diff --git a/src/BLSOperatorSetRootCalculator.sol b/src/BLSOperatorSetRootCalculator.sol
new file mode 100644
index 00000000..1e82c36d
--- /dev/null
+++ b/src/BLSOperatorSetRootCalculator.sol
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: BUSL-1.1
+pragma solidity ^0.8.12;
+
+import { OperatorSet } from "eigenlayer-contracts/src/contracts/interfaces/IAllocationManager.sol";
+import { IAllocationManager } from "eigenlayer-contracts/src/contracts/interfaces/IAllocationManager.sol";
+import { IDelegationManager } from "eigenlayer-contracts/src/contracts/interfaces/IDelegationManager.sol";
+import { IStrategy } from "eigenlayer-contracts/src/contracts/interfaces/IStrategy.sol";
+
+import { Merkle } from "eigenlayer-contracts/src/contracts/libraries/Merkle.sol";
+
+import { BN254 } from "./libraries/BN254.sol";
+
+import { IOperatorSetRootCalculator } from "./interfaces/IOperatorSetRootCalculator.sol";
+import { IBLSApkRegistry } from "./interfaces/IBLSApkRegistry.sol";
+import { IStakeRegistry } from "./interfaces/IStakeRegistry.sol";
+
+contract BLSOperatorSetRootCalculator is IOperatorSetRootCalculator {
+    using BN254 for BN254.G1Point;
+    using Merkle for bytes32[];
+    
+    IDelegationManager public immutable delegationManager;
+    IAllocationManager public immutable allocationManager;
+
+    IBLSApkRegistry public immutable blsApkRegistry;
+    IStakeRegistry public immutable stakeRegistry;
+
+    constructor(
+        IAllocationManager _allocationManager,
+        IStakeRegistry _stakeRegistry,
+        IDelegationManager _delegationManager,
+        IBLSApkRegistry _blsApkRegistry
+    ) {
+        allocationManager = _allocationManager;
+        stakeRegistry = _stakeRegistry;
+        delegationManager = _delegationManager;
+        blsApkRegistry = _blsApkRegistry;
+    }
+
+    /**
+	 * @notice called offchain by provers in order to get the operatorSetRoot
+	 * @param operatorSet the operatorSet to get the operatorSetRoot for
+	 * @return the operatorSetRoot
+	 */
+	function getOperatorLeaves(
+		OperatorSet calldata operatorSet
+	) external view returns(bytes32) {
+        // Get operators
+        address[] memory operators = allocationManager.getMembers(operatorSet);
+
+        // Get strategy params. TODO: replace this is gross
+        IStakeRegistry.StrategyParams[] memory strategyParams = new IStakeRegistry.StrategyParams[](stakeRegistry.strategyParamsLength(uint8(operatorSet.id)));
+        IStrategy[] memory strategies = new IStrategy[](strategyParams.length);
+        for (uint256 i = 0; i < strategyParams.length; i++) {
+            strategyParams[i] = stakeRegistry.strategyParamsByIndex(uint8(operatorSet.id), i);
+            strategies[i] = strategyParams[i].strategy;
+        }
+
+        // Get delegated stake
+        uint256[][] memory delegatedStake = delegationManager.getOperatorsShares(operators, strategies);
+        // Get slashable stake
+        uint256[][] memory slashableStake = allocationManager.getMinimumSlashableStake(operatorSet, operators, strategies, uint32(block.number + 14 days / 12 seconds));
+        // Get pubkey hashes    
+        BN254.G1Point[] memory pubkeys = new BN254.G1Point[](operators.length);
+        for (uint256 i = 0; i < operators.length; i++) {
+            (pubkeys[i], ) = blsApkRegistry.getRegisteredPubkey(operators[i]);
+        }
+
+        uint256 totalDelegatedStake = 0;
+        uint256 totalSlashableStake = 0;
+        BN254.G1Point memory aggPubkey = BN254.G1Point(0, 0);
+        // Get operator leaves
+        bytes32[] memory leaves = new bytes32[](operators.length);
+        for (uint256 i = 0; i < operators.length; i++) {
+            // add to totals
+            totalDelegatedStake += delegatedStake[i][operatorSet.id];
+            totalSlashableStake += slashableStake[i][operatorSet.id];
+            aggPubkey = aggPubkey.plus(pubkeys[i]);
+
+            // get operator leaf
+            leaves[i] = keccak256(abi.encodePacked(
+                totalDelegatedStake,
+                totalSlashableStake,
+                aggPubkey.X,
+                aggPubkey.Y
+            ));
+        }
+
+        // get operator tree root
+        bytes32 operatorTreeRoot = leaves.merkleizeKeccak256();
+
+        // get operator set root
+        bytes32 operatorSetRoot = keccak256(abi.encodePacked(
+            operatorTreeRoot,
+            keccak256(abi.encodePacked(
+                totalDelegatedStake,
+                totalSlashableStake,
+                aggPubkey.X,
+                aggPubkey.Y
+            ))
+        ));
+
+        return operatorSetRoot;
+	}
+}
\ No newline at end of file
diff --git a/src/interfaces/IOperatorSetRootCalculator.sol b/src/interfaces/IOperatorSetRootCalculator.sol
new file mode 100644
index 00000000..35496c0b
--- /dev/null
+++ b/src/interfaces/IOperatorSetRootCalculator.sol
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: BUSL-1.1
+pragma solidity >=0.5.0;
+
+import { OperatorSet} from "eigenlayer-contracts/src/contracts/interfaces/IAllocationManager.sol";
+
+interface IOperatorSetRootCalculator {
+	/**
+	 * @notice called offchain by provers in order to get the operatorSetRoot
+	 * @param operatorSet the operatorSet to get the operatorSetRoot for
+	 * @return the operatorSetRoot
+	 */
+	function getOperatorLeaves(
+		OperatorSet calldata operatorSet
+	) external view returns(bytes32);
+}
\ No newline at end of file