A single REST API for OTP SMS, Bulk SMS, WhatsApp OTP, and Voice Call OTP — pay only for what you send.
curl -X POST 'https://instantsms.shop/api/v1/otp/send' \
-H 'Authorization: Bearer sk_live_YOUR_API_KEY' \
-H 'Content-Type: application/json' \
-d '{"mobile": "9198XXXXXXX", "otp": "123456"}'
4 Delivery Channels
Simple REST API
Pay-as-you-go Wallet
No DLT for OTP
Everything you need to add messaging to your product, without the integration headache.
One API key, one endpoint per channel. Code samples in cURL, PHP, Node.js, and Python.
Flat per-message rates by channel. No monthly plans, no minimum commitment.
Every message logged with status, cost, and provider response from your dashboard.
Pick the channel that fits — or use all four from the same account.
Read the OTP aloud on an automated voice call — for when SMS delivery is unreliable.
The same API and wallet work whether you're shipping your first product or running an established platform.
Ship auth flows fast without negotiating a telecom contract.
No minimum spend — recharge what you need and go.
Reach students and parents reliably with SMS or WhatsApp.
Full delivery logs and per-client rate overrides for scale.
Clean REST endpoints, real request/response docs, no SDK lock-in.
Flat rate per message, by channel. Recharge your wallet, only pay for what's delivered.
₹1.00
per message
₹1.50
per message
₹1.00
per message
₹3.00
per message
Sign up and reach out from your dashboard for a custom rate on high-volume sending.
Create an account, grab your API key, and you're integrated in minutes.
Get Started FreeNo case studies to point to yet — here's what's actually true about how the platform works.
Every send is logged with status, cost, and the raw provider response — nothing is a black box.
Wallet-based billing, no contracts or monthly plans. Recharge when you need to, stop when you don't.
Real REST endpoints with documented request and response shapes — no undocumented behavior.
Per-client rate overrides and admin-managed pricing, ready for volume when you need it.
Businesses integrating OTP, SMS, WhatsApp, or voice delivery shouldn't need a separate contract and dashboard for every channel. This platform wraps all four behind one API key and one wallet, with transparent per-message pricing and full delivery records — so you can integrate once and switch channels without switching providers.
Answers to common questions about the platform.
Create a free account, and an API key is generated for you immediately — visible once on your API Credentials page right after signup.
No. OTP SMS sent through this platform does not require you to complete DLT sender ID registration yourself.
Wallet-based, pay-as-you-go. Recharge your balance, and each message is billed at a flat per-message rate for its channel — no monthly plans or minimum commitment.
Four: OTP SMS, Bulk SMS, WhatsApp OTP, and Voice Call OTP — all through the same API key from one account.
There is no separate sandbox — new accounts start with a zero balance, and any real send debits your wallet at the live rate. Recharge before your first send.