uport-lib

Introduction

Uport is a system for self-sovereign digital identity.

This is the client side library that is used to interact with the mobile application where the end-user's keys are stored.

Signing transactions thus requires that the transactions are sent to the phone where they can be signed. This is accomplished by showing the user a QR-code for each transaction. The user can then verify the transaction on the phone and send it to the Ethereum network.

In order to make this flow easy for developers, uport-lib provides a custom web3 provider which takes care of all of this.

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Using uPort in your dapp

Getting Started

First we will instantiate the Uport and Web3 objects. Then we will get the information of the connected user. Since the information of the connected user is stored on ipfs we need to provide uport-lib with an ipfs provider upon on creation of Uport instance. Here we use Infura as an example.

import { Uport } from 'uport-lib'

let uport = new Uport('MyDApp')
let web3 = uport.getWeb3()

uport.getUserPersona()
     .then((persona) => {
       let profile = persona.profile
       console.log(profile)
     })

After the above setup, you can now use the web3 object as normal.

Also, the following calls will show a QR code for the user to scan:

• web3.eth.getCoinbase() - returns your uport address
• web3.eth.getAccounts()- returns your uport address in a list
• web3.eth.sendTransaction(txObj) - returns a transaction hash
• myContract.myMethod() - returns a transaction hash

Check out the examples folder too for how to integrate uport in your DApp

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Custom Display of QR codes

uport-lib features a default QR-code display function, which injects a <div> containing the QR-code into the DOM. However, you might want to display the QR-code in a different way.

You can provide a qrDisplay object with two functions when uport is created. The openQr function is called when the user needs to confirm something on the uport app. The data argument is a uri that needs to be displayed in a QR-code so that the uport app can scan it. The closeQr function is called when the action has been confirmed in the uport app and the QR-code can be removed from the screen.

let options = {
  qrDisplay: {
    openQr(data) { // your code here },
    closeQr() { // your code here }
  }
}

The openQr function is called each time some information needs to get to the phone.

The closeQr is called once the phone has taken an action on the data in the QR-code.

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Interacting with persona objects of other users

You can also import the Persona classes from uport lib to interact with any persona in the uport-registry.

uport.getUserPersona()
     .then((persona) => {
       let profile = persona.profile
       console.log(profile)
     })

More information on how to use personas can be found in the uport-persona repo, or by reading the documentation below.

Contributing

Testing / Building (& watching) / Docs

This basic commands can be found in package.json -> scripts: { } for contributing to the library.