eth_protocolVersion - Base RPC Method

async function checkCompatibility(provider, minVersion) {
  const result = await provider.send('eth_protocolVersion', []);
  const version = parseInt(result, 16);

  if (version >= minVersion) {
    console.log(`Node supports required protocol version ${minVersion}`);
    return true;
  } else {
    console.warn(`Node protocol version ${version} is below required ${minVersion}`);
    return false;
  }
}

async function auditNodeVersions(endpoints) {
  const results = await Promise.all(
    endpoints.map(async (endpoint) => {
      const provider = new JsonRpcProvider(endpoint);
      const [protocolVersion, clientVersion] = await Promise.all([
        provider.send('eth_protocolVersion', []),
        provider.send('web3_clientVersion', [])
      ]);
      return {
        endpoint,
        protocolVersion: parseInt(protocolVersion, 16),
        clientVersion
      };
    })
  );

  const versions = new Set(results.map(r => r.protocolVersion));
  if (versions.size > 1) {
    console.warn('Protocol version mismatch detected across nodes');
  }

  return results;
}

async function getNodeCapabilities(provider) {
  try {
    const version = parseInt(await provider.send('eth_protocolVersion', []), 16);

    return {
      protocolVersion: version,
      supportsEIP1559: version >= 65,
      supportsSnapSync: version >= 66
    };
  } catch {
    // Some clients (e.g., post-Merge) may not support this method
    return { protocolVersion: null, supportsEIP1559: true, supportsSnapSync: true };
  }
}