diff --git a/src/PartyPool.sol b/src/PartyPool.sol
index dcf8aa0..fc2e0b1 100644
--- a/src/PartyPool.sol
+++ b/src/PartyPool.sol
@@ -58,7 +58,7 @@ contract PartyPool is PartyPoolBase, OwnableExternal, ERC20External, IPartyPool
     function fees() external view returns (uint256[] memory) { return _fees; }
 
     /// @notice Effective combined fee in ppm for (i as input, j as output)
-    function fee(uint256 i, uint256 j) external view returns (uint256) { return _pairFeePpm(i,j); }
+    function fee(uint256 i, uint256 j) external view returns (uint256) { return _pairFeePpmView(i,j); }
 
     /// @notice Flash-loan fee in parts-per-million (ppm) applied to flash borrow amounts.
     uint256 private immutable FLASH_FEE_PPM;
@@ -240,7 +240,7 @@ contract PartyPool is PartyPoolBase, OwnableExternal, ERC20External, IPartyPool
         uint256 maxAmountIn,
         int128 limitPrice
     ) external view returns (uint256 amountIn, uint256 amountOut, uint256 inFee) {
-        (uint256 grossIn, uint256 outUint,,,, uint256 feeUint) = _quoteSwapExactIn(inputTokenIndex, outputTokenIndex, maxAmountIn, limitPrice);
+        (uint256 grossIn, uint256 outUint,,,, uint256 feeUint) = _quoteSwapExactIn(inputTokenIndex, outputTokenIndex, maxAmountIn, limitPrice, _pairFeePpmView(inputTokenIndex, outputTokenIndex));
         return (grossIn, outUint, feeUint);
     }
 
@@ -259,7 +259,7 @@ contract PartyPool is PartyPoolBase, OwnableExternal, ERC20External, IPartyPool
 
         // Compute amounts using the same path as views
         (uint256 totalTransferAmount, uint256 amountOutUint, int128 amountInInternalUsed, int128 amountOutInternal, , uint256 feeUint) =
-            _quoteSwapExactIn(inputTokenIndex, outputTokenIndex, maxAmountIn, limitPrice);
+            _quoteSwapExactIn(inputTokenIndex, outputTokenIndex, maxAmountIn, limitPrice, _pairFeePpm(inputTokenIndex, outputTokenIndex));
 
         // Cache token references for fewer SLOADs
         IERC20 tokenIn = _tokens[inputTokenIndex];
@@ -309,7 +309,8 @@ contract PartyPool is PartyPoolBase, OwnableExternal, ERC20External, IPartyPool
         uint256 inputTokenIndex,
         uint256 outputTokenIndex,
         uint256 maxAmountIn,
-        int128 limitPrice
+        int128 limitPrice,
+        uint256 feePpm
     ) internal view
     returns (
             uint256 grossIn,
@@ -321,8 +322,7 @@ contract PartyPool is PartyPoolBase, OwnableExternal, ERC20External, IPartyPool
         )
     {
         // Estimate max net input (fee on gross rounded up, then subtract)
-        uint256 pairFeePpm = _pairFeePpm(inputTokenIndex, outputTokenIndex);
-        (, uint256 netUintForSwap) = _computeFee(maxAmountIn, pairFeePpm);
+        (, uint256 netUintForSwap) = _computeFee(maxAmountIn, feePpm);
 
         // Convert to internal (floor)
         int128 deltaInternalI = _uintToInternalFloor(netUintForSwap, _bases[inputTokenIndex]);
@@ -338,8 +338,8 @@ contract PartyPool is PartyPoolBase, OwnableExternal, ERC20External, IPartyPool
         // Compute gross transfer including fee on the used input (ceil)
         feeUint = 0;
         grossIn = amountInUintNoFee;
-        if (pairFeePpm > 0) {
-            feeUint = _ceilFee(amountInUintNoFee, pairFeePpm);
+        if (feePpm > 0) {
+            feeUint = _ceilFee(amountInUintNoFee, feePpm);
             grossIn += feeUint;
         }
 
diff --git a/src/PartyPoolBase.sol b/src/PartyPoolBase.sol
index aa3a20a..8e8ef3f 100644
--- a/src/PartyPoolBase.sol
+++ b/src/PartyPoolBase.sol
@@ -1,15 +1,15 @@
 // SPDX-License-Identifier: UNLICENSED
 pragma solidity ^0.8.30;
 
-import "./NativeWrapper.sol";
 import {ABDKMath64x64} from "../lib/abdk-libraries-solidity/ABDKMath64x64.sol";
-import {ERC20Internal} from "./ERC20Internal.sol";
 import {IERC20} from "../lib/openzeppelin-contracts/contracts/token/ERC20/IERC20.sol";
-import {LMSRStabilized} from "./LMSRStabilized.sol";
-import {PartyPoolHelpers} from "./PartyPoolHelpers.sol";
-import {ReentrancyGuard} from "../lib/openzeppelin-contracts/contracts/utils/ReentrancyGuard.sol";
 import {SafeERC20} from "../lib/openzeppelin-contracts/contracts/token/ERC20/utils/SafeERC20.sol";
+import {ReentrancyGuard} from "../lib/openzeppelin-contracts/contracts/utils/ReentrancyGuard.sol";
+import {ERC20Internal} from "./ERC20Internal.sol";
+import {LMSRStabilized} from "./LMSRStabilized.sol";
+import {NativeWrapper} from "./NativeWrapper.sol";
 import {OwnableInternal} from "./OwnableInternal.sol";
+import {PartyPoolHelpers} from "./PartyPoolHelpers.sol";
 
 /// @notice Abstract base contract that contains storage and internal helpers only.
 /// No external/public functions here.
@@ -26,6 +26,7 @@ abstract contract PartyPoolBase is OwnableInternal, ERC20Internal, ReentrancyGua
 
     /// @notice Per-asset swap fees in ppm. Fees are applied on input for swaps; see helpers for composition rules.
     uint256[] internal _fees;
+    mapping( uint256 => uint256 ) internal _pairFees;
 
     //
     // Internal state
@@ -92,12 +93,22 @@ abstract contract PartyPoolBase is OwnableInternal, ERC20Internal, ReentrancyGua
     // We implement this as: ceil( fi + fj - (fi*fj)/1e6 ) for the real-valued expression.
     // For integer arithmetic with fi,fj in ppm this is equal to: fi + fj - floor( (fi*fj)/1e6 ).
     // So we compute prod = fi * fj, prodDiv = prod / 1e6 (floor), and return fi + fj - prodDiv.
-    function _pairFeePpm(uint256 i, uint256 j) internal view returns (uint256) {
+    function _pairFeePpmView(uint256 i, uint256 j) internal view returns (uint256) {
         uint256 fi = _fees[i];
         uint256 fj = _fees[j];
         return fi + fj - fi * fj / 1_000_000;
     }
 
+    function _pairFeePpm(uint256 i, uint256 j) internal returns (uint256 fee) {
+        uint256 key = 1000 * i + j;
+        fee = _pairFees[key];
+        if (fee == 0) {
+            // store fee in cache
+            fee = _pairFeePpmView(i,j);
+            _pairFees[key] = fee;
+        }
+    }
+
     // Convert uint token amount -> internal 64.64 (floor). Uses ABDKMath64x64.divu which truncates.
     function _uintToInternalFloor(uint256 amount, uint256 base) internal pure returns (int128) {
         // internal = amount / base  (as Q64.64)
diff --git a/test/GasTest.sol b/test/GasTest.sol
index 722c90f..ef75f4c 100644
--- a/test/GasTest.sol
+++ b/test/GasTest.sol
@@ -237,10 +237,10 @@ contract GasTest is Test {
         vm.prank(alice);
         TestERC20(address(tokens[1])).approve(address(testPool), type(uint256).max);
 
-        uint256 maxIn = 1_000;
+        uint256 maxIn = 10_000;
 
-        // Perform 10 swaps alternating directions to avoid large imbalance
-        for (uint256 i = 0; i < 10; i++) {
+        // Perform swaps alternating directions to avoid large imbalance
+        for (uint256 i = 0; i < 20; i++) {
             vm.prank(alice);
             if (i % 2 == 0) {
                 // swap token0 -> token1
@@ -249,6 +249,9 @@ contract GasTest is Test {
                 // swap token1 -> token0
                 testPool.swap(alice, alice, 1, 0, maxIn, 0, 0, false);
             }
+            // shake up the bits
+            maxIn *= 787;
+            maxIn /= 1000;
         }
     }