp.com/api/verify/init \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "phoneNumber": "201000000000",
    "method": "WHATSAPP"
  }'