Solana Mainnet network identifiers for x402

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"}`);
  }
}