Docs / The mechanism / Open in place
Open in place.
At the threshold, the same pool flips from curve mode to open AMM mode. The liquidity never leaves the hook.
At the threshold the pool keeps its PoolId and its liquidity. The curve hands off to open AMM pricing in place.
The flip, not the move
When a token reaches the threshold, the hook flips the pool out of curve-pricing and seeds the accumulated quote as protocol-owned liquidity in the same PoolId. The pool is the same contract before and after. This is the physical meaning of "hooked": the hook's own position is bound to the pool and cannot be withdrawn.
The hook stays on the pool
The hook stays on the pool and keeps splitting the toll on every swap through it. One hook, many pools: one pool per token, all on the same code.
Swaps on a HyperCore book do not pass through the hook.
Why the pool can be kept The liquidity opens in place and stays, so nothing has to be burned or moved. The next pages cover the split and the kept pool.