This library is now deprecated. Please use https://github.com/Synthetixio/js-monorepo/tree/master/packages/contracts-interface from our new monorepo.

SynthetixJs library

The Synthetix-JS Library provides a simple pre-packaged API to communicate with Synthetix on ethereum. You can use it to contribute to DeFi's growing synthetic asset ecosystem.

This is particularly useful for hackathon teams to quickly npm install synthetix-js and start building in just a few minutes.

Under the hood, SynthetixJs uses ethers.js library and its concept of providers and transaction signers.

Install via npm

npm install synthetix-js

Developer Docs

developer.synthetix.io

Example for getting the total sUSD stablecoin in circulation

const { SynthetixJs } = require('synthetix-js');
const snxjs = new SynthetixJs(); //uses default ContractSettings - ethers.js default provider, mainnet
(async function() {
  const totalSUSD = await snxjs.sUSD.totalSupply();
  const totalSUSDSupply = snxjs.utils.formatEther(totalSUSD);
  console.log('sUSDTotalSupply', totalSUSDSupply);
})();

Default settings don't use any signer. That means that constants can be viewed from the contract but executing a transaction will fail. To execute transactions, set up signer.

4 signers are included in the library - Metamask (compatible with Dapp browsers), Trezor, Ledger and PrivateKey. Custom ethers.js compatible signers can be used too.

Example using a metamask signer

const { SynthetixJs } = require('synthetix-js');
const metaMaskSigner = new SynthetixJs.signers.Metamask();
const snxjs = new SynthetixJs({ signer: metaMaskSigner }); //uses Metamask signer and default infura.io provider on mainnet

Example of minting stablecoin(sUSD) with private key signer

const { SynthetixJs } = require('synthetix-js');
//parameters: default provider, default networkId, private key as a string
const signer = new SynthetixJs.signers.PrivateKey(
  null,
  0,
  '0x0123456789012345678901234567890123456789012345678901234567890123'
);
const snxjs = new SynthetixJs({ signer });

async function run() {
  const totalSupply = await snxjs.Synthetix.totalSupply();
  const snxTotalSupply = snxjs.utils.formatEther(totalSupply);
  console.log('snxTotalSupply', snxTotalSupply);

  //issue 100 synths (will throw if insufficient funds for gas)
  try {
    const txObj = await snxjs.Synthetix.issueSynths(snxjs.util.parseEther('100')); //execute transaction (requires gas)
    console.log('transaction hash', txObj.hash);
  } catch (e) {
    console.log(e);
  }
}

run();

Live examples

• Get total synth supply
• Get collateralized state

Got any questions?

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