OTP Verification for 4 Channels

SMS, WhatsApp, Telegram and Email, behind one API call. You pass a recipient, your routing picks the channel, and the user types back a code you verify the same way every time.

one call

post

/otp/send

recipient

Routing picks the channel from the recipient and your order. The response tells you which one it used.

One OTP Service for Every Channel

One endpoint sends a one-time passcode and one endpoint verifies it, across all four channels. You do not pass a channel per request: routing chooses it from the recipient you send, your channel order and any per-country overrides, so delivery can be tuned without a code change on your side.

The recipient field decides the shape of the flow. An email address is emailed. A phone number walks your channel order. The send response tells you which channel was used, and if a code does not get through, one resend call advances the same request to the next channel in your order.

Verification is identical everywhere: the user types the code they received and you call verify with it. See Channels & routing for the routing rules, or Pricing for the per-channel rates.

request

POST /otp/send
{
  "recipient": "+14155552671"
}

response

{
  "otp_id": "9f3c1b2a-…",
  "status": "pending",
  "channel": "sms",
  "masked_recipient": "+1****71",
  "action_url": null
}

No channel in the request. channel in the response.

Explore Our OTP Channels

Every channel uses the same two API calls. What differs is reach, what you ask of the user, and what it costs.

SMS OTP

SMS OTP verification is the baseline every phone can receive. There is no app to install, no account to hold and no network beyond the mobile one, which makes it the channel to reach a user you know nothing about yet. It is the widest reach of the four and the only one priced per country, because operator cost is what sets the price.

Where it fits

Works on any handset, including feature phones with no data connection
No prior relationship needed: nothing to install, nothing to opt into
Best first channel when you cannot tell what apps a user has

Worth knowing

The only channel whose price varies by destination, from a fraction of a cent to several cents
Delivery depends on the operator that accepts the message, so rates are a floor rather than a quote

$0.0008 to $0.4238 per verification, by country. Full detail on the SMS OTP page .

WhatsApp OTP

WhatsApp OTP verification runs over WhatsApp Business rather than the mobile network, so the rate is the same in every country instead of following operator pricing. The flow differs from the other channels in one way: the user opens a link to start the chat, and the code comes back to them there.

Where it fits

One flat rate worldwide, so a global user base carries no per-country surprises
High open rates on a surface users already have in the foreground
The inbound and outbound messages that carry one code count as a single verification

Worth knowing

Only ever a first channel: because the user has to open the link to start the chat, a resend cannot advance into WhatsApp, and it is skipped if it sits further down your order
It asks one extra action of the user, so it suits flows where you can show a button

$0.0012 per verification, every country. Full detail on the WhatsApp OTP page .

Telegram OTP

Telegram OTP delivers the code over Telegram instead of the mobile network, which makes it useful in markets where Telegram is the default messenger and where SMS is expensive or unreliable. Like the other chat channels it is one flat rate everywhere, so the destination does not move the price.

Where it fits

Flat rate in every country, independent of operator pricing
Delivered over data, so it reaches users with poor SMS deliverability
Strong fit for markets and communities where Telegram is the primary messenger

Worth knowing

Reaches only users who are on Telegram, so it works best with SMS behind it in your order
Priced above the other two flat channels

$0.0120 per verification, every country. Full detail on the Telegram OTP page .

Email OTP

Email OTP authentication verifies the address you already collect, which makes it the natural choice for web sign-ups, SaaS logins and any flow where asking for a phone number would cost you the conversion. It is selected by the recipient you pass rather than by channel order: an email address is emailed.

Where it fits

No phone number required, which keeps sign-up friction low
One flat rate in every country
The recipient field takes a phone number or an email address, so one call covers both

Worth knowing

Inbox delivery and spam filtering are outside the mobile network, so timing is less predictable than a chat message
Only reaches a user whose email address you already have

$0.0012 per verification, every country. Full detail on the Email OTP page .