js-multiaddr

multiaddr implementation in JavaScript.

Usage

In Node.js through npm

> npm install multiaddr --save

const multiaddr = require('multiaddr')

In the Browser through Webpack

Same as in Node.js, you just have to transpile it with Webpack before serving the code. Follow the webpack config example.

In the Browser through browserify

Same as in Node.js, you just have to browserify the code before serving it. See the browserify repo for how to do that.

In the Browser through <script> tag

Make the multiaddr.js available through your server and load it using a normal <script> tag, this will export the multiaddr on the window object, such that:

const multiaddr = window.multiaddr

Gotchas

You will need to use Node.js Buffer API compatible, if you are running inside the browser, you can access it by multiaddr.Buffer or you can install Feross's Buffer.

Examples

Simple

const multiaddr = require('multiaddr')
const addr = multiaddr("/ip4/127.0.0.1/udp/1234")
// <Multiaddr /ip4/127.0.0.1/udp/1234>
addr.buffer
// <Buffer >
addr.toString()
// /ip4/127.0.0.1/udp/1234

// construct with Buffer
addr = multiaddr(addr.buffer)
// <Multiaddr /ip4/127.0.0.1/udp/1234>

Protocols

// get the multiaddr protocol codes
addr.protoCodes()
// [4, 6]

// get the multiaddr protocol string codes
addr.protoNames()
// ['ip4', 'tcp']

// get the multiaddr protocol description objects
addr.protos()
// [{code: 4, name: 'ip4', size: 32},
//  {code: 17, name: 'udp', size: 16}]

Other formats

// get a node friendly address object
addr.nodeAddress()
// {family: "IPv4", port:1234, address: "127.0.0.1"} - note no UDP :(
addr.fromNodeAddress({family: "IPv4", port:1234, address: "127.0.0.1"}, 'udp')
// /ip4/127.0.0.1/udp/1234

// handles the stupid string version too
addr = multiaddr.fromStupidString("udp4://127.0.0.1:1234")
// <Multiaddr /ip4/127.0.0.1/udp/1234>
addr.toStupidString(buf)
// udp4://127.0.0.1:1234

En/decapsulate

addr.encapsulate('/sctp/5678')
// <Multiaddr /ip4/127.0.0.1/udp/1234/sctp/5678>
addr.decapsulate('/udp') // up to + inc last occurrence of this subaddr
// <Multiaddr /ip4/127.0.0.1>

Tunneling

Multiaddr allows expressing tunnels very nicely.

const printer = multiaddr('/ip4/192.168.0.13/tcp/80')
const proxy = multiaddr('/ip4/10.20.30.40/tcp/443')
const printerOverProxy = proxy.encapsulate(printer)
// <Multiaddr /ip4/10.20.30.40/tcp/443/ip4/192.168.0.13/tcp/80>

const proxyAgain = printerOverProxy.decapsulate('/ip4')
// <Multiaddr /ip4/10.20.30.40/tcp/443>