Keepers — compound and burn 🐝

The buzz

The hive has one worker on a schedule, and a spare door in case that worker oversleeps.

Two jobs keep the floor growing: tipping the jar into the pool (compound) and burning the FLY the floor has earned. A keeper — one hot wallet the controller names — presses the first on a schedule and gets paid for it. If the keeper ever stops, the button opens to everyone after six hours, so a dead script costs the floor hours, never the whole system. The burn needs no one at all: compound does it in the same breath. No application form, no Discord role. Wallet, gas, go.

The boring part

The keeper loop — quoteCompound says callable, the keeper (or, after six idle hours, anyone) calls compound, the bounty and the bid, the band's FLY fees burned in the same call, supply down

`compound()`

compound


Who	the keeper and the controller, always. Anyone, once six hours (`KEEPER_EXCLUSIVE_FOR`) have passed since the last compound (or since trading opened). Anyone, at any time, if no keeper is set.
What it does	moves up to 2,000 USDG from the pot into a permanent bid under the market, and burns the FLY the floor has earned in the same call
How often	once per 30 minutes (`CompoundTooSoon` otherwise)
Bounty	0.5% of the tranche, never more than 3 USDG, paid to the caller in USDG before the liquidity is placed. The controller sets the rate anywhere from 0 to 0.5%, and never above.
Reverts when	the pot is empty, the interval has not passed, the tranche is dust, or the caller is not allowed yet (`KeeperOnly`)
Where the button is	the Compound splat on the dashboard; the site simulates the call first and disables the button if it would revert

quoteCompound() tells you everything before you press: the whole pot, the bounty you would get, what would be locked, and whether the call would succeed right now. compoundOpenToAll() says whether the public window is open. No guessing, no wasted gas, no "it reverted, ser".

Why one tranche at a time: it keeps each call small and steady, and it means the floor is poured in layers rather than all at once. The bid is placed against a protected reference — the cheaper-FLY of today's price and the 4-hour average — not against the price a trader just pumped, so a pump in front of a compound cannot make the pot buy at the pumper's price.

The keeper's pay is the bounty and nothing else. The keeper is not an owner: it can call compound() and that is all. It cannot move funds, change a fee, or touch liquidity, and setKeeper(0) reopens the button to everyone at once.

`burnAccruedFly()` and `sweepBands()`

burn

	`burnAccruedFly()`	`sweepBands(start, count)`
Who	anyone	anyone
What it does	burns every FLY the hook holds — the floor's fee income in FLY	collects the trading fees of older bands (no principal moves), adds the USDG to the pot and burns the FLY
Bounty	none; there is no pot to pay one from without selling FLY, which the hook never does	none; the USDG it collects raises the pot, and so the next keeper's bounty
Reverts when	there is nothing to burn	never for an empty range; it does nothing

compound() and sweepBands() both burn what they collect in the same call, so the keeper's schedule is the burn's schedule. burnAccruedFly() stays open for FLY that arrives any other way — a donation included. Number of FLY: down. Only down. 🔥

A note for the pedantic: anyone can send FLY to the hook and then burn it. That adds FLY the engine did not earn to the "burned by the engine" counter. It is also a real burn, so nobody minds much. If you want to donate your bag to the fire, the fire accepts.

Running a keeper

During the keeper's window you can still watch: quoteCompound() and keeperExclusiveUntil() are public, and the dashboard shows whether the button is open. If the keeper has not compounded for six hours, call compound() yourself and collect the bounty (3 USDG at most for a few cents of gas on this chain). sweepBands is open all the time for anyone who likes tidying up. The hive keeps itself.

The launchpad's furnace has a keeper too

The same idea runs the launchpad's burn (The Launchpad): a keeper calls FlyFurnace.autoBurn(asset), the FLY owner stays as the backup, and nobody else can call it. The contract works out the minimum itself, so a sandwich in front of the burn makes the call revert instead of burning less. The burn runs on its own, slower schedule than the compound (every six hours), and each run first pays the furnace what the launchpad's hook has credited to it, because nothing reaches the furnace until someone calls claimFees. Launchpad fees and pairings has the details and the honest limits.