This plugin can be injected into dai.js to execute atomic trades on Eth2Dai. It uses the contract FKA Oasis Direct Proxy to interact with the underlying Maker OTC contract.

Usage

To configure the SDK with this plugin:

$ yarn add @makerdao/dai
$ yarn add @makerdao/dai-plugin-eth2dai-direct

import Maker from '@makerdao/dai';
import Eth2DaiDirect from '@makerdao/dai-plugin-eth2dai-direct';

const maker = await Maker.create('browser', {
  plugins: [Eth2DaiDirect]
});
await maker.authenticate();
await maker.service('exchange').sell('ETH', 'DAI', '0.5');

Note that the 'browser' preset above is only an example, not a specific requirement of the Eth2Dai Direct plugin. For more information about available presets, configuration options, and additional plugins, check the dai.js docs.

The Eth2DaiDirectService normalizes the syntax across different types of trades, so the main functionality is represented simply by sell and buy. The difference between these two functions is the value defined explicitly as a parameter; for example, a user might want to sell one hundred Dai for however much ETH that Dai can buy.

The valid token symbols for either side of any trade are 'ETH', 'WETH', 'PETH', and 'DAI'.

• sell takes three parameters: the sellToken (string), the buyToken (string), and the amount (string or number)

maker.service('exchange').sell('ETH', 'DAI', '1');

• buy takes three parameters: the buyToken (string), the sellToken (string), and the amount (string or number)

maker.service('exchange').buy('DAI', 'ETH', 150);

The service can also query the OTC contract for the buy amount for a supplied pay amount and the pay amount for a supplied buy amount. If the price of the exchange deviates from this estimate by more than a configurable slippage limit, the trade will be reverted.

• getBuyAmount takes three parameters: buyToken (string), sellToken (string), and sellAmount (string or number)

const amount = await maker.service('exchange').getBuyAmount('DAI', 'ETH', 150);

• getPayAmount takes three paramaters: sellToken (string), buyToken (string), and buyAmount (string or number)

const amount = await maker.service('exchange').getPayAmount('ETH', 'DAI', '1');

• setSlippageLimit takes one parameter: limit (float). The default slippage limit is 0.02, or 2%.

maker.service('exchange').setSlippageLimit(0.05);

Development

$ git clone https://github.com/makerdao/dai-plugin-eth2dai-direct.git
$ cd dai-plugin-eth2dai-direct/
$ yarn
$ git submodule update --init --recursive

• Run tests with yarn test
• Run testnet with yarn test:net. This will run by default with yarn test, but can also run independently
• Build for publication with yarn build