Convenience package for discovering and buying assets on-chain and off-chain.

Usage no npm install needed!

<script type="module">
  import 0xKlaytnAssetSwapper from 'https://cdn.skypack.dev/@0x-klaytn/asset-swapper';



Convenience package for swapping assets represented on the Ethereum blockchain using 0x. The package helps to perform all the off-chain computations to execute a marketBuy or marketSell function execution with 0x exchange contracts, or 0x extension contracts. Given some liquidity (0x signed orders), it helps estimate the cost of buying or selling a certain asset (giving a range) and then provide varying consumable outputs to execute the buy or sell.

Asset-swapper integrates with the Standard Relayer API(in the future Mesh as well) and takes care of sourcing liquidity, order-pruning, and order-validation. The final result is a library that tells you what assets are available, provides a quote based on specified assets, and provide varying consumable metadata that can be used both on-chain in smart contracts or off-chain through web3 to swap a desired amount of ERC20 for another ERC20 asset.


yarn add @0x-klaytn/asset-swapper


import { SwapQuoter } from '@0x-klaytn/asset-swapper';


var SwapQuoter = require('@0x-klaytn/asset-swapper').SwapQuoter;
var SwapQuoteConsumer = require('@0x-klaytn/asset-swapper').SwapQuoteConsumer;

If your project is in TypeScript, add the following to your tsconfig.json:

"compilerOptions": {
    "typeRoots": ["node_modules/@0x/typescript-typings/types", "node_modules/@types"],


We welcome improvements and fixes from the wider community! To report bugs within this package, please create an issue in this repository.

Please read our contribution guidelines before getting started.

Install dependencies

If you don't have yarn workspaces enabled (Yarn < v1.0) - enable them:

yarn config set workspaces-experimental true

Then install dependencies

yarn install


To build this package and all other monorepo packages that it depends on, run the following from the monorepo root directory:

PKG=@0x-klaytn/asset-swapper yarn build

Or continuously rebuild on change:

PKG=@0x-klaytn/asset-swapper yarn watch


yarn clean


yarn lint

Run Tests

yarn test