Rewards

0x5D48F7FC221ABcAC5386c374eF723a56AD03D4B4

The Rewards contract is a key piece in the liquid staking application, providing a way to distribute rewards to protocol participants, handling protocol fees, and managing checkpoints for efficient reward calculation. This contract is also the withdrawal address of the protocol's validators: where all the rewards and unstakes from the protocol's validators get sent to.

The Rewards contract interacts with various other contracts including:

1. StakedLyxToken: Tracks the staked tokens.

2. Oracles: Responsible for updating the total rewards in the Rewards contract.

3. MerkleDistributor: Distributes the rewards to the protocol's participants.

4. FeesEscrow: Handles the protocol's execution layer fees.

5. Pool: Handles incoming LYX.

Key features

The Rewards contract tracks the total rewards earned by the staking protocol and the total amount that has been cashed out. It also calculates the reward per token for user reward calculation.

Checkpointing

To optimize gas usage and enhance scalability, the contract uses a checkpoint system that keeps track of an account's rewards at a particular point in time. The reward per token is stored in each checkpoint, along with the reward value, in a single memory slot. This allows the Rewards contract to calculate the user's reward.

struct Checkpoint {
    uint128 reward;
    uint128 rewardPerToken;
}

Fee Handling

The contract calculates protocol fees and handles the distribution of these fees. It allows the protocol's admin to set the fee recipient address and fee percentage.

Oracles

An oracle system is in place that updates the total rewards in the Rewards contract.

Reward disabling

The contract provides an option to disable rewards for an account. The state is toggled by calling the setRewardsDisabled function. Rewards of addresses with rewards disabled accrue in the distributor principal, the balance of the Merkle Distributor contract, responsible for the token distribution of rewards calculated off-chain.

Auto-compounding

The contract stores a list of addresses who explicitly granted permission for rewards to be staked on their behalf and provides an interface to effectively re-stake these rewards. This operation can be done in batch and it will call the Pool contract's, transferring LYX to it.