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. Status Polling
In the frontend, the code polls for verification success every 2 seconds 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
API Reference
Advanced Features
Channel Setup
SDKs & Libraries
Security & Sync
Pricing & Billing
Verification Methods
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.
Smart 2FA + Biometric
Programming hybrid login to reduce cost and increase security.
Pure Passwordless
Eliminate passwords and messages to build a magical experience.
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
Smart Biometric Login
One biometric every 7 days — save ReOTP costs
Pure Passwordless Identity System
No password, no messages — just one biometric
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
Sân chơi API tương tác trực tiếp (Interactive API Playground)
Thử gửi yêu cầu xác thực trực tiếp và tạo code tích hợp ngôn ngữ bạn thích.
curl -X POST https://reotp.com/api/verify/init \
-H "Authorization: Bearer 15a1c1c7-ed05-40df-b7c3-69c327542a07" \
-H "Content-Type: application/json" \
-d '{
"phoneNumber": "201000000000",
"method": "WHATSAPP"
}'