Skip to content

lending.md

Latest commit

 

History

History
29 lines (20 loc) · 1.7 KB

lending.md

File metadata and controls

29 lines (20 loc) · 1.7 KB

Lending Development Notes

Deposit to a Lending Market

  • A user calls the loans.mint() extrinsic to deposit an asset into a market.
  • The user is credited with newly minted qTokens. qTokens are of type {LendToken: Id} where the Id is the market Id representing a claim on the underlying, deposited asset.
  • The loans pallet is credited with the assets deposited by the user.

qToken as Collateral

  • A user can use qTokens as collateral. qToken as collateral is subject to governance votes for both the lending protocols and the BTC bridge.
  • A single account id can declare the qTokens as collateral only in a single protocol: either all of the tokens of a specific qToken type are collateral in the lending protocol or in the bridge.
  • If a user wishes to have some qTokens as collateral in lending and some tokens as collateral in the bridge, the user has to distribute the tokens across two accounts.

qToken as Collateral in Lending

  • A user calls the loans.deposit_all_collateral() extrinsic to deposit all of their qTokens as collateral.
  • Subsequently minted qTokens of the same type will automatically be deposited as collateral.
  • When a user deposits qTokens as collateral, the {LendToken: Id} free balance is moved to the reserved balance on that account.

qToken Exchange Rates

  • The exchange rate from qTokens to the underlying asset is stored in the ExchangeRate storage map and can be fetched with the loans.exchangeRate() storage query.

  • Exchange rates are initialized at 20 * 10^15 and are updated during:

    • Minting or redeeming qTokens for the underlying token.
    • Borrowing and repaying debt from a loan.
    • Liquidations of loans.
    • Adding or removing reserves to a market.