Reference: contracts

The launch deployment is three contracts plus a shared base. Signatures are abbreviated; the authoritative source is contracts/ and the interfaces under contracts/interfaces/. Parameter values live in parameters.md.

An earlier single-sided staking pool (HAMDistributionPool) was removed before launch; see Liquidity strategy for why.

HAM — the token (contracts/HAM.sol)

UUPS-upgradeable rebasing ERC-20. Ownership: Ownable2StepUpgradeable. Deployed behind an ERC1967Proxy.

Function	Access	Notes
balanceOf(addr)	view	Display balance (fragments, 18 dec); scales every rebase.
balanceOfUnderlying(addr)	view	Rebase-invariant share (internal units, 1e24).
totalSupply()	view	Derived from initSupply × scalingFactor.
hamsScalingFactor()	view	Global rebase multiplier (genesis 1e18).
transfer / approve / allowance	public	Standard ERC-20, denominated in fragments.
mint(to, amount)	rebaser or incentivizer	Mints fragments; increases initSupply.
rebase(epoch, indexDelta, positive)	rebaser only	Moves the scaling factor within bounds.
setRebaser(addr) / setIncentivizer(addr)	owner	Set the two privileged roles.
upgradeToAndCall(impl, data)	owner	UUPS upgrade — no timelock.

Events: standard Transfer / Approval, plus Rebase(epoch, previousScalingFactor, newScalingFactor), Mint, NewRebaser, NewIncentivizer. Rebase outcomes are also observable via the rebaser's RebaseExecuted and the changed hamsScalingFactor.

HAMRebaser — rebase policy (contracts/HAMRebaser.sol)

Ownership: Ownable2Step + ReentrancyGuard. Holds immutable yam (HAM), reserveToken, uniswapPair, isToken0, and usdPegMode.

Views

Function	Notes
getCurrentExchangeRate()	Peg-denominated rate. USD mode: TWAP × reserveUsd. Use this, not getCurrentTWAP, for USD-mode price.
getCurrentTWAP()	Pool TWAP only (reserve per HAM); returns 0 if no time elapsed.
getReserveUsdPrice()	Primary reserve/USD feed (USD mode); reverts on bad/stale answer.
computeOffPegPerc(rate)	(offPegPerc, positive) vs targetRate, capped at MAX_RATE.
inRebaseWindow() · epoch · targetRate · usdPegMode · rebasingActive	state getters

Rebase flow

Function	Access	Notes
init_twap()	owner	Snapshot TWAP; once.
activate_rebasing()	anyone	After rebaseDelay warmup; one-way.
commitRebase(hash)	keeper	In-window; hash = keccak256(committer, salt, minReserveOut).
revealAndRebase(salt, minReserveOut)	keeper	25–50 blocks after commit; USD mode enforces oracle-drift bound.
cancelCommit() / cancelExpiredCommit()	committer·owner / anyone	Recover a stuck commit.
forceRebase(minReserveOut)	owner	Emergency, owner-only; bypasses commit/reveal (and its sandwich protection) but still requires the rebase window and interval.

Admin — setKeeper, setTreasury, setDeviationThreshold, setRebaseLag, setRebaseMintPerc, setMaxSlippageFactor, setRebaseTimingParameters, setRebaseDelay, secondary-oracle setters; and USD-mode: proposeReserveUsdOracles → applyReserveUsdOracles (24h timelock) / cancelReserveUsdOracleProposal, setMaxReserveOracleAge, setMaxCommitRevealOracleDrift. setTargetRate reverts in USD mode.

Key events: RebaseExecuted, UsdPegPriceComputed, RebaseCommitted, ReserveUsdOraclesProposed, NewTreasury, KeeperSet.

HAMIncentivizer — LP genesis farm (contracts/rewards/HAMIncentivizer.sol)

Synthetix-style staking on the HAM/WHYPE LP token, halving HAM emissions. Ownership: Ownable. Extends LPTokenWrapper (shared stake/withdraw base).

Function	Access	Notes
stake(amount) / withdraw(amount) / exit()	public	Stake/unstake the LP token; exit withdraws all + claims.
getReward()	public	Claims earned HAM (scaled by hamsScalingFactor at payout).
earned(addr) · balanceOf(addr) · totalSupply() · rewardRate() · periodFinish()	view	Reward + stake accounting (pre-scaling units for earned/rewardRate).
notifyRewardAmount(reward)	rewardDistribution	Starts/extends a reward period (one-time bootstrap mint before START_TIME; later periods self-fund via the halving mint).
setRewardDistribution(addr)	owner	Authorize the notifier.
governanceRecoverUnsupported(token, amt, to)	owner	Rescue stray ERC-20s (not the staking token or HAM).