Liquidity is a curve. Swaps are geometry.
Sigil ships an automated market maker as a native chain primitive. Reserves obey x·y=k. Traders slide the bead along the curve; liquidity providers widen the bracket. Slippage is deterministic, single-block, and revertible — the trader either pays the price they signed for or pays nothing at all.
The geometry
Two reserves define a curve.
Plot reserve A against reserve B and the constant-product invariant x·y=k traces a hyperbola. Every state of the pool is a single point on that curve. Every trade is a slide along it. Slippage is the curve's bend.
Step 1 · DexCreatePool
Sets x·y=k.
The first deposit fixes the initial point on the curve and the value of k. Fee tier, the two tokens, and the initial reserves are written into chain state. From this moment, every swap and every liquidity action must respect the invariant.
Step 2 · DexAddLiquidity
Widens the bracket along the curve.
An LP deposits token A and token B in the ratio implied by the current reserves. The bracket — the LP's claim — extends outward along the curve. Position tokens are minted in proportion to the share added.
Step 3 · DexSwapExactIn
The bead slides. Output is computed by curve.
A trader spends a fixed amount of token A. The bead at reserve x slides right; the bead at reserve y slides down by exactly the amount required to preserve k. If the result drops below min_out, the chain reverts the entire trade.
Step 4 · DexSwapExactOut
The slide is bounded by max_in.
Exact-out swaps fix the output and let the curve dictate the input. If the input the curve demands exceeds max_in, the transaction reverts before any state changes. The trader pays the slippage they signed for — or pays nothing at all.
Step 5 · DexRemoveLiquidity
Closes the bracket. Returns the share.
Burning a position token returns the LP's proportional share of the current reserves. The bracket retracts inward; the curve continues without the LP's contribution. Fees earned during the position's lifetime arrive baked into the curve's drift.
Slippage is geometry
The wallet can compute it. The chain enforces it.
On a constant-product curve, output is a deterministic function of input, reserves, and fee. The wallet quotes the exact result before submit. The chain re-runs the math at execution height. If the actual output is below min_out, or the actual input would exceed max_in, the transaction reverts — atomically, before any state changes. No partial fills.
Single-block settlement
No multi-block sandwich window.
Swaps settle in a single MACA-finalised block. There is no opt-in MEV protection because there is no multi-block reordering surface. Multi-hop routes execute as a sequence of legs inside one transaction; any leg below its min_out reverts the entire route. The chain is the price, the price is the chain.
Swap on the chain that priced it.
Constant-product math. Single-block settlement. Slippage you sign for. No deployed contract, no relayer dependency, no off-chain oracle. The curve lives in the chain; the chain lives in consensus.