Token Lock Contract

Simple ERC20 token lock with cliff + daily linear vesting. Intended for Polygon-compatible deployment.

Key Concepts

• ratePerDay is a percentage-per-day scaled by RATE_SCALE = 1_000_000_000_000.
  • 1_000_000_000_000 = 100% per day
  • Example: 2 years (730 days) => ratePerDay = 1_000_000_000_000 / 730.
• Vesting starts only after unlock() is called and the cliff period has elapsed.

Contract Flow

1. lock(...)
   • Transfers tokens into the contract.
   • Assigns a lockId and emits LockCreated.
   • retractUntilUnlock controls the retraction window:
     • retractUntilUnlock = true: creator may retract only until unlock() is called.
     • retractUntilUnlock = false: creator may retract until the first withdrawal.
2. unlock(lockId, unlockTime)
   • Must be called by the original lock creator.
   • Starts the cliff countdown at unlockTime.
   • unlockTime is a Unix timestamp in seconds.
3. withdraw(lockId, amount, percent, to)
   • Must be called by the withdrawAddress set in lock().
   • Can withdraw by exact amount or percent (scaled by RATE_SCALE).
   • If both amount and percent are zero, defaults to 100% of available.
   • When fully withdrawn, emits LockClosed with reason = 0 and deletes the lock.
4. retract(lockId, to)
   • Creator-only.
   • If retractUntilUnlock = true: only allowed while the lock is still locked (before unlock()).
   • If retractUntilUnlock = false: only allowed if no withdrawals have occurred.
   • Emits LockClosed with reason = 1 and deletes the lock.

Events

• LockCreated — new lock created.
• Unlocked — unlock time set.
• Withdrawn — withdrawal executed.
• Retracted — retraction executed.
• LockClosed — final snapshot emitted on full withdraw or retract.

Local Dev

npm install
npm run compile
npm test

Deploy to Polygon Amoy (Testnet)

1. Copy .env.example to .env and fill in:
   • AMOY_RPC_URL
   • PRIVATE_KEY
   • POLYGONSCAN_API_KEY
2. Deploy:

npx hardhat run scripts/deploy.js --network amoy

3. Verify on PolygonScan (to enable the contract UI there):

npx hardhat verify --network amoy <DEPLOYED_ADDRESS>

Mock ERC20 (Test Token)

Deploy a mock token to Amoy for local testing against the lock contract:

npx hardhat run scripts/deploy-mock.js --network amoy

Approve the TokenLock contract to move your tokens before calling lock:

# TokenLock address (Amoy): 0x324d9b90A07D587B4FA0D68c22645B9c8D321079
# Approve 1,000 tokens (18 decimals)
approve(spender=0x324d9b90A07D587B4FA0D68c22645B9c8D321079, amount=1000000000000000000000)

Mint to a wallet (example: 1,000,000 tokens):

npx hardhat run scripts/mint-mock.js --network amoy -- \\
  0xYourMockToken 0xYourWallet 1000000

Or via task:

npx hardhat mint-mock --network amoy --token 0xYourMockToken --to 0xYourWallet --amount 1000000

Approve via task:

npx hardhat approve-mock --network amoy --token 0xYourMockToken --spender 0x324d9b90A07D587B4FA0D68c22645B9c8D321079 --amount 1000

Notes

• This repo uses Hardhat.
• ERC20 only (no permit, no ERC777 hooks).