Descent Library

Descent SDK is a Typescript library that makes it easy to build applications on top of Descent's multi-currency Stablecoin System. You can use Descent's contracts to open Collateralized Debt Positions, withdraw loans in xNGN, trade tokens on Onboard Exchange, and more.

The library features a pluggable, service-based architecture, which allows users maximal control when integrating the Descent protocol's functionality into existing infrastructures. It also includes convenient configuration presets for out-of-the-box usability, and support for both front-end and back-end applications.

Descent's entire suite of contracts will eventually be accessible through this library—including the DAO governance and the current alpha version is limited to the following areas:

• Managing Vault Positions
• Locking and unlocking collateral
• Withdrawing and repaying xNGN
• Automated token conversions
• Buying and selling $DSN and $xNGN with built-in DEX integration

TODO

• ✅ Improve presets and configuration settings
• ✅ Make configuration services oriented
• ✅ Perform getters using MultiStaticCall in the protocol-periphery contract to interact with the VaultGetter contract
• ✅ Perform state change calls using the VaultRouter protocol-periphery contract
• [ ] Enable listening of events for state changes
• [ ] Add functionality for automated token conversions (V2)
• [ ] Add functionality for buying and selling of $DSN and $xNGN in DEXs (V2)
• [ ] Add USD onramp and xNGN offramp functionalities (V2)

Installation

Install the package with npm in your terminal:

npm install @descent-protocol/sdk

Once it's installed, import the module into your project as shown below.

import Descent from '@descent-protocol/sdk';
// or
const Descent = require('@descent-protocol/sdk');

UMD

This library is also usable as a browser module

<script src="./descent.js" />

<script>
  // once the script loads, window.Descent is available
</script>

Quick examples

Look up information about a vault

This code uses getVaultInfo to look up a vault that was created in the Descent protocol UI. Since this code is only reading data, not creating any transactions, it is not necessary to provide a private key or connect a wallet.

// you provide these values
const infuraKey = 'your-infura-api-key';
const ownerAddress = '0xf00...';

const descent = await Descent.create('https', {
  url: `https://mainnet.infura.io/v3/${infuraKey}`
  collateral: 'USDC'
});

const vaultInfo = descent.getVaultInfo(ownerAddress);

console.log(
  vault.depositedCollateral, // amount of collateral tokens deposited
  vault.collateralLocked, // amount of collateral locked in the system
  vault.borrowedAmount, // amount of currency(xNGN) debt
  vault.accruedFees, // amount of fees accrued by the vault
  vault.currentCollateralRatio, // collateralValue  to debt ratio
  vault.healthFactor, // vaults health factor to determine liquidatable status
  vault.availableCollateral, // amount of collateral in the system available
  vault.availablexNGN, // amount of xNGN in the system ready to be minted
  vault.currentRate, // current accumulated rate of vault
);

Descent.create

You can configure the behavior of descent.js by passing different arguments to Descent.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. Make sure you pass in the connected browser provider instance

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

const descentBrowser = await Descent.create('browser');

const descentHttp = await Descent.create('httpsRA_PROJECT_ID'
});

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

• url

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

• ethereum

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

// 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 descent = await Descent.create('https', {
  privateKey: YOUR_PRIVATE_KEY, // '0xabc...'
  url: 'http://some-ethereum-rpc-node.net',
  ethereum: someProviderInstance
  },
});

API Reference

1. Methods

   • 1. getVaultInfo(ownerAddress: string)
   • 2. setupVault()
   • 3. getVaultSetupStatus()
   • 4. depositCollateral(collateralAmount: string)
   • 5. borrowCurrency(borrowAmount: string)
   • 6. repayCurrency(amount: string)
   • 7. withdrawCollateral(collateralAmount: string)
   • 8. getCollateralInfo()

2. UTILITY METHODS

   • 1. getCollateralTokenBalance(ownerAddress: string)
   • 2. approveCollateral(amount: string)
   • 3. getxNGNBalance(ownerAddress: string)
   • 4. approvexNGN(amount: string)

methods

getVaultInfo

descent.getVaultInfo(ownerAddress: string): Promise<{}>

Gets detailed information about a vault specified by the owner's address.

Parameters

• `ownerAddress``: The owner's address of the vault.

Returns:

• A promise resolving to the vault information.

    {
      healthFactor: 'Safe',
      depositedCollateral: 670000000n,  // returns in 6 decimals - 1e6
      collateralLocked: 227255070n,  // returns in 6 decimals - 1e6
      borrowedAmount: 187391000000000000000000n,  // returns in 18 decimals - 1e18
      accruedFees: 94431149147375637960n,  // returns in 18 decimals - 1e18
      currentCollateralRatio: 25439000155922303400n,  // returns in 18 decimals - 1e18
      availableCollateral: 442744930n,  // returns in 6 decimals - 1e6
      availablexNGN: 365264568850852624362040n  // returns in 18 decimals - 1e18
    }

setupVault

descent.setupVault(): Promise<{}>

Initializes a vault for a first time user and sets up the appropriate configuration for the vault on the ssmart contract

Returns:

• A promise resolving to the transaction object.

getVaultSetupStatus

descent.getVaultSetupStatus(): Promise<{}>

Checks if a vault has already been initialized for the connected address or owner.

Returns:

• A boolean.

depositCollateral

descent.depositCollateral('100'): Promise<{}>

Deposits USDC for a particular vault.

Parameters

• collateralAmount: The amount of unlocked collateral to deposit.

Returns:

• A promise resolving to the transaction object.

borrowCurrency

descent.borrowCurrency('10000'): Promise<{}>

Borrows xNGN against deposited USDC.

Parameters

• borrowAmount: The amount of xNGN to borrow.

Returns:

• A promise resolving to the transaction object.

repayCurrency

descent.repayCurrency('9000'): Promise<{}>

Repays borrowed xNGN for a particular vault.

Parameters

• amount: The amount of xNGN to repay.

Returns:

• A promise resolving to the transaction object.

withdrawCollateral

descent.withdrawCollateal('9000'): Promise<{}>

Withdraws USDC for a particular vault.

Parameters

• collateralAmount: The amount of unlocked collateral to withdraw.

Returns:

• A promise resolving to the transaction object.

getCollateralInfo

descent.getCollateralInfo(): Promise<{}>

Gets information about the collateral initialized in create().

Returns:

• A promise resolving to the collateral information.

{
      totalDepositedCollateral: 4004000000n, // returns in 6 decimals - 1e6
      totalBorrowedAmount: 1668492000000000000000000n,  // returns in 18 decimals - 1e18
      liquidationThreshold: '750000000000000000',  // returns in 18 decimals - 1e16 - should be represented in percentage
      debtCeiling: 115792089237316195423570985008687907853269984665640564039457584007913129639935n,  // returns in 18 decimals - 1e18
      rate: 24999999949728000n,  // returns in 18 decimals - 1e16
      minDeposit: 0n,  // returns in 18 decimals - 1e18
      collateralPrice: 1100000000n  // returns in 6 decimals - 1e6
    }

utilities

Helper functions to ease interaction with different token contracts.

getCollateralTokenBalance

descent.getCollateralTokenBalance(ownerAddress: string): Promise<{}>

Gets the balance of USDC for an address

Parameters

• ownerAddress: The address of the account connected

Returns:

• The usdc balance of the account

approveCollateral

descent.approveCollateral('100'): Promise<{}>

Approves the vault contract to get allowance of specified amount for the USDC token

Parameters

• amount: The amount of allowance to give

Returns:

• Returns transaction object

getxNGNBalance

descent.getxNGNBalance(ownerAddress: string): Promise<{}>

Gets the balance of xNGN for an address

Parameters

• ownerAddress: The address of the account connected

Returns:

• The xNGN balance of the account

approvexNGN

descent.approvexNGN('100'): Promise<{}>

Approves the vault contract to get allowance of specified amount for the xNGN token

Parameters

• amount: The amount of allowance to give

Returns:

• Returns transaction object