web3.js version 0.14.0 supports multiple instances of web3 object. To migrate to this version, please follow the guide:
-var web3 = require('web3');
+var Web3 = require('web3');
+var web3 = new Web3();
This is the Ethereum compatible JavaScript API which implements the Generic JSON RPC spec. It's available on npm as a node module, for bower and component as an embeddable js and as a meteor.js package.
You need to run a local Ethereum node to use this library.
npm install web3yarn add web3meteor add ethereum:web3CDN
<script src="https://cdn.jsdelivr.net/gh/ethereum/web3.js/dist/web3.min.js"></script>Bower
bower install web3Component
component install ethereum/web3.jsweb3.min.js in your html file. (not required for the meteor package)Use the web3 object directly from global namespace:
console.log(web3); // {eth: .., shh: ...} // it's here!Set a provider (HttpProvider)
if (typeof web3 !== 'undefined') {
web3 = new Web3(web3.currentProvider);
} else {
// set the provider you want from Web3.providers
web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));
}Set a provider (HttpProvider using HTTP Basic Authentication)
web3.setProvider(new web3.providers.HttpProvider('http://' + BasicAuthUsername + ':' + BasicAuthPassword + '@localhost:8545'));There you go, now you can use it:
var coinbase = web3.eth.coinbase;
var balance = web3.eth.getBalance(coinbase);You can find more examples in example directory.
- Node.js
- npm
sudo apt-get update
sudo apt-get install nodejs
sudo apt-get install npm
sudo apt-get install nodejs-legacynpm run-script buildnpm test- Python Web3.py
- Haskell hs-web3
- Java web3j
- Scala web3j-scala
- Purescript purescript-web3
- PHP web3.php
- PHP ethereum-php