Configuration

Maker.create

You can configure the behavior of Dai.js by passing different arguments to Maker.create. The first argument is the name of a preset, and the second is an options object.

Presets

• 'browser'

  • Use this preset when using the library in a browser environment. It will attempt to connect using window.ethereum or window.web3.

• 'http'

  • Connect to a JSON-RPC node. Requires url to be set in the options.

• 'test'

  • Use a local node (e.g. Ganache) running at http://127.0.0.1:2000, and sign transactions using node-managed keys.

const makerBrowser = await Maker.create('browser');

const makerHttp = await Maker.create('http', {
  url: 'https://kovan.infura.io/v3/YOUR_INFURA_PROJECT_ID'
});

const makerTest = await Maker.create('test');

Options

• privateKey

  • Optional. The private key used to sign transactions. If this is omitted, the first account available from the Ethereum provider will be used. Only used with the 'http' preset.

  • If this is omitted and the provider does not have an unlocked account, the maker object will start in read-only mode.

• url

  • The URL of the node to connect to. Only used with the 'http' preset.

• web3.transactionSettings

  • Object containing transaction options to be applied to all transactions sent through the library.

  • Default value: { gasLimit: 4000000 }

• web3.confirmedBlockCount

  • Number of blocks to wait after a transaction has been mined when calling confirm. See Transactions for further explanation.

  • Default value: 5

• web3.inject

  • For advanced users. You can inject your own custom instance of a Web3 provider with this, instead of using the default HttpProvider.

• log

  • Set this to false to reduce the verbosity of logging.

• autoAuthenticate

  • Set this to false to create the Maker instance without connecting yet. If so, you must run await maker.authenticate() before using any other methods.

// It doesn't necessarily make sense to set all these
// options at the same time (e.g. `url` and `inject`),
// this is just meant to illustrate the shape of the
// options object.
const maker = await Maker.create('http', {
  privateKey: YOUR_PRIVATE_KEY, // '0xabc...'
  url: 'http://some-ethereum-rpc-node.net',
  web3: {
    statusTimerDelay: 2000,
    confirmedBlockCount: 8
    transactionSettings: {
      gasPrice: 12000000000
    },
    inject: someProviderInstance
  },
  log: false,
  autoAuthenticate: false
});

Instance methods

service()

• Returns: service object

Return a service instance that was included in this instance of maker.

const accountsService = maker.service('accounts');

Services

The MCD plugin defines several services for working with Multi-Collateral Dai. Review Getting started to see how to add the plugin.

• 'mcd:cdpManager': for working with Vaults.

• 'mcd:cdpType': for reading parameters and live data (totals and prices) for collateral types.

• 'mcd:savings': for working with the Dai Savings Rate.

• 'mcd:systemData': for reading system-wide parameters.

Read-only mode

As mentioned above, the Maker instance can be used in read-only mode, if you just want to read data from the blockchain without signing any transactions. Simply omit the privateKey option.

You can start in read-only mode and still add an account with the ability to sign transactions later on.