diff --git a/.solhint.json b/.solhint.json
index 50a2b89..a92abb0 100644
--- a/.solhint.json
+++ b/.solhint.json
@@ -1,7 +1,9 @@
 {
   "extends": "solhint:all",
   "rules": {
-    "compiler-version": ["error","^0.6.10"],
+    "foundry-test-functions": "off",
+
+    "compiler-version": ["error","^0.8.8"],
     "state-visibility": "error",
     "no-empty-blocks": "error",
     "check-send-result": "error",
diff --git a/contracts/DomainTypes.sol b/contracts/DomainTypes.sol
new file mode 100644
index 0000000..635b8fa
--- /dev/null
+++ b/contracts/DomainTypes.sol
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+
+/**
+ *   DomainTypes.sol - SKALE Interchain Messaging Agent
+ *   Copyright (C) 2024-Present SKALE Labs
+ *   @author Dmytro Stebaiev
+ *
+ *   SKALE IMA is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU Affero General Public License as published
+ *   by the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   SKALE IMA is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU Affero General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Affero General Public License
+ *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
+ */
+pragma solidity >=0.8.19 <0.9.0;
+
+
+type SchainHash is bytes32;
+
+using {
+    _schainHashEquals as ==,
+    _schainHashNotEquals as !=
+} for SchainHash global;
+
+// Operators are used by the library users
+// slither-disable-start dead-code
+
+function _schainHashEquals(SchainHash left, SchainHash right) pure returns (bool result) {
+    return SchainHash.unwrap(left) == SchainHash.unwrap(right);
+}
+
+function _schainHashNotEquals(SchainHash left, SchainHash right) pure returns (bool result) {
+    return SchainHash.unwrap(left) != SchainHash.unwrap(right);
+}
+
+// slither-disable-end dead-code
diff --git a/contracts/IGasReimbursable.sol b/contracts/IGasReimbursable.sol
index e6c8f19..07be024 100644
--- a/contracts/IGasReimbursable.sol
+++ b/contracts/IGasReimbursable.sol
@@ -19,17 +19,17 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 import "./IMessageReceiver.sol";
 
 
 interface IGasReimbursable is IMessageReceiver {
     function gasPayer(
-        bytes32 schainHash,
+        SchainHash schainHash,
         address sender,
         bytes calldata data
     )
         external
         returns (address);
-}
\ No newline at end of file
+}
diff --git a/contracts/IMessageListener.sol b/contracts/IMessageListener.sol
index d065619..00f310d 100644
--- a/contracts/IMessageListener.sol
+++ b/contracts/IMessageListener.sol
@@ -19,7 +19,9 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
+
+import {SchainHash} from "./DomainTypes.sol";
 
 
 interface IMessageListener {
@@ -52,7 +54,7 @@ interface IMessageListener {
     ) external;
 
     function postOutgoingMessage(
-        bytes32 targetChainHash,
+        SchainHash targetChainHash,
         address targetContract,
         bytes memory data
     ) external;
diff --git a/contracts/IMessageProxy.sol b/contracts/IMessageProxy.sol
index 44bc6e3..60be724 100644
--- a/contracts/IMessageProxy.sol
+++ b/contracts/IMessageProxy.sol
@@ -19,9 +19,9 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
-import { IMessageListener } from "./IMessageListener.sol";
+import { IMessageListener, SchainHash } from "./IMessageListener.sol";
 
 
 interface IMessageProxy is IMessageListener {
@@ -34,12 +34,12 @@ interface IMessageProxy is IMessageListener {
     function removeExtraContract(string memory schainName, address extraContract) external;
     function setVersion(string calldata newVersion) external;
     function isContractRegistered(
-        bytes32 schainHash,
+        SchainHash schainHash,
         address contractAddress
     ) external view returns (bool);
-    function getContractRegisteredLength(bytes32 schainHash) external view returns (uint256);
+    function getContractRegisteredLength(SchainHash schainHash) external view returns (uint256);
     function getContractRegisteredRange(
-        bytes32 schainHash,
+        SchainHash schainHash,
         uint256 from,
         uint256 to
     )
diff --git a/contracts/IMessageReceiver.sol b/contracts/IMessageReceiver.sol
index ee9ed4f..a0788f7 100644
--- a/contracts/IMessageReceiver.sol
+++ b/contracts/IMessageReceiver.sol
@@ -19,14 +19,16 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
+
+import {SchainHash} from "./DomainTypes.sol";
 
 
 interface IMessageReceiver {
     function postMessage(
-        bytes32 schainHash,
+        SchainHash schainHash,
         address sender,
         bytes calldata data
     )
         external;
-}
\ No newline at end of file
+}
diff --git a/contracts/extensions/IERC721ReferenceMintAndMetadataMainnet.sol b/contracts/extensions/IERC721ReferenceMintAndMetadataMainnet.sol
index 295d7da..112fc8a 100644
--- a/contracts/extensions/IERC721ReferenceMintAndMetadataMainnet.sol
+++ b/contracts/extensions/IERC721ReferenceMintAndMetadataMainnet.sol
@@ -19,9 +19,9 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 
 interface IERC721ReferenceMintAndMetadataMainnet {
     function setSenderContractOnSchain(address newSenderContractOnSchain) external;
-}
\ No newline at end of file
+}
diff --git a/contracts/extensions/IERC721ReferenceMintAndMetadataSchain.sol b/contracts/extensions/IERC721ReferenceMintAndMetadataSchain.sol
index 2a17413..04c3c2d 100644
--- a/contracts/extensions/IERC721ReferenceMintAndMetadataSchain.sol
+++ b/contracts/extensions/IERC721ReferenceMintAndMetadataSchain.sol
@@ -19,7 +19,7 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 
 interface IERC721ReferenceMintAndMetadataSchain {
@@ -32,4 +32,4 @@ interface IERC721ReferenceMintAndMetadataSchain {
         external
         pure
         returns (bytes memory data);
-}
\ No newline at end of file
+}
diff --git a/contracts/mainnet/DepositBoxes/IDepositBoxERC1155.sol b/contracts/mainnet/DepositBoxes/IDepositBoxERC1155.sol
index 866f3cc..a62a34b 100644
--- a/contracts/mainnet/DepositBoxes/IDepositBoxERC1155.sol
+++ b/contracts/mainnet/DepositBoxes/IDepositBoxERC1155.sol
@@ -19,7 +19,7 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 import "../IDepositBox.sol";
 
@@ -64,4 +64,4 @@ interface IDepositBoxERC1155 is IDepositBox {
         external
         view
         returns (address[] memory);
-}
\ No newline at end of file
+}
diff --git a/contracts/mainnet/DepositBoxes/IDepositBoxERC20.sol b/contracts/mainnet/DepositBoxes/IDepositBoxERC20.sol
index c26eee0..8e7ad73 100644
--- a/contracts/mainnet/DepositBoxes/IDepositBoxERC20.sol
+++ b/contracts/mainnet/DepositBoxes/IDepositBoxERC20.sol
@@ -19,7 +19,7 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 import "../IDepositBox.sol";
 
@@ -45,9 +45,9 @@ interface IDepositBoxERC20 is IDepositBox {
     function stopTrustingReceiver(string calldata schainName, address receiver) external;
     function trustReceiver(string calldata schainName, address receiver) external;
     function validateTransfer(uint transferId) external;
-    function isReceiverTrusted(bytes32 schainHash, address receiver) external view returns (bool);
-    function getArbitrageDuration(bytes32 schainHash) external view returns (uint256);
-    function getBigTransferThreshold(bytes32 schainHash, address token) external view returns (uint256);
+    function isReceiverTrusted(SchainHash schainHash, address receiver) external view returns (bool);
+    function getArbitrageDuration(SchainHash schainHash) external view returns (uint256);
+    function getBigTransferThreshold(SchainHash schainHash, address token) external view returns (uint256);
     function getDelayedAmount(address receiver, address token) external view returns (uint256 value);
     function getNextUnlockTimestamp(address receiver, address token) external view returns (uint256 unlockTimestamp);
     function getSchainToERC20(string calldata schainName, address erc20OnMainnet) external view returns (bool);
@@ -60,7 +60,7 @@ interface IDepositBoxERC20 is IDepositBox {
         external
         view
         returns (address[] memory);
-    function getTimeDelay(bytes32 schainHash) external view returns (uint256);
+    function getTimeDelay(SchainHash schainHash) external view returns (uint256);
     function getTrustedReceiver(string calldata schainName, uint256 index) external view returns (address);
-    function getTrustedReceiversAmount(bytes32 schainHash) external view returns (uint256);
-}
\ No newline at end of file
+    function getTrustedReceiversAmount(SchainHash schainHash) external view returns (uint256);
+}
diff --git a/contracts/mainnet/DepositBoxes/IDepositBoxERC721.sol b/contracts/mainnet/DepositBoxes/IDepositBoxERC721.sol
index 8fb7386..b8ff38d 100644
--- a/contracts/mainnet/DepositBoxes/IDepositBoxERC721.sol
+++ b/contracts/mainnet/DepositBoxes/IDepositBoxERC721.sol
@@ -19,7 +19,7 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 import "../IDepositBox.sol";
 
@@ -44,4 +44,4 @@ interface IDepositBoxERC721 is IDepositBox {
         external
         view
         returns (address[] memory);
-}
\ No newline at end of file
+}
diff --git a/contracts/mainnet/DepositBoxes/IDepositBoxEth.sol b/contracts/mainnet/DepositBoxes/IDepositBoxEth.sol
index 28bda7f..068a394 100644
--- a/contracts/mainnet/DepositBoxes/IDepositBoxEth.sol
+++ b/contracts/mainnet/DepositBoxes/IDepositBoxEth.sol
@@ -19,7 +19,7 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 import "../IDepositBox.sol";
 
@@ -32,4 +32,4 @@ interface IDepositBoxEth is IDepositBox {
     function getFunds(string calldata schainName, address payable receiver, uint amount) external;
     function enableActiveEthTransfers(string calldata schainName) external;
     function disableActiveEthTransfers(string calldata schainName) external;
-}
\ No newline at end of file
+}
diff --git a/contracts/mainnet/ICommunityPool.sol b/contracts/mainnet/ICommunityPool.sol
index 118a7b8..11edb94 100644
--- a/contracts/mainnet/ICommunityPool.sol
+++ b/contracts/mainnet/ICommunityPool.sol
@@ -19,7 +19,7 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 import "@skalenetwork/skale-manager-interfaces/IContractManager.sol";
 
@@ -35,17 +35,22 @@ interface ICommunityPool is ITwin {
         ILinker linker,
         IMessageProxyForMainnet messageProxyValue
     ) external;
-    function refundGasByUser(bytes32 schainHash, address payable node, address user, uint gas) external returns (uint);
+    function refundGasByUser(
+        SchainHash schainHash,
+        address payable node,
+        address user,
+        uint256 gas
+    ) external returns (uint256);
     function rechargeUserWallet(string calldata schainName, address user) external payable;
-    function withdrawFunds(string calldata schainName, uint amount) external;
-    function setMinTransactionGas(uint newMinTransactionGas) external;
-    function setMultiplier(uint newMultiplierNumerator, uint newMultiplierDivider) external;
+    function withdrawFunds(string calldata schainName, uint256 amount) external;
+    function setMinTransactionGas(uint256 newMinTransactionGas) external;
+    function setMultiplier(uint256 newMultiplierNumerator, uint256 newMultiplierDivider) external;
     function refundGasBySchainWallet(
-        bytes32 schainHash,
+        SchainHash schainHash,
         address payable node,
-        uint gas
+        uint256 gas
     ) external returns (bool);
-    function getBalance(address user, string calldata schainName) external view returns (uint);
-    function checkUserBalance(bytes32 schainHash, address receiver) external view returns (bool);
-    function getRecommendedRechargeAmount(bytes32 schainHash, address receiver) external view returns (uint256);
-}
\ No newline at end of file
+    function getBalance(address user, string calldata schainName) external view returns (uint256);
+    function checkUserBalance(SchainHash schainHash, address receiver) external view returns (bool);
+    function getRecommendedRechargeAmount(SchainHash schainHash, address receiver) external view returns (uint256);
+}
diff --git a/contracts/mainnet/IDepositBox.sol b/contracts/mainnet/IDepositBox.sol
index dafcbd0..c7318bd 100644
--- a/contracts/mainnet/IDepositBox.sol
+++ b/contracts/mainnet/IDepositBox.sol
@@ -19,7 +19,7 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 import "@skalenetwork/skale-manager-interfaces/IContractManager.sol";
 
@@ -39,4 +39,4 @@ interface IDepositBox is ITwin, IMessageReceiver, IGasReimbursable {
     function enableWhitelist(string memory schainName) external;
     function disableWhitelist(string memory schainName) external;
     function isWhitelisted(string memory schainName) external view returns (bool);
-}
\ No newline at end of file
+}
diff --git a/contracts/mainnet/ILinker.sol b/contracts/mainnet/ILinker.sol
index 8215b77..c0013bc 100644
--- a/contracts/mainnet/ILinker.sol
+++ b/contracts/mainnet/ILinker.sol
@@ -19,7 +19,7 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 import "./ITwin.sol";
 
@@ -30,7 +30,7 @@ interface ILinker is ITwin {
     function connectSchain(string calldata schainName, address[] calldata schainContracts) external;
     function kill(string calldata schainName) external;
     function disconnectSchain(string calldata schainName) external;
-    function isNotKilled(bytes32 schainHash) external view returns (bool);
+    function isNotKilled(SchainHash schainHash) external view returns (bool);
     function hasMainnetContract(address mainnetContract) external view returns (bool);
     function hasSchain(string calldata schainName) external view returns (bool connected);
-}
\ No newline at end of file
+}
diff --git a/contracts/mainnet/IMessageProxyForMainnet.sol b/contracts/mainnet/IMessageProxyForMainnet.sol
index d90bdf6..8b7839f 100644
--- a/contracts/mainnet/IMessageProxyForMainnet.sol
+++ b/contracts/mainnet/IMessageProxyForMainnet.sol
@@ -19,7 +19,7 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 import "../IMessageProxy.sol";
 import "./ICommunityPool.sol";
@@ -33,15 +33,15 @@ interface IMessageProxyForMainnet is IMessageProxy {
     function addReimbursedContract(string memory schainName, address reimbursedContract) external;
     function removeReimbursedContract(string memory schainName, address reimbursedContract) external;
     function messageInProgress() external view returns (bool);
-    function isPaused(bytes32 schainHash) external view returns (bool);
-    function isReimbursedContract(bytes32 schainHash, address contractAddress) external view returns (bool);
-    function getReimbursedContractsLength(bytes32 schainHash) external view returns (uint256);
+    function isPaused(SchainHash schainHash) external view returns (bool);
+    function isReimbursedContract(SchainHash schainHash, address contractAddress) external view returns (bool);
+    function getReimbursedContractsLength(SchainHash schainHash) external view returns (uint256);
     function getReimbursedContractsRange(
-        bytes32 schainHash,
+        SchainHash schainHash,
         uint256 from,
         uint256 to
     )
         external
         view
         returns (address[] memory contractsInRange);
-}
\ No newline at end of file
+}
diff --git a/contracts/mainnet/ISkaleManagerClient.sol b/contracts/mainnet/ISkaleManagerClient.sol
index fc0d05d..2363303 100644
--- a/contracts/mainnet/ISkaleManagerClient.sol
+++ b/contracts/mainnet/ISkaleManagerClient.sol
@@ -19,13 +19,15 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 import "@skalenetwork/skale-manager-interfaces/IContractManager.sol";
 
+import {SchainHash} from "../DomainTypes.sol";
+
 
 interface ISkaleManagerClient {
     function initialize(IContractManager newContractManagerOfSkaleManager) external;
-    function isSchainOwner(address sender, bytes32 schainHash) external view returns (bool);
-    function isAgentAuthorized(bytes32 schainHash, address sender) external view returns (bool);
-}
\ No newline at end of file
+    function isSchainOwner(address sender, SchainHash schainHash) external view returns (bool);
+    function isAgentAuthorized(SchainHash schainHash, address sender) external view returns (bool);
+}
diff --git a/contracts/mainnet/ITwin.sol b/contracts/mainnet/ITwin.sol
index 28b3802..b85b526 100644
--- a/contracts/mainnet/ITwin.sol
+++ b/contracts/mainnet/ITwin.sol
@@ -19,7 +19,7 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 import "./ISkaleManagerClient.sol";
 
@@ -27,5 +27,5 @@ interface ITwin is ISkaleManagerClient {
     function addSchainContract(string calldata schainName, address contractReceiver) external;
     function removeSchainContract(string calldata schainName) external;
     function hasSchainContract(string calldata schainName) external view returns (bool);
-    function getSchainContract(bytes32 schainHash) external view returns (address);
-}
\ No newline at end of file
+    function getSchainContract(SchainHash schainHash) external view returns (address);
+}
diff --git a/contracts/schain/ExecutionLayer/IActionExecutor.sol b/contracts/schain/ExecutionLayer/IActionExecutor.sol
new file mode 100644
index 0000000..20f84d5
--- /dev/null
+++ b/contracts/schain/ExecutionLayer/IActionExecutor.sol
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+
+/**
+ *   IActionExecutor - SKALE Interchain Messaging Agent
+ *   Copyright (C) 2024-Present SKALE Labs
+ *   @author Dmytro Stebaiev
+ *
+ *   SKALE IMA is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU Affero General Public License as published
+ *   by the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   SKALE IMA is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU Affero General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Affero General Public License
+ *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+pragma solidity >=0.8.19 <0.9.0;
+
+struct TokenInfo {
+    address token;
+    uint256 number;
+}
+
+interface IActionExecutor {
+    function execute(
+        TokenInfo[] memory inputTokens,
+        bytes memory arguments
+    )
+        external
+        returns (TokenInfo[] memory outputTokens);
+}
diff --git a/contracts/schain/ExecutionLayer/IExecutionManager.sol b/contracts/schain/ExecutionLayer/IExecutionManager.sol
new file mode 100644
index 0000000..38a4119
--- /dev/null
+++ b/contracts/schain/ExecutionLayer/IExecutionManager.sol
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+
+/**
+ *   IExecutionManager - SKALE Interchain Messaging Agent
+ *   Copyright (C) 2024-Present SKALE Labs
+ *   @author Dmytro Stebaiev
+ *
+ *   SKALE IMA is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU Affero General Public License as published
+ *   by the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   SKALE IMA is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU Affero General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Affero General Public License
+ *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+pragma solidity >=0.8.19 <0.9.0;
+
+import {IMessageReceiver} from "../../IMessageReceiver.sol";
+import {ITokenManagerERC20} from "../TokenManagers/ITokenManagerERC20.sol";
+import {SchainHash} from "../../DomainTypes.sol";
+
+
+interface IExecutionManager is IMessageReceiver {
+    function initialize(ITokenManagerERC20 erc20TokenManagerAddress) external;
+    function setRemoteExecutionManager(
+        SchainHash schainHash,
+        address executionManagerAddress
+    ) external;
+    function testSend(SchainHash targetChainHash, string calldata message) external;
+}
diff --git a/contracts/schain/ExecutionLayer/IExecutor.sol b/contracts/schain/ExecutionLayer/IExecutor.sol
new file mode 100644
index 0000000..da686f1
--- /dev/null
+++ b/contracts/schain/ExecutionLayer/IExecutor.sol
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+
+/**
+ *   IExecutor - SKALE Interchain Messaging Agent
+ *   Copyright (C) 2024-Present SKALE Labs
+ *   @author Dmytro Stebaiev
+ *
+ *   SKALE IMA is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU Affero General Public License as published
+ *   by the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   SKALE IMA is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU Affero General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Affero General Public License
+ *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+// cspell::words func-name-mixedcase
+
+pragma solidity >=0.8.19 <0.9.0;
+
+import {IActionExecutor} from "./IActionExecutor.sol";
+
+type ExecutorId is bytes32;
+
+interface IExecutor is IActionExecutor {
+    // ID will be public constant variable but not function
+    // slither-disable-start naming-convention
+    // solhint-disable-next-line func-name-mixedcase
+    function ID() external pure returns (ExecutorId executorId);
+    // slither-disable-end naming-convention
+}
diff --git a/contracts/schain/ICommunityLocker.sol b/contracts/schain/ICommunityLocker.sol
index 5fc14af..3f34045 100644
--- a/contracts/schain/ICommunityLocker.sol
+++ b/contracts/schain/ICommunityLocker.sol
@@ -19,8 +19,9 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
+import {SchainHash} from "../DomainTypes.sol";
 import "../IMessageReceiver.sol";
 
 import "./IMessageProxyForSchain.sol";
@@ -34,7 +35,11 @@ interface ICommunityLocker is IMessageReceiver {
         ITokenManagerLinker newTokenManagerLinker,
         address newCommunityPool
     ) external;
-    function checkAllowedToSendMessage(bytes32 chainHash, address receiver) external;
-    function setTimeLimitPerMessage(string memory chainName, uint newTimeLimitPerMessage) external;
-    function setGasPrice(uint gasPrice, uint timestamp, IMessageProxyForSchain.Signature memory signature) external;
-}
\ No newline at end of file
+    function checkAllowedToSendMessage(SchainHash chainHash, address receiver) external;
+    function setTimeLimitPerMessage(string memory chainName, uint256 newTimeLimitPerMessage) external;
+    function setGasPrice(
+        uint256 gasPrice,
+        uint256 timestamp,
+        IMessageProxyForSchain.Signature memory signature
+    ) external;
+}
diff --git a/contracts/schain/IKeyStorage.sol b/contracts/schain/IKeyStorage.sol
index ac5d310..c591843 100644
--- a/contracts/schain/IKeyStorage.sol
+++ b/contracts/schain/IKeyStorage.sol
@@ -19,7 +19,7 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 import "./bls/IFieldOperations.sol";
 
@@ -27,4 +27,4 @@ import "./bls/IFieldOperations.sol";
 interface IKeyStorage {
     function initialize() external;
     function getBlsCommonPublicKey() external view returns (IFieldOperations.G2Point memory);
-}
\ No newline at end of file
+}
diff --git a/contracts/schain/IMessageProxyForSchain.sol b/contracts/schain/IMessageProxyForSchain.sol
index 6ad8298..f1add85 100644
--- a/contracts/schain/IMessageProxyForSchain.sol
+++ b/contracts/schain/IMessageProxyForSchain.sol
@@ -19,14 +19,14 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 import "../IMessageProxy.sol";
 import "./IKeyStorage.sol";
 
 interface IMessageProxyForSchain is IMessageProxy {
     struct OutgoingMessageData {
-        bytes32 dstChainHash; // destination chain
+        SchainHash dstChainHash; // destination chain
         uint256 msgCounter; // message counter
         address srcContract; // origin
         address dstContract; // receiver
diff --git a/contracts/schain/ITokenManager.sol b/contracts/schain/ITokenManager.sol
index b0ee59b..d378388 100644
--- a/contracts/schain/ITokenManager.sol
+++ b/contracts/schain/ITokenManager.sol
@@ -19,7 +19,7 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 import "../IMessageReceiver.sol";
 
@@ -29,4 +29,4 @@ interface ITokenManager is IMessageReceiver {
     function addTokenManager(string calldata schainName, address newTokenManager) external;
     function removeTokenManager(string calldata schainName) external;
     function hasTokenManager(string calldata schainName) external view returns (bool);
-}
\ No newline at end of file
+}
diff --git a/contracts/schain/ITokenManagerLinker.sol b/contracts/schain/ITokenManagerLinker.sol
index 1610b31..6323210 100644
--- a/contracts/schain/ITokenManagerLinker.sol
+++ b/contracts/schain/ITokenManagerLinker.sol
@@ -19,7 +19,7 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 import "./IMessageProxyForSchain.sol";
 import "./ITokenManager.sol";
@@ -33,4 +33,4 @@ interface ITokenManagerLinker {
     function removeTokenManager(ITokenManager tokenManagerAddress) external;
     function hasSchain(string calldata schainName) external view returns (bool connected);
     function hasTokenManager(address tokenManager) external view returns (bool);
-}
\ No newline at end of file
+}
diff --git a/contracts/schain/TokenManagers/ITokenContractManager.sol b/contracts/schain/TokenManagers/ITokenContractManager.sol
index 1b7a159..67594cb 100644
--- a/contracts/schain/TokenManagers/ITokenContractManager.sol
+++ b/contracts/schain/TokenManagers/ITokenContractManager.sol
@@ -19,7 +19,7 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 import "../ICommunityLocker.sol";
 import "../IMessageProxyForSchain.sol";
@@ -34,4 +34,4 @@ interface ITokenContractManager is ITokenManager {
         ICommunityLocker newCommunityLocker,
         address newDepositBox
     ) external;
-}
\ No newline at end of file
+}
diff --git a/contracts/schain/TokenManagers/ITokenManagerERC1155.sol b/contracts/schain/TokenManagers/ITokenManagerERC1155.sol
index 7fc1226..b0c37fc 100644
--- a/contracts/schain/TokenManagers/ITokenManagerERC1155.sol
+++ b/contracts/schain/TokenManagers/ITokenManagerERC1155.sol
@@ -19,7 +19,7 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 import "./ITokenContractManager.sol";
 
@@ -52,4 +52,4 @@ interface ITokenManagerERC1155 is ITokenContractManager {
         address erc1155OnMainnet,
         address erc1155OnSchain
     ) external;
-}
\ No newline at end of file
+}
diff --git a/contracts/schain/TokenManagers/ITokenManagerERC20.sol b/contracts/schain/TokenManagers/ITokenManagerERC20.sol
index fac8071..9aac41f 100644
--- a/contracts/schain/TokenManagers/ITokenManagerERC20.sol
+++ b/contracts/schain/TokenManagers/ITokenManagerERC20.sol
@@ -19,7 +19,7 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 import "./ITokenContractManager.sol";
 
diff --git a/contracts/schain/TokenManagers/ITokenManagerERC721.sol b/contracts/schain/TokenManagers/ITokenManagerERC721.sol
index ba52996..a63dc13 100644
--- a/contracts/schain/TokenManagers/ITokenManagerERC721.sol
+++ b/contracts/schain/TokenManagers/ITokenManagerERC721.sol
@@ -19,7 +19,7 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 import "./ITokenContractManager.sol";
 
@@ -35,4 +35,4 @@ interface ITokenManagerERC721 is ITokenContractManager {
         address erc721OnMainnet,
         address erc721OnSchain
     ) external;
-}
\ No newline at end of file
+}
diff --git a/contracts/schain/TokenManagers/ITokenManagerEth.sol b/contracts/schain/TokenManagers/ITokenManagerEth.sol
index dce9c63..b02ea6d 100644
--- a/contracts/schain/TokenManagers/ITokenManagerEth.sol
+++ b/contracts/schain/TokenManagers/ITokenManagerEth.sol
@@ -19,7 +19,7 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 import "../tokens/IEthErc20.sol";
 import "../ICommunityLocker.sol";
@@ -39,4 +39,4 @@ interface ITokenManagerEth is ITokenManager {
     ) external;
     function setEthErc20Address(IEthErc20 newEthErc20Address) external;
     function exitToMain(uint256 amount) external;
-}
\ No newline at end of file
+}
diff --git a/contracts/schain/bls/IFieldOperations.sol b/contracts/schain/bls/IFieldOperations.sol
index 7c1dca3..42b2d2c 100644
--- a/contracts/schain/bls/IFieldOperations.sol
+++ b/contracts/schain/bls/IFieldOperations.sol
@@ -19,7 +19,7 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 
 interface IFieldOperations {
@@ -39,4 +39,4 @@ interface IFieldOperations {
         Fp2Point x;
         Fp2Point y;
     }
-}
\ No newline at end of file
+}
diff --git a/contracts/schain/tokens/IERC1155OnChain.sol b/contracts/schain/tokens/IERC1155OnChain.sol
index 2927793..d3be284 100644
--- a/contracts/schain/tokens/IERC1155OnChain.sol
+++ b/contracts/schain/tokens/IERC1155OnChain.sol
@@ -19,7 +19,7 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 
 interface IERC1155OnChain {
@@ -35,4 +35,4 @@ interface IERC1155OnChain {
         uint256[] memory amounts,
         bytes memory data
     ) external;
-}
\ No newline at end of file
+}
diff --git a/contracts/schain/tokens/IERC20OnChain.sol b/contracts/schain/tokens/IERC20OnChain.sol
index 3b7e991..6412bbe 100644
--- a/contracts/schain/tokens/IERC20OnChain.sol
+++ b/contracts/schain/tokens/IERC20OnChain.sol
@@ -19,9 +19,9 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 
 interface IERC20OnChain {
     function mint(address account, uint256 value) external;
-}
\ No newline at end of file
+}
diff --git a/contracts/schain/tokens/IERC721OnChain.sol b/contracts/schain/tokens/IERC721OnChain.sol
index d2a7e5a..7b8f29c 100644
--- a/contracts/schain/tokens/IERC721OnChain.sol
+++ b/contracts/schain/tokens/IERC721OnChain.sol
@@ -19,10 +19,10 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 
 interface IERC721OnChain {
     function setTokenURI(uint256 tokenId, string calldata tokenUri) external returns (bool);
     function mint(address account, uint256 tokenId) external;
-}
\ No newline at end of file
+}
diff --git a/contracts/schain/tokens/IEthErc20.sol b/contracts/schain/tokens/IEthErc20.sol
index aeb8236..ccdb667 100644
--- a/contracts/schain/tokens/IEthErc20.sol
+++ b/contracts/schain/tokens/IEthErc20.sol
@@ -19,11 +19,11 @@
  *   along with SKALE IMA.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pragma solidity >=0.6.10 <0.9.0;
+pragma solidity >=0.8.19 <0.9.0;
 
 
 interface IEthErc20 {
     function mint(address account, uint256 amount) external;
     function forceBurn(address account, uint256 amount) external;
     function initialize(address tokenManagerEthAddress) external;
-}
\ No newline at end of file
+}
diff --git a/cspell.json b/cspell.json
index 67238e1..9a10dc8 100644
--- a/cspell.json
+++ b/cspell.json
@@ -4,6 +4,7 @@
     "ignorePaths": [
         "yarn-error.log",
         ".gitignore",
+        ".solhint.json",
         "cspell.json",
         "dictionaries/**/*",
         "cache/**/*",
diff --git a/hardhat.config.ts b/hardhat.config.ts
index 15de234..5e62f92 100644
--- a/hardhat.config.ts
+++ b/hardhat.config.ts
@@ -1,7 +1,7 @@
 import { HardhatUserConfig } from "hardhat/config";
 
 const config: HardhatUserConfig = {
-  solidity: "0.8.9",
+  solidity: "0.8.27",
 };
 
 export default config;
diff --git a/slither.config.json b/slither.config.json
index fcfc6e9..23991e9 100644
--- a/slither.config.json
+++ b/slither.config.json
@@ -1,4 +1,4 @@
 {
     "detectors_to_exclude": "solc-version",
-    "filter_paths": ""
-}
\ No newline at end of file
+    "filter_paths": "node_modules"
+}