Pure liquidation in LLAMMA is possible when a borrower's health is negative and their collateral has been converted to stablecoin in a quantity that covers the outstanding debt. In such circumstances, it is possible for anybody to directly perform a "pure liquidation" of the borrower. This contrasts with cases where the user's collateral has not been fully converted to crvUSD, and more extended liquidation mechanisms must be used.
This and subsequent lessons build atop the curvefi/liquidation-demo repository by Curve team member @Macket.
New Titanoboa concepts introduced in this lesson include the generate_address and the load_abi functions.
Further details may be found in the Titanoboa documentation
Generate an EVM address. This address can optionally be aliased, and a seed can optionally be set to randomize address generation.
> boa.env.set_random_seed(100)
> boa.env.generate_address('optional alias')
Built in boa function to load an ABI from a json file and create an ABIContractFactory, which can interface with deployed contracts.
> implementation = boa.load_abi('abi_file.json', name="MyContract")
> my_contract = implementation.at('0xdeadbeef...')
Calling user_state on Llama Lend controllers returns four key loan parameters in a single call
- Amount of
collateralthe user owns - Amount of
stablecointhe user owns - Current amount of user
debt - Number of bands (
n) across which the user has spread collateral
> controller.user_state(address)
When a user is in bad health and their debt is covered by collateral converted into stablecoins, anybody may run a "pure liquidation" by calling the liquidate function.
The min_x argument is the minimum amount of stablecoins to receive, to avoid sandwich attack.
def liquidate(user: address, min_x: uint256):
"""
@notice Peform a bad liquidation (or self-liquidation) of user if health is not good
@param min_x Minimal amount of stablecoin to receive (to avoid liquidators being sandwiched)
"""