Start free

Kauthar OTP

Verification codes on WhatsApp, with one API call

Your app, website or store sends a one-time code; your customer receives it on WhatsApp in seconds and copies it with one tap.

«I send the code, I check it, I tell you if it arrived. You only pay for what goes out.» — Kauthar

Start with Kauthar OTP See the API

Free credit for 20 messagesNo AI plan needed

Kauthar, the AI assistant, waving

Why Kauthar OTP

  • WhatsApp, not SMS

    Your customers already use WhatsApp — the code arrives with a «copy code» button.

  • Your name as sender

    Connect your own WhatsApp number with one button and the message shows your verified business name.

  • Prepaid, refunded on failure

    A price per destination country. Messages WhatsApp could not deliver are refunded automatically.

  • Protection built in

    Attempt limits, resend cooldown, per-phone and per-app limits, country and IP allowlists, premium numbers blocked.

  • Arabic, English, French

    Choose the message language per app or per request.

  • Developer friendly

    Sandbox keys, idempotency, delivery status, signed callbacks, examples in curl, Node.js, PHP and Python.

Two ways to send — see the difference

Meta fixes the text of verification messages. What changes is the sender your customer sees.

Kauthar shared numberInstant
Meta's fixed text; the sender is Kauthar. No business name.
Your own WhatsApp numberRecommended
Same fixed text from Meta, but the sender is your own verified business name.

Prices

Per accepted message to a number in United States:

Kauthar shared number

USD 0.07

per message, from your wallet

Ready instantly. The sender is «Kauthar», without your business name.

Your own WhatsApp number Recommended

USD 0.02

Kauthar fee per message

Meta bills your WhatsApp account directly for the message; Kauthar charges only this fee.

Other destination countries have their own price, shown in your dashboard. Prepaid wallet, no subscription.

Three steps

  1. Sign up and create an app

    Get a sandbox key and a live key. Free credit is added to your wallet.

  2. Call send

    Send the phone number — we generate the code, store only its fingerprint and deliver it on WhatsApp.

  3. Call verify

    Send the code your customer typed: valid, invalid, expired or too many attempts.

curl -X POST https://kautharai.com/api/otp/v1/send \
  -H "Authorization: Bearer kotp_live_…" \
  -H "Content-Type: application/json" \
  -d '{"phone":"+966501234567","lang":"ar"}'

→ { "ok": true, "request_id": "otp_…", "status": "accepted" }

curl -X POST https://kautharai.com/api/otp/v1/verify -d '{"request_id":"otp_…","code":"483920"}'
→ { "ok": true, "status": "valid", "valid": true }

Questions

Do I need a Kauthar AI plan?

No. Kauthar OTP is a separate prepaid product. You can sign up for OTP only, or add it to your Kauthar account.

Will my customers see my business name?

With your own WhatsApp number, yes — your verified business name is the sender. With the Kauthar number, the sender is «Kauthar» and your name does not appear.

What happens if a message fails?

If WhatsApp refuses or cannot deliver it, the amount goes back to your wallet automatically.

Can I test without paying?

Yes. Sandbox keys go through every check but send nothing and cost nothing; the code is always 000000.

Which numbers can receive codes?

Any valid mobile number on WhatsApp worldwide, in E.164 format. Premium, shared-cost and VoIP numbers are refused; you can also restrict countries per app.

Send your first code today

Sign up, take a sandbox key and try the API in minutes.

Start with Kauthar OTP