matter-labs · zkzoomer · Feb 24, 2026 · Feb 19, 2026 · Feb 19, 2026 · Feb 19, 2026
@@ -4,11 +4,11 @@
     "minor": 31,
     "patch": 0
   },
-  "genesis_root": "0xd14523fbdf862f8c90ad9c8d4f15633f71685ca0b3a87395051af05a665521e4",
+  "genesis_root": "0xb784e2f4d87d5857ad32bf1cc8137706a870467fad8779126c3d4d0269498f85",
   "genesis_rollup_leaf_index": 104,
-  "genesis_batch_commitment": "0x3bce47b3d7a1c55c8dd067392a1a084f2470265f5a71461bcf28fe927af7195d",
-  "bootloader_hash": "0x01000997783d068e1865ddd522fd4d99fb4385e5f32bd876b953fa1415a28112",
-  "default_aa_hash": "0x010005f9b417b825b2e9faaf9c727b7afd29c5a1b65269ff6f429320b7b87e4b",
+  "genesis_batch_commitment": "0xe9a8206e98cb0a9615b867dd463b1334464581f4b341035707bb43507f916950",
+  "bootloader_hash": "0x0100099b799188da75411d9c2815a792e60e031bc5f89c2938b6deced048ad83",
+  "default_aa_hash": "0x010005f9ab7430155bfafc451c3950faf16b97a6ad45f86e0bd41308e8b04685",
   "evm_emulator_hash": "0x01000d8bae37b82f311186426184866498b357f41d7a02ced11f3e3fbfbacd63",
   "prover": {
     "recursion_scheduler_level_vk_hash": "0x1ffc56111a5cfaf5db387f6a31408ad20217e9bc1f31f2f5c1bd38b0d6d7968b",

@@ -1,9 +1,9 @@
 protocol_semantic_version = 133143986176
-genesis_root = "0xd14523fbdf862f8c90ad9c8d4f15633f71685ca0b3a87395051af05a665521e4"
+genesis_root = "0xb784e2f4d87d5857ad32bf1cc8137706a870467fad8779126c3d4d0269498f85"
 genesis_rollup_leaf_index = 104
-genesis_batch_commitment = "0x3bce47b3d7a1c55c8dd067392a1a084f2470265f5a71461bcf28fe927af7195d"
-bootloader_hash = "0x01000997783d068e1865ddd522fd4d99fb4385e5f32bd876b953fa1415a28112"
-default_aa_hash = "0x010005f9b417b825b2e9faaf9c727b7afd29c5a1b65269ff6f429320b7b87e4b"
+genesis_batch_commitment = "0xe9a8206e98cb0a9615b867dd463b1334464581f4b341035707bb43507f916950"
+bootloader_hash = "0x0100099b799188da75411d9c2815a792e60e031bc5f89c2938b6deced048ad83"
+default_aa_hash = "0x010005f9ab7430155bfafc451c3950faf16b97a6ad45f86e0bd41308e8b04685"
 evm_emulator_hash = "0x01000d8bae37b82f311186426184866498b357f41d7a02ced11f3e3fbfbacd63"
 
 [prover]

@@ -470,9 +470,8 @@ contract GWAssetTracker is AssetTrackerBase, IGWAssetTracker {
             // solhint-disable-next-line
             _processInteropCall(_chainId, bundleHash, interopCall, interopBundle.destinationChainId);
         }
-        // FIXME: this value can be zero leading to settlement failure.
-        bytes32 destinationChainBaseTokenAssetId = _bridgehub().baseTokenAssetId(interopBundle.destinationChainId);
-        _decreaseChainBalance(_chainId, destinationChainBaseTokenAssetId, totalBaseTokenAmount);
+        // We check on the InteropHandler of the destination chain that the `destinationBaseTokenAssetId` is the correct one
+        _decreaseChainBalance(_chainId, interopBundle.destinationBaseTokenAssetId, totalBaseTokenAmount);
         interopBalanceChange[interopBundle.destinationChainId][bundleHash].baseTokenAmount = totalBaseTokenAmount;
 
         // Return chargeable call count for settlement fee calculation.

@@ -250,6 +250,7 @@ enum CallStatus {
 /// @dev A set of `InteropCall`s to send to another chain.
 /// @param version Version of the InteropBundle.
 /// @param destinationChainId ChainId of the target chain.
+/// @param destinationBaseTokenAssetId Asset ID of the base token of the target chain.
 /// @param interopBundleSalt Salt of the interopBundle. It's required to ensure that all bundles have distinct hashes.
 ///                          It's equal to the keccak256(abi.encodePacked(senderOfTheBundle, NumberOfBundleSentByTheSender))
 /// @param calls Array of InteropCall structs to execute.
@@ -258,6 +259,7 @@ struct InteropBundle {
     bytes1 version;
     uint256 sourceChainId;
     uint256 destinationChainId;
+    bytes32 destinationBaseTokenAssetId;
     bytes32 interopBundleSalt;
     InteropCall[] calls;
     BundleAttributes bundleAttributes;

@@ -18,6 +18,10 @@ error ChainBatchRootAlreadyExists(uint256 chainId, uint256 batchNumber);
 error ChainBatchRootZero();
 // 0x65e8a019
 error ChainExists();
+// 0x824e4e26
+error ChainsSettlementLayerMismatch(uint256 chainToRegisterSL, uint256 chainRegisteredOnSL);
+// 0x1ed6c04f
+error ChainsSettlingOnL1();
 // 0x5d03f19d
 error CurrentBatchNumberAlreadySet();
 // 0x68d91b49

@@ -15,7 +15,7 @@ import {L2_BRIDGEHUB_ADDR} from "../../common/l2-helpers/L2ContractAddresses.sol
 import {TWO_BRIDGES_MAGIC_VALUE} from "../../common/Config.sol";
 
 import {Unauthorized, UnsupportedEncodingVersion} from "../../common/L1ContractErrors.sol";
-import {ChainAlreadyRegistered, NoEthAllowed, ZKChainNotRegistered} from "../bridgehub/L1BridgehubErrors.sol";
+import {ChainAlreadyRegistered, ChainsSettlingOnL1, ChainsSettlementLayerMismatch, NoEthAllowed, ZKChainNotRegistered} from "../bridgehub/L1BridgehubErrors.sol";
 import {IL2Bridgehub} from "../bridgehub/IL2Bridgehub.sol";
 
 /// @dev The encoding version of the data.
@@ -57,10 +57,13 @@ contract ChainRegistrationSender is
     /// @notice used to register a chain for interop via a service transaction.abi
     /// @notice this is provided for ease of use, base tokens does not have to be provided.
     /// @notice to prevent spamming, we only allow this to be called once.
+    /// @notice only chains that are settling on the same settlement layer may be registered.
     /// @param chainToBeRegistered the chain to be registered
     /// @param chainRegisteredOn the chain to register on
     function registerChain(uint256 chainToBeRegistered, uint256 chainRegisteredOn) external {
         require(!chainRegisteredOnChain[chainToBeRegistered][chainRegisteredOn], ChainAlreadyRegistered());
+        _checkSettlementLayers(chainToBeRegistered, chainRegisteredOn);
+
         chainRegisteredOnChain[chainToBeRegistered][chainRegisteredOn] = true;
 
         IMailbox chainRegisteredOnAddress = IMailbox(BRIDGE_HUB.getZKChain(chainRegisteredOn));
@@ -76,7 +79,7 @@ contract ChainRegistrationSender is
     /// @notice this is can be called by anyone (via the bridgehub), but baseTokens need to be provided.
     // slither-disable-next-line locked-ether
     function bridgehubDeposit(
-        uint256,
+        uint256 chainRegisteredOn,
         address,
         uint256,
         bytes calldata _data
@@ -94,6 +97,8 @@ contract ChainRegistrationSender is
         if (chainToBeRegisteredAddress == address(0)) {
             revert ZKChainNotRegistered();
         }
+        _checkSettlementLayers(chainToBeRegistered, chainRegisteredOn);
+
         request = L2TransactionRequestTwoBridgesInner({
             magicValue: TWO_BRIDGES_MAGIC_VALUE,
             l2Contract: L2_BRIDGEHUB_ADDR,
@@ -115,6 +120,20 @@ contract ChainRegistrationSender is
         return abi.encodeCall(IL2Bridgehub.registerChainForInterop, (chainToBeRegistered, baseTokenAssetId));
     }
 
+    /// @notice Checks that both chains are settling on the same settlement layer, which must not be the L1
+    /// @param chainToBeRegistered the chain to be registered
+    /// @param chainRegisteredOn the chain to register on
+    function _checkSettlementLayers(uint256 chainToBeRegistered, uint256 chainRegisteredOn) internal view {
+        uint256 chainToBeRegisteredSettlementLayer = BRIDGE_HUB.settlementLayer(chainToBeRegistered);
+        uint256 chainRegisteredOnSettlementLayer = BRIDGE_HUB.settlementLayer(chainRegisteredOn);
+        if (chainToBeRegisteredSettlementLayer != chainRegisteredOnSettlementLayer) {
+            revert ChainsSettlementLayerMismatch(chainToBeRegisteredSettlementLayer, chainRegisteredOnSettlementLayer);
+        }
+        if (chainToBeRegisteredSettlementLayer == block.chainid) {
+            revert ChainsSettlingOnL1();
+        }
+    }
+
     /// @inheritdoc IL1CrossChainSender
     /// @notice This function is not used for ChainRegistrationSender, since we do not need to support failed L1->L2 transactions.
     function bridgehubConfirmL2Transaction(uint256 _chainId, bytes32 _txDataHash, bytes32 _txHash) external override {}

@@ -19,7 +19,7 @@ import {BUNDLE_IDENTIFIER, BalanceChange, BundleAttributes, CallAttributes, INTE
 import {MsgValueMismatch, NotL2ToL2, Unauthorized, ZeroAddress} from "../common/L1ContractErrors.sol";
 import {NotInGatewayMode} from "../core/bridgehub/L1BridgehubErrors.sol";
 
-import {AttributeAlreadySet, AttributeViolatesRestriction, DestinationChainNotRegistered, IndirectCallValueMismatch, InteroperableAddressChainReferenceNotEmpty, InteroperableAddressNotEmpty, FeeWithdrawalFailed, ThisChainNotRegisteredForInterop, ZKTokenNotAvailable} from "./InteropErrors.sol";
+import {AttributeAlreadySet, AttributeViolatesRestriction, DestinationChainNotRegistered, IndirectCallValueMismatch, InteroperableAddressChainReferenceNotEmpty, InteroperableAddressNotEmpty, FeeWithdrawalFailed, ZKTokenNotAvailable} from "./InteropErrors.sol";
 
 import {IERC7786GatewaySource} from "./IERC7786GatewaySource.sol";
 import {IERC7786Attributes} from "./IERC7786Attributes.sol";
@@ -325,26 +325,20 @@ contract InteropCenter is
     /// @param _callCount Number of calls in the bundle for per-call fee calculation.
     function _ensureCorrectTotalValue(
         uint256 _destinationChainId,
+        bytes32 _destinationBaseTokenAssetId,
         uint256 _totalBurnedCallsValue,
         uint256 _totalIndirectCallsValue,
         bool _useFixedFee,
         uint256 _callCount
     ) internal {
-        // Note, that non-zero `destinationChainBaseTokenAssetId` does not mean that the destination chain
-        // actually settles on the GW or is able to receive the message.
-        // However, this value is provided from L1 by chain asset handler, so it can be trusted to be correct.
-        bytes32 destinationChainBaseTokenAssetId = L2_BRIDGEHUB.baseTokenAssetId(_destinationChainId);
-        require(destinationChainBaseTokenAssetId != bytes32(0), DestinationChainNotRegistered(_destinationChainId));
-        bytes32 thisChainBaseTokenAssetId = L2_BRIDGEHUB.baseTokenAssetId(block.chainid);
+        bytes32 thisChainBaseTokenAssetId = L2_NATIVE_TOKEN_VAULT.BASE_TOKEN_ASSET_ID();
 
         // Calculate protocol fee - only charge base token fee if not using fixed ZK fees.
         // Fee is charged per-call.
         uint256 protocolFee = _useFixedFee ? 0 : interopProtocolFee * _callCount;
 
-        require(thisChainBaseTokenAssetId != bytes32(0), ThisChainNotRegisteredForInterop(block.chainid));
-
         // We burn the value that is passed along the bundle here, on source chain.
-        if (destinationChainBaseTokenAssetId == thisChainBaseTokenAssetId) {
+        if (_destinationBaseTokenAssetId == thisChainBaseTokenAssetId) {
             uint256 expectedValue = _totalBurnedCallsValue + _totalIndirectCallsValue + protocolFee;
             require(msg.value == expectedValue, MsgValueMismatch(expectedValue, msg.value));
 
@@ -361,7 +355,7 @@ contract InteropCenter is
             if (_totalBurnedCallsValue > 0) {
                 IAssetRouterShared(L2_ASSET_ROUTER_ADDR).bridgehubDepositBaseToken(
                     _destinationChainId,
-                    destinationChainBaseTokenAssetId,
+                    _destinationBaseTokenAssetId,
                     msg.sender,
                     _totalBurnedCallsValue
                 );
@@ -391,10 +385,13 @@ contract InteropCenter is
         require(L2_SYSTEM_CONTEXT_SYSTEM_CONTRACT.currentSettlementLayerChainId() != L1_CHAIN_ID, NotInGatewayMode());
 
         // Form an InteropBundle.
+        bytes32 destinationBaseTokenAssetId = L2_BRIDGEHUB.baseTokenAssetId(_destinationChainId);
+        require(destinationBaseTokenAssetId != bytes32(0), DestinationChainNotRegistered(_destinationChainId));
         InteropBundle memory bundle = InteropBundle({
             version: INTEROP_BUNDLE_VERSION,
             sourceChainId: block.chainid,
             destinationChainId: _destinationChainId,
+            destinationBaseTokenAssetId: destinationBaseTokenAssetId,
             interopBundleSalt: keccak256(abi.encodePacked(msg.sender, interopBundleNonce[msg.sender])),
             calls: new InteropCall[](_callStarters.length),
             bundleAttributes: _bundleAttributes
@@ -433,6 +430,7 @@ contract InteropCenter is
         // solhint-disable-next-line
         _ensureCorrectTotalValue(
             bundle.destinationChainId,
+            bundle.destinationBaseTokenAssetId,
             totalBurnedCallsValue,
             totalIndirectCallsValue,
             _bundleAttributes.useFixedFee,
@@ -449,21 +447,38 @@ contract InteropCenter is
             bundleHash = InteropDataEncoding.encodeInteropBundleHash(block.chainid, interopBundleBytes);
         }
 
-        // Emit ERC-7786 MessageSent event for each call in the bundle
-        for (uint256 i = 0; i < callStartersLength; ++i) {
-            InteropCall memory currentCall = bundle.calls[i];
+        _emitMessageSent({
+            _calls: bundle.calls,
+            _destinationChainId: _destinationChainId,
+            _bundleHash: bundleHash,
+            _callStarters: _callStarters,
+            _originalCallAttributes: _originalCallAttributes
+        });
+
+        // Emit event stating that the bundle was sent out successfully.
+        emit InteropBundleSent(msgHash, bundleHash, bundle);
+    }
+
+    /// @notice Emits ERC-7786 MessageSent events for each call in a bundle.
+    function _emitMessageSent(
+        InteropCall[] memory _calls,
+        uint256 _destinationChainId,
+        bytes32 _bundleHash,
+        InteropCallStarterInternal[] memory _callStarters,
+        bytes[][] memory _originalCallAttributes
+    ) internal {
+        uint256 callsLength = _callStarters.length;
+        for (uint256 i = 0; i < callsLength; ++i) {
+            InteropCall memory currentCall = _calls[i];
             emit MessageSent({
-                sendId: keccak256(abi.encodePacked(bundleHash, i)),
+                sendId: keccak256(abi.encodePacked(_bundleHash, i)),
                 sender: InteroperableAddress.formatEvmV1(block.chainid, currentCall.from),
                 recipient: InteroperableAddress.formatEvmV1(_destinationChainId, currentCall.to),
                 payload: _callStarters[i].data,
                 value: _callStarters[i].callAttributes.interopCallValue,
                 attributes: _originalCallAttributes[i]
             });
         }
-
-        // Emit event stating that the bundle was sent out successfully.
-        emit InteropBundleSent(msgHash, bundleHash, bundle);
     }
 
     function _processCallStarter(

@@ -33,8 +33,6 @@ error InvalidInteropCallVersion();
 error InteropRootAlreadyExists();
 // 0x32c2e156
 error MessageNotIncluded();
-// 0x95eb7603
-error ThisChainNotRegisteredForInterop(uint256 chainId);
 // 0x2f59bd0d
 error SidesLengthNotOne();
 // 0x89fd2c76
@@ -45,6 +43,8 @@ error UnbundlingNotAllowed(bytes32 bundleHash, bytes callerAddress, bytes unbund
 error WrongCallStatusLength(uint256 bundleCallsLength, uint256 providedCallStatusLength);
 // 0x4534e972
 error WrongDestinationChainId(bytes32 bundleHash, uint256 expected, uint256 actual);
+// 0xb99d46dc
+error WrongDestinationBaseTokenAssetId(bytes32 bundleHash, bytes32 expected, bytes32 actual);
 // 0x534ab1b2
 error WrongSourceChainId(bytes32 bundleHash, uint256 expected, uint256 actual);
 // 0x92196069

@@ -4,13 +4,13 @@ pragma solidity ^0.8.24;
 
 import {InteroperableAddress} from "../vendor/draft-InteroperableAddress.sol";
 
-import {L2_BASE_TOKEN_SYSTEM_CONTRACT, L2_INTEROP_CENTER_ADDR, L2_MESSAGE_VERIFICATION, L2_TO_L1_MESSENGER_SYSTEM_CONTRACT, L2_SYSTEM_CONTEXT_SYSTEM_CONTRACT, L2_COMPLEX_UPGRADER_ADDR} from "../common/l2-helpers/L2ContractInterfaces.sol";
+import {L2_BASE_TOKEN_SYSTEM_CONTRACT, L2_INTEROP_CENTER_ADDR, L2_NATIVE_TOKEN_VAULT, L2_MESSAGE_VERIFICATION, L2_TO_L1_MESSENGER_SYSTEM_CONTRACT, L2_SYSTEM_CONTEXT_SYSTEM_CONTRACT, L2_COMPLEX_UPGRADER_ADDR} from "../common/l2-helpers/L2ContractInterfaces.sol";
 import {IInteropHandler} from "./IInteropHandler.sol";
 import {BUNDLE_IDENTIFIER, INTEROP_BUNDLE_VERSION, INTEROP_CALL_VERSION, BundleStatus, CallStatus, InteropBundle, InteropCall, MessageInclusionProof} from "../common/Messaging.sol";
 import {IERC7786Recipient} from "./IERC7786Recipient.sol";
 import {ReentrancyGuard} from "../common/ReentrancyGuard.sol";
 import {InteropDataEncoding} from "./InteropDataEncoding.sol";
-import {BundleAlreadyProcessed, CallAlreadyExecuted, CallNotExecutable, CanNotUnbundle, ExecutingNotAllowed, MessageNotIncluded, UnauthorizedMessageSender, UnbundlingNotAllowed, WrongCallStatusLength, WrongDestinationChainId, WrongSourceChainId, InvalidInteropBundleVersion, InvalidInteropCallVersion} from "./InteropErrors.sol";
+import {BundleAlreadyProcessed, CallAlreadyExecuted, CallNotExecutable, CanNotUnbundle, ExecutingNotAllowed, MessageNotIncluded, UnauthorizedMessageSender, UnbundlingNotAllowed, WrongCallStatusLength, WrongDestinationChainId, WrongDestinationBaseTokenAssetId, WrongSourceChainId, InvalidInteropBundleVersion, InvalidInteropCallVersion} from "./InteropErrors.sol";
 import {InvalidSelector, Unauthorized} from "../common/L1ContractErrors.sol";
 import {NotInGatewayMode} from "../core/bridgehub/L1BridgehubErrors.sol";
 
@@ -62,6 +62,13 @@ contract InteropHandler is IInteropHandler, ReentrancyGuard {
             WrongDestinationChainId(bundleHash, interopBundle.destinationChainId, block.chainid)
         );
 
+        // Verify that the destination base token asset ID of the bundle is equal to the base token asset ID of the chain
+        bytes32 baseTokenAssetId = L2_NATIVE_TOKEN_VAULT.BASE_TOKEN_ASSET_ID();
+        require(
+            interopBundle.destinationBaseTokenAssetId == baseTokenAssetId,
+            WrongDestinationBaseTokenAssetId(bundleHash, baseTokenAssetId, interopBundle.destinationBaseTokenAssetId)
+        );
+
         // If the execution address is not specified then the execution is permissionless.
         if (interopBundle.bundleAttributes.executionAddress.length != 0) {
             (uint256 executionChainId, address executionAddress) = InteroperableAddress.parseEvmV1(
@@ -137,6 +144,13 @@ contract InteropHandler is IInteropHandler, ReentrancyGuard {
             WrongDestinationChainId(bundleHash, interopBundle.destinationChainId, block.chainid)
         );
 
+        // Verify that the destination base token asset ID of the bundle is equal to the base token asset ID of the chain
+        bytes32 baseTokenAssetId = L2_NATIVE_TOKEN_VAULT.BASE_TOKEN_ASSET_ID();
+        require(
+            interopBundle.destinationBaseTokenAssetId == baseTokenAssetId,
+            WrongDestinationBaseTokenAssetId(bundleHash, baseTokenAssetId, interopBundle.destinationBaseTokenAssetId)
+        );
+
         // If the bundle was already fully executed or unbundled, we revert stating that it was processed already.
         require(status == BundleStatus.Unreceived, BundleAlreadyProcessed(bundleHash));
 
@@ -150,6 +164,8 @@ contract InteropHandler is IInteropHandler, ReentrancyGuard {
         bytes memory _bundle,
         CallStatus[] calldata _providedCallStatus
     ) public {
+        require(L2_SYSTEM_CONTEXT_SYSTEM_CONTRACT.currentSettlementLayerChainId() != L1_CHAIN_ID, NotInGatewayMode());
+
         // Decode the bundle data, calculate its hash and get the current status of the bundle.
         (InteropBundle memory interopBundle, bytes32 bundleHash, BundleStatus status) = _getBundleData(
             _bundle,