# What you can build. Six SMS use cases, each with working code and the rules that apply.

Source: https://joinsimplesms.com/use-cases
Index: https://joinsimplesms.com/llms.txt

Each guide is a complete build against the real API: what to call, a code sample you can run in the sandbox, the compliance notes for that kind of message, and what it costs.

- [OTP and phone verification](/use-cases/otp): Send a one-time code and check it in two calls, and pay only when the code is verified.
- [Appointment reminders](/use-cases/appointment-reminders): Schedule a reminder per appointment, cancel it if the booking moves, and handle replies by webhook.
- [Order and delivery notifications](/use-cases/order-notifications): Send one text per order event with an idempotency key, and track delivery by webhook.
- [Alerts and on-call paging](/use-cases/alerts): Page by SMS with deduplicated sends, delivery receipts for escalation, and a spend cap for alert storms.
- [Two-way support](/use-cases/two-way-support): Receive customer texts in a shared inbox or by webhook, reply through the API, and auto-reply after hours.
- [Marketing broadcasts](/use-cases/marketing-broadcasts): Send one personalized message to a segment of opted-in contacts, with a dry run before anything goes out.

## One API, the same rules for every use case

Each guide above is a complete build: the endpoints involved, a working code sample, the compliance rules that apply to that kind of message, what it costs at the published rates, and the limits to plan around. They share a foundation.

The same primitives. Messages (`POST /v1/messages`), verification (`POST /v1/verify` and `/v1/verify/check`), batches for lists, webhooks for delivery status and replies, and scheduled sends. The [API reference](/docs/api) documents every endpoint.

The same price list. $0.009 per outbound message with carrier fees included, and $0.025 per successful verification. See [pricing](/pricing).

The same guardrails. Opt-out keywords are handled on every number, a suppression list gates every send, and a US local number can text the public only after its A2P 10DLC registration is approved. Marketing messages need the recipient's prior express written consent; transactional messages still need consent and a way to opt out. [Opt-out and consent](/docs/opt-out) and [compliance and registration](/docs/compliance) explain what the platform enforces and what stays your responsibility.

The same sandbox. Every use case can be built and tested end to end with a free test key: simulated delivery, forced failures, signed webhooks and simulated replies. The free tier adds 100 live texts a month to numbers you have verified.

## What SimpleSMS is not for

SimpleSMS sends SMS in the United States and Canada. It does not do voice calls, WhatsApp or outbound MMS, and it does not deliver to other countries. Messaging that the [Messaging Policy](/messaging-policy) prohibits is blocked whatever the use case.