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

# Networks & Token Support

> Which Stellar networks and SEP-41 tokens StellarX402 supports, and how amounts are formatted.

StellarX402 payments happen on Stellar's Soroban smart contract layer. Two networks and any SEP-41 token whitelisted by the facilitator are supported.

## Networks

| Identifier        | Purpose                                                                     |
| ----------------- | --------------------------------------------------------------------------- |
| `stellar:testnet` | Development, integration testing, and CI. Uses Stellar Testnet Soroban RPC. |
| `stellar:pubnet`  | Production (Stellar Mainnet). Real value, real settlement.                  |

Both identifiers follow [CAIP-2](https://chainagnostic.org/CAIPs/caip-2). Clients and servers must agree on the network in both `PaymentRequirements` and `PaymentPayload`. See [Supported Networks](/reference/supported-networks) for the full reference.

## Tokens

Any [SEP-41](https://github.com/stellar/stellar-protocol/blob/master/ecosystem/sep-0041.md) compliant Soroban token can be used, subject to the facilitator's `ALLOWED_ASSETS` whitelist. The default and only widely deployed choice today is USDC.

| Asset | Testnet contract  | Mainnet contract | Decimals |
| ----- | ----------------- | ---------------- | -------- |
| USDC  | `CBIELTK6...DAMA` | `CCW67TS...VG7A` | 7        |

Full list and up-to-date addresses: [Supported Assets](/reference/supported-assets).

## Amount formatting

Amounts in `PaymentRequirements.amount` are stringified integers in the token's smallest unit (`amount * 10^decimals`). For USDC with 7 decimals:

| Human          | Wire         |
| -------------- | ------------ |
| 1 USDC         | `"10000000"` |
| 0.005 USDC     | `"50000"`    |
| 0.0000001 USDC | `"1"`        |

Use the SDK's `formatAmount` and `parseAmount` helpers rather than doing this by hand.

## Operator flags

Operators control which networks and assets their facilitator serves via:

* `NETWORK` (single network per instance)
* `ALLOWED_ASSETS` (comma-separated symbols)

See [Configuration Reference](/guides/operators/configuration-reference).