feat(permitter): Add minTokensPerBidder, remove maxBid from Permit struct

.gitmodules

@@ -4,3 +4,6 @@
 [submodule "lib/openzeppelin-contracts"]
 	path = lib/openzeppelin-contracts
 	url = https://github.com/OpenZeppelin/openzeppelin-contracts
+[submodule ".claude/commands"]
+	path = .claude/commands
+	url = https://github.com/withtally/claude-commands

.mcp.json

@@ -0,0 +1,20 @@
+{
+  "mcpServers": {
+    "linear": {
+      "type": "stdio",
+      "command": "npx",
+      "args": [
+        "mcp-remote",
+        "https://mcp.linear.app/sse"
+      ],
+      "env": {}
+    },
+    "context7": {
+      "command": "npx",
+      "args": [
+        "-y",
+        "@upstash/context7-mcp@latest"
+      ]
+    }
+  }
+}

foundry.lock

@@ -1,4 +1,7 @@
 {
+  ".claude/commands": {
+    "rev": "8d9bfb8d1b8c029d9984cada2fa834cece331469"
+  },
   "lib/forge-std": {
     "tag": {
       "name": "v1.11.0",

src/Permitter.sol

@@ -12,8 +12,7 @@
 /// chainId and verifyingContract to prevent cross-chain and cross-auction replay attacks.
 contract Permitter is IPermitter, EIP712 {
   /// @notice EIP-712 typehash for the Permit struct.
-  bytes32 public constant PERMIT_TYPEHASH =
-    keccak256("Permit(address bidder,uint256 maxBidAmount,uint256 expiry)");
+  bytes32 public constant PERMIT_TYPEHASH = keccak256("Permit(address bidder,uint256 expiry)");
 
   /// @notice Timelock delay for parameter updates (1 hour).
   uint256 public constant UPDATE_DELAY = 1 hours;
@@ -27,6 +26,9 @@
   /// @notice Maximum tokens any single bidder can purchase.
   uint256 public maxTokensPerBidder;
 
+  /// @notice Minimum tokens any single bidder must purchase per bid.
+  uint256 public minTokensPerBidder;
+
   /// @notice Cumulative bid amounts per address.
   mapping(address bidder => uint256 amount) public cumulativeBids;
 
@@ -70,23 +72,29 @@
   /// @param _trustedSigner Address authorized to sign permits.
   /// @param _maxTotalEth Maximum total ETH that can be raised.
   /// @param _maxTokensPerBidder Maximum tokens any single bidder can purchase.
+  /// @param _minTokensPerBidder Minimum tokens any single bidder must purchase per bid.
   /// @param _owner Address that can update caps and pause.
   /// @param _authorizedCaller CCA contract authorized to call validateBid.
   constructor(
     address _trustedSigner,
     uint256 _maxTotalEth,
     uint256 _maxTokensPerBidder,
+    uint256 _minTokensPerBidder,
     address _owner,
     address _authorizedCaller
   ) EIP712("Permitter", "1") {
     if (_trustedSigner == address(0)) revert InvalidTrustedSigner();
     if (_owner == address(0)) revert InvalidOwner();
     if (_maxTotalEth == 0) revert InvalidCap();
     if (_maxTokensPerBidder == 0) revert InvalidCap();
+    if (_minTokensPerBidder > _maxTokensPerBidder) {
+      revert MinTokensExceedsMaxTokens(_minTokensPerBidder, _maxTokensPerBidder);
+    }
 
     trustedSigner = _trustedSigner;
     maxTotalEth = _maxTotalEth;
     maxTokensPerBidder = _maxTokensPerBidder;
+    minTokensPerBidder = _minTokensPerBidder;
     owner = _owner;
     authorizedCaller = _authorizedCaller;
   }
@@ -104,45 +112,45 @@
     // 1. CHEAPEST: Check if paused
     if (paused) revert ContractPaused();
 
-    // 2. Decode permit data
+    // 2. CHEAP: Check minimum bid amount
+    if (bidAmount < minTokensPerBidder) {
+      revert BidBelowMinimum(bidAmount, minTokensPerBidder);
+    }
+
+    // 3. Decode permit data
     (Permit memory permit, bytes memory signature) = abi.decode(permitData, (Permit, bytes));
 
-    // 3. CHEAP: Check time window
+    // 4. CHEAP: Check time window
     if (block.timestamp > permit.expiry) {
       revert SignatureExpired(permit.expiry, block.timestamp);
     }
 
-    // 4. MODERATE: Verify EIP-712 signature
+    // 5. MODERATE: Verify EIP-712 signature
     address recovered = _recoverSigner(permit, signature);
     if (recovered != trustedSigner) revert InvalidSignature(trustedSigner, recovered);
 
-    // 5. Check permit is for this bidder
+    // 6. Check permit is for this bidder
     if (permit.bidder != bidder) revert InvalidSignature(bidder, permit.bidder);
 
-    // 6. STORAGE READ: Check individual cap
+    // 7. STORAGE READ: Check individual cap using maxTokensPerBidder
     uint256 alreadyBid = cumulativeBids[bidder];
     uint256 newCumulative = alreadyBid + bidAmount;
-    if (newCumulative > permit.maxBidAmount) {
-      revert ExceedsPersonalCap(bidAmount, permit.maxBidAmount, alreadyBid);
-    }
-
-    // Also check against global maxTokensPerBidder if it's lower
     if (newCumulative > maxTokensPerBidder) {
       revert ExceedsPersonalCap(bidAmount, maxTokensPerBidder, alreadyBid);
     }
 
-    // 7. STORAGE READ: Check global cap
+    // 8. STORAGE READ: Check global cap
     uint256 alreadyRaised = totalEthRaised;
     uint256 newTotalEth = alreadyRaised + ethValue;
     if (newTotalEth > maxTotalEth) revert ExceedsTotalCap(ethValue, maxTotalEth, alreadyRaised);
 
-    // 8. STORAGE WRITE: Update state
+    // 9. STORAGE WRITE: Update state
     cumulativeBids[bidder] = newCumulative;
     totalEthRaised = newTotalEth;
 
-    // 9. Emit event for monitoring
+    // 10. Emit event for monitoring
     emit PermitVerified(
-      bidder, bidAmount, permit.maxBidAmount - newCumulative, maxTotalEth - newTotalEth
+      bidder, bidAmount, maxTokensPerBidder - newCumulative, maxTotalEth - newTotalEth
     );
 
     return true;
@@ -279,8 +287,7 @@
     view
     returns (address)
   {
-    bytes32 structHash =
-      keccak256(abi.encode(PERMIT_TYPEHASH, permit.bidder, permit.maxBidAmount, permit.expiry));
+    bytes32 structHash = keccak256(abi.encode(PERMIT_TYPEHASH, permit.bidder, permit.expiry));
     bytes32 digest = _hashTypedDataV4(structHash);
     return ECDSA.recover(digest, signature);
   }

src/PermitterFactory.sol

@@ -15,6 +15,7 @@ contract PermitterFactory is IPermitterFactory {
     address trustedSigner,
     uint256 maxTotalEth,
     uint256 maxTokensPerBidder,
+    uint256 minTokensPerBidder,
     address owner,
     address authorizedCaller,
     bytes32 salt
@@ -25,12 +26,18 @@ contract PermitterFactory is IPermitterFactory {
     // Deploy the Permitter using CREATE2
     permitter = address(
       new Permitter{salt: finalSalt}(
-        trustedSigner, maxTotalEth, maxTokensPerBidder, owner, authorizedCaller
+        trustedSigner, maxTotalEth, maxTokensPerBidder, minTokensPerBidder, owner, authorizedCaller
       )
     );
 
     emit PermitterCreated(
-      permitter, owner, trustedSigner, authorizedCaller, maxTotalEth, maxTokensPerBidder
+      permitter,
+      owner,
+      trustedSigner,
+      authorizedCaller,
+      maxTotalEth,
+      maxTokensPerBidder,
+      minTokensPerBidder
     );
   }
 
@@ -39,6 +46,7 @@ contract PermitterFactory is IPermitterFactory {
     address trustedSigner,
     uint256 maxTotalEth,
     uint256 maxTokensPerBidder,
+    uint256 minTokensPerBidder,
     address owner,
     address authorizedCaller,
     bytes32 salt
@@ -49,7 +57,9 @@ contract PermitterFactory is IPermitterFactory {
     // Compute the init code hash
     bytes memory initCode = abi.encodePacked(
       type(Permitter).creationCode,
-      abi.encode(trustedSigner, maxTotalEth, maxTokensPerBidder, owner, authorizedCaller)
+      abi.encode(
+        trustedSigner, maxTotalEth, maxTokensPerBidder, minTokensPerBidder, owner, authorizedCaller
+      )
     );
     bytes32 initCodeHash = keccak256(initCode);
 

src/interfaces/IPermitter.sol

@@ -13,11 +13,9 @@ interface IPermitter {
 
   /// @notice The permit structure containing bidder authorization data.
   /// @param bidder Address authorized to bid.
-  /// @param maxBidAmount Maximum tokens this bidder can purchase (cumulative).
   /// @param expiry Timestamp when permit expires.
   struct Permit {
     address bidder;
-    uint256 maxBidAmount;
     uint256 expiry;
   }
 
@@ -46,6 +44,11 @@ interface IPermitter {
   /// @param alreadyRaised The amount already raised.
   error ExceedsTotalCap(uint256 requested, uint256 cap, uint256 alreadyRaised);
 
+  /// @notice Emitted when a bid is below the minimum amount.
+  /// @param bidAmount The bid amount that was attempted.
+  /// @param minRequired The minimum required bid amount.
+  error BidBelowMinimum(uint256 bidAmount, uint256 minRequired);
+
   /// @notice Emitted when the caller is not authorized.
   error Unauthorized();
 
@@ -58,6 +61,11 @@ interface IPermitter {
   /// @notice Emitted when a cap value is invalid (zero).
   error InvalidCap();
 
+  /// @notice Emitted when minTokensPerBidder exceeds maxTokensPerBidder.
+  /// @param minTokens The minimum tokens per bidder.
+  /// @param maxTokens The maximum tokens per bidder.
+  error MinTokensExceedsMaxTokens(uint256 minTokens, uint256 maxTokens);
+
   /// @notice Emitted when proposed cap is below current amount.
   /// @param proposed The proposed new cap.
   /// @param current The current amount that would exceed the cap.
@@ -194,6 +202,10 @@ interface IPermitter {
   /// @return The maximum tokens per bidder cap.
   function maxTokensPerBidder() external view returns (uint256);
 
+  /// @notice Get the minimum tokens per bidder.
+  /// @return The minimum tokens per bidder.
+  function minTokensPerBidder() external view returns (uint256);
+
   /// @notice Get the owner address.
   /// @return The owner address.
   function owner() external view returns (address);

src/interfaces/IPermitterFactory.sol

@@ -12,19 +12,22 @@ interface IPermitterFactory {
   /// @param authorizedCaller The CCA contract authorized to call validateBid.
   /// @param maxTotalEth The maximum total ETH that can be raised.
   /// @param maxTokensPerBidder The maximum tokens any single bidder can purchase.
+  /// @param minTokensPerBidder The minimum tokens any single bidder must purchase per bid.
   event PermitterCreated(
     address indexed permitter,
     address indexed owner,
     address indexed trustedSigner,
     address authorizedCaller,
     uint256 maxTotalEth,
-    uint256 maxTokensPerBidder
+    uint256 maxTokensPerBidder,
+    uint256 minTokensPerBidder
   );
 
   /// @notice Create a new Permitter instance for an auction.
   /// @param trustedSigner Address authorized to sign permits (Tally backend).
   /// @param maxTotalEth Maximum total ETH that can be raised in the auction.
   /// @param maxTokensPerBidder Maximum tokens any single bidder can purchase.
+  /// @param minTokensPerBidder Minimum tokens any single bidder must purchase per bid.
   /// @param owner Address that can update caps and pause (auction creator).
   /// @param authorizedCaller CCA contract address authorized to call validateBid.
   /// @param salt Salt for CREATE2 deployment to enable deterministic addresses.
@@ -33,6 +36,7 @@ interface IPermitterFactory {
     address trustedSigner,
     uint256 maxTotalEth,
     uint256 maxTokensPerBidder,
+    uint256 minTokensPerBidder,
     address owner,
     address authorizedCaller,
     bytes32 salt
@@ -42,6 +46,7 @@ interface IPermitterFactory {
   /// @param trustedSigner Address authorized to sign permits.
   /// @param maxTotalEth Maximum total ETH that can be raised.
   /// @param maxTokensPerBidder Maximum tokens any single bidder can purchase.
+  /// @param minTokensPerBidder Minimum tokens any single bidder must purchase per bid.
   /// @param owner Address that can update caps and pause.
   /// @param authorizedCaller CCA contract address authorized to call validateBid.
   /// @param salt Salt for CREATE2 deployment.
@@ -50,6 +55,7 @@ interface IPermitterFactory {
     address trustedSigner,
     uint256 maxTotalEth,
     uint256 maxTokensPerBidder,
+    uint256 minTokensPerBidder,
     address owner,
     address authorizedCaller,
     bytes32 salt

test/ExploitTests.t.sol

@@ -19,16 +19,21 @@ contract ExploitTests is Test {
 
   uint256 public constant INITIAL_MAX_TOTAL_ETH = 100 ether;
   uint256 public constant INITIAL_MAX_TOKENS_PER_BIDDER = 1000 ether;
+  uint256 public constant INITIAL_MIN_TOKENS_PER_BIDDER = 10 ether;
 
-  bytes32 public constant PERMIT_TYPEHASH =
-    keccak256("Permit(address bidder,uint256 maxBidAmount,uint256 expiry)");
+  bytes32 public constant PERMIT_TYPEHASH = keccak256("Permit(address bidder,uint256 expiry)");
 
   function setUp() public {
     signerPrivateKey = 0x1234;
     trustedSigner = vm.addr(signerPrivateKey);
 
     target = new Permitter(
-      trustedSigner, INITIAL_MAX_TOTAL_ETH, INITIAL_MAX_TOKENS_PER_BIDDER, owner, authorizedCaller
+      trustedSigner,
+      INITIAL_MAX_TOTAL_ETH,
+      INITIAL_MAX_TOKENS_PER_BIDDER,
+      INITIAL_MIN_TOKENS_PER_BIDDER,
+      owner,
+      authorizedCaller
     );
 
     vm.label(address(target), "Permitter");
@@ -37,16 +42,14 @@ contract ExploitTests is Test {
     vm.label(authorizedCaller, "AuthorizedCaller");
   }
 
-  function _createPermitSignature(address _bidder, uint256 _maxBidAmount, uint256 _expiry)
+  function _createPermitSignature(address _bidder, uint256 _expiry)
     internal
     view
     returns (bytes memory permitData)
   {
-    IPermitter.Permit memory permit =
-      IPermitter.Permit({bidder: _bidder, maxBidAmount: _maxBidAmount, expiry: _expiry});
+    IPermitter.Permit memory permit = IPermitter.Permit({bidder: _bidder, expiry: _expiry});
 
-    bytes32 structHash =
-      keccak256(abi.encode(PERMIT_TYPEHASH, permit.bidder, permit.maxBidAmount, permit.expiry));
+    bytes32 structHash = keccak256(abi.encode(PERMIT_TYPEHASH, permit.bidder, permit.expiry));
 
     bytes32 domainSeparator = target.domainSeparator();
     bytes32 digest = keccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash));
@@ -71,6 +74,7 @@ contract ExploitTests is Test {
       trustedSigner,
       0, // maxTotalEth = 0 - REJECTED
       INITIAL_MAX_TOKENS_PER_BIDDER,
+      INITIAL_MIN_TOKENS_PER_BIDDER,
       owner,
       authorizedCaller
     );
@@ -82,6 +86,7 @@ contract ExploitTests is Test {
       trustedSigner,
       INITIAL_MAX_TOTAL_ETH,
       0, // maxTokensPerBidder = 0 - REJECTED
+      INITIAL_MIN_TOKENS_PER_BIDDER,
       owner,
       authorizedCaller
     );
@@ -124,7 +129,7 @@ contract ExploitTests is Test {
     console.log("Fixes: H-01 (High)");
 
     uint256 expiry = block.timestamp + 2 hours;
-    bytes memory permitData = _createPermitSignature(bidder, 500 ether, expiry);
+    bytes memory permitData = _createPermitSignature(bidder, expiry);
 
     // First bid succeeds
     vm.prank(authorizedCaller);
@@ -159,7 +164,7 @@ contract ExploitTests is Test {
     console.log("Fixes: H-02 (High)");
 
     uint256 expiry = block.timestamp + 2 hours;
-    bytes memory permitData = _createPermitSignature(bidder, 500 ether, expiry);
+    bytes memory permitData = _createPermitSignature(bidder, expiry);
 
     // Raise 50 ETH
     vm.prank(authorizedCaller);
@@ -201,7 +206,7 @@ contract ExploitTests is Test {
     console.log("Fixes: M-01 (Medium/High)");
 
     uint256 expiry = block.timestamp + 1 hours;
-    bytes memory permitData = _createPermitSignature(bidder, 500 ether, expiry);
+    bytes memory permitData = _createPermitSignature(bidder, expiry);
 
     address attacker = makeAddr("attacker");
     console.log("Attacker (not authorized):", attacker);
@@ -229,7 +234,7 @@ contract ExploitTests is Test {
     console.log("Fixes: M-02 (Medium)");
 
     uint256 expiry = block.timestamp + 2 hours;
-    bytes memory permitData = _createPermitSignature(bidder, 500 ether, expiry);
+    bytes memory permitData = _createPermitSignature(bidder, expiry);
 
     console.log("Bidder has valid permit signed by:", trustedSigner);