Nonce workarounds

per_multicall/src/Errors.sol

@@ -45,3 +45,9 @@ error InvalidMagicValue();
 
 // Signature: 0x0601f697
 error InvalidFeeSplit();
+
+// Signature: 0xb40d37c3
+error DuplicateRelayerSubwallet();
+
+// Signature: 0xac4d92b3
+error RelayerSubwalletNotFound();

per_multicall/src/ExpressRelay.sol

@@ -28,6 +28,7 @@ contract ExpressRelay is ExpressRelayHelpers, ExpressRelayState {
     ) {
         state.admin = admin;
         state.relayer = relayer;
+        state.relayerSubwallets = new address[](0);
 
         validateFeeSplit(feeSplitProtocolDefault);
         state.feeSplitProtocolDefault = feeSplitProtocolDefault;

per_multicall/src/ExpressRelayState.sol

@@ -10,8 +10,10 @@ contract ExpressRelayStorage {
     struct State {
         // address of admin of express relay, handles setting fees and relayer role
         address admin;
-        // address of relayer EOA uniquely permissioned to call ExpressRelay.multicall
+        // address of primary relayer EOA, where relayer will ultimately receive fees
         address relayer;
+        // store of relayer subwallets permissioned to call ExpressRelay.multicall
+        address[] relayerSubwallets;
         // stores custom fee splits for protocol fee receivers
         mapping(address => uint256) feeConfig;
         // stores the flags for whether permission keys are currently allowed
@@ -40,6 +42,23 @@ contract ExpressRelayState is IExpressRelay {
     }
 
     modifier onlyRelayer() {
+        if (msg.sender != state.relayer) {
+            bool isSubwallet = false;
+            for (uint i = 0; i < state.relayerSubwallets.length; i++) {
+                if (state.relayerSubwallets[i] == msg.sender) {
+                    isSubwallet = true;
+                    break;
+                }
+            }
+
+            if (!isSubwallet) {
+                revert Unauthorized();
+            }
+        }
+        _;
+    }
+
+    modifier onlyRelayerPrimary() {
         if (msg.sender != state.relayer) {
             revert Unauthorized();
         }
@@ -66,6 +85,7 @@ contract ExpressRelayState is IExpressRelay {
      */
     function setRelayer(address relayer) public onlyAdmin {
         state.relayer = relayer;
+        state.relayerSubwallets = new address[](0);
     }
 
     /**
@@ -75,6 +95,50 @@ contract ExpressRelayState is IExpressRelay {
         return state.relayer;
     }
 
+    /**
+     * @notice addRelayerSubwallet function - adds a relayer subwallet
+     *
+     * @param subwallet: address of the relayer subwallet to be added
+     */
+    function addRelayerSubwallet(address subwallet) public onlyRelayerPrimary {
+        for (uint i = 0; i < state.relayerSubwallets.length; i++) {
+            if (state.relayerSubwallets[i] == subwallet) {
+                revert DuplicateRelayerSubwallet();
+            }
+        }
+        state.relayerSubwallets.push(subwallet);
+    }
+
+    /**
+     * @notice removeRelayerSubwallet function - removes a relayer subwallet
+     *
+     * @param subwallet: address of the relayer subwallet to be removed
+     */
+    function removeRelayerSubwallet(
+        address subwallet
+    ) public onlyRelayerPrimary {
+        for (uint i = 0; i < state.relayerSubwallets.length; i++) {
+            if (state.relayerSubwallets[i] == subwallet) {
+                state.relayerSubwallets[i] = state.relayerSubwallets[
+                    state.relayerSubwallets.length - 1
+                ];
+                state.relayerSubwallets.pop();
+                break;
+            }
+
+            if (i == state.relayerSubwallets.length - 1) {
+                revert RelayerSubwalletNotFound();
+            }
+        }
+    }
+
+    /**
+     * @notice getRelayerSubwallets function - returns the relayer subwallets
+     */
+    function getRelayerSubwallets() public view returns (address[] memory) {
+        return state.relayerSubwallets;
+    }
+
     /**
      * @notice setFeeProtocolDefault function - sets the default fee split for the protocol
      *

per_multicall/test/ExpressRelayUnit.t.sol

@@ -36,6 +36,96 @@ contract ExpressRelayUnitTest is Test, ExpressRelayTestSetup {
         expressRelay.setRelayer(newRelayer);
     }
 
+    function testAddRelayerSubwalletByRelayerPrimary() public {
+        address subwallet = makeAddr("subwallet");
+        vm.prank(relayer);
+        expressRelay.addRelayerSubwallet(subwallet);
+        address[] memory relayerSubwallets = expressRelay
+            .getRelayerSubwallets();
+
+        assertAddressInArray(subwallet, relayerSubwallets, true);
+    }
+
+    function testAddRelayerSubwalletByNonRelayerPrimaryFail() public {
+        address subwallet1 = makeAddr("subwallet1");
+        vm.prank(relayer);
+        expressRelay.addRelayerSubwallet(subwallet1);
+
+        address subwallet2 = makeAddr("subwallet2");
+        vm.expectRevert(Unauthorized.selector);
+        vm.prank(subwallet1);
+        expressRelay.addRelayerSubwallet(subwallet2);
+    }
+
+    function testAddDuplicateRelayerSubwalletByRelayerPrimaryFail() public {
+        address subwallet = makeAddr("subwallet");
+        vm.prank(relayer);
+        expressRelay.addRelayerSubwallet(subwallet);
+        vm.expectRevert(DuplicateRelayerSubwallet.selector);
+        vm.prank(relayer);
+        expressRelay.addRelayerSubwallet(subwallet);
+    }
+
+    function testRemoveRelayerSubwalletByRelayerPrimary() public {
+        address subwallet1 = makeAddr("subwallet1");
+        address subwallet2 = makeAddr("subwallet2");
+        vm.prank(relayer);
+        expressRelay.addRelayerSubwallet(subwallet1);
+        vm.prank(relayer);
+        expressRelay.addRelayerSubwallet(subwallet2);
+        address[] memory relayerSubwalletsPre = expressRelay
+            .getRelayerSubwallets();
+
+        vm.prank(relayer);
+        expressRelay.removeRelayerSubwallet(subwallet1);
+        address[] memory relayerSubwalletsPost = expressRelay
+            .getRelayerSubwallets();
+
+        assertEq(relayerSubwalletsPre.length, relayerSubwalletsPost.length + 1);
+        assertAddressInArray(subwallet1, relayerSubwalletsPost, false);
+        assertAddressInArray(subwallet2, relayerSubwalletsPost, true);
+    }
+
+    function testRemoveRelayerSubwalletByNonRelayerPrimaryFail() public {
+        address subwallet1 = makeAddr("subwallet1");
+        address subwallet2 = makeAddr("subwallet2");
+        vm.prank(relayer);
+        expressRelay.addRelayerSubwallet(subwallet1);
+        vm.prank(relayer);
+        expressRelay.addRelayerSubwallet(subwallet2);
+
+        vm.expectRevert(Unauthorized.selector);
+        vm.prank(subwallet1);
+        expressRelay.removeRelayerSubwallet(subwallet2);
+    }
+
+    function testRemoveNonExistentRelayerSubwalletByRelayerFail() public {
+        address subwallet = makeAddr("subwallet");
+        vm.prank(relayer);
+        expressRelay.addRelayerSubwallet(subwallet);
+
+        address nonExistentSubwallet = makeAddr("nonExistentSubwallet");
+        vm.expectRevert(RelayerSubwalletNotFound.selector);
+        vm.prank(relayer);
+        expressRelay.removeRelayerSubwallet(nonExistentSubwallet);
+    }
+
+    function testChangeRelayerAfterAddingRelayerSubwallet() public {
+        address subwallet = makeAddr("subwallet");
+        vm.prank(relayer);
+        expressRelay.addRelayerSubwallet(subwallet);
+        address[] memory expectedSubwallets = new address[](1);
+        expectedSubwallets[0] = subwallet;
+        assertEq(expressRelay.getRelayerSubwallets(), expectedSubwallets);
+
+        address newRelayer = makeAddr("newRelayer");
+        vm.prank(admin);
+        expressRelay.setRelayer(newRelayer);
+
+        assertEq(expressRelay.getRelayer(), newRelayer);
+        assertEq(expressRelay.getRelayerSubwallets(), new address[](0));
+    }
+
     function testSetFeeProtocolDefaultByAdmin() public {
         uint256 feeSplitProtocolDefaultPre = expressRelay
             .getFeeProtocolDefault();
@@ -130,7 +220,6 @@ contract ExpressRelayUnitTest is Test, ExpressRelayTestSetup {
         uint256 feeMax = 10 ** 18;
         vm.prank(admin);
         expressRelay.setFeeRelayer(feeMax);
-        uint256 feeRelayerPost = expressRelay.getFeeRelayer();
 
         // test setting fee to a value higher than the highest valid value, should fail
         uint256 fee = 10 ** 18 + 1;
@@ -153,6 +242,18 @@ contract ExpressRelayUnitTest is Test, ExpressRelayTestSetup {
         expressRelay.multicall(permission, multicallData);
     }
 
+    function testMulticallByRelayerSubwalletEmpty() public {
+        address subwallet = makeAddr("subwallet");
+        vm.prank(relayer);
+        expressRelay.addRelayerSubwallet(subwallet);
+
+        bytes memory permission = abi.encode("random permission");
+        MulticallData[] memory multicallData;
+
+        vm.prank(subwallet);
+        expressRelay.multicall(permission, multicallData);
+    }
+
     function testMulticallByNonRelayerFail() public {
         bytes memory permission = abi.encode("random permission");
         MulticallData[] memory multicallData;

per_multicall/test/helpers/TestParsingHelpers.sol

@@ -42,6 +42,21 @@ contract TestParsingHelpers is Test {
         return BidInfo(bid, 1_000_000_000_000, vm.addr(executorSk), executorSk);
     }
 
+    function assertAddressInArray(
+        address addr,
+        address[] memory arr,
+        bool exists
+    ) internal pure {
+        bool found = false;
+        for (uint256 i = 0; i < arr.length; i++) {
+            if (arr[i] == addr) {
+                found = true;
+                break;
+            }
+        }
+        assert(found == exists);
+    }
+
     function assertEqBalances(
         AccountBalance memory a,
         AccountBalance memory b