Idle Token Helper is a collection of smart contracts to simplify interaction with Idle Protocol.

How it works

Idle Protocol has fees on yield you get which are collected during redeem. You can abstract this concept considering two prices during minting and redeeming, respectively mintingPrice and redeemPrice.

IdleTokenHelper facilitates your day implementing the formula for redeemPrice.

Usage

You just need to call getMintingPrice(address idleYieldToken) to get minting price and getRedeemPrice(address idleYieldToken, address user) for redeemPrice. You can use also getRedeemPrice(address idleYieldToken) which provides redeemPrice for msg.sender.

For both, you need to pass the address of the IdleToken you are considering. For redeem, you have to provide the address which holds the tokens because the formula leverages the avgUserPrice. Technically, it keeps track of the weighted average of the token minted by the specific address, to calculate the yield needed for applying the fees on top.

You can version I deployed for you at 0x04Ce60ed10F6D2CfF3AA015fc7b950D13c113be5 or embed in your contracts.

The latter could be more expensive at deploy time but cheaper at runtime, remember to use the internal methods (i.e. _getMintingPrice(address idleYieldToken) and _getRedeemPrice(address idleYieldToken, address user)).

Below an example

import "@emilianobonassi/idle-token-helper/IdleTokenHelper.sol";

contract MyContract is IdleTokenHelper {

...

function myMintMethod()
    external
    returns (bool) {
        ...
        uint256 mintingPrice = _getMintingPrice(idleYieldToken);
        ...
    }
...

function myRedeemMethod()
    external
    returns (bool) {
        ...
        uint256 redeemPrice = _getRedeemPrice(idleYieldToken, address(this));
        ...
    }
...

}