The law, in full.

Proton is one shared nucleus. What decides the element is the mass fused into it. Everything below is either a rule the contract enforces or a limit we are telling you about. Nothing is a promise.

1 · The nucleus

The nucleus holds a mass, written M: the sum of every $PROTON currently fused into it. Its proton count, Z, is the largest number of protons whose cumulative cost is covered by M. Each additional proton costs more than the last, in every regime: the bond gets more expensive as the nucleus grows.

The element is simply the periodic table's cell number Z, from hydrogen (1) to oganesson (118). Z = 0 is an empty nucleus. Crossing into a new Z is a public event, carrying the element's name and symbol.

2 · Fusing

Fusing locks $PROTON into the nucleus and dates the position. At or below iron (Z ≤ 26), the full amount enters: fusion here releases energy, and nothing is held back.

Above iron (Z > 26), a share of the fused amount is burned before it enters: past iron, fusion absorbs energy instead of releasing it, and that cost is real.

3 · Unfusing

At or below iron, tokens can be unfused at any time, after the exit delay set at deploy. Above iron, unfusing is refused outright: nothing leaves a nucleus heavier than iron except through fission.

4 · Binding energy

Every swap in the $PROTON pool pays a share into the nucleus as binding energy, independent of whether anyone is fusing. It accrues even while the nucleus is empty, waiting for the first proton. It only ever leaves at a fission.

5 · Iron

Iron, element 26, is the wall the whole design turns on. Below it, the nucleus cannot be broken: no function in the contract can force protons out, and none is needed, since anyone can unfuse freely anyway. Above it, the nucleus becomes unstable by rule: fusion burns, exit is blocked, and the only way out is a neutron.

6 · The neutron

A neutron does not exist below iron; there is nothing to fire it at. Above iron, anyone can fire one. Its price falls as Z grows (a heavier nucleus is easier to split) and falls further the longer the nucleus goes without a fusion (an unfed nucleus becomes unstable on its own). The price is burned, and firing fissions the nucleus in the same transaction.

7 · Fission

Fission releases every unit of binding energy at once, split among the protons present, weighted by their mass times how long they had been held. The account that fired the neutron gets no extra share for doing so. Every lock is released, the nucleus returns to Z = 0, and the next proton fused restarts the climb at hydrogen.

8 · Invariants

These hold on every block. If any of them fails, the contract is wrong, not the rule.

9 · What can go wrong

The whale who carries and cracks

An account can fuse enough to cross iron, then fire the neutron and take a large share of the energy. It pays the burned share of its own fusion and the neutron itself, and duration works against it: protons held the longest weigh more per unit of mass than a position opened moments before the split.

A nucleus that never reaches iron

The energy accrues without ever paying out, but no one is trapped: below iron, exit is always free. The energy grows until reaching iron is worth it. This is the "nobody plays" risk, and the only one with no mechanical fix.

A heavy nucleus that stalls

Above iron, if nobody fuses and nobody fires, the neutron's price keeps falling with time until someone does. That is the self-restart, by design.

The race to fire

Once a nucleus is cheap to crack, more than one account may try to fire in the same block; the sequencer orders them, the first succeeds and the rest simply find Z already reset. There is no bonus for firing first, so the order decides nothing worth racing for.

The accumulator

Mass-times-duration weighting, updated on every fusion, is a standard component and a frequent source of bugs. If it is wrong, the shares paid at a fission are wrong, and no other part of the contract would reveal it.

10 · Parameters

Every parameter is a constant of the deployment. Their values are published on this page at launch, and they never change afterward.

11 · Chain and venue

Proton runs on Robinhood Chain, chain id 4663 (0x1237), an Ethereum L2 on the Arbitrum Orbit stack. Gas is paid in ETH, at a gas price around 0.02 gwei on this chain.

The hook

The Proton hook does one thing: after every swap, it moves a share of the pool's fee into the nucleus as binding energy. It keeps no data per address, so it has no idea who is trading, and cannot be fooled about it. Fusing, unfusing, and firing a neutron are direct calls to the nucleus contract, not swaps.

12 · Launch

No launchpad. $PROTON launches directly in its own Uniswap v4 pool on Robinhood Chain. The initial liquidity position belongs to the protocol and is locked in a locker with no withdraw function, verifiable on the explorer. During the first blocks, an extra launch fee decays to zero, so a snipe pays full price.

13 · FAQ