# OTP Flow

> OTP Flow is an Indian SMS OTP gateway with a simple REST API. Developers send one-time passwords to 10 digit Indian mobile numbers over DLT-registered routes and verify them with a second call. Pay-as-you-go wallet in INR.

## Key facts
- Base URL: https://otpflow.in
- Auth: `Authorization: Bearer <api_key>` (create keys in the dashboard after signing in)
- Endpoints: POST /send-otp, POST /verify-otp, GET /balance
- send-otp body: number (10 digit, required), purpose (3-40 chars, required), ttl (5-120 minutes, default 10), otp (optional 3-40 digits), otp_length (3-40, used when otp omitted)
- send-otp returns an otp_id; verify-otp takes { otp_id, otp }. OTPs are encrypted at rest, single-use, max 5 attempts.
- Pricing per OTP depends on the user's largest single deposit (deposits are not summed): INR 100-999 => INR 0.7; INR 1000-4999 => INR 0.6; INR 5000+ => INR 0.4
- Payments: Razorpay (UPI/cards/netbanking), Binance Pay, OxaPay (crypto)
- Sign-in: Google or email one-time code

## Docs
- [API documentation](https://otpflow.in/docs): full reference with cURL, Node.js, Python and PHP samples
- [OpenAPI 3.1 spec](https://otpflow.in/openapi.json): machine-readable API description
- [Pricing](https://otpflow.in/pricing): volume pricing tiers
- [Send SMS in India without DLT registration](https://otpflow.in/send-sms-without-dlt-registration): Send OTP SMS to Indian mobile numbers without registering your own DLT entity, header or template. Use OTP Flow's pre-approved template and sender ID through a simple REST API.
- [Send SMS without KYC — start in minutes](https://otpflow.in/send-sms-without-kyc): No business paperwork to begin: sign in with Google or email, add funds and send OTP SMS in India straight away with OTP Flow's REST API.
- [Send OTP API for India: two calls, done](https://otpflow.in/send-otp-api): OTP Flow's send OTP API delivers SMS OTPs to Indian mobile numbers and verifies them with a second call. Custom or auto-generated 3–40 digit OTPs, 5–120 minute expiry, from ₹0.40 per OTP.
- [The best SMS API in India without DLT and KYC](https://otpflow.in/best-sms-api-india-without-dlt-kyc): Looking for the best SMS API in India without DLT registration and KYC? OTP Flow offers instant OTP delivery, pay-as-you-go pricing from ₹0.40 and UPI, card and crypto payments.
- [OTP SMS gateway for India](https://otpflow.in/otp-sms-gateway-india): A developer-first OTP SMS gateway for India: instant delivery, encrypted OTP storage, automatic refunds on failure and simple pay-as-you-go pricing in rupees.
- [Cheap OTP SMS API for India](https://otpflow.in/cheap-otp-sms-api-india): Low-cost OTP SMS API for India from ₹0.40 per OTP. Pay-as-you-go wallet, volume pricing by single deposit, auto-refund on failed SMS. No setup fee, no monthly plan, no DLT registration, no KYC.
- [Sign in / create account](https://otpflow.in/login)

## Optional
- [Terms](https://otpflow.in/terms)
- [Privacy](https://otpflow.in/privacy)