diff --git a/src/onchain/TestArbitrage.sol b/src/onchain/TestArbitrage.sol
index 95aee21..6d60451 100644
--- a/src/onchain/TestArbitrage.sol
+++ b/src/onchain/TestArbitrage.sol
@@ -207,6 +207,42 @@ contract TestArbitrage is IFlashLoanRecipient, ReentrancyGuard, Ownable, Pausabl
     /// @param executor Address executing the emergency action
     event EmergencyAction(string action, address token, uint256 amount, address executor);
 
+    //////////////////////////////////////////////////////////////
+    //                        MODIFIERS                       //
+    //////////////////////////////////////////////////////////////
+
+    /// @notice Restricts access to authorized traders or owner
+    /// @dev Prevents unauthorized trade execution
+    modifier onlyAuthorized() {
+        require(authorizedTraders[msg.sender] || msg.sender == owner(), "TestArbitrage: Not authorized to trade");
+        _;
+    }
+
+    /// @notice Validates trade parameters before execution
+    /// @param params Trade parameters to validate
+    /// @dev Comprehensive validation of all trade inputs
+    modifier validTradeParams(TradeParams memory params) {
+        require(params.routerPath.length == 2, "TestArbitrage: Must provide exactly 2 routers");
+        require(params.tokenPath.length == 2, "TestArbitrage: Must provide exactly 2 tokens");
+        require(params.tokenPath[0] != params.tokenPath[1], "TestArbitrage: Tokens must be different");
+        require(
+            params.routerPath[0] != address(0) && params.routerPath[1] != address(0),
+            "TestArbitrage: Invalid router addresses"
+        );
+        require(
+            params.tokenPath[0] != address(0) && params.tokenPath[1] != address(0),
+            "TestArbitrage: Invalid token addresses"
+        );
+        require(params.fee > 0 && params.fee <= 10000, "TestArbitrage: Invalid fee tier");
+        require(
+            params.minProfitBps >= MIN_PROFIT_BPS && params.minProfitBps <= MAX_BPS,
+            "TestArbitrage: Invalid profit threshold"
+        );
+        require(params.maxSlippageBps <= MAX_SLIPPAGE_BPS, "TestArbitrage: Slippage too high");
+        require(params.deadline >= block.timestamp, "TestArbitrage: Trade deadline passed");
+        _;
+    }
+
     //////////////////////////////////////////////////////////////
     //                        CONSTRUCTOR                     //
     //////////////////////////////////////////////////////////////