verbs_examples.agents.liquidation_agent.AdversarialLiquidationAgent#

class AdversarialLiquidationAgent[source]#

Liquidation agent that manipulates the price in Uniswap to bring borrowers positions into distress

__init__(env, i: int, pool_implementation_abi: type, mintable_erc20_abi: type, pool_address: bytes, token_a_address: bytes, token_b_address: bytes, liquidation_addresses: List, uniswap_pool_abi: type, quoter_abi: type, swap_router_abi, uniswap_pool_address: bytes, quoter_address: bytes, swap_router_address: bytes, uniswap_fee: int, aave_oracle_abi: type, aave_oracle_address: bytes)[source]#

Initialise the Liquidator agent and create the corresponding account in the EVM.

The agent stores the ABIs of the Aave contracts, the Uniswap contracts and the token contracts that they will be interacting with. ABIs are previously loaded using the function verbs.abi.load_abi().

Parameters:

  • env (verbs.types.Env) – Simulation environment

  • i (int) – Agent index in the simulation

  • pool_implementation_abi (type) – abi of the Aave v3 pool contract

  • mintable_erc20_abi (type) – abi of ERC20 contract

  • pool_address (bytes) – Addres of Aave v3 pool contract

  • token_a_address (bytes) – Address of collateral token (usually the risky token)

  • token_b_address (bytes) – Address of debt token (usually the less risky token)

  • liquidation_addresses (list[bytes]) – List of borrowers’ addresses that the liquidator will be monitoring.

  • uniswap_pool_abi (type) – abi of the Uniswap v3 pool contract

  • quoter_abi (type) – abi of the Uniswap v3 QuoterV2 contract

  • swap_router_abi (type) – abi of the Uniswap v3 SwapRouter contract

  • uniswap_pool_address (bytes) – Addres of Uniswap v3 pool for the pair (token_a, token_b)

  • quoter_address (bytes) – Address of the QuoterV2 contract

  • swap_router_address (bytes) – Address of the SwapRouter contract

  • uniswap_fee (int) – Fee tier of the Uniswap v3 pool for the pair (token_a, token_b)

  • aave_oracle_abi (type) – abi of the Aave oracle contract for the pair (token_a, token_b)

  • aave_oracle_address (bytes) – Address of the Aave oracle contract for the pair (token_a, token_b)

accountability(env, liquidation_address, amount: int) → bool[source]#

Calculates if a liquidation is profitable

Makes the accountability of a liquidation and returns a boolean indicating whether the liquidation is profitable or not

Parameters:

  • env (verbs.types.Env) – Simulation environment.

  • liquidation_address (bytes) – Liquidation address for which the Liquidator calculates the profitability of the liquidation.

  • amount (int) – Amount to be liquidated

Returns:

bool – True if the liquidation is profitable.

record(env) → Tuple[float, float]#

Record the state of the agent

This method is called at the end of each step for all agents. It should return any data to be recorded over the course of the simulation.

Parameters:

env (verbs.types.Env) – Network/EVM that the simulation interacts with.

Returns:

tuple[float, float] – Tuple containing: - Balance of collateral asset in the current step. - Balance of debt asset in the current step.

update(rng: Generator, env)[source]#

Update the state of the agent and returns list of transactions according to their policy.

The liquidator agent will

  • Monitor those positions in Aave that are close to being in distress, and check whether it would be profitable to make a trade in Uniswap to decrease the price of collateral in order to trigger liquidations.

  • Liquidate positions in Aave that are in distress.

  • Realize a profit on Uniswap by selling the collateral obtained from liquidations.

References

  1. https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4540333

Parameters:

  • rng (np.random.Generator) – Numpy random generator, used for any random sampling to ensure determinism of the simulation.

  • env (verbs.types.Env) – Network/EVM that the simulation interacts with.

Returns:

list – List of transactions to be processed in the next block of the simulation. This can be an empty list if the agent is not submitting any transactions.