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

# Networks

> The chains Reclack settles on, what they are called in the API, and what differs between them.

Reclack settles one asset, USDC, across several chains. The objects are the
same wherever a payment lands: a price, a checkout, a subscription and an
invoice do not change shape per network. What changes is where the money
arrives and what the payer waits for.

## Live networks

| Network | API name | Chain id | Recurring |
| - | - | - | - |
| Arc | `arc` | 5042 | Yes |
| Base | `base` | 8453 | Yes |
| Ethereum | `ethereum` | 1 | Yes |
| Polygon | `polygon` | 137 | Yes |
| Solana | `solana` | — | One-time only |

## Sandbox networks

Each live chain has a test counterpart. The names differ, so a sandbox key and
a live key never address the same chain by accident.

| Network | API name | Chain id |
| - | - | - |
| Arc Testnet | `arc-testnet` | 5042002 |
| Base Sepolia | `base-sepolia` | 84532 |
| Ethereum Sepolia | `ethereum-sepolia` | 11155111 |
| Polygon Amoy | `polygon-amoy` | 80002 |
| Solana Devnet | `solana-devnet` | — |

## Arc

Arc is Circle's own chain, and the one difference worth knowing is that USDC
is its native token. Gas is paid in the same dollars the payment settles in,
so there is no second asset to hold and no native token to top up before a
customer can pay.

> [!NOTE]
>
> Reclack pays the network fee on Arc as it does everywhere else. Your customer
> needs USDC and nothing besides.

Blocks finalize deterministically, so a payment is settled rather than
probably settled: Reclack waits two blocks on Arc, against twelve on Ethereum
and sixty-four on Polygon. Transactions are visible at
[explorer.arc.io](https://explorer.arc.io).

## Choosing which networks you accept

A price carries the networks it may be bought on, and a checkout may narrow
that list further.

```bash theme={null}
curl -X POST "https://api.reclack.com/v1/checkouts" \
  -H "Api-Key: $RECLACK_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "price_id": "price_7Fh2PqX9",
    "networks": ["arc", "base"]
  }'
```

The payer picks from that list on the checkout page. The picker is
alphabetical, and opens on Base where Base is one of the options.

Leave `networks` out and the checkout offers everything the price allows.
Offer fewer where you have a reason to: a chain you have no settlement address
for cannot be paid on.

## Before you accept a network

Each network needs an address you control, registered once. See
[Settlement](https://docs.reclack.com/guides/settlement.md) for how to add one, and
[Environments](https://docs.reclack.com/environments.md) for what differs between sandbox and live.

> [!WARNING]
>
> An address is per network. The same bytes may be valid on several EVM chains,
> but Reclack sends to the address registered for the chain the payment arrived
> on, so register each one deliberately.


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