veHemi

A decentralized voting escrow system for HEMI tokens implementing time-locked staking with voting power and incentive distribution.

Overview

veHemi consists of two main contracts:

1. veHemi - Main voting escrow contract handling token locking, voting power calculation, and NFT transfers
2. HemiVoteDelegation - Delegation system for voting power

Core Mechanics

Voting Power & Incentives

veHemi uses a linear decay system where both voting power and incentives are calculated using the same formula:

• Formula: locked_amount * (lock_end_time - current_time) / max_lock_duration
• Voting power: Determines governance voting weight
• Incentive distribution: Determines reward allocation proportion
• Longer locks = more weight: Users locking for longer durations get proportionally more voting power and incentives

Example: Lock Duration Impact

Consider two users in veHemi:

• User A: Locks 100 HEMI for 4 years (single lock)
• User B: Locks 100 HEMI for 2 years, then relocks for 2 more years

User A gets more weight because:

• Single 4-year lock has higher average voting power over the entire period
• Linear decay curve favors longer initial lock durations
• More consistent incentive distribution throughout the lock period

Lock Management

• Duration: Up to 4 years maximum
• NFT representation: Each lock is a unique NFT
• Transferability: Default transferable, can be non-transferable
• Extensions: Only NFT owner can extend lock duration
• Amount increases: Anyone can increase locked amount

NFT Transferability

• Default: Transferable by default
• Non-transferable: Created with transferable = false (e.g., protocol distributions)
• Auto-transferable: Non-transferable NFTs become transferable after first lock duration ends
• Delegation reset: Transfers automatically move delegation to self

Delegation System

• Epoch-based: Delegations take effect at next day boundary
• Flexible: Delegate to any token ID or self
• Revocable: Change or revoke at any time

Installation & Testing

# Install and build
forge install
forge build

# Run tests
forge test

Usage Examples

Creating Locks

// Transferable lock
uint256 tokenId = veHemi.createLock(amount, 4 * 365 days);

// Non-transferable lock
uint256 tokenId = veHemi.createLockFor(amount, 4 * 365 days, recipient, false);

Delegation

// Direct delegation
hemiVoteDelegation.delegate(delegatorTokenId, delegateeTokenId);

// Check voting power
uint256 votes = hemiVoteDelegation.getVotes(tokenId);

Transfers

// Check transferability
bool isTransferable = veHemi.isTransferable(tokenId);

// Transfer NFT
veHemi.transferFrom(from, to, tokenId);

Installation

This repo uses both foundry and hardhat frameworks, it uses npm to manages all dependencies (foundry libs included), meaning the foundry test will only work after running:

npm i

Tests

forge t

Deployment

Preparation

Before any deployment/upgrade it's recommended to run scripts against local fork chain:

Make sure that the .env file has correct params and then run:

./scripts/start-forked-node.sh
./scripts/test-next-deployment-on-fork.sh

Deployment

Make sure that the .env file has correct params and then run:

npx hardhat deploy --network hemi

Verification

npx hardhat etherscan-verify --network hemi

License

MIT License