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

# Use cases overview

> Payment patterns on Stable: P2P transfers, subscription billing, invoice settlement, pay-per-call APIs.

Stable supports multiple payment patterns, from simple wallet-to-wallet transfers to agent-driven service payments. The use cases below cover the patterns that are production-ready today. For patterns on the horizon (guaranteed settlement, confidential payments, agent-to-agent commerce), see [Upcoming use cases](/en/explanation/upcoming-use-cases).

## Live use cases

<CardGroup cols={2}>
  <Card title="P2P payments" icon="users" href="/en/reference/p2p-payments">
    Wallet-to-wallet USDT0 transfers. Sub-second settlement, zero gas via Gas Waiver.
  </Card>

  <Card title="Subscription billing" icon="repeat" href="/en/reference/subscriptions">
    Pull-based recurring billing via EIP-7702. Subscriber authorizes once, provider collects each cycle.
  </Card>

  <Card title="Invoice settlement" icon="file-text" href="/en/reference/invoices">
    B2B invoice payment with deterministic nonces. On-chain settlement links automatically to the invoice.
  </Card>

  <Card title="Pay-per-call APIs" icon="zap" href="/en/reference/pay-per-call">
    Per-request HTTP payments via x402 middleware. No accounts, no API keys, no billing cycles.
  </Card>
</CardGroup>

## Shared foundations

Most patterns build on the same two protocols:

* **[ERC-3009](/en/explanation/erc-3009)**: signed authorizations for delegated settlement. Used by invoices, pay-per-call, and P2P application-initiated transfers.
* **[x402](/en/explanation/x402)**: HTTP-native payments over standard headers. Used by pay-per-call APIs and MCP-driven payment flows.
* **[EIP-7702](/en/explanation/eip-7702)**: EOA delegation for recurring authorization. Used by subscription billing.

## Next recommended

<CardGroup cols={2}>
  <Card title="ERC-3009" icon="signature" href="/en/explanation/erc-3009">
    Start with the core settlement standard.
  </Card>

  <Card title="Upcoming use cases" icon="clock" href="/en/explanation/upcoming-use-cases">
    Preview agent-to-agent commerce, guaranteed settlement, and confidential payments.
  </Card>
</CardGroup>