SMS for Quick Onboarding in AI-Driven Apps

Why onboarding is hard for AI-driven apps

An AI app often asks a lot of a new user in the first session. They sign up, connect data or upload a file, write a first prompt and wait for a result. Every extra step loses people. An email verification link adds one more step, and many mobile users never come back from their inbox.

AI apps also carry a cost that most apps do not. Every free account can run model calls that cost real money. When sign-up needs only an email address, one person can open many accounts and use several free tiers. Phone verification by SMS ties each account to a real number that can receive a code.

How to set up phone OTP sign-up in one step

Ask for a mobile number on the first screen, send a one-time code through our API and let the user type it in, or let Android fill it in automatically. Once the code matches, create the account and take the user straight into the product. There is no password to set and no inbox to check.

Keep the screen simple. Show a country code picker, pre-fill +91 for users in India, offer a resend after 30 seconds and a voice call as a fallback. Send OTPs with an approved OTP template so they reach DND numbers at any hour.

• Generate a 6-digit code with a secure random function and expire it in 5 to 10 minutes.
• Limit OTP requests per number, per IP address and per device to stop SMS pumping.
• Allow only the countries you serve, so bots cannot send codes to premium-rate destinations.
• Create a fresh code on every resend and cancel the old one.

Activation messages that bring new users back

Many users verify their number and leave before they see what the AI can do. A short SMS a few hours later, with a link that opens the step they skipped, often brings them back. Good examples are finishing a profile, connecting a data source or trying a sample prompt.

Send these as service messages to people who signed up, keep each one to a single action, and stop once the user is active. Two or three well-timed messages in the first week usually work better than a daily drip. Track clicks per template and drop the ones that do not help.

Can an AI model write the SMS text in India?

Only inside a template. Every commercial SMS in India must match a template registered on DLT, so free-form model output cannot be sent as it is. Register templates with variables instead. Each {#var#} field can hold up to 30 characters, so your model can fill in a name, a plan, a task or a short tip while the rest of the text stays fixed.

Links need care too. Since 1 October 2024 operators block links that are not whitelisted for your templates, and public link shorteners are not allowed. Register your app's domain, or a branded short domain, before launch.

For open conversations with an AI agent, use the WhatsApp Business API. Inside the 24-hour window that a user opens by messaging you, your bot can reply freely, and the first 1,000 service replies per number each month are free. Keep SMS for OTPs and short alerts, because it works on every phone without data.

Measuring onboarding with delivery reports

Delivery report webhooks tell your app when each OTP reaches the handset. Join them with your own events to see where users drop: code sent but not delivered, delivered but not entered, or entered with no first task. Each gap has a different fix.

Compare OTP success by operator and by telecom circle each week. If one network lags, our team can check the routing. If codes arrive but users do not enter them, the cause is usually the screen design or the template wording, and both are quick to test.