PREVIEW RELEASE This is a beta preview release with breaking changes! The current stable version is 0.20.0

This is the Ethereum JavaScript API which connects to the Generic JSON RPC spec.

You need to run a local or remote Ethereum node to use this library.

Please read the documentation for more.

npm install web3

Note: works only in the Browser for now. (PRs welcome)

meteor add ethereum:web3

Use the prebuild dist/web3.min.js, or build using the web3.js repository:

npm run-script build

Then include dist/web3.js in your html file. This will expose the Web3 object on the window object.

// in node.js
var Web3 = require('web3');

var web3 = new Web3('ws://localhost:8546');
console.log(web3);
> {
    eth: ... ,
    shh: ... ,
    utils: ...,
    ...
}

Additionally you can set a provider using web3.setProvider() (e.g. WebsocketProvider)

web3.setProvider('ws://localhost:8546');
// or
web3.setProvider(new Web3.providers.WebsocketProvider('ws://localhost:8546'));

There you go, now you can use it:

web3.eth.getAccounts()
.then(console.log);

Documentation can be found at read the docs

• Node.js
• npm

sudo apt-get update
sudo apt-get install nodejs
sudo apt-get install npm

Build only the web3.js package

npm run-script build

Or build all sub packages as well

npm run-script build-all

This will put all the browser build files into the dist folder.

npm test

• Gitter
• Forum

• Python Web3.py
• Haskell hs-web3
• Java web3j