> For the complete Linea documentation index, see [llms.txt](/llms.txt). > Agents can fetch this page as Markdown at [https://docs.linea.build/api/linea-smart-contracts/messageservice/l1/l1messagemanager.md](https://docs.linea.build/api/linea-smart-contracts/messageservice/l1/l1messagemanager.md). # L1MessageManager # `L1MessageManager` ### rollingHashes ```solidity mapping(uint256 => bytes32) rollingHashes ``` Contains the L1 to L2 messaging rolling hashes mapped to message number computed on L1. ### _messageClaimedBitMap ```solidity struct BitMaps.BitMap _messageClaimedBitMap ``` This maps which message numbers have been claimed to prevent duplicate claiming. ### l2MerkleRootsDepths ```solidity mapping(bytes32 => uint256) l2MerkleRootsDepths ``` Contains the L2 messages Merkle roots mapped to their tree depth. ### _addRollingHash ```solidity function _addRollingHash(uint256 _messageNumber, bytes32 _messageHash) internal ``` Take an existing message hash, calculates the rolling hash and stores at the message number. #### Parameters | Name | Type | Description | | --- | --- | --- | | _messageNumber | uint256 | The current message number being sent. | | _messageHash | bytes32 | The hash of the message being sent. | ### _setL2L1MessageToClaimed ```solidity function _setL2L1MessageToClaimed(uint256 _messageNumber) internal ``` Set the L2->L1 message as claimed when a user claims a message on L1. #### Parameters | Name | Type | Description | | --- | --- | --- | | _messageNumber | uint256 | The message number on L2. | ### _addL2MerkleRoots ```solidity function _addL2MerkleRoots(bytes32[] _newRoots, uint256 _treeDepth) internal ``` Add the L2 Merkle roots to the storage. _This function is called during block finalization. The `_treeDepth` does not need to be checked to be non-zero as it is, already enforced to be non-zero in the circuit, and used in the proof's public input._ #### Parameters | Name | Type | Description | | --- | --- | --- | | _newRoots | bytes32[] | New L2 Merkle roots. | | _treeDepth | uint256 | | ### _anchorL2MessagingBlocks ```solidity function _anchorL2MessagingBlocks(bytes _l2MessagingBlocksOffsets, uint256 _currentL2BlockNumber) internal ``` Emit an event for each L2 block containing L2->L1 messages. _This function is called during block finalization._ #### Parameters | Name | Type | Description | | --- | --- | --- | | _l2MessagingBlocksOffsets | bytes | Is a sequence of uint16 values, where each value plus the last finalized L2 block number. indicates which L2 blocks have L2->L1 messages. | | _currentL2BlockNumber | uint256 | Last L2 block number finalized on L1. | ### isMessageClaimed ```solidity function isMessageClaimed(uint256 _messageNumber) external view returns (bool isClaimed) ``` Checks if the L2->L1 message is claimed or not. #### Parameters | Name | Type | Description | | --- | --- | --- | | _messageNumber | uint256 | The message number on L2. | #### Return Values | Name | Type | Description | | --- | --- | --- | | isClaimed | bool | Returns whether or not the message with _messageNumber has been claimed. | Contributions not accepted These reference pages are automatically generated based on Linea's [smart contracts](https://github.com/Consensys/linea-monorepo/tree/main/contracts/src). To ensure they accurately match the deployed smart contracts, we cannot accept any contributions that edit these pages.