diff --git a/contracts/IBountyV2.sol b/contracts/IBountyV2.sol
index 4205072..8770119 100644
--- a/contracts/IBountyV2.sol
+++ b/contracts/IBountyV2.sol
@@ -22,10 +22,6 @@
 pragma solidity >=0.6.10 <0.9.0;
 
 interface IBountyV2 {
-    struct BountyHistory {
-        uint month;
-        uint bountyPaid;
-    }
 
     /**
      * @dev Emitted when bounty reduction is turned on or turned off.
diff --git a/contracts/IKeyStorage.sol b/contracts/IKeyStorage.sol
index 616b95e..8700f68 100644
--- a/contracts/IKeyStorage.sol
+++ b/contracts/IKeyStorage.sol
@@ -24,10 +24,6 @@ pragma solidity >=0.6.10 <0.9.0;
 import "./ISkaleDKG.sol";
 
 interface IKeyStorage {
-    struct BroadcastedData {
-        KeyShare[] secretKeyContribution;
-        ISkaleDKG.G2Point[] verificationVector;
-    }
 
     struct KeyShare {
         bytes32[2] publicKey;
diff --git a/contracts/ISchains.sol b/contracts/ISchains.sol
index 4973c75..012a351 100644
--- a/contracts/ISchains.sol
+++ b/contracts/ISchains.sol
@@ -22,14 +22,7 @@
 pragma solidity >=0.6.10 <0.9.0;
 
 interface ISchains {
-    struct SchainParameters {
-        uint lifetime;
-        uint8 typeOfSchain;
-        uint16 nonce;
-        string name;
-        address originator;
-    }
-
+    
     /**
      * @dev Emitted when an schain is created.
      */
diff --git a/contracts/ISkaleDKG.sol b/contracts/ISkaleDKG.sol
index 4c83aba..494e9f5 100644
--- a/contracts/ISkaleDKG.sol
+++ b/contracts/ISkaleDKG.sol
@@ -23,8 +23,6 @@ pragma solidity >=0.6.10 <0.9.0;
 
 interface ISkaleDKG {
 
-    enum DkgFunction {Broadcast, Alright, ComplaintBadData, PreResponse, Complaint, Response}
-
     struct Fp2Point {
         uint a;
         uint b;
@@ -62,12 +60,6 @@ interface ISkaleDKG {
         bytes32[2] publicKey;
         bytes32 share;
     }
-
-    struct Context {
-        bool isDebt;
-        uint delta;
-        DkgFunction dkgFunction;
-    }
     
     /**
      * @dev Emitted when a channel is opened.
diff --git a/contracts/delegation/IDelegationController.sol b/contracts/delegation/IDelegationController.sol
new file mode 100644
index 0000000..0b5c5fe
--- /dev/null
+++ b/contracts/delegation/IDelegationController.sol
@@ -0,0 +1,120 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+
+/*
+    IDelegationController.sol - SKALE Manager
+    Copyright (C) 2018-Present SKALE Labs
+    @author Artem Payvin
+
+    SKALE Manager 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 Manager 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 Manager.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+pragma solidity >=0.6.10 <0.9.0;
+
+interface IDelegationController {
+    enum State {
+        PROPOSED,
+        ACCEPTED,
+        CANCELED,
+        REJECTED,
+        DELEGATED,
+        UNDELEGATION_REQUESTED,
+        COMPLETED
+    }
+
+    struct Delegation {
+        address holder; // address of token owner
+        uint validatorId;
+        uint amount;
+        uint delegationPeriod;
+        uint created; // time of delegation creation
+        uint started; // month when a delegation becomes active
+        uint finished; // first month after a delegation ends
+        string info;
+    }
+
+    /**
+     * @dev Emitted when validator was confiscated.
+     */
+    event Confiscated(
+        uint indexed validatorId,
+        uint amount
+    );
+
+    /**
+     * @dev Emitted when validator was confiscated.
+     */
+    event SlashesProcessed(
+        address indexed holder,
+        uint limit
+    );
+
+    /**
+     * @dev Emitted when a delegation is proposed to a validator.
+     */
+    event DelegationProposed(
+        uint delegationId
+    );
+
+    /**
+     * @dev Emitted when a delegation is accepted by a validator.
+     */
+    event DelegationAccepted(
+        uint delegationId
+    );
+
+    /**
+     * @dev Emitted when a delegation is cancelled by the delegator.
+     */
+    event DelegationRequestCanceledByUser(
+        uint delegationId
+    );
+
+    /**
+     * @dev Emitted when a delegation is requested to undelegate.
+     */
+    event UndelegationRequested(
+        uint delegationId
+    );
+    
+    function getAndUpdateDelegatedToValidatorNow(uint validatorId) external returns (uint);
+    function getAndUpdateDelegatedAmount(address holder) external returns (uint);
+    function getAndUpdateEffectiveDelegatedByHolderToValidator(address holder, uint validatorId, uint month)
+        external
+        returns (uint effectiveDelegated);
+    function delegate(
+        uint validatorId,
+        uint amount,
+        uint delegationPeriod,
+        string calldata info
+    )
+        external;
+    function cancelPendingDelegation(uint delegationId) external;
+    function acceptPendingDelegation(uint delegationId) external;
+    function requestUndelegation(uint delegationId) external;
+    function confiscate(uint validatorId, uint amount) external;
+    function getAndUpdateEffectiveDelegatedToValidator(uint validatorId, uint month) external returns (uint);
+    function getAndUpdateDelegatedByHolderToValidatorNow(address holder, uint validatorId) external returns (uint);
+    function processSlashes(address holder, uint limit) external;
+    function processAllSlashes(address holder) external;
+    function getEffectiveDelegatedValuesByValidator(uint validatorId) external view returns (uint[] memory);
+    function getEffectiveDelegatedToValidator(uint validatorId, uint month) external view returns (uint);
+    function getDelegatedToValidator(uint validatorId, uint month) external view returns (uint);
+    function getDelegation(uint delegationId) external view returns (Delegation memory);
+    function getFirstDelegationMonth(address holder, uint validatorId) external view returns(uint);
+    function getDelegationsByValidatorLength(uint validatorId) external view returns (uint);
+    function getDelegationsByHolderLength(address holder) external view returns (uint);
+    function getState(uint delegationId) external view returns (State state);
+    function getLockedInPendingDelegations(address holder) external view returns (uint);
+    function hasUnprocessedSlashes(address holder) external view returns (bool);
+}
diff --git a/contracts/delegation/IDelegationPeriodManager.sol b/contracts/delegation/IDelegationPeriodManager.sol
new file mode 100644
index 0000000..b20782a
--- /dev/null
+++ b/contracts/delegation/IDelegationPeriodManager.sol
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+
+/*
+    IDelegationPeriodManager.sol - SKALE Manager
+    Copyright (C) 2018-Present SKALE Labs
+    @author Artem Payvin
+
+    SKALE Manager 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 Manager 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 Manager.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+pragma solidity >=0.6.10 <0.9.0;
+
+interface IDelegationPeriodManager {
+    /**
+     * @dev Emitted when a new delegation period is specified.
+     */
+    event DelegationPeriodWasSet(
+        uint length,
+        uint stakeMultiplier
+    );
+    
+    function setDelegationPeriod(uint monthsCount, uint stakeMultiplier) external;
+    function isDelegationPeriodAllowed(uint monthsCount) external view returns (bool);
+}
diff --git a/contracts/delegation/IDistributor.sol b/contracts/delegation/IDistributor.sol
new file mode 100644
index 0000000..9988d11
--- /dev/null
+++ b/contracts/delegation/IDistributor.sol
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+
+/*
+    IDistributor.sol - SKALE Manager
+    Copyright (C) 2018-Present SKALE Labs
+    @author Artem Payvin
+
+    SKALE Manager 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 Manager 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 Manager.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+pragma solidity >=0.6.10 <0.9.0;
+
+interface IDistributor {
+    /**
+     * @dev Emitted when bounty is withdrawn.
+     */
+    event WithdrawBounty(
+        address holder,
+        uint validatorId,
+        address destination,
+        uint amount
+    );
+
+    /**
+     * @dev Emitted when a validator fee is withdrawn.
+     */
+    event WithdrawFee(
+        uint validatorId,
+        address destination,
+        uint amount
+    );
+
+    /**
+     * @dev Emitted when bounty is distributed.
+     */
+    event BountyWasPaid(
+        uint validatorId,
+        uint amount
+    );
+    
+    function getAndUpdateEarnedBountyAmount(uint validatorId) external returns (uint earned, uint endMonth);
+    function withdrawBounty(uint validatorId, address to) external;
+    function withdrawFee(address to) external;
+    function getAndUpdateEarnedBountyAmountOf(address wallet, uint validatorId)
+        external
+        returns (uint earned, uint endMonth);
+    function getEarnedFeeAmount() external view returns (uint earned, uint endMonth);
+    function getEarnedFeeAmountOf(uint validatorId) external view returns (uint earned, uint endMonth);
+}
diff --git a/contracts/delegation/IPunisher.sol b/contracts/delegation/IPunisher.sol
new file mode 100644
index 0000000..afe38c1
--- /dev/null
+++ b/contracts/delegation/IPunisher.sol
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+
+/*
+    IPunisher.sol - SKALE Manager
+    Copyright (C) 2018-Present SKALE Labs
+    @author Artem Payvin
+
+    SKALE Manager 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 Manager 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 Manager.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+pragma solidity >=0.6.10 <0.9.0;
+
+interface IPunisher {
+    /**
+     * @dev Emitted upon slashing condition.
+     */
+    event Slash(
+        uint validatorId,
+        uint amount
+    );
+
+    /**
+     * @dev Emitted upon forgive condition.
+     */
+    event Forgive(
+        address wallet,
+        uint amount
+    );
+    
+    function slash(uint validatorId, uint amount) external;
+    function forgive(address holder, uint amount) external;
+    function handleSlash(address holder, uint amount) external;
+}
diff --git a/contracts/delegation/ITimeHelpers.sol b/contracts/delegation/ITimeHelpers.sol
new file mode 100644
index 0000000..62d594b
--- /dev/null
+++ b/contracts/delegation/ITimeHelpers.sol
@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+
+/*
+    ITimeHelpers.sol - SKALE Manager
+    Copyright (C) 2018-Present SKALE Labs
+    @author Artem Payvin
+
+    SKALE Manager 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 Manager 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 Manager.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+pragma solidity >=0.6.10 <0.9.0;
+
+interface ITimeHelpers {
+    function calculateProofOfUseLockEndTime(uint month, uint lockUpPeriodDays) external view returns (uint timestamp);
+    function getCurrentMonth() external view returns (uint);
+    function timestampToYear(uint timestamp) external view returns (uint);
+    function timestampToMonth(uint timestamp) external view returns (uint);
+    function monthToTimestamp(uint month) external view returns (uint timestamp);
+    function addDays(uint fromTimestamp, uint n) external pure returns (uint);
+    function addMonths(uint fromTimestamp, uint n) external pure returns (uint);
+    function addYears(uint fromTimestamp, uint n) external pure returns (uint);
+}
diff --git a/contracts/delegation/ITokenState.sol b/contracts/delegation/ITokenState.sol
new file mode 100644
index 0000000..3731ecc
--- /dev/null
+++ b/contracts/delegation/ITokenState.sol
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+
+/*
+    ITokenState.sol - SKALE Manager
+    Copyright (C) 2018-Present SKALE Labs
+    @author Artem Payvin
+
+    SKALE Manager 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 Manager 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 Manager.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+pragma solidity >=0.6.10 <0.9.0;
+
+interface ITokenState {
+    /**
+     * @dev Emitted when a contract is added to the locker.
+     */
+    event LockerWasAdded(
+        string locker
+    );
+
+    /**
+     * @dev Emitted when a contract is removed from the locker.
+     */
+    event LockerWasRemoved(
+        string locker
+    );
+    
+    function removeLocker(string calldata locker) external;
+    function addLocker(string memory locker) external;
+}
diff --git a/contracts/delegation/IValidatorService.sol b/contracts/delegation/IValidatorService.sol
new file mode 100644
index 0000000..05697d0
--- /dev/null
+++ b/contracts/delegation/IValidatorService.sol
@@ -0,0 +1,149 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+
+/*
+    IValidatorService.sol - SKALE Manager
+    Copyright (C) 2018-Present SKALE Labs
+    @author Artem Payvin
+
+    SKALE Manager 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 Manager 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 Manager.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+pragma solidity >=0.6.10 <0.9.0;
+
+interface IValidatorService {
+    struct Validator {
+        string name;
+        address validatorAddress;
+        address requestedAddress;
+        string description;
+        uint feeRate;
+        uint registrationTime;
+        uint minimumDelegationAmount;
+        bool acceptNewRequests;
+    }
+    
+    /**
+     * @dev Emitted when a validator registers.
+     */
+    event ValidatorRegistered(
+        uint validatorId
+    );
+
+    /**
+     * @dev Emitted when a validator address changes.
+     */
+    event ValidatorAddressChanged(
+        uint validatorId,
+        address newAddress
+    );
+
+    /**
+     * @dev Emitted when a validator is enabled.
+     */
+    event ValidatorWasEnabled(
+        uint validatorId
+    );
+
+    /**
+     * @dev Emitted when a validator is disabled.
+     */
+    event ValidatorWasDisabled(
+        uint validatorId
+    );
+
+    /**
+     * @dev Emitted when a node address is linked to a validator.
+     */
+    event NodeAddressWasAdded(
+        uint validatorId,
+        address nodeAddress
+    );
+
+    /**
+     * @dev Emitted when a node address is unlinked from a validator.
+     */
+    event NodeAddressWasRemoved(
+        uint validatorId,
+        address nodeAddress
+    );
+
+    /**
+     * @dev Emitted when whitelist disabled.
+     */
+    event WhitelistDisabled(bool status);
+
+    /**
+     * @dev Emitted when validator requested new address.
+     */
+    event RequestNewAddress(uint indexed validatorId, address previousAddress, address newAddress);
+
+    /**
+     * @dev Emitted when validator set new minimum delegation amount.
+     */
+    event SetMinimumDelegationAmount(uint indexed validatorId, uint previousMDA, uint newMDA);
+
+    /**
+     * @dev Emitted when validator set new name.
+     */
+    event SetValidatorName(uint indexed validatorId, string previousName, string newName);
+
+    /**
+     * @dev Emitted when validator set new description.
+     */
+    event SetValidatorDescription(uint indexed validatorId, string previousDescription, string newDescription);
+
+    /**
+     * @dev Emitted when validator start or stop accepting new delegation requests.
+     */
+    event AcceptingNewRequests(uint indexed validatorId, bool status);
+    
+    function registerValidator(
+        string calldata name,
+        string calldata description,
+        uint feeRate,
+        uint minimumDelegationAmount
+    )
+        external
+        returns (uint validatorId);
+    function enableValidator(uint validatorId) external;
+    function disableValidator(uint validatorId) external;
+    function disableWhitelist() external;
+    function requestForNewAddress(address newValidatorAddress) external;
+    function confirmNewAddress(uint validatorId) external;
+    function linkNodeAddress(address nodeAddress, bytes calldata sig) external;
+    function unlinkNodeAddress(address nodeAddress) external;
+    function setValidatorMDA(uint minimumDelegationAmount) external;
+    function setValidatorName(string calldata newName) external;
+    function setValidatorDescription(string calldata newDescription) external;
+    function startAcceptingNewRequests() external;
+    function stopAcceptingNewRequests() external;
+    function removeNodeAddress(uint validatorId, address nodeAddress) external;
+    function getAndUpdateBondAmount(uint validatorId) external returns (uint);
+    function getMyNodesAddresses() external view returns (address[] memory);
+    function getTrustedValidators() external view returns (uint[] memory);
+    function checkValidatorAddressToId(address validatorAddress, uint validatorId)
+        external
+        view
+        returns (bool);
+    function getValidatorIdByNodeAddress(address nodeAddress) external view returns (uint validatorId);
+    function checkValidatorCanReceiveDelegation(uint validatorId, uint amount) external view;
+    function getNodeAddresses(uint validatorId) external view returns (address[] memory);
+    function validatorExists(uint validatorId) external view returns (bool);
+    function validatorAddressExists(address validatorAddress) external view returns (bool);
+    function checkIfValidatorAddressExists(address validatorAddress) external view;
+    function getValidator(uint validatorId) external view returns (Validator memory);
+    function getValidatorId(address validatorAddress) external view returns (uint);
+    function isAcceptingNewRequests(uint validatorId) external view returns (bool);
+    function isAuthorizedValidator(uint validatorId) external view returns (bool);
+}
diff --git a/contracts/thirdparty/IECDH.sol b/contracts/thirdparty/IECDH.sol
new file mode 100644
index 0000000..6630524
--- /dev/null
+++ b/contracts/thirdparty/IECDH.sol
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+
+/*
+    IECDH.sol - SKALE Manager
+    Copyright (C) 2018-Present SKALE Labs
+    @author Artem Payvin
+
+    SKALE Manager 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 Manager 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 Manager.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+pragma solidity >=0.6.10 <0.9.0;
+
+interface IECDH {
+    function publicKey(uint256 privKey) external pure returns (uint256 qx, uint256 qy);
+    function deriveKey(
+        uint256 privKey,
+        uint256 pubX,
+        uint256 pubY
+    )
+        external
+        pure
+        returns (uint256 qx, uint256 qy);
+    function jAdd(
+        uint256 x1,
+        uint256 z1,
+        uint256 x2,
+        uint256 z2
+    )
+        external
+        pure
+        returns (uint256 x3, uint256 z3);
+    function jSub(
+        uint256 x1,
+        uint256 z1,
+        uint256 x2,
+        uint256 z2
+    )
+        external
+        pure
+        returns (uint256 x3, uint256 z3);
+    function jMul(
+        uint256 x1,
+        uint256 z1,
+        uint256 x2,
+        uint256 z2
+    )
+        external
+        pure
+        returns (uint256 x3, uint256 z3);
+    function jDiv(
+        uint256 x1,
+        uint256 z1,
+        uint256 x2,
+        uint256 z2
+    )
+        external
+        pure
+        returns (uint256 x3, uint256 z3);
+    function inverse(uint256 a) external pure returns (uint256 invA);
+    function ecAdd(
+        uint256 x1,
+        uint256 y1,
+        uint256 z1,
+        uint256 x2,
+        uint256 y2,
+        uint256 z2
+    )
+        external
+        pure
+        returns (uint256 x3, uint256 y3, uint256 z3);
+    function ecDouble(
+        uint256 x1,
+        uint256 y1,
+        uint256 z1
+    )
+        external
+        pure
+        returns (uint256 x3, uint256 y3, uint256 z3);
+    function ecMul(
+        uint256 d,
+        uint256 x1,
+        uint256 y1,
+        uint256 z1
+    )
+        external
+        pure
+        returns (uint256 x3, uint256 y3, uint256 z3);
+}
diff --git a/contracts/thirdparty/openzeppelin/IAccessControlUpgradeableLegacy.sol b/contracts/thirdparty/openzeppelin/IAccessControlUpgradeableLegacy.sol
new file mode 100644
index 0000000..b4ee669
--- /dev/null
+++ b/contracts/thirdparty/openzeppelin/IAccessControlUpgradeableLegacy.sol
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+
+/*
+    IAccessControlUpgradeableLegacy.sol - SKALE Manager
+    Copyright (C) 2018-Present SKALE Labs
+    @author Artem Payvin
+
+    SKALE Manager 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 Manager 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 Manager.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+pragma solidity >=0.6.10 <0.9.0;
+
+interface IAccessControlUpgradeableLegacy {
+    /**
+     * @dev Emitted when `account` is granted `role`.
+     *
+     * `sender` is the account that originated the contract call, an admin role
+     * bearer except when using {_setupRole}.
+     */
+    event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
+
+    /**
+     * @dev Emitted when `account` is revoked `role`.
+     *
+     * `sender` is the account that originated the contract call:
+     *   - if using `revokeRole`, it is the admin role bearer
+     *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
+     */
+    event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
+    
+    function grantRole(bytes32 role, address account) external;
+    function revokeRole(bytes32 role, address account) external;
+    function renounceRole(bytes32 role, address account) external;
+    function hasRole(bytes32 role, address account) external view returns (bool);
+    function getRoleMemberCount(bytes32 role) external view returns (uint256);
+    function getRoleMember(bytes32 role, uint256 index) external view returns (address);
+    function getRoleAdmin(bytes32 role) external view returns (bytes32);
+}