feat(contracts/core): add additional actions to inbox

contracts/core/.gas-snapshot

@@ -3,7 +3,7 @@ Admin_Test:test_pause_unpause_bridge() (gas: 21501844)
 Admin_Test:test_pause_unpause_xcall() (gas: 26426087)
 Admin_Test:test_pause_unpause_xsubmit() (gas: 26425838)
 Admin_Test:test_upgrade() (gas: 30507332)
-AllocPredeploys_Test:test_num_allocs() (gas: 1181198035)
+AllocPredeploys_Test:test_num_allocs() (gas: 1181152549)
 AllocPredeploys_Test:test_predeploys() (gas: 1181134337)
 AllocPredeploys_Test:test_preinstalls() (gas: 1181850775)
 AllocPredeploys_Test:test_proxies() (gas: 1408777576)
@@ -22,12 +22,30 @@ FeeOracleV2_Test:test_setExecGasPrice() (gas: 44247)
 FeeOracleV2_Test:test_setManager() (gas: 45775)
 FeeOracleV2_Test:test_setProtocolFee() (gas: 32226)
 FeeOracleV2_Test:test_setToNativeRate() (gas: 43640)
-Inbox_request_Test:test_request_multiToken() (gas: 547583)
-Inbox_request_Test:test_request_nativeMultiToken() (gas: 605757)
-Inbox_request_Test:test_request_reverts() (gas: 891165)
-Inbox_request_Test:test_request_singleNative() (gas: 364015)
-Inbox_request_Test:test_request_singleToken() (gas: 426691)
-Inbox_request_Test:test_request_two() (gas: 671465)
+Inbox_request_Test:test_accept_one_request() (gas: 399801)
+Inbox_request_Test:test_accept_reverts() (gas: 801467)
+Inbox_request_Test:test_accept_skip_first() (gas: 717578)
+Inbox_request_Test:test_accept_two_requests() (gas: 740791)
+Inbox_request_Test:test_cancel_multiToken() (gas: 534734)
+Inbox_request_Test:test_cancel_nativeMultiToken() (gas: 605436)
+Inbox_request_Test:test_cancel_oldest_request() (gas: 560631)
+Inbox_request_Test:test_cancel_one_request() (gas: 314120)
+Inbox_request_Test:test_cancel_rejected_nativeMultiToken_request() (gas: 611928)
+Inbox_request_Test:test_cancel_rejected_nativeToken_request() (gas: 320258)
+Inbox_request_Test:test_cancel_reverts() (gas: 825676)
+Inbox_request_Test:test_cancel_singleToken() (gas: 389059)
+Inbox_request_Test:test_cancel_two_requests() (gas: 566788)
+Inbox_request_Test:test_reject_nativeMultiToken() (gas: 614992)
+Inbox_request_Test:test_reject_oldest_request() (gas: 681251)
+Inbox_request_Test:test_reject_one_request() (gas: 372690)
+Inbox_request_Test:test_reject_reverts() (gas: 565842)
+Inbox_request_Test:test_reject_two_requests() (gas: 684264)
+Inbox_request_Test:test_request_multiToken() (gas: 548172)
+Inbox_request_Test:test_request_nativeMultiToken() (gas: 606437)
+Inbox_request_Test:test_request_reverts() (gas: 891638)
+Inbox_request_Test:test_request_singleNative() (gas: 364446)
+Inbox_request_Test:test_request_singleToken() (gas: 427141)
+Inbox_request_Test:test_request_two() (gas: 672268)
 InitializableHelper_Test:test_disableInitalizers() (gas: 181686)
 InitializableHelper_Test:test_getInitialized() (gas: 178023)
 OmniBridgeL1_Test:test_bridge() (gas: 233678)

contracts/core/package.json

@@ -24,6 +24,7 @@
     "@openzeppelin/contracts-upgradeable": "^5.0.2",
     "eigenlayer-contracts": "github:Layr-Labs/eigenlayer-contracts",
     "eigenlayer-middleware": "github:Layr-Labs/eigenlayer-middleware",
+    "solady": "^0.0.261",
     "solmate": "^6.2.0"
   }
 }

contracts/core/src/solve/Inbox.sol

@@ -1,21 +1,25 @@
 // SPDX-License-Identifier: GPL-3.0-only
 pragma solidity =0.8.24;
 
-import { ReentrancyGuardUpgradeable } from "@openzeppelin/contracts-upgradeable/utils/ReentrancyGuardUpgradeable.sol";
+import { OwnableRoles } from "solady/src/auth/OwnableRoles.sol";
+import { ReentrancyGuard } from "solady/src/utils/ReentrancyGuard.sol";
+import { Initializable } from "solady/src/utils/Initializable.sol";
 import { SafeERC20, IERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
 import { Solve } from "./Solve.sol";
 
 /**
  * @title Inbox
  * @notice Entrypoint and alt-mempoool for user solve requests.
  */
-contract Inbox is ReentrancyGuardUpgradeable {
+contract Inbox is OwnableRoles, ReentrancyGuard, Initializable {
     using SafeERC20 for IERC20;
 
     error NoDeposits();
     error InvalidCall();
     error InvalidDeposit();
-    error ZeroDeposit();
+    error RequestNotOpen();
+    error TransferFailed();
+    error RequestNotCancelable();
 
     /**
      * @notice Emitted when a request is created.
@@ -26,6 +30,32 @@ contract Inbox is ReentrancyGuardUpgradeable {
      */
     event Requested(bytes32 indexed id, address indexed from, Solve.Call call, Solve.Deposit[] deposits);
 
+    /**
+     * @notice Emitted when a request is accepted.
+     * @param id  ID of the request.
+     * @param by  Address of the solver who accepted the request.
+     */
+    event Accepted(bytes32 indexed id, address indexed by);
+
+    /**
+     * @notice Emitted when a request is rejected.
+     * @param id  ID of the request.
+     * @param by  Address of the solver who rejected the request.
+     */
+    event Rejected(bytes32 indexed id, address indexed by);
+
+    /**
+     * @notice Emitted when a request is cancelled.
+     * @param id  ID of the request.
+     */
+    event Cancelled(bytes32 indexed id);
+
+    /**
+     * @notice Role for solvers.
+     * @dev _ROLE_0 evaluates to '1'.
+     */
+    uint256 internal constant SOLVER = _ROLE_0;
+
     /**
      * @dev uint repr of last assigned request ID.
      */
@@ -36,8 +66,15 @@ contract Inbox is ReentrancyGuardUpgradeable {
      */
     mapping(bytes32 id => Solve.Request) internal _requests;
 
-    function initialize() public initializer {
-        __ReentrancyGuard_init();
+    /**
+     * @notice Initialize the contract's owner and solver.
+     * @dev Used instead of constructor as we want to use the transparent upgradeable proxy pattern.
+     * @param owner_  Address of the owner.
+     * @param solver_ Address of the solver.
+     */
+    function initialize(address owner_, address solver_) external initializer {
+        _initializeOwner(owner_);
+        _grantRoles(solver_, SOLVER);
     }
 
     /**
@@ -71,6 +108,52 @@ contract Inbox is ReentrancyGuardUpgradeable {
         return req.id;
     }
 
+    /**
+     * @notice Accept an open request.
+     * @dev Only a whitelisted solver can accept.
+     * @param id  ID of the request.
+     */
+    function accept(bytes32 id) external onlyRoles(SOLVER) {
+        Solve.Request storage req = _requests[id];
+        if (req.status != Solve.Status.Open) revert RequestNotOpen();
+
+        req.updatedAt = uint40(block.timestamp);
+        req.status = Solve.Status.Accepted;
+        req.acceptedBy = msg.sender;
+
+        emit Accepted(id, msg.sender);
+    }
+
+    /**
+     * @notice Reject an open request.
+     * @dev Only a whitelisted solver can reject.
+     * @param id  ID of the request.
+     */
+    function reject(bytes32 id) external onlyRoles(SOLVER) {
+        Solve.Request storage req = _requests[id];
+        if (req.status != Solve.Status.Open) revert RequestNotOpen();
+
+        req.updatedAt = uint40(block.timestamp);
+        req.status = Solve.Status.Rejected;
+
+        emit Rejected(id, msg.sender);
+    }
+
+    /**
+     * @notice Cancel an open or rejected request and refund deposits.
+     * @dev Only request initiator can cancel.
+     * @param id  ID of the request.
+     */
+    function cancel(bytes32 id) external {
+        Solve.Request storage req = _requests[id];
+        if (req.status != Solve.Status.Open && req.status != Solve.Status.Rejected) revert RequestNotCancelable();
+        if (req.from != msg.sender) revert Unauthorized();
+
+        _cancelRequest(req);
+
+        emit Cancelled(id);
+    }
+
     /**
      * @dev Open a new request in storage at `id`.
      *      Transfer token deposits from msg.sender to this inbox.
@@ -85,6 +168,7 @@ contract Inbox is ReentrancyGuardUpgradeable {
         req = _requests[id];
         req.id = id;
         req.updatedAt = uint40(block.timestamp);
+        req.status = Solve.Status.Open;
         req.from = from;
         req.call = call;
 
@@ -104,6 +188,23 @@ contract Inbox is ReentrancyGuardUpgradeable {
         }
     }
 
+    function _cancelRequest(Solve.Request storage req) internal {
+        // Refund deposits
+        uint256 length = req.deposits.length;
+        for (uint256 i = 0; i < length; i++) {
+            Solve.Deposit memory deposit = req.deposits[i];
+            if (deposit.isNative) {
+                (bool success,) = payable(msg.sender).call{ value: deposit.amount }("");
+                if (!success) revert TransferFailed();
+            } else {
+                IERC20(deposit.token).safeTransfer(msg.sender, deposit.amount);
+            }
+        }
+
+        // Delete request
+        delete _requests[req.id];
+    }
+
     /**
      * @dev Increment and return _lastId.
      */

contracts/core/src/solve/Solve.sol

@@ -3,20 +3,19 @@ pragma solidity =0.8.24;
 
 library Solve {
     enum Status {
+        Invalid,
         Open,
         Accepted,
-        Cancelled,
         Rejected,
-        Fulfilled,
-        Paid
+        Fulfilled
     }
 
     /**
      * @notice A request to execute a call on another chain, backed by a deposit.
      * @param id            ID for the request, globally unique per inbox.
      * @param updatedAt     Timestamp request status was last updated.
      * @param from          Address of the user who created the request.
-     * @param fulfilledBy   Address of the solver that fulfilled the request.
+     * @param acceptedBy    Address of the solver that accepted the request.
      * @param status        Request status (open, accepted, cancelled, rejected, fulfilled, paid).
      * @param call          Details of the call to be executed on another chain.
      * @param deposits      Array of deposits backing the request.
@@ -26,7 +25,7 @@ library Solve {
         uint40 updatedAt;
         Status status;
         address from;
-        address fulfilledBy;
+        address acceptedBy;
         Call call;
         Deposit[] deposits;
     }