echo-web3

echo-web3 is a wrapper over Web3 that allows you to use web3's instance methods by calling to Echo blockchain

Setup

Firstly, for work with echo-web3 you need to install web3.

Note: supported versions of web3 are 0.20.3 - 0.20.7.

npm install [email protected]

After you can install echo-web3:

npm install echo-web3

Basic Usage of EchoProvider

Before usage of wrapped web3 methods ECHO-compatible provider(that is exported from echo-web3) should be initiated by calling of providerInstance.init() async method.

Example:

import Web3 from 'web3';
import EchoWeb3, { EchoProvider } from 'echo-web3';

// 1. wrap your web3 lib
// Note: the minimum supported web3 version is 0.20.3 
const WrappedWeb3 = EchoWeb3(Web3);

// 2. define the echo network host
const echoNetwork = 'wss://testnet.echo-dev.io/ws';

(async () => {

	//3. create echoProvider instance. Default asset is 1.3.0
	const echoProvider = new EchoProvider(echoNetwork, { assetId: '1.3.0' });
	
	//4. pass the provider in web3 instance
	const web3 = new WrappedWeb3(echoProvider);
	
	//5. init provider
	await echoProvider.init();

	web3.eth.getBalance('0x00000000000000000000000000000000000001A9', (err, res) => {
		console.log(res);   // BigNumber { s: 1, e: 19, c: [ 500000 ] } (50 ECHO in wei)
		//6. disconnect from echo network
		web3.disconnect();
	});

})();

List of implemented methods and properties

All of this implemented methods can be executed by calling:

web3.eth.<methodName>(param1, param2, callback).

All async methods receive payload parameters like in original Web3 JSON-RPC and the callback as last parameter. The signature of callback is:

(error, result) => {}.

Implemented methods and async request (use <...> as method with callback):

• eth_call <call>
• eth_getBlockByNumber <getBlock>
• eth_getBlockByHash <getBlock>
• eth_getBalance <getBalance>
• eth_sendRawTransaction <sendRawTransaction>
• eth_blockNumber <getBlockNumber>
• eth_getTransactionCount <getTransactionCount>
• eth_getTransactionReceipt <getTransactionReceipt>
• eth_getTransactionByHash <getTransaction>
• eth_getCode <getCode>
• eth_getLogs <getLogs>
• net_version
• eth_estimateGas

Sync request (use as property):

• gasPrice

Bridge extension

Like the MetaMask that inject web3 instance on page, there was designed BridgeProvider that helps you to work with echo-web3 instance on frontend pages with Bridge extension.

Example:

import Web3 from 'web3';
import EchoWeb3, { BridgeProvider } from 'echo-web3';

// 1. wrap your web3 lib
// Note: the minimum supported web3 version is 0.2.3
const WrappedWeb3 = EchoWeb3(Web3);

(async () => {

	//2. create bridgeProvider instance. Default asset is 1.3.0
	const bridgeProvider = new BridgeProvider({ assetId: '1.3.0' });

	//3. pass the provider in web3 instance
	const web3 = new WrappedWeb3(bridgeProvider);

	//3. init provider
	await bridgeProvider.init();
	
	//4. get access to extension from your page
	await web3.currentProvider.enable();

	console.log(web3.eth.accounts); // ["0x000000000000000000000000000000000000013a"]
	
	web3.eth.sendTransaction({
		to: '0x00000000000000000000000000000000000001e9',  // 1.2.489
		value: '500000000000000000'                        // 0.5 ECHO
	}, (err, res) => {
		console.log(res);                                  // <txHash>
		web3.disconnect();
	});

})();

Before calling web3 method's you should give your page access to bridge extension by calling of web3.currentProvider.enable().

List of implemented methods

See description of method usage above.

Implemented methods and async request (use <...> as method with callback):

• eth_sendTransaction <sendTransaction>
• eth_call <call>
• eth_getBlockByNumber <getBlock>
• eth_getBlockByHash <getBlock>
• eth_getBalance <getBalance>
• eth_sendRawTransaction <sendRawTransaction>
• eth_blockNumber <getBlockNumber>
• eth_getTransactionCount <getTransactionCount>
• eth_getTransactionReceipt <getTransactionReceipt>
• eth_getTransactionByHash <getTransaction>
• eth_getCode <getCode>
• eth_getLogs <getLogs>
• eth_sign <sign>
• personal_sign (with auto prefixing and hashing a message)
• net_version
• eth_accounts
• eth_estimateGas

Sync request (use as property):

• eth_gasPrice
• eth_accounts

Ehtereumjs-wallet

For backward compatibility with the Ethereumjs-wallet was designed similar class as ethWallet and hdKey that received a ECHO instance. The access to this classes is echoWeb3Instance.ethereumjsWallet.

Supported methods

All implemented methods have the same signatures of input and output as methods and they were inherited from original library. The list of implemented methods that works with ECHO network:

• hdKey.getPrivateKey() ⇒ Promise.<Buffer> - register account in ECHO network by associated with walletInstance private key and returns private key in buffer.
• walletInstance.getAddress() ⇒ Promise.<String> - call ECHO network with a getting accountId by associated with walletInstance private key. Returns a accountId in ETH address format

Example of code migration from original library

Before

import * as ethWallet from 'ethereumjs-wallet';
import * as hdKey from 'ethereumjs-wallet/hdkey';

...
const DERIVATION_PATH = "m/0'/0'/0'/0";

const hdWallet = hdKey.fromMasterSeed('asdasdahd99wry9834ht93j498');
const wallet = hdWallet.derivePath(DERIVATION_PATH).getWallet();

const privateKey = wallet.getPrivateKey();

const restoredWallet = ethWallet.fromPrivateKey(privateKey);
console.log(`0x${restoredWallet.getAddress().toString('hex')}`) // 0x856A7c355CE3120E4Ae9f98C09e3BD1f9dbaF89E

After

import Web3 from 'web3';
import EchoWeb3, { EchoProvider } from 'echo-web3';
const WrappedWeb3 = EchoWeb3(Web3);

(async () => {
	
	const echoNetwork = 'wss://testnet.echo-dev.io/ws';
	const echoProvider = new EchoProvider(echoNetwork, { assetId: '1.3.0' });
	const web3 = new WrappedWeb3(echoProvider);
	await echoProvider.init();
	
	const { hdKey, ethWallet } = web3.ethereumjsWallet;
	
	const DERIVATION_PATH = "m/0'/0'/0'/0";
	
	const hdWallet = hdKey.fromMasterSeed('asdasdahd99wry9834ht93j498');
	const wallet = hdWallet.derivePath(DERIVATION_PATH).getWallet();
	
	const privateKey = await wallet.getPrivateKey();
	
	const restoredWallet = ethWallet.fromPrivateKey(privateKey);
	console.log(`0x${(await restoredWallet.getAddress()).toString('hex')}`) // 0x0000000000000000000000000000000000000205
})();

Ehtereumjs-tx

For backward compatibility with the Ethereumjs-tx was designed class EthereumjsTx that received a ECHO instance when is created by echoWeb3Instance.EthereumjsTx.

Supported methods

All implemented methods have the same signatures of input and output as methods from original library. The list of implemented methods:

• sign(privateKey: Buffer) ⇒ Promise.<void> - signs created transaction
• serialize() ⇒ Promise.<Buffer> - returns serialized tx

Example of code migration from original library

Before

import Transaction from 'ethereumjs-tx';

...

const template = {
	to: "0x010000000000000000000000000000000000014d",
	from: "0x0000000000000000000000000000000000000189",
	value: '0xDE0B6B3A7640000',
} // contract call

const transaction = new Transaction(template);
transaction.sign(privateKey);
const serializedTxString = `0x${transaction.serialize().toString('hex')}`

web3.sendRawTransaction(serializedTxString, (err, result) => {
	console.log(result); // <txHash>
});

After

import Web3 from 'web3';
import EchoWeb3, { EchoProvider } from 'echo-web3';
const WrappedWeb3 = EchoWeb3(Web3);


(async () => {
	const echoNetwork = 'wss://testnet.echo-dev.io/ws';
	const echoProvider = new EchoProvider(echoNetwork, { assetId: '1.3.0' });
	const web3 = new WrappedWeb3(echoProvider);
	await echoProvider.init();

	const privateKey = Buffer.from(process.env.PRIVATE_KEY, 'hex')
	const template = {
		to: "0x010000000000000000000000000000000000014d",
		from: "0x0000000000000000000000000000000000000189",
		value: '0xDE0B6B3A7640000', // 1 ECHO
	}
	
	const transaction = new web3.EthereumjsTx(template);
	await transaction.sign(privateKey); 
	const serializedTxString = `0x${transaction.serialize().toString('hex')}`
	
	web3.eth.sendRawTransaction(serializedTxString, (err, result) => {
		console.log(result); // <txHash>
	});

})();

Browser page Web3 polyfill

Metamask injects the ethereum object into web page that is Metamask custom provider object with methods as send, sendAsync, enable, on etc.

EchoPolyfill replaces Metamask's ethereum to BridgeProvider instance that has a similar with ethereum methods.

import { EchoPolyfill } from 'echo-web3';

window.addEventListener('load', async () => {
	// Modern dapp browsers...
	await EchoPolyfill();
	const { ethereum } = window;
	if (window.ethereum) {
		window.web3 = new Web3(ethereum);
		// Request account access if needed
		await ethereum.enable();
		// Acccounts now exposed
		window.web3.eth.getBlockNumber((err, res)=>{
			console.log(res) // 2230 ECHO block number
		})
	}
});

Specific ECHO RPC methods

For both providers have been implemented additional JSON RPC methods:

echo_accountKeys

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"eth_coinbase","params":["0x010000000000000000000000000000000000014d"],"id":64}'

// Result
{
  "id":64,
  "jsonrpc": "2.0",
  "result": ["0xe1c964148ede57465478780707a6e1aef12b5ddc47774028166dc67f3bf580ec", "0xa7c964148ede57465478780707a6e1aef12b5ddc47774028166dc67f3bf58022"]
}

License

The MIT License (MIT)

Copyright (c) 2019 Echo Technological Solutions LLC

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.