feat: add consumer and sdk contracts

package.json

@@ -7,7 +7,7 @@
     "type": "git",
     "url": "git+https://github.com/defi-wonderland/solidity-foundry-boilerplate.git"
   },
-  "license": "PPL",
+  "license": "MIT",
   "author": "Breadchain, fork ofWonderland",
   "scripts": {
     "build": "forge build",

src/contracts/LayerConsumer.sol

@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.23;
+
+import {ECDSAStakeRegistry} from '@eigenlayer-middleware/unaudited/ECDSAStakeRegistry.sol';
+import {ILayerConsumer} from 'interfaces/ILayerConsumer.sol';
+
+contract LayerConsumer is ILayerConsumer {
+  /// @notice bytes4(keccak256("isValidSignature(bytes32,bytes)")
+  bytes4 internal constant _ERC1271_SIGNATURE = 0x1626ba7e;
+
+  /// @inheritdoc ILayerConsumer
+  ECDSAStakeRegistry public immutable STAKE_REGISTRY;
+
+  /// @notice Enforce that the caller is an operator
+  modifier onlyOperator() {
+    if (!STAKE_REGISTRY.operatorRegistered(msg.sender)) revert NotOperator();
+    _;
+  }
+
+  /**
+   * @notice Initializer
+   * @param _stakeRegistry The address of the stake registry contract
+   */
+  constructor(address _stakeRegistry) {
+    STAKE_REGISTRY = ECDSAStakeRegistry(_stakeRegistry);
+  }
+
+  /**
+   * @notice Validates a layer task from off-chain AVS operator
+   * @param _task The message and signatures to verify
+   * @return _isValid Whether the task is valid
+   */
+  function _validateLayerTask(Task memory _task) internal view returns (bool _isValid) {
+    _isValid = (_ERC1271_SIGNATURE == STAKE_REGISTRY.isValidSignature(_task.dataHash, _task.signatureData));
+  }
+}

src/contracts/LayerSDK.sol

@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.23;
+
+import {LayerConsumer} from 'contracts/LayerConsumer.sol';
+import {ILayerSDK} from 'interfaces/ILayerSDK.sol';
+
+contract LayerSDK is LayerConsumer, ILayerSDK {
+  /// @notice Initializer
+  constructor(address _stakeRegistry) LayerConsumer(_stakeRegistry) {}
+
+  /// @inheritdoc ILayerSDK
+  function validateLayerTask(string calldata _offchainData) external view onlyOperator returns (bool _isValid) {
+    Task memory _task = Task({dataHash: bytes32(bytes(_offchainData[0:32])), signatureData: bytes(_offchainData[32:])});
+    _isValid = _validateLayerTask(_task);
+  }
+}

src/interfaces/ILayerConsumer.sol

@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.23;
+
+import {ECDSAStakeRegistry} from '@eigenlayer-middleware/unaudited/ECDSAStakeRegistry.sol';
+
+/**
+ * @title AVSConsumer Contract
+ * @author Breadchain
+ * @notice LayerConsumer contract to validate layer tasks from off-chain AVS operators
+ */
+interface ILayerConsumer {
+  /*///////////////////////////////////////////////////////////////
+                            DATA STRUCTURES
+  //////////////////////////////////////////////////////////////*/
+
+  /**
+   * @notice The task structure
+   * @param dataHash The hash of the data to verify
+   * @param signatureData The signature(s) to verify
+   */
+  struct Task {
+    bytes32 dataHash;
+    bytes signatureData;
+  }
+
+  /*///////////////////////////////////////////////////////////////
+                            ERRORS
+  //////////////////////////////////////////////////////////////*/
+
+  /// @notice Error thrown when the caller is not an operator
+  error NotOperator();
+
+  /*///////////////////////////////////////////////////////////////
+                            VARIABLES
+  //////////////////////////////////////////////////////////////*/
+
+  /**
+   * @notice The stake registry contract
+   * @return _stakeRegistry The stake registry address
+   */
+  function STAKE_REGISTRY() external view returns (ECDSAStakeRegistry _stakeRegistry); // solhint-disable-line func-name-mixedcase
+}

src/interfaces/ILayerSDK.sol

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.23;
+
+import {ILayerConsumer} from 'interfaces/ILayerConsumer.sol';
+
+interface ILayerSDK is ILayerConsumer {
+  /*///////////////////////////////////////////////////////////////
+                            LOGIC
+  //////////////////////////////////////////////////////////////*/
+
+  /**
+   * @notice Validates a layer task from off-chain AVS operator
+   * @param _offchainData The off-chain data to verify
+   * @return _isValid Whether the task is valid
+   */
+  function validateLayerTask(string calldata _offchainData) external view returns (bool _isValid);
+}

test/unit/LayerConsumer.t.sol

@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.23;
+
+import {Test} from 'forge-std/Test.sol';
+
+contract UnitLayerConsumer is Test {}