MetaMask

Note

A Web (HTTP(S)) server is required also for local development: due to browser security restrictions, MetaMask can’t communicate with dapps running on file://. Please use a local server for development.

Installing MetaMask

Install MetaMask from here or by opening the extension management in your browser.

Install MetaMask for Chrome, Firefox or Opera

MetaMask with Ganache CLI

Generate a new seed phrase or import one:

Importing a seed phrase in MetaMask

Create a total of 6 accounts:

Create an account

At the end, you should see your list of accounts switchable by clicking the top right account logo:

List of switchable accounts

Connect to the locally running Ganache CLI test blockchain at http://localhost:8545:

Connecting to Ganache CLI

MetaMask with Ganache GUI

Start Ganache GUI, copy and import the seed phrase into MetaMask:

Importing Ganache GUI seedphrase in MetaMask

Connect to the locally running Ganache CLI test blockchain at http://localhost:7545:

Connecting to Ganache CLI

Creating XBR Test Accounts

For testing, create the following accounts in MetaMask:

Account	Actor / Stakeholder
Account 1	The XBR project
Account 2	XBR Market Maker M1
Account 3	XBR Data Provider P1
Account 4	XBR Data Provider P2
Account 5	XBR Data Consumer C1
Account 6	XBR Data Consumer C2

Account 1 (The XBR project) is used to deploy the XBR Protocol smart contracts.

Account 2 (XBR Market Maker M1) will call smart contract functions:

• XBRNetwork.register to register in the XBR network

• XBRNetwork.open_market to open a new market

Account 3/4 (XBR Data Provider P1/P2) will call smart contract functions:

• XBRNetwork.register to register in the XBR network

• XBRNetwork.join_market to join a market, depositing an amount of XBR token as a security and for the market maker to open a payment channel with this data provider

• XBRNetwork.request_channel to request a payment channel receiving money from the market maker, depositing an amount of XBR token. this returns a new XBRPaymentChannel SC

• XBRPaymentChannel.close to close a payment channel.

Select Account 5/6 (XBR Data Consumer C1/C2) will call smart contract functions:

• XBRNetwork.register to register in the XBR network

• XBRNetwork.join_market to join a market, depositing an amount of XBR token as a security

• XBRNetwork.open_channel to open a payment channel, depositing an amount of XBR token. this returns a new XBRPaymentChannel SC

• XBRPaymentChannel.close to close a payment channel.

Call Structure and Control Flow

Typically, a Dapp written in JavaScript using XBR and MetaMask will have the following call structure when submitting a transaction to the blockchain:

1. User ---(click)--->

2. Your app (JavaScript in browser) ---(call)--->

3. xbr.js / web3.js (injected) ---(call)--->

4. MetaMask ---(user dialog)--->

5. User ---(click)--->

6. MetaMask ---(http)--->

7. Infura ---(native etherum protocol)--->

8. Ethereum Mainnet (the set of worldwide public nodes)