FixedStakingRewards

A modernized version of the Synthetix StakingRewards contract with fixed reward rates and additional security features.

Overview

FixedStakingRewards is a staking contract that allows users to stake tokens and earn rewards at a fixed rate. It's based on the Synthetix StakingRewards contract but has been significantly modernized and modified to account for new requirements.

Key Features & Changes

Modernized Solidity Standards

• Solidity ^0.8.29: Uses the latest Solidity version with built-in overflow protection
• Custom Errors: Replaced require statements with gas-efficient custom errors
• Modern OpenZeppelin Contracts: Uses latest versions of OpenZeppelin libraries

Updated Reward Rate System

• Fixed APY: Uses a fixed Annual Percentage Yield instead of a floating rate based on the number of deposited tokens
• Owner-Controlled: Only owner can set reward rates via setRewardYieldForYear()
• 2-Week Minimum: Contract ensures there are enough rewards for at least 2 weeks before allowing deposit

Delayed Reward Access

• Rewards Available Date: Withdrawals and reward claims blocked until rewardsAvailableDate
• Early Release: Owner can call releaseRewards() to enable withdrawals early
• Default Lock: Initially set to 1 year from deployment (block.timestamp + 86400 * 365)

Owner Functions

• No Reward Distributor: Removed the rewardDistributor role, owner handles all admin functions
• Direct Control: Owner has direct access to all administrative functions
• Reclaim Function: Owner can recover previously supplied and unclaimed rewards with reclaim()

Whitelist Functionality

• Permissioned Access: Only whitelisted addresses can stake tokens and withdraw/claim rewards
• Owner-Controlled: Only owner can add/remove addresses from whitelist
• Simple Management: Add or remove one address at a time with addToWhitelist() and removeFromWhitelist()
• Complete Access Control: All user operations (stake, withdraw, getReward, exit) require whitelist approval

Emergency Controls

• Pausable: Contract can be paused by owner to halt all user operations in emergencies
• Selective Pause: Only user functions (stake, withdraw, getReward, exit) are paused - owner functions remain active
• Emergency Recovery: Owner can still manage whitelist, rewards, and other admin functions while paused

Usage

Development Setup

This project uses Foundry for development and testing.

# Install dependencies
forge install

# Build the project
forge build

# Run tests
forge test

# Format code
forge fmt

Deployment

This project uses Cannon for deployments.

Security Considerations

• Minimum Reward Guarantee: The contract ensures there are always enough rewards for at least 2 weeks of staking upon supply (after 2 weeks more would need to be deposited)
• Pausable: Can be paused in emergency situations

License

MIT