diff --git a/src/libraries/PositionConfig.sol b/src/libraries/PositionConfig.sol
new file mode 100644
index 00000000..007e7bb9
--- /dev/null
+++ b/src/libraries/PositionConfig.sol
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+pragma solidity ^0.8.0;
+
+import {PoolKey} from "@uniswap/v4-core/src/types/PoolKey.sol";
+
+// A PositionConfig is the input for creating and modifying a Position in core, whose truncated hash is set per tokenId
+struct PositionConfig {
+    PoolKey poolKey;
+    int24 tickLower;
+    int24 tickUpper;
+}
+
+/// @notice Library to calculate the PositionConfigId from the PositionConfig struct
+library PositionConfigLibrary {
+    function toId(PositionConfig calldata config) internal pure returns (bytes32 id) {
+        // id = keccak256(abi.encodePacked(currency0, currency1, fee, tickSpacing, hooks, tickLower, tickUpper))) >> 1
+        assembly ("memory-safe") {
+            let fmp := mload(0x40)
+            mstore(add(fmp, 0x34), calldataload(add(config, 0xc0))) // tickUpper: [0x51, 0x54)
+            mstore(add(fmp, 0x31), calldataload(add(config, 0xa0))) // tickLower: [0x4E, 0x51)
+            mstore(add(fmp, 0x2E), calldataload(add(config, 0x80))) // hooks: [0x3A, 0x4E)
+            mstore(add(fmp, 0x1A), calldataload(add(config, 0x60))) // tickSpacing: [0x37, 0x3A)
+            mstore(add(fmp, 0x17), calldataload(add(config, 0x40))) // fee: [0x34, 0x37)
+            mstore(add(fmp, 0x14), calldataload(add(config, 0x20))) // currency1: [0x20, 0x34)
+            mstore(fmp, calldataload(config)) // currency0: [0x0c, 0x20)
+
+            id := shr(1, keccak256(add(fmp, 0x0c), 0x48)) // len is 72 bytes, truncate lower bit of the hash
+
+            // now clean the memory we used
+            mstore(add(fmp, 0x40), 0) // fmp+0x40 held hooks (14 bytes), tickLower, tickUpper
+            mstore(add(fmp, 0x20), 0) // fmp+0x20 held currency1, fee, tickSpacing, hooks (6 bytes)
+            mstore(fmp, 0) // fmp held currency0
+        }
+    }
+}
diff --git a/src/libraries/PositionConfigId.sol b/src/libraries/PositionConfigId.sol
new file mode 100644
index 00000000..4e31c760
--- /dev/null
+++ b/src/libraries/PositionConfigId.sol
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+pragma solidity ^0.8.0;
+
+/// @notice A configId is set per tokenId
+/// The lower 255 bits are used to store the truncated hash of the corresponding PositionConfig
+/// The upper bit is used to signal if the tokenId has a subscriber
+struct PositionConfigId {
+    bytes32 id;
+}
+
+library PositionConfigIdLibrary {
+    bytes32 constant MASK_UPPER_BIT = 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF;
+    bytes32 constant DIRTY_UPPER_BIT = 0x8000000000000000000000000000000000000000000000000000000000000000;
+
+    /// @notice returns the truncated hash of the PositionConfig for a given tokenId
+    function getConfigId(PositionConfigId storage _configId) internal view returns (bytes32 configId) {
+        configId = _configId.id & MASK_UPPER_BIT;
+    }
+
+    /// @dev We only set the config on mint, guaranteeing that the most significant bit is unset, so we can just assign the entire 32 bytes to the id.
+    function setConfigId(PositionConfigId storage _configId, bytes32 configId) internal {
+        _configId.id = configId;
+    }
+
+    function setSubscribe(PositionConfigId storage configId) internal {
+        configId.id |= DIRTY_UPPER_BIT;
+    }
+
+    function setUnsubscribe(PositionConfigId storage configId) internal {
+        configId.id &= MASK_UPPER_BIT;
+    }
+
+    function hasSubscriber(PositionConfigId storage configId) internal view returns (bool subscribed) {
+        bytes32 _id = configId.id;
+        assembly ("memory-safe") {
+            subscribed := shr(255, _id)
+        }
+    }
+}