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OTP verification API without building the plumbing

Every login flow ends up needing one-time codes, and then someone on your team spends a week on code generation, storage, expiry, retries and delivery. With RCSZilla it is two REST calls: one sends the code by SMS or email, one verifies what the user typed. Expiry and matching are handled on our side.

The whole flow in two calls

  1. SendPOST the user's phone number (or email). RCSZilla generates the code, delivers it and starts the expiry timer.
  2. User types the codeYour form collects it. Six digits, nothing exotic.
  3. VerifyPOST the code back and you get a yes or no. Expired, wrong or reused codes all come back as no.

Full request and response schemas are in the API documentation, alongside the rest of the messaging API.

Where teams use it

Login & signup

Verify phone numbers at registration to keep fake accounts out. Two-factor login without an authenticator app.

Order & payment confirmation

Ask for a code before the expensive actions: confirming a large order, changing a payout account, deleting data.

Delivery & pickup

The courier asks for the code you texted the customer. Proof of handover without a signature pad.

Engineering questions

What do you handle for me?

Code generation, delivery by SMS or email, expiry and verification. Your side is two HTTP calls and a form field. You never store codes, so there is nothing for you to leak.

What does it cost per verification?

The SMS carrying the code is billed at the normal per-country rate, from €0.02 per message with no monthly fee (see the calculator), or free through your own Android device for local users. Email delivery is included.

How reliable is code delivery?

Cloud codes go out over carrier-grade routes with automatic least-cost routing. The code itself is short plain GSM-7 text, the most reliably delivered kind of message. If you customise the template, check the encoding with the character counter.

Ship verification this sprint

Create a free account, grab an API key from the dashboard, and send your first code in minutes.

Start verifying

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