> ## Documentation Index
> Fetch the complete documentation index at: https://docs.launchtoday.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# OneSignal and SMS OTP

> How OneSignal and SMS OTP are wired into onboarding

## Overview

Launch uses OneSignal for push notifications and Twilio Verify for SMS OTP.
During onboarding, SMS OTP is optional and can be disabled via the feature
registry. When enabled, the app collects a phone number, sends an OTP via the
API, and verifies it before moving on.

## Feature registry

OneSignal is registered as a feature module in
`apps/mobile/features/one-signal/feature.ts` and toggled via the `oneSignal`
flag in `apps/mobile/features/feature-registry.tsx`.

When this feature is disabled, the onboarding flow skips the phone and OTP
screens and continues directly to the push notification step.

## How SMS OTP works

The onboarding screens call user endpoints on the API:

* `user.savePhoneNumber`
* `user.sendPhoneOtp`
* `user.verifyPhoneOtp`

These endpoints live in `apps/api/src/routers/user.ts` and use the Twilio
client in `apps/api/src/lib/twilio.ts` to send and verify OTPs.

## Required environment variables

Mobile:

* `ONESIGNAL_APP_ID`

API (Twilio Verify):

* `TWILIO_ACCOUNT_SID`
* `TWILIO_AUTH_TOKEN`
* `TWILIO_SERVICE_SID`

Optional dev-only flag:

* `SKIP_TWILIO_OTP_VERIFICATION` (useful for local testing when Twilio is not
  configured)

## Where it is used in the app

* Onboarding screens: `apps/mobile/app/onboarding/phone.tsx`,
  `apps/mobile/app/onboarding/verify-otp.tsx`
* Push permissions: `apps/mobile/app/onboarding/push-notifications.tsx`
* Flow control: `apps/mobile/lib/hooks/useAppNavigation.ts`