Web3JS: How to Identify that a given transaction was send with either "ERC Token" or "Ether" in value

Question

I'm working on a Smart Contract and it almost ready. To watch transactions I'm using web2js on my server and its working fine.

But from a transaction detail how I get confirm that given transaction value is in either "Ether" or "ERC Token". I didn't any flag that define about the transaction type. Here is the response of transaction detail:

{ blockHash:'0x9bac7d85939a018cb1d075167c770ec489198ed33b7f80891aacef69bd4f87a0',
  blockNumber: 9240102,
  chainId: '0x1',
  condition: null,
  creates: null,
  from: '0x66527C1CA4d42b5134Eb68DCCd84cD731C683a09',
  gas: 43992,
  gasPrice: '3000000000',
  hash: '0x5e3c2be06257889894a9b486dee5f0009768905a42bb7d88c248a4df9e6cfb7a',
  input: '0xa9059cbb000000000000000000000000d8335af9a17bebba3b418755ab832bc7b5d11269000000000000000000000000000000000000000000000002b5e3af16b1880000',
  nonce: 63,
  publicKey: '0x093c647b00303b10f8fadb83bf25e76516d385c3b82724e454bc2ce0c044fb5b9e4fa32e5e70a837244f6312621f554b4424d801eecf0457f59a345dcb679d2b',
  r: '0xe0e5e40894b99f43d32a10ea0594eca8ff5a81dd7bc63b01e9f5da422ebda82f',
  raw: '0xf8a83f84b2d05e0082abd894410af23334e26aa13c1f3e630bae006bdd31326480b844a9059cbb000000000000000000000000d8335af9a17bebba3b418755ab832bc7b5d11269000000000000000000000000000000000000000000000002b5e3af16b188000025a0e0e5e40894b99f43d32a10ea0594eca8ff5a81dd7bc63b01e9f5da422ebda82fa00cd88104353205455666a4cc30e22892926dded16e73766d03fab94619e80c70',
  s: '0xcd88104353205455666a4cc30e22892926dded16e73766d03fab94619e80c70',
  standardV: '0x0',
  to: '0x410af23334e26aa13C1f3e630Bae006bdD313264',
  transactionIndex: 61,
  v: '0x25',
  value: '0'
}

In this above response how I identify that what was sent from sender (ETH or Token)

Lauri Peltonen · Answer

Token transfers are not actually transfers of value at all. Only Ether transfers explicitly transfer (and contain) value. So a transaction transfers Ether if and only if its value field is non-zero.

Detecting a token transfer is much more tricky. A token transfer is simply calling a function in a token contract. So first you need to know whether the receiving contract is a token contract (this is quite difficult to find out: Detect token transaction to a contract How is a contract determined to be ERC20 compliant? ). After that you can monitor for Transfer events but unfortunately this does not guarantee anything either - it's just basically the best we can do.

A token transfer may also contain value but not typically.

Web3JS: How to Identify that a given transaction was send with either "ERC Token" or "Ether" in value

One Answer

Add your own answers!

Ask a Question