@rtoken/utils

Easy to use library for fetching rDAI / rToken data for your Dapp.

What does it do?

This library wraps the rDAI subgraph, so you can make simple calls. It supports rDAI on Mainnet, Kovan, but you can also bring your own subgraph.

const user = rutils.user("0xaaa...");
console.log(await user.interestSentTo("0xbbb..."));
// > 1.230495
console.log(await user.interestReceivedList());
// >
[
  {
    sender: "0x0efe994201e2b0136dd40d5033b5f437e4c5f958", // Who sent the interest
    amount: "100.000000000000000000", // Amount of rDAI the sender is using to generate interest for this user
    interestRedeemed: "0.07179777866578322382540442607287171", // Amount of rDAI this user has redeemed from the sender
    interestSent: 2.683831612180583, // Sum of interestRedeemd and all outstanding interest (unredeemed) from the sender
    sInternal: "10.000000012701007569669278674669046802622" // Internal Savings Asset for this loan
  }
];

Getting started

1. Connect to the Data :raised_hands: :rainbow:

This will be your connection to the rToken subgraph, which provides the blockchain data. Use the helper function to set it up, or see Using your own Apollo client.

import {getClient} from "@rtoken/utils";

const apolloInstance = getClient(); // Defaults to mainnet/homestead

// OR

const apolloInstance = getClient({network: "kovan"});

Available options:

| option | default | description | | --------- | --------- | ------------------------------------------- | | network | homestead | Must be homestead or kovan | | url | n/a | Useful if you have your own custom subgraph | | debug | false | Display logs on Apollo errors |

You also need an Ethers.js v5 web3 provider instance. If you only care about the interest that's actually been redeemed, then you do not need this.

import {InfuraProvider} from "@ethersproject/providers";

const web3Provider = new InfuraProvider("kovan", process.env.INFURA_KEY);

2. Instantiate the @rtoken/utils library

Pass the apolloInstance to create the RTokenUtils object.

import RTokenUtils, {getClient} from "@rtoken/utils";

const rutils = new RTokenUtils(apolloInstance, web3Provider, {
  network: "kovan"
});

Available options:

| option | default | description | | --------- | --------- | -------------------------- | | network | homestead | Must be homestead or kovan | | debug | false | Display logs |

3. Create and use your entities

Create User and Hat objects

// Users
const user = rutils.user("0xabc...123");
const userDetails = await user.details();

// Hats
const myHat = rutils.hat(11);
const allUsers = await myHat.allUsers();

If you have any questions, please contact us via Discord.

API

Major Entities

rutils.user(address)

rutils.hat(hatID)

:bust_in_silhouette: User

If you are not using a Web3 Provider, then you must always set redeemedOnly to true.

When redeemedOnly is true the response will only include the amount of redeemed interest. The list response (eg. interestSentList) will not include interestSent.

user.details()

Returns details about an account, including balance.

user.interestSentTo(recipient[, redeemedOnly])

Returns amount of interest sent from the user to a recipient.

| Argument | Type | default | | :----------- | :------ | -------- | | recipient | Address | required | | redeemedOnly | Boolean | false |

user.interestSentList([redeemedOnly])

Returns a list of every recipient the user has ever sent interest to.

| Argument | Type | default | | :----------- | :------ | ------- | | redeemedOnly | Boolean | false |

example return value:

[
  {
    "amount": "100.000000000000000000", // current amount of rDAI pointed at the recipient
    "interestRedeemed": "0.07179777866578322382540442607287171",
    "recipient": "0x0efe994201e2b0136dd40d5033b5f437e4c5f958",
    "sInternal": "10.000000012701007569669278674669046802622", //
    "interestSent": 2.683831612180583 // Only included if redeemedOnly is false
  }
  //...
]

user.interestSentSum([redeemedOnly])

Returns the sum of all interest from the method interestSentList().

| Argument | Type | default | | :----------- | :------ | ------- | | redeemedOnly | Boolean | false |

user.interestReceivedList([redeemedOnly])

Returns a list of every sender which has ever sent interest to the user.

| Argument | Type | default | | :----------- | :------ | ------- | | redeemedOnly | Boolean | false |

Return value is similar to interestSentList()

user.interestReceivedSum([redeemedOnly])

Returns amount of interest received.

| Argument | Type | default | | :----------- | :------ | ------- | | redeemedOnly | Boolean | false |

:tophat: Hat

• hat.allUsers()

Price / Compound Rate data

getCompoundRate()

Returns the current interest rate for DAI on Compound using the Compound API.

Example:

import {getCompoundRate} from "@rtoken/utils";
const {
  rate, // 0.0015121234345343435345
  formattedRate // 15.12
} = getCompoundRate();

getCompoundRateAtBlock()

Returns the interest rate at a specific block for DAI on Compound using the Compound API.

getEthPrice(web3Provider)

Returns the current Ethereum price in DAI, using the Medianizer Contract. A Web3 Provider is required.

Additional options

Using your own Apollo client

This might be helpful if you want more control over the apollo-client, such as custom caching options or authentication of a private client. See /src/utils/client for how we instantiate the client.

const {ApolloClient} = require("apollo-client");
const {InMemoryCache} = require("apollo-cache-inmemory");
const {HttpLink} = require("apollo-link-http");
const fetch = require("cross-fetch");

const cache = new InMemoryCache();
const link = new HttpLink({
  uri: "http://localhost:4000/",
  fetch
});

const apolloInstance = new ApolloClient({
  link,
  cache,
  onError: e => {
    console.log(e);
  },
  defaultOptions: {
    query: {
      fetchPolicy: "network-only"
    }
  }
});

const rutils = new RTokenUtils(apolloInstance);

Developing

After installing packages, run the command yarn get-abi to pull in the latest contract abis from @rtoken/contracts

Contributing

Contributions, suggestions, and issues are welcome. At the moment, there are no strict guidelines to follow.