Sending ETH with web3.eth.sendSignedTransaction on Ropsten network

Question

I have two question about how can I send ethereum programmatically.

1. How can I use the https://api.myetherapi.com/ropsten address to test my code?

I tried something like this:

...
web3 = new Web3(newWeb3.providers.HttpProvider("https://api.myetherapi.com/ropsten?apikey=mykey"));
...

But I get this response: {"message":"Missing Authentication Token"}

Do api.myetherapi.com and ropsten.infura.io uses the same ledger?

---

2. I cannot send any ETH over Ropsten network. For this one I use infura.io, and whatever I try, is not working. Here is my code:

    var Web3 = require('web3');

    if (typeof web3 !== 'undefined') {
      web3 = new Web3(web3.currentProvider);
    } else { 
      web3 = new Web3(new Web3.providers.HttpProvider("https://ropsten.infura.io/DvTaqzNZpFvErBoHkvwL"));   // SANDBOX
    }

    var txDecoder = require('ethereum-tx-decoder');

    gasPrice = 0;
    web3.eth.getGasPrice(function(error, result) {
            console.log('Gas Price: '+ result);
            gasPrice = result;

            const ethTx = require('ethereumjs-tx');

            const txParams = {
                      nonce: '1',           // Replace by nonce for your account on geth node
                      gasPrice: gasPrice,   // maximum price of gas you are willing to pay for this transaction
                      gasLimit: 0.0000001,  // maximum gas you are willing to pay for this transaction
                      to: '0xb8412c93aefe25937d1f5f43393d6d74382ae987',
                      value: 0.000000001,
            };

            // Transaction is created
            const tx = new ethTx(txParams);
            const privKey = Buffer.from('7dc2...private_key', 'hex');

            // Transaction is signed
            tx.sign(privKey);
            const serializedTx = tx.serialize();
            const rawTx = '0x' + serializedTx.toString('hex');
            console.log(rawTx);
            console.log(txDecoder.decodeTx(rawTx));


            web3.eth.sendSignedTransaction(rawTx, function(err, hash) {
                    if (!err) {
                            console.log(hash); // "0x7f9fade1c0d57a7af66ab4ead79fade1c0d57a7af66ab4ead7c2c2eb7b11a91385"
                     } else {
                            console.log(err)
                      }
            });

    });

My private key is related to this: https://ropsten.etherscan.io/address/0x25D8A20E97fE8af009e9A67eE5DBd4bB92751d9a - where I have 20 ETH

All the errors I get are related with the gas price/limit, or the transaction is not mined in the next 50 blocks.

Thanks in advance!

Answer 1

Per myetherapi.com, I think you want https://api.myetherapi.com/rop:

web3 = new Web3(newWeb3.providers.HttpProvider("https://api.myetherapi.com/rop"));

The nonce should be 0 for that account, the gasLimit needs to be at least 21000 (the base limit for a transaction), and value should be expressed in wei:

const txParams = {
  nonce: 0,             // Replace by nonce for your account on geth node
  gasPrice: gasPrice,   // maximum price of gas you are willing to pay for this transaction
  gasLimit: 21000,      // maximum gas you are willing to pay for this transaction
  to: '0xb8412c93aefe25937d1f5f43393d6d74382ae987',
  value: web3.toWei(0.000000001, "ether"),
};