> For the complete documentation index, see [llms.txt](https://docs.sms4sats.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.sms4sats.com/getting-started/getting-started.md).

# Overview

sms4sats is a pay-per-use SMS service backed by Bitcoin Lightning Network. There are no accounts required — just generate an order, pay the Lightning invoice, and receive your SMS activation code.

### How It Works

1. **Create an order** with your desired country and service (e.g. USA + Google).
2. **Pay the Lightning invoice** returned by the API using any Lightning wallet.
3. **Poll the order status** endpoint until your activation code arrives.
4. **Cancel** anytime after 2 minutes if no code has arrived — your payment is automatically returned.

{% hint style="success" %}
sms4sats uses [hold invoices](https://bolt.fun/guide/invoices/hodl-invoice). Your funds are only settled when an activation code is successfully delivered. If no code arrives within 21 minutes, the invoice is automatically canceled and funds returned.
{% endhint %}

### Payment Options

| Method            | Details                                                                                |
| ----------------- | -------------------------------------------------------------------------------------- |
| Bitcoin Lightning | Native payment method. Instant, no fees, no account.                                   |
| USDT / LTC / ETH  | Swap to Lightning BTC via [FixedFloat](https://fixedfloat.com/ETH/BTCLN?ref=pmdxabka). |

### Prepaid Account (API Key)

For automated or high-volume usage, you can fund a prepaid account with an API Key to skip the per-order invoice payment step. See [Fund Account](/api-reference/fund-account.md) and [Get Balance](/api-reference/get-balance.md).

### L402 / AI Agents

AI agents can use <https://api.sms4sats.com/skill.md> to operate the service autonomously via the [L402 protocol](https://github.com/lightninglabs/L402) with no human intervention.


---

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