API Integration for India Businesses
OTPs, transactional email and push notifications that actually land on time.
SMS OTP integration is the most common request -- almost always for signup/login verification or checkout confirmation, using a provider like MSG91, Twilio or a local SMS gateway depending on delivery reliability and cost per SMS in India. Twilio itself gets requested specifically when a business also needs voice calls or international SMS, not just Indian numbers.
SendGrid (or a similar transactional email provider) comes up once a business notices their order-confirmation or password-reset emails are landing in spam when sent through a regular hosting mail server -- a dedicated transactional email API fixes that deliverability problem directly. Firebase Cloud Messaging (FCM) is specifically for push notifications on a mobile app or PWA.
Everything needed to get this API live, tested and reliable
RELIABLE DELIVERY
OTP and transactional SMS through a provider chosen for delivery reliability and cost in India.
STOPS EMAILS HITTING SPAM
Order confirmations, invoices and password resets sent through a dedicated email API instead of shared hosting mail.
FOR APPS & PWAs
FCM push notifications for a mobile app or installable web app, triggered from your backend.
SMS, email and push solve different problems -- most projects end up using more than one
| Option | Best For | Worth Knowing |
|---|---|---|
| MSG91 (SMS) | India-only SMS OTP and alerts at the lowest cost per message | DLT (sender ID + template) registration with your telecom operator is required before any transactional SMS can be sent -- this is set up as part of the integration. |
| Twilio (SMS / Voice) | Businesses needing international SMS, voice calls, or a single provider across multiple countries | Higher per-SMS cost in India than a local gateway, but far broader country and channel coverage. |
| SendGrid (Email) | Order confirmations, invoices and password resets that need to reliably reach the inbox, not spam | Requires SPF/DKIM domain authentication to get full deliverability benefit -- part of the setup, not optional. |
| Firebase Cloud Messaging (Push) | Mobile apps and installable web apps (PWAs) needing native push notifications | Free to use directly from Google; only relevant if you actually have an app or PWA, not a regular website. |
Issues seen often enough on real projects to plan around from day one
In India, TRAI's DLT (Distributed Ledger Technology) framework requires your sender ID and message templates to be pre-registered -- unregistered transactional SMS gets silently blocked by the operator, not bounced with an error you'd notice.
Shared hosting IPs get flagged by spam filters constantly -- order confirmations and password resets sent this way often just never reach the inbox, with no error on your end to indicate why.
An OTP sent over one channel only, with no retry or fallback, means a single provider hiccup blocks someone from logging in or checking out entirely.
Provider account created, and for SMS specifically, DLT sender ID and template registration completed -- this step alone can take a few days and is started early.
A quote covering however many channels (SMS, email, push) are needed, back within 24-48 hours.
Triggers wired into your signup/checkout flow and tested for actual inbox/SMS delivery, not just an API success response.
Switched to production sending with delivery-status handling in place so failures are visible, not silent.
Free consultation. No obligation. Get a fixed-scope quote in INR within 24-48 hours.
Start a Project See My WorkNeed more than one API connected? These are usually scoped together as a single project.