POST /otp/resend

Advance the same OTP to the next enabled channel after a cooldown. The response has the same shape as send, with the new channel. Pass an optional channel to move the OTP onto a specific channel instead of the next one. You do not re-send client_ip: the resend is evaluated with the IP declared on the original send.

curl -X POST https://api.otp.com/api/v1/otp/resend \
  -H "Authorization: Bearer otp_live_•••" \
  -H "Content-Type: application/json" \
  -d '{"otp_id":"9f3c1b2a-…"}'

Request body

Field	Type	Required	Description
otp_id	string	yes	The id of the verification to advance.
channel	string	no	Move the OTP onto this exact channel (sms, whatsapp, telegram, email) instead of advancing to the next one. Must be enabled for your app and the recipient.

Verify by SMS when the user has no WhatsApp

WhatsApp needs the user to open the action_url to receive their code, so a user without WhatsApp (or one whose code does not arrive) cannot complete it there. Resend with {"otp_id":"…","channel":"sms"} to move that pending OTP onto SMS: it delivers a fresh code and the response comes back with action_url: null, so you continue with the normal verify step. This is a user-initiated switch (WhatsApp still never auto-falls-back on its own).

Response

{
  "otp_id": "9f3c1b2a-…",
  "status": "pending",
  "channel": "whatsapp",
  "masked_recipient": "+1****71",
  "action_url": "https://wa.me/13845555555?text=Verify%20me%3A%20aB3xZ-…"
}

channel reflects the next channel in your order. On SMS, email, and Telegram the same code is re-issued; a fresh code is not generated. When the next channel is WhatsApp the response returns an action_url the user opens to receive the code over chat, and a later resend re-returns the same link. WhatsApp is terminal: once an OTP is on WhatsApp, resend does not advance it to another channel.

Common errors

Status	Type	When
409	ResendNotAllowedError	No further channel to fall back to.
429	ResendCooldownError	Resend attempted within the cooldown window.

See How verification works for the fallback model, or Error codes for the full list.