# Ethereum JavaScript API
This is the Ethereum compatible JavaScript API using `Promise` s
which implements the [Generic JSON RPC ](https://github.com/ethereum/wiki/wiki/Generic-JSON-RPC ) spec. It's available on npm as a node module and also for bower and component as an embeddable js
[![NPM version][npm-image]][npm-url] [![Build Status][travis-image]][travis-url] [![dependency status][dep-image]][dep-url] [![dev dependency status][dep-dev-image]][dep-dev-url]
[![browser support ](https://ci.testling.com/ethereum/ethereum.js.png )](https://ci.testling.com/ethereum/ethereum.js)
## Installation
### Node.js
npm install ethereum.js
### For browser
Bower
bower install ethereum.js
Component
component install ethereum/ethereum.js
* Include `ethereum.min.js` in your html file.
* Include [es6-promise ](https://github.com/jakearchibald/es6-promise ) or another ES6-Shim if your browser doesn't support ECMAScript 6.
## Usage
Require the library:
var web3 = require('web3');
Set a provider (QtProvider, WebSocketProvider, HttpRpcProvider)
var web3.setProvider(new web3.providers.WebSocketProvider('ws://localhost:40404/eth'));
There you go, now you can use it:
```
web3.eth.coinbase.then(function(result){
console.log(result);
return web3.eth.balanceAt(result);
}).then(function(balance){
console.log(web3.toDecimal(balance));
}).catch(function(err){
console.log(err);
});
```
For another example see `example/index.html` .
## Building
* `gulp build`
### Testing
**Please note this repo is in it's early stage.**
If you'd like to run a WebSocket ethereum node check out
[go-ethereum ](https://github.com/ethereum/go-ethereum ).
To install ethereum and spawn a node:
```
go get github.com/ethereum/go-ethereum/ethereum
ethereum -ws -loglevel=4
```
[npm-image]: https://badge.fury.io/js/ethereum.js.png
[npm-url]: https://npmjs.org/package/ethereum.js
[travis-image]: https://travis-ci.org/ethereum/ethereum.js.svg
[travis-url]: https://travis-ci.org/ethereum/ethereum.js
[dep-image]: https://david-dm.org/ethereum/ethereum.js.svg
[dep-url]: https://david-dm.org/ethereum/ethereum.js
[dep-dev-image]: https://david-dm.org/ethereum/ethereum.js/dev-status.svg
[dep-dev-url]: https://david-dm.org/ethereum/ethereum.js#info=devDependencies