> 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/interfaces/l1/il1messagemanager.md](https://docs.linea.build/api/linea-smart-contracts/interfaces/l1/il1messagemanager.md). # IL1MessageManager # `IL1MessageManager` ### RollingHashUpdated ```solidity event RollingHashUpdated(uint256 messageNumber, bytes32 rollingHash, bytes32 messageHash) ``` Emitted when a new message is sent and the rolling hash updated. #### Parameters | Name | Type | Description | | --- | --- | --- | | messageNumber | uint256 | The unique indexed message number for the message. | | rollingHash | bytes32 | The indexed rolling hash computed for the current message number. | | messageHash | bytes32 | The indexed hash of the message parameters. | ### L2MerkleRootAdded ```solidity event L2MerkleRootAdded(bytes32 l2MerkleRoot, uint256 treeDepth) ``` Emitted when the L2 Merkle root has been anchored on L1. _There may be more than one of these in a finalization depending on the amount of L2->L1 messages in the finalization._ #### Parameters | Name | Type | Description | | --- | --- | --- | | l2MerkleRoot | bytes32 | The indexed L2 Merkle root that has been anchored on L1 Ethereum. | | treeDepth | uint256 | The indexed tree depth of the Merkle root. | ### L2MessagingBlockAnchored ```solidity event L2MessagingBlockAnchored(uint256 l2Block) ``` Emitted when the L2 block contains L2 messages during finalization. _This is used externally in the logic for determining which messages belong to which Merkle root when claiming._ #### Parameters | Name | Type | Description | | --- | --- | --- | | l2Block | uint256 | The indexed L2 block containing L2 to L1 messages. | ### MessageAlreadyClaimed ```solidity error MessageAlreadyClaimed(uint256 messageIndex) ``` _Thrown when the message has already been claimed._ ### L2MerkleRootAlreadyAnchored ```solidity error L2MerkleRootAlreadyAnchored(bytes32 merkleRoot) ``` _Thrown when the L2 Merkle root has already been anchored on L1._ ### BytesLengthNotMultipleOfTwo ```solidity error BytesLengthNotMultipleOfTwo(uint256 bytesLength) ``` _Thrown when the L2 messaging blocks offsets bytes length is not a multiple of 2._ ### 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.