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

# Solana Mainnet network identifiers for x402

> Use the correct x402 CAIP-2 network, full Solana RPC genesis hash, native USDC mint and Token Program on Solana Mainnet.

Solana Mainnet has two similar-looking identifiers. They serve different purposes and both are correct.

| Use | Value |
| - | - |
| x402 v2 network (CAIP-2) | `solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp` |
| Full `getGenesisHash` RPC result | `5eykt4UsFv8P8NJdTREpY1vzqKqZKvdpKuc147dw2N9d` |

The CAIP-2 chain reference is the first 32 characters of the genesis hash because CAIP-2 chain references have a 32-character limit. Do not append the remaining genesis-hash characters to an x402 `network` field. Conversely, do not compare the shortened CAIP-2 reference with the full result returned by `getGenesisHash`.

## Fail closed on the RPC network

Before loading a buyer signer or making a payment, call `getGenesisHash` and compare the complete result:

```ts theme={null}
const SOLANA_MAINNET_GENESIS =
  "5eykt4UsFv8P8NJdTREpY1vzqKqZKvdpKuc147dw2N9d";

export async function assertSolanaMainnetRpc(rpcUrl: string): Promise<void> {
  const response = await fetch(rpcUrl, {
    method: "POST",
    headers: { "content-type": "application/json" },
    body: JSON.stringify({
      jsonrpc: "2.0",
      id: 1,
      method: "getGenesisHash",
      params: [],
    }),
  });
  if (!response.ok) throw new Error(`Solana RPC returned HTTP ${response.status}`);

  const body = (await response.json()) as {
    result?: string;
    error?: unknown;
  };
  if (body.error || body.result !== SOLANA_MAINNET_GENESIS) {
    throw new Error(`Expected Solana Mainnet genesis hash; received ${body.result ?? "RPC error"}`);
  }
}
```

This check catches a wrong cluster and the common error of comparing the RPC result with the shortened x402 identifier.

## Native USDC

The tested asset is Circle-issued native USDC on Solana Mainnet:

| Field | Value |
| - | - |
| Mint | `EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v` |
| Decimals | `6` |
| Token program | `TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA` |

The mint uses the original SPL Token Program, not Token-2022. An x402 `payTo` value is the merchant wallet address. That wallet's associated token account for this mint must exist before settlement.

Creating the associated token account is a separate setup transaction. The account-creation transaction's signer pays its SOL network fee and rent-exempt balance. PayAI's fee payer, discovered from the live facilitator capability response, sponsors the ordinary x402 payment transaction; that sponsorship does not fund merchant account setup.

<Note>
  These constants are also published in the [machine-readable integration metadata](/solana-mainnet-integration.json). For changing facilitator capabilities, always query [`/supported`](https://facilitator.payai.network/supported).
</Note>

Continue with the [x402 Solana Mainnet Express guide](/x402/solana-mainnet-express).

## Primary references

* [Solana namespace CAIP identifiers](https://github.com/ChainAgnostic/namespaces/blob/main/solana/caip10.md)
* [Solana `getGenesisHash` RPC method](https://solana.com/docs/rpc/http/getgenesishash)
* [Circle native USDC on Solana](https://www.circle.com/multi-chain-usdc/solana)
* [Solana Token Program account](https://explorer.solana.com/address/TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA?cluster=mainnet)