A claim you can carry
Calcite spar is the crystal that grows in a cavity out of the water moving through it. It is solid, it is portable, you can hand it to somebody without draining anything, and it got there because flow passed this way. That is a fungible claim on a position that is still working, which is the only thing this product does that a pool position cannot.
One token, one position, no lock
Deposit into an Aquifer and receive Spar: a plain ERC-20 whose supply is the vault's share count. It transfers, it composes, it can be lent against or taken apart, and none of that touches the position underneath. That is the ordinary promise of a liquid LP receipt and it is genuinely useful.
It is also the promise where this category stops talking. A receipt is liquid if somebody will take the other side of it, at your size, today. That is a measurement, and nobody publishes it.
Two prices, and they are different promises
Every ERC-4626 receipt has a redemption value — assets over supply — and it is the number the front page shows. It is not a price. It is what the vault's accounting says you are owed, and getting it requires the position to be unwound at the size you are asking for.
The second price is what the secondary market for the receipt will pay, which is capped by the narrowest hop between that market and cash. A receipt whose secondary market is thinner than the pool underneath it has made a position less liquid while being sold as the opposite.
What Karst publishes beside every Spar
- Redemption value, per share
- read from reserves at a block, with the block
- Size at which unwinding moves the pool 1%
- measured against the venue’s quoter
- Size the secondary market absorbs at 1%
- measured the same way, separately
- The narrower of the two
- because that is the one that binds
Three of these four are measurements the Conduit page already makes against real pools. The fourth needs a Spar to exist. G1
Recharge, and why it is not a rate
Fees accrue to the position and are harvested into it. A harvest raises every Spar by the same factor, so a small holder and a large one gain the same percentage on the same event — that is what Recharge means and it is the honest part of the design.
The dishonest part, everywhere, is calling the result an APY. A karst spring answers a storm in hours and then falls away for months; the mean of that curve describes none of the days you were actually in it. Karst publishes the Hydrograph: fees per day, as a series, with the events left in.
A hydrograph is discharge against time, and a karst spring has a famously flashy one: it answers a storm in hours and then falls away for months. A single number called APY is the mean of that curve, which is the one summary that describes none of the days you were actually in it.
Written and tested; not deployed
Spar is the Aquifer's own share token — a plain ERC-20 in the same contract, because a receipt that needs a second contract to move is not liquid. It compiles, and 45 of its properties are executed on an EVM by every build, including the two this page is about: the price it redeems at is a mark that can fall, and the shares a withdrawal burns are always worth at least what it takes out.
It has no address and no audit. Nothing on this site can give you one, the contract pill removes itself rather than printing a row of zeroes, and the state table says the same thing in a row you can check.
What runs today is Route — real pools, real quotes, a real swap — and the measurement behind it on Conduit.