Libra Core

Libra Core is a javascript library client that can be used to interact with libra nodes. It is built using typescript.

This is still under heavy testing, so please report any issues that you might encounter using it.

The end goal is to make it usable both in node and on browser clients too, but currently it is mostly compatible with node.

Table of Content

• Prepare
• Installation
• Usage
  • Creating an Account
  • Minting Amount
  • Checking an address balance
  • Transferring Libra Coins
  • Executing Transactions with Custom Program
  • Query Transaction with Sequence Number
• Development
• Contribution
• License

Prepare

• Node ^v12.0.0 is required for sha3-256. You can use nvm to download/use node v12 by following.

nvm install 12
nvm use 12

Installation

To install with npm run:

npm install libra-core

Usage

You would most likely interact with these two modules

import { LibraWallet, LibraClient } from 'libra-core';

Creating an Account

In order to create a libra account, you would need to instantiate the LibraWallet like:

// you may need to use require for node
import { LibraWallet, Account as LibraAccount } from 'libra-core';

// please don't use this mnemonic outside of this sample code
// also mnemonics are optional. If you don't specify one a random mnemonic is generated and used.
const wallet = new LibraWallet({
        mnemonic: 'upgrade salt toy stable drop paddle'
      });

// generate a new account
const account = wallet.newAccount();

// or if you have your secret key you can create an account from it
// const secretKey = 'pub-hex-secret-key-here' 
// const account = LibraAccount.fromSecretKey(secretKey);


// you can see your address by:
console.log(account.getAddress().toHex());

Minting Amount

Currently minting only works for testnet and uses the faucet service.

To mint you need to create a LibraClient and use it to mint

import { LibraClient, LibraNetwork } from 'libra-core';

async function main() {
  const client = new LibraClient({ network: LibraNetwork.Testnet });

  const account = wallet.newAccount();

  // mint 2 libracoins to users accounts
  await client.mintWithFaucetService(account.getAddress(), 20e6);
}

await main();

Checking an address balance

async function main() {
  const client = new LibraClient({ network: LibraNetwork.Testnet });

  const accountAddress = '854563c50d20788fb6c11fac1010b553d722edb0c02f87c2edbdd3923726d13f';
  const accountState = await client.getAccountState(accountAddress);

  // log account balance
  console.log(accountState.balance.toString());

  // Account state has other information that you could be interested in such as `sequenceNumber`.
}

await main();

Transferring Libra Coins

async function main() {
  const client = new LibraClient({ network: LibraNetwork.Testnet });
  const wallet = new LibraWallet({
    mnemonic:
     'lend arm arm addict trust release grid unlock exhibit surround deliver front link bean night dry tuna pledge expect net ankle process mammal great',

  });
  const account = wallet.newAccount();
  const account2Address = '854563c50d20788fb6c11fac1010b553d722edb0c02f87c2edbdd3923726d13f';
  const response = await client.transferCoins(account, account2Address, 1e6);

  // wait for transaction confirmation
  await response.awaitConfirmation(client);
}

await main();

Executing Transactions with Custom Program

You can execute a program using client.execute() take a look at how client.transferCoins() uses it for transfer transactions. You are welcome to help contribute to making this documentation better.

Query Transaction with Sequence Number

async function main() {
  const client = new LibraClient({ network: LibraNetwork.Testnet });
  const accountAddress = '7f58df27522872ecfac340c5c072427e6f8083ca3c79bb748cdd1ae073dacc42';
  const sequenceNumber = 43; //can also use a string for really large sequence numbers;

  const transaction = await client.getAccountTransaction(accountAddress, sequenceNumber);
}

await main();

Development

• Clone the repository
• Run npm install to install the dependency
• Test with npm test
• You might need to run npm install -g grpc-tools if you want to regenerate protobuffer classes

Contribution

• If you notices a bug or anomaly, please open an issue to track it.
• If you intend on working on a feature that doesn't have an issue yet. Please open an issue first so we can track its progress together.

License

MIT