> ## Documentation Index
> Fetch the complete documentation index at: https://docs.rail402.dev/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> Rail402 is an x402 payment facilitator, Stellar-native Bazaar discovery layer, and agent tooling for the Stellar network. It currently targets stellar:testnet.
> The live testnet facilitator is https://facilitator.rail402.dev with endpoints /verify, /settle, /supported, /health, and /discovery/*.
> Payment amounts use 7-decimal SEP-41 integer (stroop) arithmetic. Never use floating-point math for amounts.
> Every rejection returns a machine-readable error code and a non-null human-readable reason. When explaining a failure, surface both.

# Install and first payment

> See the live facilitator respond with no setup, then make your first real testnet payment from the command line and verify it on the explorer.

By the end of this page you will have watched the live Rail402 facilitator respond, then settled a
real payment on `stellar:testnet` and confirmed it on the explorer. It takes about five minutes.

## See it live, with no setup

The `rail402` CLI talks to the hosted testnet facilitator by default. These read-only commands need
no account and no funding.

```bash theme={null}
# What the facilitator supports
npx @rail402.dev/cli supported

# Search the live Bazaar in natural language
npx @rail402.dev/cli search "convert a currency or asset price"
```

`supported` prints the schemes and networks, and `search` returns real services from the catalog with
their price and description. Nothing is paid.

## Make your first payment

To pay, you need a funded testnet account that holds the payment asset.

<Steps>
  <Step title="Create and fund an account">
    `fund` generates a testnet keypair and funds it with XLM from friendbot. Save the secret it
    prints.

    ```bash theme={null}
    npx @rail402.dev/cli fund
    export RAIL402_SECRET=S...   # the secret it printed
    ```
  </Step>

  <Step title="Add the payment asset">
    Bazaar services are priced in testnet USDC. Add a USDC trustline to your account, then fund it
    from the [Circle faucet](https://faucet.circle.com) (select Stellar testnet). The trustline is a
    step you take yourself; the faucet only sends the USDC. See
    [Trustlines](/concepts/stellar#trustlines) for how to add one and why an account needs it.

    <Note>friendbot funds XLM; testnet USDC comes from the Circle faucet.</Note>
  </Step>

  <Step title="Discover and pay">
    `buy` searches the Bazaar, picks the best-ranked match within your cap, and pays it. Amounts on the
    CLI are decimals, so `--max 0.10` is 0.10 USDC.

    ```bash theme={null}
    npx @rail402.dev/cli buy "convert a currency or asset price" --max 0.10
    ```

    It prints the settled transaction hash and the resource response.
  </Step>

  <Step title="Verify it on chain">
    Look the settlement up on the explorer.

    ```bash theme={null}
    npx @rail402.dev/cli tx <hash>
    ```

    Or open it at [explorer.rail402.dev](https://explorer.rail402.dev). The fee was charged to the
    facilitator, not to your account, because fees are sponsored.
  </Step>
</Steps>

<Tip>
  Every command accepts `--json` for a machine-readable `{ ok, data | error }` result, so an agent can
  drive this flow. See [The rail402 CLI](/buyers/cli).
</Tip>

## Build the real thing

The CLI is the fastest way to see a payment. To build a buyer, a seller, or run your own facilitator,
follow the path for what you are building.

<CardGroup cols={3}>
  <Card title="Buyers and agents" icon="wallet" href="/buyers/quickstart">
    Pay for services from code with `@rail402.dev/sdk`.
  </Card>

  <Card title="Sellers" icon="store" href="/sellers/quickstart">
    Put a paid, discoverable endpoint online.
  </Card>

  <Card title="Operators" icon="server" href="/operators/run">
    Run the facilitator yourself.
  </Card>
</CardGroup>

## Next steps

<CardGroup cols={2}>
  <Card title="How Rail402 works" icon="diagram-project" href="/start/how-it-works">
    The payment loop, the four addresses, and exact versus upto.
  </Card>

  <Card title="Packages" icon="cube" href="/reference/packages">
    Every published package and which to use.
  </Card>
</CardGroup>