> 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/l2/l2messagemanager.md](https://docs.linea.build/api/linea-smart-contracts/messageservice/l2/l2messagemanager.md). # L2MessageManager # `L2MessageManager` ### L1_L2_MESSAGE_SETTER_ROLE ```solidity bytes32 L1_L2_MESSAGE_SETTER_ROLE ``` The role required to anchor L1 to L2 message hashes. ### lastAnchoredL1MessageNumber ```solidity uint256 lastAnchoredL1MessageNumber ``` Contains the last L1 message number anchored on L2. ### l1RollingHashes ```solidity mapping(uint256 => bytes32) l1RollingHashes ``` Contains the L1 to L2 messaging rolling hashes mapped to message number computed on L2. ### anchorL1L2MessageHashes ```solidity function anchorL1L2MessageHashes(bytes32[] _messageHashes, uint256 _startingMessageNumber, uint256 _finalMessageNumber, bytes32 _finalRollingHash) external ``` Add cross-chain L1->L2 message hashes in storage. _Only address that has the role 'L1_L2_MESSAGE_SETTER_ROLE' are allowed to call this function. NB: In the unlikely event of a duplicate anchoring, the lastAnchoredL1MessageNumber MUST NOT be incremented. and the rolling hash not calculated, else synchronisation will break. If starting number is zero, an underflow error is expected._ #### Parameters | Name | Type | Description | | --- | --- | --- | | _messageHashes | bytes32[] | New message hashes to anchor on L2. | | _startingMessageNumber | uint256 | The expected L1 message number to start when anchoring. | | _finalMessageNumber | uint256 | The expected L1 message number to end on when anchoring. | | _finalRollingHash | bytes32 | The expected L1 rolling hash to end on when anchoring. | 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.