Contracts discovery
System-level contracts
Each interaction with Gearbox starts from retrieving the addresses of important contracts. AddressProviderV3 stores the addresses of all system-level contracts in a mapping. getAddressOrRevert(bytes32 key, uint256 _version) is used to retrieve addresses, where key is a symbolic key for the desired contact, _version - a version of the contract from the IVersion interface (for V3 contracts, this is 3_00).
The list of supported keys can be found here (opens in a new tab).
List of all deployed contracts on mainnet.
Retrieving pools and credit manager
ContractsRegister keeps a list of all active pools and Credit Managers:
interface IContractsRegisterEvents {
// emits each time when new pool was added to register
event NewPoolAdded(address indexed pool);
// emits each time when new credit Manager was added to register
event NewCreditManagerAdded(address indexed creditManager);
}
/// @title Optimised for front-end Address Provider interface
interface IContractsRegister is IContractsRegisterEvents {
//
// POOLS
//
/// @dev Returns array of registered pool addresses
function getPools() external view returns (address[] memory);
/// @dev Returns pool address for i-element
function pools(uint256 i) external returns (address);
/// @return Returns quantity of registered pools
function getPoolsCount() external view returns (uint256);
/// @dev Returns true if address is pool
function isPool(address) external view returns (bool);
//
// CREDIT MANAGERS
//
/// @dev Returns array of registered credit manager addresses
function getCreditManagers() external view returns (address[] memory);
/// @dev Returns pool address for i-element
function creditManagers(uint256 i) external returns (address);
/// @return Returns quantity of registered credit managers
function getCreditManagersCount() external view returns (uint256);
/// @dev Returns true if address is pool
function isCreditManager(address) external view returns (bool);
}Note that the ContractsRegister returns pools and CMs of all versions, including outdated ones. To filter out older contracts, make sure to check that IVersion(contractAddress).version() >= 3_00.
Versioning
Each contract in the protocol implements an IVersion interface that has a version function. It returns the contract's version as a uint256 value. Contract ABIs can change between versions, so it is recommended to get and verify the value before interacting with a particular contract.
Code snippet from CreditManager:
// Contract version
uint256 public constant override version = 3_00;