README.md

peggedassets-server

How to list a new pegged asset

1. Fork this repository.
2. npm i in root folder.
3. Create folder in src/adapters/peggedAssets with the same name as the CoinGecko id for the pegged asset.
4. In that folder, write an adapter in Typescript and name it index.ts (see below for spec).
5. In src/adapters/peggedAssets, npm i and then test your adapter with npx ts-node test YOURPEGGEDASSET/index peggedXYZ, where "peggedXYZ" is the key of the balance object returned by your adapter. or npx ts-node --transpile-only test.ts YOURPEGGEDASSET peggedXYZ
6. Import your adapter in src/adapters/peggedAssets/index.ts and then add it to the exports.
7. (Optional) if the pegged asset has a ChainLink price feed or a liquid Uniswap V3 pool, you can add the ChainLink smart contract/Uniswap V3 pool info to src/adapters/peggedAssets/prices/index.ts.

After submitting a PR, you can submit basic info about the pegged asset (website, ticker, icon, etc.) in the Defillama Discord.

Pegged asset adapters

An adapter is a Typescript file that exports an object in the following format:

const  adapter: PeggedIssuanceAdapter = {
  [chain1]: {
    minted: async fn,
    unreleased: async fn,
    [bridgedFromChain1]: async fn,
    [bridgedFromChain2]: async fn,
    .
    .
  },
  [chain2]: {
    minted: async fn,
    unreleased: async fn,
  },
.
.
}

The minted and unreleased properties are required to be present on every chain object. minted means pegged assets that have been issued on that chain (not bridged from anywhere). unreleased means pegged assets that are in a reserve wallet and have never been circulating. If either of these are 0, you can use async () => ({}).

The bridgedFromChain properties are optional. The property name should simply be the name of the chain the pegged assets are bridged from.

The async functions should take timestamp, ethBlock, and chainBlocks as parameters, just like Defillama TVL Adapters. They must return an object { peggedXYZ: x }, where peggedXYZ is a supported pegged asset type, and x is a Number. Currently we support peggedUSD, peggedEUR,peggedVAR (variable peg) and more you can see the full list here https://github.com/DefiLlama/peggedassets-server/blob/master/src/adapters/peggedAssets/peggedAsset.type.ts#L7 If we are not supporting a particular peggedTYPE, please inform us on discord.

Here is an example adapter:

const sdk = require("@defillama/sdk");
import {
  ChainBlocks,
  PeggedIssuanceAdapter,
} from "../peggedAsset.type";

const chainContracts = {
    ethereum: {
        issued: "0x853d955acef822db058eb8505911ed77f175b99e",
    },
    bsc: {
        bridgedFromETH: "0x90c97f71e18723b0cf0dfa30ee176ab653e89f40",
    },
};

async function ethereumMinted() {
return async function (
    _timestamp: number,
    _ethBlock: number,
    _chainBlocks: ChainBlocks
) {
    const totalSupply = (
      await sdk.api.abi.call({
        abi: "erc20:totalSupply",
        target: chainContracts.ethereum.issued,
        block: _ethBlock,
        chain: "ethereum",
      })
    ).output;
    return { peggedUSD: totalSupply / 10 ** 18 };
  };
}

async function bridgedFromEthereum(chain: string, decimals: number, address: string) {
return async function (
    _timestamp: number,
    _ethBlock: number,
    _chainBlocks: ChainBlocks
) {
    const totalSupply = (
      await sdk.api.abi.call({
        abi: "erc20:totalSupply",
        target: address,
        block: _chainBlocks[chain],
        chain: chain,
      })
    ).output;
    return { peggedUSD: totalSupply / 10 ** decimals };
  };
}

const adapter: PeggedIssuanceAdapter = {
  ethereum: {
    minted: ethereumMinted(),
  },
  bsc: {
    ethereum: bridgedFromEthereum("bsc", 18, chainContracts.bsc.bridgedFromETH),
  },
};

export default adapter;

Running the Server

If you want to run your own copy of this server on AWS:

npm run build # Build with webpack & check for type errors
npm run format # Format code

aws configure
serverless deploy