Hatchery

HATCHERY · TECHNICAL BRIEF@ARKIUMLIFE

01 /The Binding — initialize_binding

Hatchery is a Robinhood Chain contract paired with a single ERC‑20 token. The mint carries the transfer‑hook extension, and the hook authority points at the Hatchery program. At deployment the program derives a binding account — a storage record keyed by the mint and the target liquidity pool — and writes the pool identity into it exactly once.

The binding is one‑way and permanent. Every later instruction re‑derives the record and asserts that the pool account passed by the caller matches the stored key. A swap routed through any other pool fails account validation before a single wei moves. The program refuses to operate on any market other than the one it was bound to.

02 /The Coefficient — after_swap

After a swap settles against the bound pool, the program reads the pool state account: the active bin index, the bin step, and the liquidity held in each loaded bin array. From that snapshot it recomputes the concentration coefficient.

Each populated bin within a fixed window of the active bin contributes to the sum, weighted by the inverse of its distance from the active bin — near liquidity counts for more, far liquidity for less. The weighted sum is normalized by total pool liquidity to produce a unitless value between zero and one. The result is stored in the coefficient store as a uint256 in nine‑decimal fixed point and emitted as a CoefficientUpdated event through the contract event log.

03 /The Gate — before_add_liquidity

Every deposit into the bound pool is routed through the program, which rejects positions whose bin span exceeds an allowable width. The bound is derived live from the current coefficient: max_allowable_bins = MAX_BIN_SPAN × (1 − coefficient).

At coefficient zero any span is accepted — wide bands, narrow bands, anywhere across the bin range. Near coefficient one, only positions inside a single bin step of the active bin pass. The gate is not advisory. A deposit outside the window returns HatcheryError::SpanExceedsAllowable, and because Robinhood Chain transactions are atomic, the whole transaction — token transfers included — is rolled back.

04 /The Withdrawal — before_remove_liquidity

Withdrawals are never blocked. Instead the program computes how far the global coefficient relaxes as a result of the position being pulled.

Positions clustered tightly around the active bin release less coefficient than wide bands do. The asymmetry is deliberate: it preserves the shape past swaps have already produced, so the pool’s geometry is sticky against ordinary exits. Easy to concentrate, hard to dilute.

05 /The Hook Interface

Transfer hooks are resolved through a hook permission map published by the program. Wallets and routers read that account, expand it into the transfer instruction, and the token contract calls into Hatchery on every transfer of the mint.

The account list is fixed at initialization: the binding record, the coefficient store, the pool state, and the bin arrays adjacent to the active bin. Nothing is upgradable at runtime, and the hook cannot request accounts it was not declared with. If the list does not resolve, the transfer itself fails — the mint and the program cannot be separated.

06 /The Invariant

The pool’s pricing math is untouched. Hatchery does not alter the bin curve, the swap amounts, or the fee schedule. It operates purely on the geometry of where liquidity is permitted to sit, never on how that liquidity prices a trade.

The distinction matters. Traders see an ordinary Robinhood Chain pool with ordinary slippage. Liquidity providers see a pool whose deposit window narrows as the market matures. Both views are correct: the AMM is unchanged, and the geography of the AMM is what Hatchery shapes.

Hatchery is deployed on Robinhood Chain mainnet.

PRICE—

MARKET CAP—

24H VOLUME—

LIQUIDITY—

HOLDERS—

24H TRADES—

EVOLUTIONSeven stages, defined by coefficient.

0.000.140.280.420.570.710.851.00

pristine0.00 – 0.14

marbled0.14 – 0.28

veined0.28 – 0.42

etched0.42 – 0.57

fractured0.57 – 0.71

breaching0.71 – 0.85

hatched0.85 – 1.00