There is no drop, no supply cap and no allowlist. A Bun exists only when somebody's machine finds a hash that satisfies the contract, and every Bun found afterwards pays rent to the people who already hold one.
An ERC-721 token on Arc, Circle's settlement chain, where USDC is also the gas token. You do not buy one from us. You run a proof-of-work search in your browser while you work a shift in the restaurant, and when your machine finds a qualifying hash you pay the current price and the contract mints it to you.
Supply is not capped, because nobody decides it. Buns exist at the rate people find them, and they get harder to find as the collection deepens.
A candidate is the keccak-256 digest of five values packed together: the chain id, the contract, the current challenge, the recipient, and a nonce. It qualifies when the digest is numerically below the current target.
The leading zeros are the work. At launch the target is type(uint256).max >> 18, so a qualifying digest turns up roughly once in 262,144 attempts.
Because the recipient is inside the digest, a proof belongs to one address and cannot be taken, resold or replayed by anyone else. The challenge is derived from the contract's own history — the mint count and the last accepted digest — rather than from a block variable, because Arc's PREVRANDAO is always zero.
Every check runs before any money moves, so losing a race costs only gas. Mining is off until you turn it on, and nothing is charged for searching.
The first Bun cost $0.50. Every Bun already found adds $0.10 to the next one. The ladder is arithmetic and public; there is no curve to discover and no private allocation at a better price.
The first epoch, at its real prices. Epoch 0 holds 8 Buns; each epoch after it holds twice as many, and the difficulty target tightens 10% at every boundary.
Every unit of every payment is assigned on the way in. Rounding dust is reported, never redistributed.
Rent is split among everyone already holding a Bun, through an O(1) accumulator. A Bun earns nothing during the epoch it was born in, and unclaimed rent travels with the token when it is sold. Studio is the only line that is profit, and the contract refuses any withdrawal that would dip into money owed to holders. Buyback accrues to buy $BUN on the open market and burn it.
Rent is a share of payments that have already happened. It is not a yield, not a promise, and it is zero if nobody finds anything.
The first payment is the one case where the rules are most easily fudged, so it is worth reading closely. There were no existing holders, so the 70% had no one to pay. It did not go to us and it was not left stranded: it fell through to the buyback queue, which is why buyback shows $0.40 rather than $0.05. The studio took exactly its 20% and not a unit more.
A Bun can be burned for $BUN, an ERC-20. A freshly found Bun converts to 1,000 $BUN, and the amount halves for every epoch the Bun has aged — burn late and you get less. The conversion is a discrete shift, not an interpolation.
There is no premine, no treasury allocation and no team supply, because there is no mint. The token's issuer address is fixed at construction with no setter, so issuance can never be redirected. The only way a single $BUN exists is somebody burning a Bun they found.
Conversion is disabled by the contract until epoch 6 — 1,016 Buns deep.
Discovery, payment and rent. Deployed to Arc mainnet and exercised: Bun #1 found, paid, split and recorded on chain.
$BUN conversion. Built and tested, refused by the contract until epoch 6. Nothing to enable; it opens on depth.
Buybacks. The adapter is built and passes against real Uniswap v3 contracts on a fork, but Arc has no exchange deployed on either network — Circle's own contract reference lists none. The 10% accrues in the queue until a venue exists. Nothing is spent in the meantime.
Mining is permissionless. submitProof has no allowlist, no roles and no gate, so anyone can mine without our client — including against us. That is the point: the game is where mining is pleasant, not where it is permitted.