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Use case

WhatsApp OTP for login and verification

A WhatsApp OTP is a one-time passcode sent through Meta's authentication template category, with a copy-code button, instead of an SMS. BotPulsar sends it with one REST API call from your backend; Meta charges its authentication rate per message, and there is no DLT registration step as there is for SMS in India.

Typical cost: 10,000 messages a month on the Growth plan costs about ₹2,149 before GST — ₹999 platform fee plus ₹1,150 in Meta charges at India rates effective 1 July 2026 — or ₹2,536 including 18% GST.

How it works

OTP & verification on BotPulsar, step by step

Create an API key

In BotPulsar, create a scoped API key for your backend. Growth and above include REST API access.

Approve an authentication template

Meta's authentication templates have fixed wording with a code variable and a copy-code button; you choose the expiry text.

Call the send endpoint

Your backend generates the code and calls the template-send endpoint with the phone number and the code.

Fall back if undelivered

Delivery status arrives on your webhook; if the message is not delivered within your timeout, fall back to SMS or voice.

Worked example

Monthly cost: OTP & verification

Meta's India rates effective 1 July 2026, passed through at cost. BotPulsar adds no markup.

LineVolumeRateMonthly
BotPulsar Growth plan (unlimited users)—flat₹999
Meta authentication: OTP messages10,000₹0.115₹1,150
Total before GST10,000₹2,149
GST at 18%₹387
Total including GST₹2,536

See every plan and Meta rate

Limitations to know first

  • BotPulsar delivers the code; generating and verifying it stays in your backend.
  • The customer must have WhatsApp on that number — keep an SMS fallback for the few who do not.
  • Authentication template wording is fixed by Meta; you cannot add marketing copy to it.

Ready-made templates

Terms used on this page: Authentication template · API key · Webhook

FAQ

OTP & verification on WhatsApp: common questions

Is WhatsApp OTP cheaper than SMS OTP in India?

Often, once DLT and route costs are included, but compare against your actual SMS contract. The WhatsApp side is Meta's authentication rate shown in the cost example, with no BotPulsar markup.

Do we need DLT registration for WhatsApp OTP?

No. DLT is a TRAI requirement for SMS. WhatsApp OTPs instead need an authentication template approved by Meta.

Can the OTP have a copy-code or autofill button?

Yes. Authentication templates support a copy-code button, and Meta's one-tap autofill on Android for apps that implement it.

Which plan includes API access for OTP?

Growth (₹999/month) and above include the REST API and outgoing webhooks. Starter does not include API access.

How fast is a WhatsApp OTP delivered?

Usually within seconds. Delivery is Meta's network, so we recommend a timeout with SMS fallback rather than relying on a single channel.

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