efx-api-node/src/api/eth/get_network.js

<img src="https://avatars3.githubusercontent.com/u/33315316?s=200&v=4" align="right" />

/*
 * Returns current network id and name
 * see:
 * https://github.com/MetaMask/faq/blob/master/DEVELOPERS.md#construction_worker-network-check
 *
 **/
module.exports = async (efx) => {
  const id = await efx.web3.eth.net.getId()

  const labels = {
    '1': 'mainnet',
    '2': 'morden',
    '3': 'ropsten',
    '4': 'Rinkeby',
    '42': 'Kovan'
  }

  return {
    id: id,
    name: labels[id] || 'unknown'
  }
}