> ## 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.

# Hosted testnet

> The public Rail402 facilitator on the Stellar testnet. Free, no API key.

A public Rail402 instance serves the Stellar testnet. Point any stock x402 seller at it to accept testnet
payments, and read its Bazaar catalog without an account.

```text theme={null}
https://testnet.rail402.dev
```

| Property | Value |
| - | - |
| Network | `stellar:testnet` only |
| Scheme | `exact`, x402 version 2 |
| Asset | Circle testnet USDC, contract `CBIELTK6YBZJU5UP2WWQEUCYKLPU6AUNZ2BQ4WWFEIE3USCIHMXQDAMA`, 7 decimals |
| Fees | Sponsored: `extra.areFeesSponsored` is `true`; the payer pays no network fee |
| Access | Free, no API key |
| Extensions | `bazaar` |

It runs the repository's Docker image on [Railway](/facilitator/railway), with Postgres, and `/health` reports
the commit it was built from. It does not serve `stellar:pubnet`.

## Check it

```sh theme={null}
curl https://testnet.rail402.dev/supported
```

```json theme={null}
{
  "kinds": [
    {
      "x402Version": 2,
      "scheme": "exact",
      "network": "stellar:testnet",
      "extra": { "areFeesSponsored": true }
    }
  ],
  "extensions": ["bazaar"],
  "signers": {
    "stellar:*": [
      "GAX6MVOC5O5VZCSCCY26RM33AKPODAEHAMUS76IT4DBAGED46VIOWEPC",
      "GDZREJ6UXJDL7IMLRMHP4F6RM37TF3WUGRB7GPE5G4IUIXKS6ISZPVEQ",
      "..."
    ]
  }
}
```

`signers` lists the fee sponsor followed by the channel accounts. A payment in which any of them is the payer,
a transaction or operation source, or a party to an authorization is refused.

```sh theme={null}
curl https://testnet.rail402.dev/health
```

```json theme={null}
{ "status": "ok", "version": "0.2.1" }
```

```sh theme={null}
curl https://testnet.rail402.dev/ready
```

```json theme={null}
{
  "ready": true,
  "checks": {
    "database": { "ok": true },
    "stellar:testnet:rpc": { "ok": true },
    "stellar:testnet:sponsor": { "ok": true, "detail": "99993241283 stroops" },
    "stellar:testnet:channels": { "ok": true, "detail": "24 channels" },
    "search": { "ok": true }
  }
}
```

The version and balance above are examples; the live values differ.

## Pay through it

The quickest end-to-end check is the canonical client run from a [source checkout](/install). It creates and
funds a fresh buyer and seller with Friendbot, buys 1 testnet USDC for the buyer, starts a stock
`@x402/express` seller on `127.0.0.1` that uses the hosted facilitator, and pays it with stock `@x402/fetch`:

```sh theme={null}
node tools/conformance/src/canonical-exact.ts --facilitator https://testnet.rail402.dev
```

It prints the settlement transaction, a Stellar Expert link and the buyer's and seller's USDC balances before
and after, and it fails unless the transaction succeeded on-chain and the buyer's loss equals the seller's
gain. Recorded runs are on the [Conformance evidence](/reference/conformance) page.

To build your own, follow the [buyer](/quickstart/buyers) and [seller](/quickstart/sellers) quickstarts.

## Limits

* **Rate limits.** Requests are limited per client address; the instance runs with `TRUSTED_PROXY_HOPS=1`,
  so the address is the one Railway's edge proxy reports in `X-Forwarded-For`. A limited request gets HTTP
  `429` with a `Retry-After` header and the code `rate_limited`.
* **Operator policy.** The accepted asset, amount bounds, `maxTimeoutSeconds` range and settlement fee ceiling
  are configuration; the defaults are on the [Configuration](/configuration#per-network) page. A payment
  outside them is refused with a specific `invalid_exact_stellar_requirements_*` or
  `invalid_exact_stellar_payload_fee_exceeds_maximum` code. Amounts are SEP-41 base units: `10000000` is
  1 USDC.
* **Cataloging.** Only resources on public hosts are cataloged. A seller on `localhost` or a private address is
  paid normally, but its listing is refused with `bazaar_resource_unsafe`.
* **Testnet only.** Testnet accounts, balances and the catalog carry no value.

## Discovery

The catalog is public:

```sh theme={null}
curl "https://testnet.rail402.dev/discovery/resources?limit=5"
curl "https://testnet.rail402.dev/discovery/search?query=weather%20data%20under%201%20cent"
```

The hosted catalog lists the resources of the public demo seller (`apps/demo-seller`, at
`https://demo.rail402.dev`), paid through this facilitator, with their payment options,
bazaar metadata, trust and Stellar facts.

See [Discovery API](/bazaar/discovery) and [Search](/bazaar/search).


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