pure kappa formulation: target slippage extracted into pool creator code

src/PartyPlanner.sol

@@ -3,6 +3,7 @@ pragma solidity ^0.8.30;
 
 import "./IPartyPlanner.sol";
 import "./PartyPool.sol";
+import "./LMSRStabilized.sol";
 import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
 import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
 
@@ -19,15 +20,14 @@ contract PartyPlanner is IPartyPlanner {
     mapping(IERC20 => bool) private _tokenSupported;
     mapping(IERC20 => PartyPool[]) private _poolsByToken;
 
-    /// @inheritdoc IPartyPlanner
+    /// Main createPool variant: accepts kappa directly (preferred).
     function createPool(
         // Pool constructor args
         string memory name_,
         string memory symbol_,
         IERC20[] memory _tokens,
         uint256[] memory _bases,
-        int128 _tradeFrac,
-        int128 _targetSlippage,
+        int128 _kappa,
         uint256 _swapFeePpm,
         uint256 _flashFeePpm,
         bool _stable,
@@ -37,25 +37,23 @@ contract PartyPlanner is IPartyPlanner {
         uint256[] memory initialDeposits,
         uint256 initialLpAmount,
         uint256 deadline
-    ) external returns (PartyPool pool, uint256 lpAmount) {
+    ) public returns (PartyPool pool, uint256 lpAmount) {
         // Validate inputs
         require(deadline == 0 || block.timestamp <= deadline, "Planner: deadline exceeded");
         require(_tokens.length == initialDeposits.length, "Planner: tokens and deposits length mismatch");
         require(payer != address(0), "Planner: payer cannot be zero address");
         require(receiver != address(0), "Planner: receiver cannot be zero address");
 
-        // Validate fixed-point fractions: must be less than 1.0 in 64.64 fixed-point
-        require(_tradeFrac < FIXED_ONE_64x64, "Planner: tradeFrac must be < 1 (64.64)");
-        require(_targetSlippage < FIXED_ONE_64x64, "Planner: targetSlippage must be < 1 (64.64)");
+        // Validate kappa > 0 (Q64.64)
+        require(_kappa > int128(0), "Planner: kappa must be > 0");
 
-        // Create a new PartyPool instance
+        // Create a new PartyPool instance (kappa-based constructor)
         pool = new PartyPool(
             name_,
             symbol_,
             _tokens,
             _bases,
-            _tradeFrac,
-            _targetSlippage,
+            _kappa,
             _swapFeePpm,
             _flashFeePpm,
             _stable
@@ -90,6 +88,50 @@ contract PartyPlanner is IPartyPlanner {
         // Call mint on the new pool to initialize it with the transferred tokens
         lpAmount = pool.initialMint(receiver, initialLpAmount);
     }
+
+    /// Backwards-compatible convenience overload: compute kappa from (tradeFrac, targetSlippage) then call kappa-based createPool.
+    function createPool(
+        // Pool constructor args (old signature)
+        string memory name_,
+        string memory symbol_,
+        IERC20[] memory _tokens,
+        uint256[] memory _bases,
+        int128 _tradeFrac,
+        int128 _targetSlippage,
+        uint256 _swapFeePpm,
+        uint256 _flashFeePpm,
+        bool _stable,
+        // Initial deposit information
+        address payer,
+        address receiver,
+        uint256[] memory initialDeposits,
+        uint256 initialLpAmount,
+        uint256 deadline
+    ) external returns (PartyPool pool, uint256 lpAmount) {
+        // Validate fixed-point fractions: must be less than 1.0 in 64.64 fixed-point
+        require(_tradeFrac < FIXED_ONE_64x64, "Planner: tradeFrac must be < 1 (64.64)");
+        require(_targetSlippage < FIXED_ONE_64x64, "Planner: targetSlippage must be < 1 (64.64)");
+
+        // Compute kappa from slippage params using LMSR helper (kappa depends only on n, f and s)
+        int128 computedKappa = LMSRStabilized.computeKappaFromSlippage(_tokens.length, _tradeFrac, _targetSlippage);
+
+        // Delegate to the kappa-based createPool variant
+        return createPool(
+            name_,
+            symbol_,
+            _tokens,
+            _bases,
+            computedKappa,
+            _swapFeePpm,
+            _flashFeePpm,
+            _stable,
+            payer,
+            receiver,
+            initialDeposits,
+            initialLpAmount,
+            deadline
+        );
+    }
     
     /// @inheritdoc IPartyPlanner
     function getPoolSupported(address pool) external view returns (bool) {