Solidity API - LayerZero

EndpointV2

lzToken

address lzToken

This stores the address of the LayerZero token, which may be used for paying messaging fees. It enables applications to settle crosschain communication costs using LayerZero’s native token, where applicable.

delegates

mapping(address => address) delegates

A mapping that allows address-based delegation. Applications (OApps) can delegate certain privileges to another address, authorizing the delegate to perform tasks on behalf of the original sender.

constructor

constructor(uint32 _eid, address _owner) public

The constructor initializes the LayerZero endpoint on a specific chain. It assigns a unique Endpoint ID (_eid) to this instance, ensuring each chain has a distinct identifier for crosschain messaging.

Parameters

Name	Type	Description
_eid	uint32	the unique Endpoint Id for this deploy that all other Endpoints can use to send to it
_owner	address

quote

function quote(struct MessagingParams _params, address _sender) external view returns (struct MessagingFee)

This function returns a fee estimate for sending a crosschain message, based on the parameters specified in _params. The fee quote takes into account the current messaging cost, which might vary over time. Note that the actual messaging cost could differ if the fees change between the quote and the message send operation. MESSAGING STEP 0

Parameters

Name	Type	Description
_params	struct MessagingParams	the messaging parameters
_sender	address	the sender of the message

send

function send(struct MessagingParams _params, address _refundAddress) external payable returns (struct MessagingReceipt)

This function sends a message to a destination chain through the LayerZero network. It also processes the associated fees, which can be either in native tokens or LayerZero tokens (lzToken). If excess fees are supplied, the surplus is refunded to the provided _refundAddress. MESSAGING STEP 1 - OApp need to transfer the fees to the endpoint before sending the message

Parameters

Name	Type	Description
_params	struct MessagingParams	the messaging parameters
_refundAddress	address	the address to refund both the native and lzToken

_send

function _send(address _sender, struct MessagingParams _params) internal returns (struct MessagingReceipt, address)

An internal version of the send function that handles the underlying mechanics of sending a message. This function is called by external message-sending methods and ensures the message is routed to the appropriate destination with the correct fee management. internal function for sending the messages used by all external send methods

Parameters

Name	Type	Description
_sender	address	the address of the application sending the message to the destination chain
_params	struct MessagingParams	the messaging parameters

verify

function verify(struct Origin _origin, address _receiver, bytes32 _payloadHash) external

On the destination chain, the message needs to be verified before being processed. This function checks the validity of the incoming message by comparing its origin and payload hash with the expected values. MESSAGING STEP 2 - on the destination chain configured receive library verifies a message

Parameters

Name	Type	Description
_origin	struct Origin	a struct holding the srcEid, nonce, and sender of the message
_receiver	address	the receiver of the message
_payloadHash	bytes32	the payload hash of the message

lzReceive

function lzReceive(struct Origin _origin, address _receiver, bytes32 _guid, bytes _message, bytes _extraData) external payable

This is the final step in the message execution process. After the message has been verified, it is delivered to the intended recipient address. The function can pass additional extraData if needed for execution. MESSAGING STEP 3 - the last step execute a verified message to the designated receiver the execution provides the execution context (caller, extraData) to the receiver. the receiver can optionally assert the caller and validate the untrusted extraData cant reentrant because the payload is cleared before execution

Parameters

Name	Type	Description
_origin	struct Origin	the origin of the message
_receiver	address	the receiver of the message
_guid	bytes32	the guid of the message
_message	bytes	the message
_extraData	bytes	the extra data provided by the executor. this data is untrusted and should be validated.

lzReceiveAlert

function lzReceiveAlert(struct Origin _origin, address _receiver, bytes32 _guid, uint256 _gas, uint256 _value, bytes _message, bytes _extraData, bytes _reason) external

This function handles a failure in message delivery and provides an alert to the application. It logs the reason for the failure and the state of the message, allowing developers to debug message processing errors.

Parameters

Name	Type	Description
_origin	struct Origin	the origin of the message
_receiver	address	the receiver of the message
_guid	bytes32	the guid of the message
_gas	uint256
_value	uint256
_message	bytes	the message
_extraData	bytes	the extra data provided by the executor.
_reason	bytes	the reason for failure

clear

function clear(address _oapp, struct Origin _origin, bytes32 _guid, bytes _message) external

This function allows an OApp (Omnichain Application) to clear a pending message manually. Instead of pushing the message through the standard delivery flow, the message is cleared from the queue, effectively marking it as processed or ignored. _Oapp uses this interface to clear a message. this is a PULL mode versus the PUSH mode of lzReceive the cleared message can be ignored by the app (effectively burnt) authenticated by oapp_

Parameters

Name	Type	Description
_oapp	address
_origin	struct Origin	the origin of the message
_guid	bytes32	the guid of the message
_message	bytes	the message

setLzToken

function setLzToken(address _lzToken) public virtual

This function allows the owner to set or change the LayerZero token (lzToken). This token may be used to pay for messaging fees. The function is designed to provide flexibility in case the initial configuration of the token was incorrect or needs to be updated. It should only be called by the contract owner. Users should avoid approving non-LayerZero tokens to be spent by the EndpointV2 contract, as this function can override the token used for fees. allows reconfiguration to recover from wrong configurations users should never approve the EndpointV2 contract to spend their non-layerzero tokens override this function if the endpoint is charging ERC20 tokens as native only owner

Parameters

Name	Type	Description
_lzToken	address	the new layer zero token address

recoverToken

function recoverToken(address _token, address _to, uint256 _amount) external

This function allows the owner to recover tokens that were mistakenly sent to the EndpointV2 contract. It supports both native tokens (if _token is set to 0x0) and ERC20 tokens. This ensures that tokens accidentally locked in the contract can be safely retrieved by the owner. recover the token sent to this contract by mistake only owner

Parameters

Name	Type	Description
_token	address	the token to recover. if 0x0 then it is native token
_to	address	the address to send the token to
_amount	uint256	the amount to send

_payToken

function _payToken(address _token, uint256 _required, uint256 _supplied, address _receiver, address _refundAddress) internal

This internal function handles payments in ERC20 tokens. It ensures that the sender has approved the endpoint to spend the specified tokens and processes the payment. If the supplied token amount exceeds the required amount, the excess is refunded to the specified _refundAddress. handling token payments on endpoint. the sender must approve the endpoint to spend the token internal function

Parameters

Name	Type	Description
_token	address	the token to pay
_required	uint256	the amount required
_supplied	uint256	the amount supplied
_receiver	address	the receiver of the token
_refundAddress	address

_payNative

function _payNative(uint256 _required, uint256 _supplied, address _receiver, address _refundAddress) internal virtual

This internal function manages payments in native tokens (such as ETH). It processes the payment and refunds any excess amount to the _refundAddress. If the endpoint charges ERC20 tokens as native, this function can be overridden. handling native token payments on endpoint override this if the endpoint is charging ERC20 tokens as native internal function

Parameters

Name	Type	Description
_required	uint256	the amount required
_supplied	uint256	the amount supplied
_receiver	address	the receiver of the native token
_refundAddress	address	the address to refund the excess to

_suppliedLzToken

function _suppliedLzToken(bool _payInLzToken) internal view returns (uint256 supplied)

This internal view function returns the amount of LayerZero tokens (lzToken) supplied for payment, but only if _payInLzToken is set to true. It checks the balance of the lzToken used to pay for the messaging fee. get the balance of the lzToken as the supplied lzToken fee if payInLzToken is true

_suppliedNative

function _suppliedNative() internal view virtual returns (uint256)

This internal function returns the amount of native tokens supplied for the payment. If the endpoint charges ERC20 tokens as native tokens, this function can be overridden to handle such cases. override this if the endpoint is charging ERC20 tokens as native

_assertMessagingFee

function _assertMessagingFee(struct MessagingFee _required, uint256 _suppliedNativeFee, uint256 _suppliedLzTokenFee) internal pure

This internal function verifies that the supplied fees (both native and lzToken) are sufficient to cover the required messaging fees. If the supplied fees are insufficient, the function will assert an error. Assert the required fees and the supplied fees are enough

nativeToken

function nativeToken() external view virtual returns (address)

This external view function returns the address of the native ERC20 token used by the endpoint if it charges ERC20 tokens as native tokens. If the contract uses actual native tokens (like ETH), it returns 0x0. override this if the endpoint is charging ERC20 tokens as native

Return Values

Name	Type	Description
[0]	address	0x0 if using native. otherwise the address of the native ERC20 token

setDelegate

function setDelegate(address _delegate) external

This function allows an OApp to authorize a delegate to act on its behalf. The delegate can configure settings or perform other operations related to the LayerZero endpoint, effectively giving another address certain administrative permissions over the OApp’s endpoint interaction. delegate is authorized by the oapp to configure anything in layerzero

_initializable

function _initializable(struct Origin _origin, address _receiver, uint64 _lazyInboundNonce) internal view returns (bool)

This internal view function checks whether a message from a specific origin can be initialized for delivery to the receiver. The function verifies that the message can be safely processed based on the lazyInboundNonce, which controls the message order and flow.

_verifiable

function _verifiable(struct Origin _origin, address _receiver, uint64 _lazyInboundNonce) internal view returns (bool)

This internal function checks whether a message from the given origin is verifiable for the receiver. It ensures that the message payload is valid and ready for execution based on the provided nonce and other checks. A payload with a hash of bytes(0) can never be submitted. bytes(0) payloadHash can never be submitted

_assertAuthorized

function _assertAuthorized(address _oapp) internal view

This internal function ensures that the caller is either the OApp or its authorized delegate. It acts as an access control check to verify that only trusted entities can configure or interact with the OApp’s LayerZero-related settings. assert the caller to either be the oapp or the delegate

initializable

function initializable(struct Origin _origin, address _receiver) external view returns (bool)

This external view function checks whether a message from the given origin is ready to be initialized and processed for the specified receiver. It returns true if the message can be initialized.

verifiable

function verifiable(struct Origin _origin, address _receiver) external view returns (bool)

This external view function checks whether a message from the given origin is verifiable for the receiver. It confirms that the message payload has been received and validated.

EndpointV2Alt

EndpointV2Alt is the LayerZero V2 endpoint contract designed for blockchain networks where ERC20 tokens are used as native tokens (instead of standard native tokens like ETH or BNB). This contract supports altFeeTokens, which are ERC20 tokens that can be used for paying messaging fees. The architecture is optimized to reduce gas costs by making certain configurations immutable.

LZ_OnlyAltToken

error LZ_OnlyAltToken()

This error is thrown when a non-ERC20 token is used in a context where only the altFeeToken (an ERC20 token) is allowed. It enforces that only the designated ERC20 token is used for certain operations in the contract.

nativeErc20

address nativeErc20

This holds the address of the ERC20 token used as the native currency in this contract. The nativeErc20 token is immutable, meaning that once it’s set, it cannot be changed. This saves gas by preventing unnecessary updates and checks. This token is used for paying fees when the chain doesn’t have a standard native token. the altFeeToken is used for fees when the native token has no value it is immutable for gas saving. only 1 endpoint for such chains

constructor

constructor(uint32 _eid, address _owner, address _altToken) public

The constructor initializes the EndpointV2Alt contract, associating it with a unique Endpoint ID (_eid). It also specifies the owner of the contract and the altFeeToken (an ERC20 token) used for fees on the chain.

_payNative

function _payNative(uint256 _required, uint256 _supplied, address _receiver, address _refundAddress) internal

This internal function handles native payments in the context of this contract. Since the contract operates on chains using ERC20 tokens as native tokens, _payNative processes payments in those tokens. If the supplied amount exceeds the required amount, the excess is refunded to the _refundAddress. handling native token payments on endpoint internal function

Parameters

Name	Type	Description
_required	uint256	the amount required
_supplied	uint256	the amount supplied
_receiver	address	the receiver of the native token
_refundAddress	address	the address to refund the excess to

_suppliedNative

function _suppliedNative() internal view returns (uint256)

This internal view function returns the amount of native tokens (ERC20 tokens, in this case) supplied for the payment. It is used to track the exact amount of tokens provided for a transaction, ensuring that the necessary fees are met. return the balance of the native token

setLzToken

function setLzToken(address _lzToken) public

This function allows the contract owner to set or change the LayerZero token (lzToken). The function checks if the new token address matches the current one before applying changes. The lzToken can be used for paying fees when applicable. check if lzToken is set to the same address

nativeToken

function nativeToken() external view returns (address)

This external view function returns the address of the native ERC20 token used by the contract. If the contract uses actual native tokens, it returns 0x0. Otherwise, it returns the address of the ERC20 token acting as the native currency on the chain. override this if the endpoint is charging ERC20 tokens as native

Return Values

Name	Type	Description
[0]	address	0x0 if using native. otherwise the address of the native ERC20 token

EndpointV2View

EndpointV2View is a contract used for viewing the state of LayerZero V2 messages, particularly related to whether a message is verifiable, executable, or initializable. This contract is typically used by other contracts or off-chain services that need to check the status of crosschain messages.

initialize

function initialize(address _endpoint) external

The initialize function sets the reference to the LayerZero endpoint (_endpoint). This endpoint is used for all subsequent verifications and message status checks. This function must be called before the contract can be used.

ExecutionState

enum ExecutionState {
  NotExecutable,
  VerifiedButNotExecutable,
  Executable,
  Executed
}

This enum defines the possible execution states for a message within the LayerZero system: NotExecutable: The message is not yet ready for execution. VerifiedButNotExecutable: The message has been verified, but something is preventing its execution (e.g., not enough gas). Executable: The message is ready to be executed. Executed: The message has been successfully executed.

EndpointV2ViewUpgradeable

EndpointV2ViewUpgradeable is an upgradeable version of the EndpointV2View, adding support for certain upgrades while maintaining compatibility with existing state.

EMPTY_PAYLOAD_HASH

bytes32 EMPTY_PAYLOAD_HASH

This constant represents an empty payload hash, which can be used to signal that no payload is associated with a message.

NIL_PAYLOAD_HASH

bytes32 NIL_PAYLOAD_HASH

This constant represents a “nil” payload hash, often used to indicate that a payload has been intentionally left out or invalidated.

endpoint

contract ILayerZeroEndpointV2 endpoint

This contract reference stores the LayerZero endpoint that the EndpointV2ViewUpgradeable is interacting with. It is used for all message-related queries and verifications.

__EndpointV2View_init

function __EndpointV2View_init(address _endpoint) internal

This internal initialization function sets the reference to the LayerZero endpoint. This function must be called during the deployment process to initialize the contract.

__EndpointV2View_init_unchained

function __EndpointV2View_init_unchained(address _endpoint) internal

This is a version of the initialization function that is not chained. It can be used in scenarios where the contract needs to be initialized without triggering additional logic.

initializable

function initializable(struct Origin _origin, address _receiver) public view returns (bool)

This function checks if a message from a specific origin can be initialized for the provided receiver. It returns true if the message is ready to be processed (initialized).

verifiable

function verifiable(struct Origin _origin, address _receiver, address _receiveLib, bytes32 _payloadHash) public view returns (bool)

This function checks if a message from the given origin is verifiable for the provided receiver. It ensures that the payload hash matches and the message has been validated by the correct messaging library. check if a message is verifiable.

executable

function executable(struct Origin _origin, address _receiver) public view returns (enum ExecutionState)

This function checks the execution state of a message for a given origin and receiver. It returns the current execution state, whether the message is NotExecutable, VerifiedButNotExecutable, Executable, or Executed. check if a message is executable.

Return Values

Name	Type	Description
[0]	enum ExecutionState	ExecutionState of Executed, Executable, or NotExecutable

MessageLibManager

MessageLibManager manages the messaging libraries (msgLib) that are used for sending and receiving messages in the LayerZero protocol. It controls the libraries that each application (OApp) can use, either by directly assigning libraries or defaulting to LayerZero’s settings.

blockedLibrary

address blockedLibrary

The blockedLibrary is a specific library that is no longer allowed for sending or receiving messages.

registeredLibraries

address[] registeredLibraries

An array storing the addresses of all libraries that are registered and can be used for message sending or receiving.

isRegisteredLibrary

mapping(address => bool) isRegisteredLibrary

This mapping tracks whether a given library is registered, providing a quick way to verify if a library is eligible for use.

sendLibrary

mapping(address => mapping(uint32 => address)) sendLibrary

A mapping that stores the send libraries for each OApp (address) and endpoint ID (uint32). Each OApp can specify a library it wants to use for sending messages to a specific endpoint.

receiveLibrary

mapping(address => mapping(uint32 => address)) receiveLibrary

This mapping stores the receive libraries for each OApp (address) and endpoint ID (uint32). Each OApp can specify a library for handling received messages.

receiveLibraryTimeout

mapping(address => mapping(uint32 => struct IMessageLibManager.Timeout)) receiveLibraryTimeout

This mapping tracks the timeout period for a receive library. After a timeout period, the receive library may need to be updated or replaced. This helps manage library versioning and ensure that OApps can handle breaking changes in a safe manner.

defaultSendLibrary

mapping(uint32 => address) defaultSendLibrary

This mapping holds the default send library for each endpoint (uint32). If an OApp does not specify a send library, the default send library for that endpoint is used.

defaultReceiveLibrary

mapping(uint32 => address) defaultReceiveLibrary

The default receive library for each endpoint is stored here. If an OApp does not specify a receive library, the system defaults to the configured library for that endpoint.

defaultReceiveLibraryTimeout

mapping(uint32 => struct IMessageLibManager.Timeout) defaultReceiveLibraryTimeout

This mapping tracks the timeout period for default receive libraries. After this period, the default library may need to be updated or retired.

constructor

constructor() internal

The constructor is internal and initializes the MessageLibManager. It ensures that all the necessary mappings and configurations are properly set up when the contract is deployed.

onlyRegistered

modifier onlyRegistered(address _lib)

This modifier ensures that only libraries registered with MessageLibManager can call certain functions. It restricts access to unregistered libraries, safeguarding the system from misuse.

isSendLib

modifier isSendLib(address _lib)

This modifier ensures that only valid send libraries can call specific functions. It checks if the library is properly configured for sending messages.

isReceiveLib

modifier isReceiveLib(address _lib)

This modifier ensures that only valid receive libraries can call certain functions. It verifies the library’s eligibility for processing received messages.

onlyRegisteredOrDefault

modifier onlyRegisteredOrDefault(address _lib)

This modifier allows both registered libraries and default libraries to access certain functions, ensuring that the system works even when custom libraries are not defined.

onlySupportedEid

modifier onlySupportedEid(address _lib, uint32 _eid)

This modifier ensures that a library supports a specific endpoint ID (_eid). It checks if the library has been configured to handle messages for that endpoint. check if the library supported the eid.

getRegisteredLibraries

function getRegisteredLibraries() external view returns (address[])

This function returns a list of all registered libraries. It allows users and applications to query which libraries are available for use.

getSendLibrary

function getSendLibrary(address _sender, uint32 _dstEid) public view returns (address lib)

This function retrieves the send library for a specific OApp (_sender) and destination endpoint (_dstEid). If the OApp has not specified a library, the default one is used. If the Oapp does not have a selected Send Library, this function will resolve to the default library configured by LayerZero

Parameters

Name	Type	Description
_sender	address	The address of the Oapp that is sending the message
_dstEid	uint32	The destination endpoint id

Return Values

Name	Type	Description
lib	address	address of the Send Library

isDefaultSendLibrary

function isDefaultSendLibrary(address _sender, uint32 _dstEid) public view returns (bool)

This function checks if the send library in use for a specific OApp and endpoint is the default one.

getReceiveLibrary

function getReceiveLibrary(address _receiver, uint32 _srcEid) public view returns (address lib, bool isDefault)

This function retrieves the receive library for a specific OApp (_receiver) and source endpoint (_srcEid). If the OApp has not specified a library, the default one is used. the receiveLibrary can be lazily resolved that if not set it will point to the default configured by LayerZero

isValidReceiveLibrary

function isValidReceiveLibrary(address _receiver, uint32 _srcEid, address _actualReceiveLib) public view returns (bool)

This function checks if the specified receive library is valid for a given OApp, ensuring that the OApp can trust the message verification and processing done by the library. called when the endpoint checks if the msgLib attempting to verify the msg is the configured msgLib of the Oapp this check provides the ability for Oapp to lock in a trusted msgLib it will fist check if the msgLib is the currently configured one. then check if the msgLib is the one in grace period of msgLib versioning upgrade

registerLibrary

function registerLibrary(address _lib) public

This function registers a new library with the MessageLibManager. Only the contract owner can register new libraries. all libraries have to implement the erc165 interface to prevent wrong configurations only owner

setDefaultSendLibrary

function setDefaultSendLibrary(uint32 _eid, address _newLib) external

The contract owner sets the default send library for a specific endpoint. The new library must be registered and have support for the endpoint. owner setting the defaultSendLibrary can set to the blockedLibrary, which is a registered library the msgLib must enable the support before they can be registered to the endpoint as the default only owner

setDefaultReceiveLibrary

function setDefaultReceiveLibrary(uint32 _eid, address _newLib, uint256 _gracePeriod) external

The contract owner sets the default receive library for a specific endpoint and may define a grace period during which the old library can still be used. owner setting the defaultSendLibrary must be a registered library (including blockLibrary) with the eid support enabled in version migration, it can add a grace period to the old library. if the grace period is 0, it will delete the timeout configuration. only owner

setDefaultReceiveLibraryTimeout

function setDefaultReceiveLibraryTimeout(uint32 _eid, address _lib, uint256 _expiry) external

This function allows the contract owner to set a timeout for the default receive library for a given endpoint. After the timeout, the library may need to be updated or retired. owner setting the defaultSendLibrary must be a registered library (including blockLibrary) with the eid support enabled can used to (1) extend the current configuration (2) force remove the current configuration (3) change to a new configuration

Parameters

Name	Type	Description
_eid	uint32
_lib	address
_expiry	uint256	the block number when lib expires

isSupportedEid

function isSupportedEid(uint32 _eid) external view returns (bool)

This function checks if an endpoint is supported, returning true only if both the default send and receive libraries are set. returns true only if both the default send/receive libraries are set

setSendLibrary

function setSendLibrary(address _oapp, uint32 _eid, address _newLib) external

This function allows an OApp to set a custom send library for a specific endpoint. The library must be registered and support the endpoint. Oapp setting the sendLibrary must be a registered library (including blockLibrary) with the eid support enabled authenticated by the Oapp

setReceiveLibrary

function setReceiveLibrary(address _oapp, uint32 _eid, address _newLib, uint256 _gracePeriod) external

An OApp can use this function to set a custom receive library, with an optional grace period during which the old library can still be used. Oapp setting the receiveLibrary must be a registered library (including blockLibrary) with the eid support enabled in version migration, it can add a grace period to the old library. if the grace period is 0, it will delete the timeout configuration. authenticated by the Oapp

Parameters

Name	Type	Description
_oapp	address
_eid	uint32
_newLib	address
_gracePeriod	uint256	the number of blocks from now until oldLib expires

setReceiveLibraryTimeout

function setReceiveLibraryTimeout(address _oapp, uint32 _eid, address _lib, uint256 _expiry) external

This function allows the OApp to set a timeout for its custom receive library. After the timeout, the OApp may need to update the library. Oapp setting the defaultSendLibrary must be a registered library (including blockLibrary) with the eid support enabled can used to (1) extend the current configuration (2) force remove the current configuration (3) change to a new configuration

Parameters

Name	Type	Description
_oapp	address
_eid	uint32
_lib	address
_expiry	uint256	the block number when lib expires

setConfig

function setConfig(address _oapp, address _lib, struct SetConfigParam[] _params) external

This function allows the OApp to configure the messaging libraries with specific parameters. authenticated by the _oapp

getConfig

function getConfig(address _oapp, address _lib, uint32 _eid, uint32 _configType) external view returns (bytes config)

This function retrieves the current configuration of the OApp’s messaging libraries for a given endpoint and config type. a view function to query the current configuration of the OApp

_assertAuthorized

function _assertAuthorized(address _oapp) internal virtual

MessagingChannel

The MessagingChannel contract manages the lifecycle of messages sent across different blockchains using the LayerZero protocol. It tracks the nonces, payloads, and statuses of messages to ensure censorship resistance and reliable crosschain communication.

EMPTY_PAYLOAD_HASH

bytes32 EMPTY_PAYLOAD_HASH

A constant representing an empty payload hash. This value is used when a message has no payload associated with it.

NIL_PAYLOAD_HASH

bytes32 NIL_PAYLOAD_HASH

A constant representing a “nil” payload hash, used to indicate that a payload is invalidated or should be ignored.

eid

uint32 eid

The unique Endpoint ID associated with this deployed messaging channel. It ensures that messages are routed correctly across different endpoints in LayerZero.

lazyInboundNonce

mapping(address => mapping(uint32 => mapping(bytes32 => uint64))) lazyInboundNonce

A mapping that tracks the inbound nonces for messages received. The nonces are updated lazily, meaning the nonce is incremented only when messages are processed, ensuring message order is preserved.

inboundPayloadHash

mapping(address => mapping(uint32 => mapping(bytes32 => mapping(uint64 => bytes32)))) inboundPayloadHash

This mapping stores the hash of the payload for inbound messages. Each payload is uniquely identified by its sender, source endpoint, and nonce.

outboundNonce

mapping(address => mapping(uint32 => mapping(bytes32 => uint64))) outboundNonce

This mapping tracks the next outbound nonce for a given sender, destination endpoint, and receiver. Nonces ensure that messages are delivered in order and without duplication.

constructor

constructor(uint32 _eid) internal

The internal constructor initializes the messaging channel with the unique Endpoint ID (_eid). This ID is used to identify the channel in LayerZero’s messaging system.

Parameters

Name	Type	Description
_eid	uint32	is the universally unique id (UUID) of this deployed Endpoint

_outbound

function _outbound(address _sender, uint32 _dstEid, bytes32 _receiver) internal returns (uint64 nonce)

This internal function increments and returns the next outbound nonce for the sender. It ensures that outbound messages are properly sequenced. increase and return the next outbound nonce

_inbound

function _inbound(address _receiver, uint32 _srcEid, bytes32 _sender, uint64 _nonce, bytes32 _payloadHash) internal

The _inbound function updates the inbound message state lazily. It doesn’t immediately increment the nonce, allowing for out-of-order message verification while preserving censorship resistance. inbound won’t update the nonce eagerly to allow unordered verification instead, it will update the nonce lazily when the message is received messages can only be cleared in order to preserve censorship-resistance

inboundNonce

function inboundNonce(address _receiver, uint32 _srcEid, bytes32 _sender) public view returns (uint64)

This function returns the highest contiguous verified inbound nonce. It iterates over the nonces, starting from the lazy inbound nonce, to find the last verified message. returns the max index of the longest gapless sequence of verified msg nonces. the uninitialized value is 0. the first nonce is always 1 it starts from the lazyInboundNonce (last checkpoint) and iteratively check if the next nonce has been verified this function can OOG if too many backlogs, but it can be trivially fixed by just clearing some prior messages NOTE: Oapp explicitly skipped nonces count as “verified” for these purposes eg. [1,2,3,4,6,7] => 4, [1,2,6,8,10] => 2, [1,3,4,5,6] => 1

_hasPayloadHash

function _hasPayloadHash(address _receiver, uint32 _srcEid, bytes32 _sender, uint64 _nonce) internal view returns (bool)

This function checks if a given payload hash exists for a specific nonce. It assumes that a payload hash of zero means the payload has not been initialized. checks if the storage slot is not initialized. Assumes computationally infeasible that payload can hash to 0

skip

function skip(address _oapp, uint32 _srcEid, bytes32 _sender, uint64 _nonce) external

The skip function allows an OApp to skip a specific nonce, preventing the message from being verified or executed. This can be useful in race conditions or when a message is flagged as malicious. After skipping, the lazy inbound nonce is updated. the caller must provide _nonce to prevent skipping the unintended nonce it could happen in some race conditions, e.g. to skip nonce 3, but nonce 3 was consumed first usage: skipping the next nonce to prevent message verification, e.g. skip a message when Precrime throws alerts if the Oapp wants to skip a verified message, it should call the clear() function instead after skipping, the lazyInboundNonce is set to the provided nonce, which makes the inboundNonce also the provided nonce ie. allows the Oapp to increment the lazyInboundNonce without having had that corresponding msg be verified

nilify

function nilify(address _oapp, uint32 _srcEid, bytes32 _sender, uint64 _nonce, bytes32 _payloadHash) external

This function marks a verified packet as nil, preventing it from being executed. A nilified packet cannot be verified or executed again unless it is re-verified with the correct payload hash. Marks a packet as verified, but disallows execution until it is re-verified. Reverts if the provided _payloadHash does not match the currently verified payload hash. A non-verified nonce can be nilified by passing EMPTY_PAYLOAD_HASH for _payloadHash. Assumes the computational intractability of finding a payload that hashes to bytes32.max. Authenticated by the caller

burn

function burn(address _oapp, uint32 _srcEid, bytes32 _sender, uint64 _nonce, bytes32 _payloadHash) external

The burn function permanently marks a packet as unexecutable and un-verifiable. This action is irreversible and can only be performed on packets that have not yet been executed. Marks a nonce as unexecutable and un-verifiable. The nonce can never be re-verified or executed. Reverts if the provided _payloadHash does not match the currently verified payload hash. Only packets with nonces less than or equal to the lazy inbound nonce can be burned. Reverts if the nonce has already been executed. Authenticated by the caller

_clearPayload

function _clearPayload(address _receiver, uint32 _srcEid, bytes32 _sender, uint64 _nonce, bytes _payload) internal returns (bytes32 actualHash)

This function clears the stored payload for a message and updates the lazy inbound nonce. If there are many queued messages, the payload can be cleared in smaller batches to prevent out-of-gas errors. calling this function will clear the stored message and increment the lazyInboundNonce to the provided nonce if a lot of messages are queued, the messages can be cleared with a smaller step size to prevent OOG NOTE: this function does not change inboundNonce, it only changes the lazyInboundNonce up to the provided nonce

nextGuid

function nextGuid(address _sender, uint32 _dstEid, bytes32 _receiver) external view returns (bytes32)

The nextGuid function returns the GUID for the next message in a specific path, providing a unique identifier for the message that can be included in the payload. returns the GUID for the next message given the path the Oapp might want to include the GUID into the message in some cases

_assertAuthorized

function _assertAuthorized(address _oapp) internal virtual

This internal function ensures that the caller of specific messaging operations is authorized, either by being the OApp or its delegate.

MessagingComposer

The MessagingComposer contract is responsible for composing LayerZero messages, enabling applications (OApps) to send messages in smaller piecewise operations or add extra steps to messages.

composeQueue

mapping(address => mapping(address => mapping(bytes32 => mapping(uint16 => bytes32)))) composeQueue

The composeQueue stores composed message fragments for each OApp. It maps the OApp’s address, the receiver’s address, a message GUID, and an index (for multi-part messages) to the hash of the composed message fragment. This ensures that messages can be composed and sent in a fragmented manner.

sendCompose

function sendCompose(address _to, bytes32 _guid, uint16 _index, bytes _message) external

The sendCompose function allows an OApp to send a composed message fragment to the receiver. The sender must be authenticated, ensuring that only the intended OApp can send the message. Multiple fragments can be sent with the same GUID, allowing for more flexible message composition. the Oapp sends the lzCompose message to the endpoint the composer MUST assert the sender because anyone can send compose msg with this function with the same GUID, the Oapp can send compose to multiple _composer at the same time authenticated by the msg.sender

Parameters

Name	Type	Description
_to	address	the address which will receive the composed message
_guid	bytes32	the message guid
_index	uint16
_message	bytes	the message

lzCompose

function lzCompose(address _from, address _to, bytes32 _guid, uint16 _index, bytes _message, bytes _extraData) external payable

The lzCompose function executes a composed message from the sender to the receiver. It provides the execution context (caller and extraData) to the receiver, allowing for additional validation. execute a composed messages from the sender to the composer (receiver) the execution provides the execution context (caller, extraData) to the receiver. the receiver can optionally assert the caller and validate the untrusted extraData can not re-entrant

Parameters

Name	Type	Description
_from	address	the address which sends the composed message. in most cases, it is the Oapp’s address.
_to	address	the address which receives the composed message
_guid	bytes32	the message guid
_index	uint16
_message	bytes	the message
_extraData	bytes	the extra data provided by the executor. this data is untrusted and should be validated.

lzComposeAlert

function lzComposeAlert(address _from, address _to, bytes32 _guid, uint16 _index, uint256 _gas, uint256 _value, bytes _message, bytes _extraData, bytes _reason) external

The lzComposeAlert function is triggered when an issue occurs during message composition. It allows the contract to report why a composed message could not be processed.

Parameters

Name	Type	Description
_from	address	the address which sends the composed message
_to	address	the address which receives the composed message
_guid	bytes32	the message guid
_index	uint16
_gas	uint256
_value	uint256
_message	bytes	the message
_extraData	bytes	the extra data provided by the executor
_reason	bytes	the reason why the message is not received

MessagingContext

The MessagingContext contract acts as a guard for preventing reentrancy and also provides execution context for messages sent and received in LayerZero. this contract acts as a non-reentrancy guard and a source of messaging context the context includes the remote eid and the sender address it separates the send and receive context to allow messaging receipts (send back on receive())

sendContext

modifier sendContext(uint32 _dstEid, address _sender)

The sendContext modifier sets the execution context for the message being sent. It encodes the context as a combination of the destination endpoint ID (_dstEid) and the sender’s address. This context helps track the message’s origin and ensures that only authorized parties can interact with it. the sendContext is set to 8 bytes 0s + 4 bytes eid + 20 bytes sender

isSendingMessage

function isSendingMessage() public view returns (bool)

The isSendingMessage function returns true if the contract is in the process of sending a message. It helps prevent reentrant calls during message processing. returns true if sending message

getSendContext

function getSendContext() external view returns (uint32, address)

The getSendContext function retrieves the current send context, returning the destination endpoint ID and sender’s address if a message is being sent. If no message is being sent, it returns (0, 0). returns (eid, sender) if sending message, (0, 0) otherwise

_getSendContext

function _getSendContext(uint256 _context) internal pure returns (uint32, address)

The _getSendContext function decodes the provided _context into its component parts: the destination endpoint ID and the sender’s address. This function is used internally to reconstruct the message context when needed.

ILayerZeroComposer

ILayerZeroComposer defines the interface for composing messages in LayerZero. It standardizes how OApps send composed messages and ensures non-reentrancy.

lzCompose

function lzCompose(address _from, bytes32 _guid, bytes _message, address _executor, bytes _extraData) external payable

The lzCompose function is responsible for composing LayerZero messages from an OApp. To ensure that reentrancy is avoided, this function asserts that msg.sender is the corresponding EndpointV2 contract and from the correct OApp. To ensure non-reentrancy, implementers of this interface MUST assert msg.sender is the corresponding EndpointV2 contract (i.e., onlyEndpointV2).

Parameters

Name	Type	Description
_from	address	The address initiating the composition, typically the OApp where the lzReceive was called.
_guid	bytes32	The unique identifier for the corresponding LayerZero src/dst tx.
_message	bytes	The composed message payload in bytes. NOT necessarily the same payload passed via lzReceive.
_executor	address	The address of the executor for the composed message.
_extraData	bytes	Additional arbitrary data in bytes passed by the entity who executes the lzCompose.

MessagingParams

struct MessagingParams {
  uint32 dstEid;
  bytes32 receiver;
  bytes message;
  bytes options;
  bool payInLzToken;
}

The MessagingParams struct is used to define the parameters required for sending a LayerZero message. These parameters specify the destination endpoint, the message’s recipient, the actual message payload, and any additional options for the message.

Name	Type	Description
dstEid	uint32	The destination endpoint ID for the message. This identifies the chain and endpoint to which the message is being sent.
receiver	bytes32	The address (in bytes32 format) of the receiver on the destination chain.
message	bytes	The actual message payload to be transmitted.
options	bytes	Additional options for the message, such as execution settings or gas limitations.
payInLzToken	bool	A boolean indicating whether the fees for the message will be paid in LayerZero (LZ) tokens.

MessagingReceipt

struct MessagingReceipt {
  bytes32 guid;
  uint64 nonce;
  struct MessagingFee fee;
}

The MessagingReceipt struct provides information about a successfully sent LayerZero message, including a unique identifier (GUID), the nonce, and the fee details.

MessagingFee

struct MessagingFee {
  uint256 nativeFee;
  uint256 lzTokenFee;
}

The MessagingFee struct details the costs involved in sending a message, specifying the native token fee and the fee in LayerZero tokens (if applicable).

Origin

struct Origin {
  uint32 srcEid;
  bytes32 sender;
  uint64 nonce;
}

The Origin struct provides details about the source of a LayerZero message, including the source endpoint ID, the sender’s address, and the message’s nonce.

ILayerZeroEndpointV2

This interface defines the main interaction points for the LayerZero V2 protocol, which includes message quoting, sending, verification, and event logging for the protocol.

PacketSent

event PacketSent(bytes encodedPayload, bytes options, address sendLibrary)

Emitted when a message packet is sent to a destination endpoint.

PacketVerified

event PacketVerified(struct Origin origin, address receiver, bytes32 payloadHash)

Emitted when a message packet is verified on the destination endpoint.

PacketDelivered

event PacketDelivered(struct Origin origin, address receiver)

Emitted when a message packet is successfully delivered to the destination receiver.

LzReceiveAlert

event LzReceiveAlert(address receiver, address executor, struct Origin origin, bytes32 guid, uint256 gas, uint256 value, bytes message, bytes extraData, bytes reason)

Emitted when an issue occurs during the receipt of a message, such as insufficient gas or a failure in message execution.

LzTokenSet

event LzTokenSet(address token)

Emitted when the LayerZero token address is set or updated.

DelegateSet

event DelegateSet(address sender, address delegate)

Emitted when a delegate is authorized by an OApp to configure LayerZero settings.

quote

function quote(struct MessagingParams _params, address _sender) external view returns (struct MessagingFee)

send

function send(struct MessagingParams _params, address _refundAddress) external payable returns (struct MessagingReceipt)

verify

function verify(struct Origin _origin, address _receiver, bytes32 _payloadHash) external

verifiable

function verifiable(struct Origin _origin, address _receiver) external view returns (bool)

initializable

function initializable(struct Origin _origin, address _receiver) external view returns (bool)

lzReceive

function lzReceive(struct Origin _origin, address _receiver, bytes32 _guid, bytes _message, bytes _extraData) external payable

clear

function clear(address _oapp, struct Origin _origin, bytes32 _guid, bytes _message) external

setLzToken

function setLzToken(address _lzToken) external

lzToken

function lzToken() external view returns (address)

nativeToken

function nativeToken() external view returns (address)

setDelegate

function setDelegate(address _delegate) external

ILayerZeroReceiver

This interface defines the core message-receiving functionality on LayerZero to be implemented by receiver applications.

allowInitializePath

function allowInitializePath(struct Origin _origin) external view returns (bool)

Returns whether the path from the origin can be initialized.

nextNonce

function nextNonce(uint32 _eid, bytes32 _sender) external view returns (uint64)

Returns the next nonce for a sender on the specified endpoint.

lzReceive

function lzReceive(struct Origin _origin, bytes32 _guid, bytes _message, address _executor, bytes _extraData) external payable

Processes the received message on the destination chain.

MessageLibType

enum MessageLibType {
  Send,
  Receive,
  SendAndReceive
}

The MessageLibType enum defines the possible types of messaging libraries in LayerZero.

Send: A library that only handles sending messages.
Receive: A library that only handles receiving messages.
SendAndReceive: A library that handles both sending and receiving messages.

IMessageLib

The IMessageLib interface defines functions that allow configuration of messaging libraries, checking endpoint support, and obtaining versioning and library type details.

setConfig

function setConfig(address _oapp, struct SetConfigParam[] _config) external

Allows an OApp (Omnichain Application) to set configuration parameters for a specific messaging library.

getConfig

function getConfig(uint32 _eid, address _oapp, uint32 _configType) external view returns (bytes config)

Fetches the configuration of an OApp for a specific endpoint and configuration type.

isSupportedEid

function isSupportedEid(uint32 _eid) external view returns (bool)

Checks if the messaging library supports a specific endpoint ID (_eid).

version

function version() external view returns (uint64 major, uint8 minor, uint8 endpointVersion)

Returns the version of the messaging library, including the major, minor, and endpoint version numbers.

messageLibType

function messageLibType() external view returns (enum MessageLibType)

Returns the type of the messaging library (Send, Receive, or SendAndReceive) as defined in the MessageLibType enum.

SetConfigParam

struct SetConfigParam {
  uint32 eid;
  uint32 configType;
  bytes config;
}

The SetConfigParam struct defines configuration settings for registered Message Libraries.

IMessageLibManager

The IMessageLibManager interface manages the registration of messaging libraries, setting default libraries, and handling receive library timeouts.

Timeout

struct Timeout {
  address lib;
  uint256 expiry;
}

The Timeout struct defines the expiration settings for a messaging library that has been changed.

LibraryRegistered

event LibraryRegistered(address newLib)

Emitted when a new library is registered.

DefaultSendLibrarySet

event DefaultSendLibrarySet(uint32 eid, address newLib)

Emitted when the default send library is set for a specific endpoint.

DefaultReceiveLibrarySet

event DefaultReceiveLibrarySet(uint32 eid, address newLib)

Emitted when the default receive library is set for a specific endpoint.

DefaultReceiveLibraryTimeoutSet

event DefaultReceiveLibraryTimeoutSet(uint32 eid, address oldLib, uint256 expiry)

Emitted when a timeout is set for the default receive library.

SendLibrarySet

event SendLibrarySet(address sender, uint32 eid, address newLib)

Emitted when a send library is set for an OApp.

ReceiveLibrarySet

event ReceiveLibrarySet(address receiver, uint32 eid, address newLib)

Emitted when a receive library is set for an OApp.

ReceiveLibraryTimeoutSet

event ReceiveLibraryTimeoutSet(address receiver, uint32 eid, address oldLib, uint256 timeout)

Emitted when a receive library timeout is set for an OApp.

registerLibrary

function registerLibrary(address _lib) external

Registers a new messaging library that will be available for endpoints.

isRegisteredLibrary

function isRegisteredLibrary(address _lib) external view returns (bool)

Checks if a messaging library is registered.

getRegisteredLibraries

function getRegisteredLibraries() external view returns (address[])

Returns a list of all registered libraries.

setDefaultSendLibrary

function setDefaultSendLibrary(uint32 _eid, address _newLib) external

Sets the default send library for a specific endpoint.

defaultSendLibrary

function defaultSendLibrary(uint32 _eid) external view returns (address)

Gets the current default send library for a specific endpoint.

setDefaultReceiveLibrary

function setDefaultReceiveLibrary(uint32 _eid, address _newLib, uint256 _gracePeriod) external

Sets the default receive library for a specific endpoint and specifies a grace period for migration.

defaultReceiveLibrary

function defaultReceiveLibrary(uint32 _eid) external view returns (address)

Gets the current default receive library for a specific endpoint.

setDefaultReceiveLibraryTimeout

function setDefaultReceiveLibraryTimeout(uint32 _eid, address _lib, uint256 _expiry) external

Sets the timeout for a default receive library.

defaultReceiveLibraryTimeout

function defaultReceiveLibraryTimeout(uint32 _eid) external view returns (address lib, uint256 expiry)

Gets the default receive library timeout for a specific endpoint.

isSupportedEid

function isSupportedEid(uint32 _eid) external view returns (bool)

isValidReceiveLibrary

function isValidReceiveLibrary(address _receiver, uint32 _eid, address _lib) external view returns (bool)

setSendLibrary

function setSendLibrary(address _oapp, uint32 _eid, address _newLib) external

Sets a send library for an OApp for a specific endpoint.

getSendLibrary

function getSendLibrary(address _sender, uint32 _eid) external view returns (address lib)

isDefaultSendLibrary

function isDefaultSendLibrary(address _sender, uint32 _eid) external view returns (bool)

setReceiveLibrary

function setReceiveLibrary(address _oapp, uint32 _eid, address _newLib, uint256 _gracePeriod) external

getReceiveLibrary

function getReceiveLibrary(address _receiver, uint32 _eid) external view returns (address lib, bool isDefault)

setReceiveLibraryTimeout

function setReceiveLibraryTimeout(address _oapp, uint32 _eid, address _lib, uint256 _expiry) external

receiveLibraryTimeout

function receiveLibraryTimeout(address _receiver, uint32 _eid) external view returns (address lib, uint256 expiry)

setConfig

function setConfig(address _oapp, address _lib, struct SetConfigParam[] _params) external

getConfig

function getConfig(address _oapp, address _lib, uint32 _eid, uint32 _configType) external view returns (bytes config)

IMessagingChannel

InboundNonceSkipped

event InboundNonceSkipped(uint32 srcEid, bytes32 sender, address receiver, uint64 nonce)

PacketNilified

event PacketNilified(uint32 srcEid, bytes32 sender, address receiver, uint64 nonce, bytes32 payloadHash)

PacketBurnt

event PacketBurnt(uint32 srcEid, bytes32 sender, address receiver, uint64 nonce, bytes32 payloadHash)

eid

function eid() external view returns (uint32)

skip

function skip(address _oapp, uint32 _srcEid, bytes32 _sender, uint64 _nonce) external

nilify

function nilify(address _oapp, uint32 _srcEid, bytes32 _sender, uint64 _nonce, bytes32 _payloadHash) external

burn

function burn(address _oapp, uint32 _srcEid, bytes32 _sender, uint64 _nonce, bytes32 _payloadHash) external

nextGuid

function nextGuid(address _sender, uint32 _dstEid, bytes32 _receiver) external view returns (bytes32)

inboundNonce

function inboundNonce(address _receiver, uint32 _srcEid, bytes32 _sender) external view returns (uint64)

outboundNonce

function outboundNonce(address _sender, uint32 _dstEid, bytes32 _receiver) external view returns (uint64)

inboundPayloadHash

function inboundPayloadHash(address _receiver, uint32 _srcEid, bytes32 _sender, uint64 _nonce) external view returns (bytes32)

lazyInboundNonce

function lazyInboundNonce(address _receiver, uint32 _srcEid, bytes32 _sender) external view returns (uint64)

IMessagingComposer

ComposeSent

event ComposeSent(address from, address to, bytes32 guid, uint16 index, bytes message)

ComposeDelivered

event ComposeDelivered(address from, address to, bytes32 guid, uint16 index)

LzComposeAlert

event LzComposeAlert(address from, address to, address executor, bytes32 guid, uint16 index, uint256 gas, uint256 value, bytes message, bytes extraData, bytes reason)

composeQueue

function composeQueue(address _from, address _to, bytes32 _guid, uint16 _index) external view returns (bytes32 messageHash)

sendCompose

function sendCompose(address _to, bytes32 _guid, uint16 _index, bytes _message) external

lzCompose

function lzCompose(address _from, address _to, bytes32 _guid, uint16 _index, bytes _message, bytes _extraData) external payable

IMessagingContext

isSendingMessage

function isSendingMessage() external view returns (bool)

getSendContext

function getSendContext() external view returns (uint32 dstEid, address sender)

Packet

struct Packet {
  uint64 nonce;
  uint32 srcEid;
  address sender;
  uint32 dstEid;
  bytes32 receiver;
  bytes32 guid;
  bytes message;
}

The Packet struct represents the data structure used for LayerZero messaging between endpoints. It includes important metadata such as sender, receiver, nonce, and the message itself.

ISendLib

The ISendLib interface defines the functions necessary for sending packets, estimating messaging fees, and handling fee withdrawals for LayerZero messaging.

send

function send(struct Packet _packet, bytes _options, bool _payInLzToken) external returns (struct MessagingFee, bytes encodedPacket)

Sends a LayerZero message packet and returns the required fees and the encoded packet data.

_packet: The Packet struct containing the message to be sent.
_options: Byte-encoded options for the message.
_payInLzToken: Boolean flag indicating whether fees should be paid in LzToken.

Returns:

MessagingFee: The fees for the message, divided into native and LzToken fees.
encodedPacket: The encoded message packet in bytes.

quote

function quote(struct Packet _packet, bytes _options, bool _payInLzToken) external view returns (struct MessagingFee)

Estimates the messaging fee for sending a LayerZero packet.

setTreasury

function setTreasury(address _treasury) external

Sets the treasury address to receive collected fees.

withdrawFee

function withdrawFee(address _to, uint256 _amount) external

Withdraws native token fees collected by the contract.

withdrawLzTokenFee

function withdrawLzTokenFee(address _lzToken, address _to, uint256 _amount) external

Withdraws LayerZero token fees collected by the contract.

AddressCast

The AddressCast library provides utility functions for casting between addresses and their byte representations. It also includes error handling for invalid address sizes.

AddressCast_InvalidSizeForAddress

error AddressCast_InvalidSizeForAddress()

Thrown when the size of the byte array for an address is invalid.

AddressCast_InvalidAddress

error AddressCast_InvalidAddress()

Thrown when an invalid address is provided.

toBytes32

function toBytes32(bytes _addressBytes) internal pure returns (bytes32 result)

Casts a byte array to a bytes32 representation of an address.

toBytes32

function toBytes32(address _address) internal pure returns (bytes32 result)

Casts an address to its bytes32 representation.

toBytes

function toBytes(bytes32 _addressBytes32, uint256 _size) internal pure returns (bytes result)

Casts a bytes32 address to its byte array form, with a specified size.

toAddress

function toAddress(bytes32 _addressBytes32) internal pure returns (address result)

Casts a bytes32 representation of an address back to an address.

toAddress

function toAddress(bytes _addressBytes) internal pure returns (address result)

Casts a byte array back to an address.

CalldataBytesLib

The CalldataBytesLib provides functions to convert portions of calldata (byte arrays) into various Solidity types. These functions help when dealing with raw calldata.

toU8

function toU8(bytes _bytes, uint256 _start) internal pure returns (uint8)

Converts a portion of a byte array to a uint8 starting at the given position.

toU16

function toU16(bytes _bytes, uint256 _start) internal pure returns (uint16)

Converts a portion of a byte array to a uint16 starting at the given position.

toU32

function toU32(bytes _bytes, uint256 _start) internal pure returns (uint32)

Converts a portion of a byte array to a uint32 starting at the given position.

toU64

function toU64(bytes _bytes, uint256 _start) internal pure returns (uint64)

Converts a portion of a byte array to a uint64 starting at the given position.

toU128

function toU128(bytes _bytes, uint256 _start) internal pure returns (uint128)

Converts a portion of a byte array to a uint128 starting at the given position.

toU256

function toU256(bytes _bytes, uint256 _start) internal pure returns (uint256)

Converts a portion of a byte array to a uint256 starting at the given position.

toAddr

function toAddr(bytes _bytes, uint256 _start) internal pure returns (address)

Converts a portion of a byte array to an address starting at the given position.

toB32

function toB32(bytes _bytes, uint256 _start) internal pure returns (bytes32)

Converts a portion of a byte array to a bytes32 starting at the given position.

Errors

LZ_LzTokenUnavailable

error LZ_LzTokenUnavailable()

LZ_InvalidReceiveLibrary

error LZ_InvalidReceiveLibrary()

LZ_InvalidNonce

error LZ_InvalidNonce(uint64 nonce)

LZ_InvalidArgument

error LZ_InvalidArgument()

LZ_InvalidExpiry

error LZ_InvalidExpiry()

LZ_InvalidAmount

error LZ_InvalidAmount(uint256 required, uint256 supplied)

LZ_OnlyRegisteredOrDefaultLib

error LZ_OnlyRegisteredOrDefaultLib()

LZ_OnlyRegisteredLib

error LZ_OnlyRegisteredLib()

LZ_OnlyNonDefaultLib

error LZ_OnlyNonDefaultLib()

LZ_Unauthorized

error LZ_Unauthorized()

LZ_DefaultSendLibUnavailable

error LZ_DefaultSendLibUnavailable()

LZ_DefaultReceiveLibUnavailable

error LZ_DefaultReceiveLibUnavailable()

LZ_PathNotInitializable

error LZ_PathNotInitializable()

LZ_PathNotVerifiable

error LZ_PathNotVerifiable()

LZ_OnlySendLib

error LZ_OnlySendLib()

LZ_OnlyReceiveLib

error LZ_OnlyReceiveLib()

LZ_UnsupportedEid

error LZ_UnsupportedEid()

LZ_UnsupportedInterface

error LZ_UnsupportedInterface()

LZ_AlreadyRegistered

error LZ_AlreadyRegistered()

LZ_SameValue

error LZ_SameValue()

LZ_InvalidPayloadHash

error LZ_InvalidPayloadHash()

LZ_PayloadHashNotFound

error LZ_PayloadHashNotFound(bytes32 expected, bytes32 actual)

LZ_ComposeNotFound

error LZ_ComposeNotFound(bytes32 expected, bytes32 actual)

LZ_ComposeExists

error LZ_ComposeExists()

LZ_SendReentrancy

error LZ_SendReentrancy()

LZ_NotImplemented

error LZ_NotImplemented()

LZ_InsufficientFee

error LZ_InsufficientFee(uint256 requiredNative, uint256 suppliedNative, uint256 requiredLzToken, uint256 suppliedLzToken)

LZ_ZeroLzTokenFee

error LZ_ZeroLzTokenFee()

GUID

generate

function generate(uint64 _nonce, uint32 _srcEid, address _sender, uint32 _dstEid, bytes32 _receiver) internal pure returns (bytes32)

Transfer

ADDRESS_ZERO

address ADDRESS_ZERO

Transfer_NativeFailed

error Transfer_NativeFailed(address _to, uint256 _value)

Transfer_ToAddressIsZero

error Transfer_ToAddressIsZero()

native

function native(address _to, uint256 _value) internal

token

function token(address _token, address _to, uint256 _value) internal

nativeOrToken

function nativeOrToken(address _token, address _to, uint256 _value) internal

BlockedMessageLib

supportsInterface

function supportsInterface(bytes4 interfaceId) public view returns (bool)

See IERC165 and supportsInterface.

version

function version() external pure returns (uint64 major, uint8 minor, uint8 endpointVersion)

messageLibType

function messageLibType() external pure returns (enum MessageLibType)

isSupportedEid

function isSupportedEid(uint32) external pure returns (bool)

fallback

fallback() external

BitMaps

get

function get(BitMap256 bitmap, uint8 index) internal pure returns (bool)

Returns whether the bit at index is set.

set

function set(BitMap256 bitmap, uint8 index) internal pure returns (BitMap256)

Sets the bit at index.

ExecutorOptions

WORKER_ID

uint8 WORKER_ID

OPTION_TYPE_LZRECEIVE

uint8 OPTION_TYPE_LZRECEIVE

OPTION_TYPE_NATIVE_DROP

uint8 OPTION_TYPE_NATIVE_DROP

OPTION_TYPE_LZCOMPOSE

uint8 OPTION_TYPE_LZCOMPOSE

OPTION_TYPE_ORDERED_EXECUTION

uint8 OPTION_TYPE_ORDERED_EXECUTION

Executor_InvalidLzReceiveOption

error Executor_InvalidLzReceiveOption()

Executor_InvalidNativeDropOption

error Executor_InvalidNativeDropOption()

Executor_InvalidLzComposeOption

error Executor_InvalidLzComposeOption()

nextExecutorOption

function nextExecutorOption(bytes _options, uint256 _cursor) internal pure returns (uint8 optionType, bytes option, uint256 cursor)

decode the next executor option from the options starting from the specified cursor

Parameters

Name	Type	Description
_options	bytes	[executor_id][executor_option][executor_id][executor_option]… executor_option = [option_size][option_type][option] option_size = len(option_type) + len(option) executor_id: uint8, option_size: uint16, option_type: uint8, option: bytes
_cursor	uint256	the cursor to start decoding from

Return Values

Name	Type	Description
optionType	uint8	the type of the option
option	bytes	the option of the executor
cursor	uint256	the cursor to start decoding the next executor option

decodeLzReceiveOption

function decodeLzReceiveOption(bytes _option) internal pure returns (uint128 gas, uint128 value)

decodeNativeDropOption

function decodeNativeDropOption(bytes _option) internal pure returns (uint128 amount, bytes32 receiver)

decodeLzComposeOption

function decodeLzComposeOption(bytes _option) internal pure returns (uint16 index, uint128 gas, uint128 value)

encodeLzReceiveOption

function encodeLzReceiveOption(uint128 _gas, uint128 _value) internal pure returns (bytes)

encodeNativeDropOption

function encodeNativeDropOption(uint128 _amount, bytes32 _receiver) internal pure returns (bytes)

encodeLzComposeOption

function encodeLzComposeOption(uint16 _index, uint128 _gas, uint128 _value) internal pure returns (bytes)

PacketV1Codec

PACKET_VERSION

uint8 PACKET_VERSION

encode

function encode(struct Packet _packet) internal pure returns (bytes encodedPacket)

encodePacketHeader

function encodePacketHeader(struct Packet _packet) internal pure returns (bytes)

encodePayload

function encodePayload(struct Packet _packet) internal pure returns (bytes)

function header(bytes _packet) internal pure returns (bytes)

version

function version(bytes _packet) internal pure returns (uint8)

nonce

function nonce(bytes _packet) internal pure returns (uint64)

srcEid

function srcEid(bytes _packet) internal pure returns (uint32)

sender

function sender(bytes _packet) internal pure returns (bytes32)

senderAddressB20

function senderAddressB20(bytes _packet) internal pure returns (address)

dstEid

function dstEid(bytes _packet) internal pure returns (uint32)

receiver

function receiver(bytes _packet) internal pure returns (bytes32)

receiverB20

function receiverB20(bytes _packet) internal pure returns (address)

guid

function guid(bytes _packet) internal pure returns (bytes32)

message

function message(bytes _packet) internal pure returns (bytes)

payload

function payload(bytes _packet) internal pure returns (bytes)

payloadHash

function payloadHash(bytes _packet) internal pure returns (bytes32)

MessageLibBase

This contract serves as a base for handling the communication between the LayerZero endpoint and a specific chain (referred to by its localEid). It simplifies the initialization and enforcement of endpoint-specific logic. simply a container of endpoint address and local eid

endpoint

address endpoint

Holds the address of the LayerZero endpoint on this chain.

localEid

uint32 localEid

A unique identifier (Eid) for the local chain.

LZ_MessageLib_OnlyEndpoint

error LZ_MessageLib_OnlyEndpoint()

Error thrown when a function is accessed by a non-endpoint address.

onlyEndpoint

modifier onlyEndpoint()

A modifier ensuring that only the LayerZero endpoint can call specific functions.

constructor

constructor(address _endpoint, uint32 _localEid) internal

Initializes the contract with the LayerZero endpoint and localEid.

ReceiveLibBaseE2

This is the base contract for handling the receive-side logic of messages in LayerZero V2. It simplifies the process compared to V1 by removing complexities like nonce management and executor whitelisting. receive-side message library base contract on endpoint v2. it does not have the complication as the one of endpoint v1, such as nonce, executor whitelist, etc.

constructor

constructor(address _endpoint) internal

Initializes the contract with the LayerZero endpoint.

supportsInterface

function supportsInterface(bytes4 _interfaceId) public view virtual returns (bool)

Determines whether the contract supports a specific interface.

messageLibType

function messageLibType() external pure virtual returns (enum MessageLibType)

Specifies the type of the message library being used (e.g., for differentiation between send and receive libraries).

WorkerOptions

struct WorkerOptions {
  uint8 workerId;
  bytes options;
}

Defines options for specific worker configurations (e.g., a worker ID and additional options).

SetDefaultExecutorConfigParam

struct SetDefaultExecutorConfigParam {
  uint32 eid;
  struct ExecutorConfig config;
}

Used to configure the default settings for an executor, including the executor’s address and max message size for a given chain (eid).

ExecutorConfig

struct ExecutorConfig {
  uint32 maxMessageSize;
  address executor;
}

SendLibBase

base contract for both SendLibBaseE1 and SendLibBaseE2

TREASURY_MAX_COPY

uint16 TREASURY_MAX_COPY

treasuryGasLimit

uint256 treasuryGasLimit

treasuryNativeFeeCap

uint256 treasuryNativeFeeCap

treasury

address treasury

executorConfigs

mapping(address => mapping(uint32 => struct ExecutorConfig)) executorConfigs

fees

mapping(address => uint256) fees

ExecutorFeePaid

event ExecutorFeePaid(address executor, uint256 fee)

TreasurySet

event TreasurySet(address treasury)

DefaultExecutorConfigsSet

event DefaultExecutorConfigsSet(struct SetDefaultExecutorConfigParam[] params)

ExecutorConfigSet

event ExecutorConfigSet(address oapp, uint32 eid, struct ExecutorConfig config)

TreasuryNativeFeeCapSet

event TreasuryNativeFeeCapSet(uint256 newTreasuryNativeFeeCap)

LZ_MessageLib_InvalidMessageSize

error LZ_MessageLib_InvalidMessageSize(uint256 actual, uint256 max)

LZ_MessageLib_InvalidAmount

error LZ_MessageLib_InvalidAmount(uint256 requested, uint256 available)

LZ_MessageLib_TransferFailed

error LZ_MessageLib_TransferFailed()

LZ_MessageLib_InvalidExecutor

error LZ_MessageLib_InvalidExecutor()

LZ_MessageLib_ZeroMessageSize

error LZ_MessageLib_ZeroMessageSize()

constructor

constructor(address _endpoint, uint32 _localEid, uint256 _treasuryGasLimit, uint256 _treasuryNativeFeeCap) internal

setDefaultExecutorConfigs

function setDefaultExecutorConfigs(struct SetDefaultExecutorConfigParam[] _params) external

setTreasuryNativeFeeCap

function setTreasuryNativeFeeCap(uint256 _newTreasuryNativeFeeCap) external

the new value can not be greater than the old value, i.e. down only

getExecutorConfig

function getExecutorConfig(address _oapp, uint32 _remoteEid) public view returns (struct ExecutorConfig rtnConfig)

_assertMessageSize

function _assertMessageSize(uint256 _actual, uint256 _max) internal pure

_payExecutor

function _payExecutor(address _executor, uint32 _dstEid, address _sender, uint256 _msgSize, bytes _executorOptions) internal returns (uint256 executorFee)

_payTreasury

function _payTreasury(address _sender, uint32 _dstEid, uint256 _totalNativeFee, bool _payInLzToken) internal returns (uint256 treasuryNativeFee, uint256 lzTokenFee)

_quote

function _quote(address _sender, uint32 _dstEid, uint256 _msgSize, bool _payInLzToken, bytes _options) internal view returns (uint256, uint256)

the abstract process for quote() is: 0/ split out the executor options and options of other workers 1/ quote workers 2/ quote executor 3/ quote treasury

Return Values

Name	Type	Description
[0]	uint256	nativeFee, lzTokenFee
[1]	uint256

_quoteTreasury

function _quoteTreasury(address _sender, uint32 _dstEid, uint256 _totalNativeFee, bool _payInLzToken) internal view returns (uint256 nativeFee, uint256 lzTokenFee)

this interface should be DoS-free if the user is paying with native. properties 1/ treasury can return an overly high lzToken fee 2/ if treasury returns an overly high native fee, it will be capped by maxNativeFee, which can be reasoned with the configurations 3/ the owner can not configure the treasury in a way that force this function to revert

_parseTreasuryResult

function _parseTreasuryResult(uint256 _totalNativeFee, bool _payInLzToken, bool _success, bytes _result) internal view returns (uint256 nativeFee, uint256 lzTokenFee)

_debitFee

function _debitFee(uint256 _amount) internal

authenticated by msg.sender only

_setTreasury

function _setTreasury(address _treasury) internal

_setExecutorConfig

function _setExecutorConfig(uint32 _remoteEid, address _oapp, struct ExecutorConfig _config) internal

_quoteVerifier

function _quoteVerifier(address _oapp, uint32 _eid, struct WorkerOptions[] _options) internal view virtual returns (uint256 nativeFee)

these two functions will be overridden with specific logics of the library function

_splitOptions

function _splitOptions(bytes _options) internal view virtual returns (bytes executorOptions, struct WorkerOptions[] validationOptions)

this function will split the options into executorOptions and validationOptions

SendLibBaseE2

send-side message library base contract on endpoint v2. design: the high level logic is the same as SendLibBaseE1 1/ with added interfaces 2/ adapt the functions to the new types, like uint32 for eid, address for sender.

NativeFeeWithdrawn

event NativeFeeWithdrawn(address worker, address receiver, uint256 amount)

LzTokenFeeWithdrawn

event LzTokenFeeWithdrawn(address lzToken, address receiver, uint256 amount)

LZ_MessageLib_NotTreasury

error LZ_MessageLib_NotTreasury()

LZ_MessageLib_CannotWithdrawAltToken

error LZ_MessageLib_CannotWithdrawAltToken()

constructor

constructor(address _endpoint, uint256 _treasuryGasLimit, uint256 _treasuryNativeFeeCap) internal

supportsInterface

function supportsInterface(bytes4 _interfaceId) public view virtual returns (bool)

send

function send(struct Packet _packet, bytes _options, bool _payInLzToken) public virtual returns (struct MessagingFee, bytes)

setTreasury

function setTreasury(address _treasury) external

withdrawFee

function withdrawFee(address _to, uint256 _amount) external

E2 only

withdrawLzTokenFee

function withdrawLzTokenFee(address _lzToken, address _to, uint256 _amount) external

_lzToken is a user-supplied value because lzToken might change in the endpoint before all lzToken can be taken out E2 only treasury only function

quote

function quote(struct Packet _packet, bytes _options, bool _payInLzToken) external view returns (struct MessagingFee)

messageLibType

function messageLibType() external pure virtual returns (enum MessageLibType)

_payWorkers

function _payWorkers(struct Packet _packet, bytes _options) internal returns (bytes encodedPacket, uint256 totalNativeFee)

1/ handle executor 2/ handle other workers

_payVerifier

function _payVerifier(struct Packet _packet, struct WorkerOptions[] _options) internal virtual returns (uint256 otherWorkerFees, bytes encodedPacket)

receive

receive() external payable virtual

Treasury

nativeBP

uint256 nativeBP

lzTokenFee

uint256 lzTokenFee

lzTokenEnabled

bool lzTokenEnabled

LZ_Treasury_LzTokenNotEnabled

error LZ_Treasury_LzTokenNotEnabled()

getFee

function getFee(address, uint32, uint256 _totalFee, bool _payInLzToken) external view returns (uint256)

payFee

function payFee(address, uint32, uint256 _totalFee, bool _payInLzToken) external payable returns (uint256)

setLzTokenEnabled

function setLzTokenEnabled(bool _lzTokenEnabled) external

setNativeFeeBP

function setNativeFeeBP(uint256 _nativeBP) external

setLzTokenFee

function setLzTokenFee(uint256 _lzTokenFee) external

withdrawLzToken

function withdrawLzToken(address _messageLib, address _lzToken, address _to, uint256 _amount) external

withdrawNativeFee

function withdrawNativeFee(address _messageLib, address payable _to, uint256 _amount) external

withdrawToken

function withdrawToken(address _token, address _to, uint256 _amount) external

_getFee

function _getFee(uint256 _totalFee, bool _payInLzToken) internal view returns (uint256)

Worker

MESSAGE_LIB_ROLE

bytes32 MESSAGE_LIB_ROLE

ALLOWLIST

bytes32 ALLOWLIST

DENYLIST

bytes32 DENYLIST

ADMIN_ROLE

bytes32 ADMIN_ROLE

workerFeeLib

address workerFeeLib

allowlistSize

uint64 allowlistSize

defaultMultiplierBps

uint16 defaultMultiplierBps

priceFeed

address priceFeed

supportedOptionTypes

mapping(uint32 => uint8[]) supportedOptionTypes

constructor

constructor(address[] _messageLibs, address _priceFeed, uint16 _defaultMultiplierBps, address _roleAdmin, address[] _admins) internal

Parameters

Name	Type	Description
_messageLibs	address[]	array of message lib addresses that are granted the MESSAGE_LIB_ROLE
_priceFeed	address	price feed address
_defaultMultiplierBps	uint16	default multiplier for worker fee
_roleAdmin	address	address that is granted the DEFAULT_ADMIN_ROLE (can grant and revoke all roles)
_admins	address[]	array of admin addresses that are granted the ADMIN_ROLE

onlyAcl

modifier onlyAcl(address _sender)

hasAcl

function hasAcl(address _sender) public view returns (bool)

_Access control list using allowlist and denylist

if one address is in the denylist -> deny
else if address in the allowlist OR allowlist is empty (allows everyone)-> allow
else deny_

Parameters

Name	Type	Description
_sender	address	address to check

setPaused

function setPaused(bool _paused) external

flag to pause execution of workers (if used with whenNotPaused modifier)

Parameters

Name	Type	Description
_paused	bool	true to pause, false to unpause

setPriceFeed

function setPriceFeed(address _priceFeed) external

Parameters

Name	Type	Description
_priceFeed	address	price feed address

setWorkerFeeLib

function setWorkerFeeLib(address _workerFeeLib) external

Parameters

Name	Type	Description
_workerFeeLib	address	worker fee lib address

setDefaultMultiplierBps

function setDefaultMultiplierBps(uint16 _multiplierBps) external

Parameters

Name	Type	Description
_multiplierBps	uint16	default multiplier for worker fee

withdrawFee

function withdrawFee(address _lib, address _to, uint256 _amount) external

supports withdrawing fee from ULN301, ULN302 and more

Parameters

Name	Type	Description
_lib	address	message lib address
_to	address	address to withdraw fee to
_amount	uint256	amount to withdraw

withdrawToken

function withdrawToken(address _token, address _to, uint256 _amount) external

supports withdrawing token from the contract

Parameters

Name	Type	Description
_token	address	token address
_to	address	address to withdraw token to
_amount	uint256	amount to withdraw

setSupportedOptionTypes

function setSupportedOptionTypes(uint32 _eid, uint8[] _optionTypes) external

getSupportedOptionTypes

function getSupportedOptionTypes(uint32 _eid) external view returns (uint8[])

_grantRole

function _grantRole(bytes32 _role, address _account) internal

overrides AccessControl to allow for counting of allowlistSize

Parameters

Name	Type	Description
_role	bytes32	role to grant
_account	address	address to grant role to

_revokeRole

function _revokeRole(bytes32 _role, address _account) internal

overrides AccessControl to allow for counting of allowlistSize

Parameters

Name	Type	Description
_role	bytes32	role to revoke
_account	address	address to revoke role from

renounceRole

function renounceRole(bytes32, address) public pure

overrides AccessControl to disable renouncing of roles

TargetParam

struct TargetParam {
  uint8 idx;
  address addr;
}

DVNParam

struct DVNParam {
  uint16 idx;
  address addr;
}

IExecutor

DstConfigParam

struct DstConfigParam {
  uint32 dstEid;
  uint64 lzReceiveBaseGas;
  uint64 lzComposeBaseGas;
  uint16 multiplierBps;
  uint128 floorMarginUSD;
  uint128 nativeCap;
}

DstConfig

struct DstConfig {
  uint64 lzReceiveBaseGas;
  uint16 multiplierBps;
  uint128 floorMarginUSD;
  uint128 nativeCap;
  uint64 lzComposeBaseGas;
}

ExecutionParams

struct ExecutionParams {
  address receiver;
  struct Origin origin;
  bytes32 guid;
  bytes message;
  bytes extraData;
  uint256 gasLimit;
}

NativeDropParams

struct NativeDropParams {
  address receiver;
  uint256 amount;
}

DstConfigSet

event DstConfigSet(struct IExecutor.DstConfigParam[] params)

NativeDropApplied

event NativeDropApplied(struct Origin origin, uint32 dstEid, address oapp, struct IExecutor.NativeDropParams[] params, bool[] success)

dstConfig

function dstConfig(uint32 _dstEid) external view returns (uint64, uint16, uint128, uint128, uint64)

IExecutorFeeLib

FeeParams

struct FeeParams {
  address priceFeed;
  uint32 dstEid;
  address sender;
  uint256 calldataSize;
  uint16 defaultMultiplierBps;
}

Executor_NoOptions

error Executor_NoOptions()

Executor_NativeAmountExceedsCap

error Executor_NativeAmountExceedsCap(uint256 amount, uint256 cap)

Executor_UnsupportedOptionType

error Executor_UnsupportedOptionType(uint8 optionType)

Executor_InvalidExecutorOptions

error Executor_InvalidExecutorOptions(uint256 cursor)

Executor_ZeroLzReceiveGasProvided

error Executor_ZeroLzReceiveGasProvided()

Executor_ZeroLzComposeGasProvided

error Executor_ZeroLzComposeGasProvided()

Executor_EidNotSupported

error Executor_EidNotSupported(uint32 eid)

getFeeOnSend

function getFeeOnSend(struct IExecutorFeeLib.FeeParams _params, struct IExecutor.DstConfig _dstConfig, bytes _options) external returns (uint256 fee)

getFee

function getFee(struct IExecutorFeeLib.FeeParams _params, struct IExecutor.DstConfig _dstConfig, bytes _options) external view returns (uint256 fee)

ILayerZeroExecutor

assignJob

function assignJob(uint32 _dstEid, address _sender, uint256 _calldataSize, bytes _options) external returns (uint256 price)

getFee

function getFee(uint32 _dstEid, address _sender, uint256 _calldataSize, bytes _options) external view returns (uint256 price)

ILayerZeroTreasury

getFee

function getFee(address _sender, uint32 _dstEid, uint256 _totalNativeFee, bool _payInLzToken) external view returns (uint256 fee)

payFee

function payFee(address _sender, uint32 _dstEid, uint256 _totalNativeFee, bool _payInLzToken) external payable returns (uint256 fee)

IWorker

SetWorkerLib

event SetWorkerLib(address workerLib)

SetPriceFeed

event SetPriceFeed(address priceFeed)

SetDefaultMultiplierBps

event SetDefaultMultiplierBps(uint16 multiplierBps)

SetSupportedOptionTypes

event SetSupportedOptionTypes(uint32 dstEid, uint8[] optionTypes)

Withdraw

event Withdraw(address lib, address to, uint256 amount)

Worker_NotAllowed

error Worker_NotAllowed()

Worker_OnlyMessageLib

error Worker_OnlyMessageLib()

Worker_RoleRenouncingDisabled

error Worker_RoleRenouncingDisabled()

setPriceFeed

function setPriceFeed(address _priceFeed) external

priceFeed

function priceFeed() external view returns (address)

setDefaultMultiplierBps

function setDefaultMultiplierBps(uint16 _multiplierBps) external

defaultMultiplierBps

function defaultMultiplierBps() external view returns (uint16)

withdrawFee

function withdrawFee(address _lib, address _to, uint256 _amount) external

setSupportedOptionTypes

function setSupportedOptionTypes(uint32 _eid, uint8[] _optionTypes) external

getSupportedOptionTypes

function getSupportedOptionTypes(uint32 _eid) external view returns (uint8[])

SafeCall

copied from https://github.com/nomad-xyz/ExcessivelySafeCall/blob/main/src/ExcessivelySafeCall.sol.

safeCall

function safeCall(address _target, uint256 _gas, uint256 _value, uint16 _maxCopy, bytes _calldata) internal returns (bool, bytes)

calls a contract with a specified gas limit and value and captures the return data

Parameters

Name	Type	Description
_target	address	The address to call
_gas	uint256	The amount of gas to forward to the remote contract
_value	uint256	The value in wei to send to the remote contract to memory.
_maxCopy	uint16	The maximum number of bytes of returndata to copy to memory.
_calldata	bytes	The data to send to the remote contract

Return Values

Name	Type	Description
[0]	bool	success and returndata, as `.call()`. Returndata is capped to `_maxCopy` bytes.
[1]	bytes

safeStaticCall

function safeStaticCall(address _target, uint256 _gas, uint16 _maxCopy, bytes _calldata) internal view returns (bool, bytes)

Use when you really really really don’t trust the called contract. This prevents the called contract from causing reversion of the caller in as many ways as we can. The main difference between this and a solidity low-level call is that we limit the number of bytes that the callee can cause to be copied to caller memory. This prevents stupid things like malicious contracts returning 10,000,000 bytes causing a local OOG when copying to memory.

Parameters

Name	Type	Description
_target	address	The address to call
_gas	uint256	The amount of gas to forward to the remote contract
_maxCopy	uint16	The maximum number of bytes of returndata to copy to memory.
_calldata	bytes	The data to send to the remote contract

Return Values

Name	Type	Description
[0]	bool	success and returndata, as `.call()`. Returndata is capped to `_maxCopy` bytes.
[1]	bytes

DVNMock

Executed

event Executed(uint32 vid, address target, bytes callData, uint256 expiration, bytes signatures)

vid

uint32 vid

constructor

constructor(uint32 _vid) public

execute

function execute(struct ExecuteParam[] _params) external

verify

function verify(bytes _packetHeader, bytes32 _payloadHash, uint64 _confirmations) external

ExecutorMock

NativeDropMeta

event NativeDropMeta(uint32 srcEid, bytes32 sender, uint64 nonce, uint32 dstEid, address oapp, uint256 nativeDropGasLimit)

NativeDropped

event NativeDropped(address receiver, uint256 amount)

Executed301

event Executed301(bytes packet, uint256 gasLimit)

Executed302

event Executed302(uint32 srcEid, bytes32 sender, uint64 nonce, address receiver, bytes32 guid, bytes message, bytes extraData, uint256 gasLimit)

dstEid

uint32 dstEid

constructor

constructor(uint32 _dstEid) public

nativeDrop

function nativeDrop(struct Origin _origin, uint32 _dstEid, address _oapp, struct IExecutor.NativeDropParams[] _nativeDropParams, uint256 _nativeDropGasLimit) external payable

nativeDropAndExecute301

function nativeDropAndExecute301(struct Origin _origin, struct IExecutor.NativeDropParams[] _nativeDropParams, uint256 _nativeDropGasLimit, bytes _packet, uint256 _gasLimit) external payable

execute301

function execute301(bytes _packet, uint256 _gasLimit) external

nativeDropAndExecute302

function nativeDropAndExecute302(struct IExecutor.NativeDropParams[] _nativeDropParams, uint256 _nativeDropGasLimit, struct IExecutor.ExecutionParams _executionParams) external payable

_nativeDrop

function _nativeDrop(struct Origin _origin, uint32 _dstEid, address _oapp, struct IExecutor.NativeDropParams[] _nativeDropParams, uint256 _nativeDropGasLimit) internal

LzReceiveParam

struct LzReceiveParam {
  struct Origin origin;
  address receiver;
  bytes32 guid;
  bytes message;
  bytes extraData;
  uint256 gas;
  uint256 value;
}

NativeDropParam

struct NativeDropParam {
  address _receiver;
  uint256 _amount;
}

IReceiveUlnView

verifiable

function verifiable(bytes _packetHeader, bytes32 _payloadHash) external view returns (enum VerificationState)

Verification

struct Verification {
  bool submitted;
  uint64 confirmations;
}

ReceiveUlnBase

includes the utility functions for checking ULN states and logics

hashLookup

mapping(bytes32 => mapping(bytes32 => mapping(address => struct Verification))) hashLookup

PayloadVerified

event PayloadVerified(address dvn, bytes header, uint256 confirmations, bytes32 proofHash)

LZ_ULN_InvalidPacketHeader

error LZ_ULN_InvalidPacketHeader()

LZ_ULN_InvalidPacketVersion

error LZ_ULN_InvalidPacketVersion()

LZ_ULN_InvalidEid

error LZ_ULN_InvalidEid()

LZ_ULN_Verifying

error LZ_ULN_Verifying()

verifiable

function verifiable(struct UlnConfig _config, bytes32 _headerHash, bytes32 _payloadHash) external view returns (bool)

assertHeader

function assertHeader(bytes _packetHeader, uint32 _localEid) external pure

_verify

function _verify(bytes _packetHeader, bytes32 _payloadHash, uint64 _confirmations) internal

per DVN signing function

_verified

function _verified(address _dvn, bytes32 _headerHash, bytes32 _payloadHash, uint64 _requiredConfirmation) internal view returns (bool verified)

_verifyAndReclaimStorage

function _verifyAndReclaimStorage(struct UlnConfig _config, bytes32 _headerHash, bytes32 _payloadHash) internal

_assertHeader

function _assertHeader(bytes _packetHeader, uint32 _localEid) internal pure

_checkVerifiable

function _checkVerifiable(struct UlnConfig _config, bytes32 _headerHash, bytes32 _payloadHash) internal view returns (bool)

for verifiable view function checks if this verification is ready to be committed to the endpoint

SendUlnBase

includes the utility functions for checking ULN states and logics

DVNFeePaid

event DVNFeePaid(address[] requiredDVNs, address[] optionalDVNs, uint256[] fees)

_splitUlnOptions

function _splitUlnOptions(bytes _options) internal pure returns (bytes, struct WorkerOptions[])

_payDVNs

function _payDVNs(mapping(address => uint256) _fees, struct Packet _packet, struct WorkerOptions[] _options) internal returns (uint256 totalFee, bytes encodedPacket)

---------- pay and assign jobs ----------

_assignJobs

function _assignJobs(mapping(address => uint256) _fees, struct UlnConfig _ulnConfig, struct ILayerZeroDVN.AssignJobParam _param, bytes dvnOptions) internal returns (uint256 totalFee, uint256[] dvnFees)

_quoteDVNs

function _quoteDVNs(address _sender, uint32 _dstEid, struct WorkerOptions[] _options) internal view returns (uint256 totalFee)

---------- quote ----------

_getFees

function _getFees(struct UlnConfig _config, uint32 _dstEid, address _sender, bytes[] _optionsArray, uint8[] _dvnIds) internal view returns (uint256 totalFee)

UlnConfig

struct UlnConfig {
  uint64 confirmations;
  uint8 requiredDVNCount;
  uint8 optionalDVNCount;
  uint8 optionalDVNThreshold;
  address[] requiredDVNs;
  address[] optionalDVNs;
}

SetDefaultUlnConfigParam

struct SetDefaultUlnConfigParam {
  uint32 eid;
  struct UlnConfig config;
}

UlnBase

includes the utility functions for checking ULN states and logics

DEFAULT

uint8 DEFAULT

NIL_DVN_COUNT

uint8 NIL_DVN_COUNT

NIL_CONFIRMATIONS

uint64 NIL_CONFIRMATIONS

ulnConfigs

mapping(address => mapping(uint32 => struct UlnConfig)) ulnConfigs

LZ_ULN_Unsorted

error LZ_ULN_Unsorted()

LZ_ULN_InvalidRequiredDVNCount

error LZ_ULN_InvalidRequiredDVNCount()

LZ_ULN_InvalidOptionalDVNCount

error LZ_ULN_InvalidOptionalDVNCount()

LZ_ULN_AtLeastOneDVN

error LZ_ULN_AtLeastOneDVN()

LZ_ULN_InvalidOptionalDVNThreshold

error LZ_ULN_InvalidOptionalDVNThreshold()

LZ_ULN_InvalidConfirmations

error LZ_ULN_InvalidConfirmations()

LZ_ULN_UnsupportedEid

error LZ_ULN_UnsupportedEid(uint32 eid)

DefaultUlnConfigsSet

event DefaultUlnConfigsSet(struct SetDefaultUlnConfigParam[] params)

UlnConfigSet

event UlnConfigSet(address oapp, uint32 eid, struct UlnConfig config)

setDefaultUlnConfigs

function setDefaultUlnConfigs(struct SetDefaultUlnConfigParam[] _params) external

_about the DEFAULT ULN config

its values are all LITERAL (e.g. 0 is 0). whereas in the oapp ULN config, 0 (default value) points to the default ULN config this design enables the oapp to point to DEFAULT config without explicitly setting the config
its configuration is more restrictive than the oapp ULN config that a) it must not use NIL value, where NIL is used only by oapps to indicate the LITERAL 0 b) it must have at least one DVN_

getUlnConfig

function getUlnConfig(address _oapp, uint32 _remoteEid) public view returns (struct UlnConfig rtnConfig)

getAppUlnConfig

function getAppUlnConfig(address _oapp, uint32 _remoteEid) external view returns (struct UlnConfig)

Get the uln config without the default config for the given remoteEid.

_setUlnConfig

function _setUlnConfig(uint32 _remoteEid, address _oapp, struct UlnConfig _param) internal

_isSupportedEid

function _isSupportedEid(uint32 _remoteEid) internal view returns (bool)

a supported Eid must have a valid default uln config, which has at least one dvn

_assertSupportedEid

function _assertSupportedEid(uint32 _remoteEid) internal view

ExecuteParam

struct ExecuteParam {
  uint32 vid;
  address target;
  bytes callData;
  uint256 expiration;
  bytes signatures;
}

ISendLibBase

fees

function fees(address _worker) external view returns (uint256)

IReceiveUln

verify

function verify(bytes _packetHeader, bytes32 _payloadHash, uint64 _confirmations) external

ReceiveLibParam

struct ReceiveLibParam {
  address sendLib;
  uint32 dstEid;
  bytes32 receiveLib;
}

DVNAdapterBase

base contract for DVN adapters _limitations:

doesn’t accept alt token
doesn’t respect block confirmations_

DVNAdapter_InsufficientBalance

error DVNAdapter_InsufficientBalance(uint256 actual, uint256 requested)

DVNAdapter_NotImplemented

error DVNAdapter_NotImplemented()

DVNAdapter_MissingRecieveLib

error DVNAdapter_MissingRecieveLib(address sendLib, uint32 dstEid)

ReceiveLibsSet

event ReceiveLibsSet(struct ReceiveLibParam[] params)

MAX_CONFIRMATIONS

uint64 MAX_CONFIRMATIONS

on change of application config, dvn adapters will not perform any additional verification to avoid messages from being stuck, all verifications from adapters will be done with the maximum possible confirmations

receiveLibs

mapping(address => mapping(uint32 => bytes32)) receiveLibs

receive lib to call verify() on at destination

constructor

constructor(address _roleAdmin, address[] _admins, uint16 _defaultMultiplierBps) internal

setReceiveLibs

function setReceiveLibs(struct ReceiveLibParam[] _params) external

sets receive lib for destination chains DEFAULT_ADMIN_ROLE can set MESSAGE_LIB_ROLE for sendLibs and use below function to set receiveLibs

_getAndAssertReceiveLib

function _getAndAssertReceiveLib(address _sendLib, uint32 _dstEid) internal view returns (bytes32 lib)

_encode

function _encode(bytes32 _receiveLib, bytes _packetHeader, bytes32 _payloadHash) internal pure returns (bytes)

_encodeEmpty

function _encodeEmpty() internal pure returns (bytes)

_decodeAndVerify

function _decodeAndVerify(uint32 _srcEid, bytes _payload) internal

_withdrawFeeFromSendLib

function _withdrawFeeFromSendLib(address _sendLib, address _to) internal

_assertBalanceAndWithdrawFee

function _assertBalanceAndWithdrawFee(address _sendLib, uint256 _messageFee) internal

receive

receive() external payable

to receive refund

DVNAdapterMessageCodec

DVNAdapter_InvalidMessageSize

error DVNAdapter_InvalidMessageSize()

PACKET_HEADER_SIZE

uint256 PACKET_HEADER_SIZE

MESSAGE_SIZE

uint256 MESSAGE_SIZE

encode

function encode(bytes32 _receiveLib, bytes _packetHeader, bytes32 _payloadHash) internal pure returns (bytes payload)

decode

function decode(bytes _message) internal pure returns (address receiveLib, bytes packetHeader, bytes32 payloadHash)

srcEid

function srcEid(bytes _message) internal pure returns (uint32)

IDVN

DstConfigParam

struct DstConfigParam {
  uint32 dstEid;
  uint64 gas;
  uint16 multiplierBps;
  uint128 floorMarginUSD;
}

DstConfig

struct DstConfig {
  uint64 gas;
  uint16 multiplierBps;
  uint128 floorMarginUSD;
}

SetDstConfig

event SetDstConfig(struct IDVN.DstConfigParam[] params)

dstConfig

function dstConfig(uint32 _dstEid) external view returns (uint64, uint16, uint128)

IDVNFeeLib

FeeParams

struct FeeParams {
  address priceFeed;
  uint32 dstEid;
  uint64 confirmations;
  address sender;
  uint64 quorum;
  uint16 defaultMultiplierBps;
}

DVN_UnsupportedOptionType

error DVN_UnsupportedOptionType(uint8 optionType)

DVN_EidNotSupported

error DVN_EidNotSupported(uint32 eid)

getFeeOnSend

function getFeeOnSend(struct IDVNFeeLib.FeeParams _params, struct IDVN.DstConfig _dstConfig, bytes _options) external payable returns (uint256 fee)

getFee

function getFee(struct IDVNFeeLib.FeeParams _params, struct IDVN.DstConfig _dstConfig, bytes _options) external view returns (uint256 fee)

ILayerZeroDVN

AssignJobParam

struct AssignJobParam {
  uint32 dstEid;
  bytes packetHeader;
  bytes32 payloadHash;
  uint64 confirmations;
  address sender;
}

assignJob

function assignJob(struct ILayerZeroDVN.AssignJobParam _param, bytes _options) external payable returns (uint256 fee)

getFee

function getFee(uint32 _dstEid, uint64 _confirmations, address _sender, bytes _options) external view returns (uint256 fee)

IReceiveUlnE2

should be implemented by the ReceiveUln302 contract and future ReceiveUln contracts on EndpointV2

verify

function verify(bytes _packetHeader, bytes32 _payloadHash, uint64 _confirmations) external

for each dvn to verify the payload this function signature 0x0223536e

commitVerification

function commitVerification(bytes _packetHeader, bytes32 _payloadHash) external

verify the payload at endpoint, will check if all DVNs verified

DVNOptions

WORKER_ID

uint8 WORKER_ID

OPTION_TYPE_PRECRIME

uint8 OPTION_TYPE_PRECRIME

DVN_InvalidDVNIdx

error DVN_InvalidDVNIdx()

DVN_InvalidDVNOptions

error DVN_InvalidDVNOptions(uint256 cursor)

groupDVNOptionsByIdx

function groupDVNOptionsByIdx(bytes _options) internal pure returns (bytes[] dvnOptions, uint8[] dvnIndices)

group dvn options by its idx

Parameters

Name	Type	Description
_options	bytes	[dvn_id][dvn_option][dvn_id][dvn_option]… dvn_option = [option_size][dvn_idx][option_type][option] option_size = len(dvn_idx) + len(option_type) + len(option) dvn_id: uint8, dvn_idx: uint8, option_size: uint16, option_type: uint8, option: bytes

Return Values

Name	Type	Description
dvnOptions	bytes[]	the grouped options, still share the same format of _options
dvnIndices	uint8[]	the dvn indices

_insertDVNOptions

function _insertDVNOptions(bytes[] _dvnOptions, uint8[] _dvnIndices, uint8 _dvnIdx, bytes _newOptions) internal pure

getNumDVNs

function getNumDVNs(bytes _options) internal pure returns (uint8 numDVNs)

get the number of unique dvns

Parameters

Name	Type	Description
_options	bytes	the format is the same as groupDVNOptionsByIdx

nextDVNOption

function nextDVNOption(bytes _options, uint256 _cursor) internal pure returns (uint8 optionType, bytes option, uint256 cursor)

decode the next dvn option from _options starting from the specified cursor

Parameters

Name	Type	Description
_options	bytes	the format is the same as groupDVNOptionsByIdx
_cursor	uint256	the cursor to start decoding

Return Values

Name	Type	Description
optionType	uint8	the type of the option
option	bytes	the option
cursor	uint256	the cursor to start decoding the next option

UlnOptions

TYPE_1

uint16 TYPE_1

TYPE_2

uint16 TYPE_2

TYPE_3

uint16 TYPE_3

LZ_ULN_InvalidWorkerOptions

error LZ_ULN_InvalidWorkerOptions(uint256 cursor)

LZ_ULN_InvalidWorkerId

error LZ_ULN_InvalidWorkerId(uint8 workerId)

LZ_ULN_InvalidLegacyType1Option

error LZ_ULN_InvalidLegacyType1Option()

LZ_ULN_InvalidLegacyType2Option

error LZ_ULN_InvalidLegacyType2Option()

LZ_ULN_UnsupportedOptionType

error LZ_ULN_UnsupportedOptionType(uint16 optionType)

decode

function decode(bytes _options) internal pure returns (bytes executorOptions, bytes dvnOptions)

decode the options into executorOptions and dvnOptions

Parameters

Name	Type	Description
_options	bytes	the options can be either legacy options (type 1 or 2) or type 3 options

Return Values

Name	Type	Description
executorOptions	bytes	the executor options, share the same format of type 3 options
dvnOptions	bytes	the dvn options, share the same format of type 3 options

decodeLegacyOptions

function decodeLegacyOptions(uint16 _optionType, bytes _options) internal pure returns (bytes executorOptions)

decode the legacy options (type 1 or 2) into executorOptions

Parameters

Name	Type	Description
_optionType	uint16	the legacy option type
_options	bytes	the legacy options, which still has the option type in the first 2 bytes

Return Values

Name	Type	Description
executorOptions	bytes	the executor options, share the same format of type 3 options Data format: legacy type 1: [extraGas] legacy type 2: [extraGas][dstNativeAmt][dstNativeAddress] extraGas: uint256, dstNativeAmt: uint256, dstNativeAddress: bytes

AddressSizeConfig

addressSizes

mapping(uint32 => uint256) addressSizes

AddressSizeSet

event AddressSizeSet(uint16 eid, uint256 size)

AddressSizeConfig_InvalidAddressSize

error AddressSizeConfig_InvalidAddressSize()

AddressSizeConfig_AddressSizeAlreadySet

error AddressSizeConfig_AddressSizeAlreadySet()

setAddressSize

function setAddressSize(uint16 _eid, uint256 _size) external

ILayerZeroReceiveLibrary

setConfig

function setConfig(uint16 _chainId, address _userApplication, uint256 _configType, bytes _config) external

getConfig

function getConfig(uint16 _chainId, address _userApplication, uint256 _configType) external view returns (bytes)

SetDefaultExecutorParam

struct SetDefaultExecutorParam {
  uint32 eid;
  address executor;
}

ReceiveLibBaseE1

receive-side message library base contract on endpoint v1. design: 1/ it provides an internal execute function that calls the endpoint. It enforces the path definition on V1. 2/ it provides interfaces to configure executors that is whitelisted to execute the msg to prevent grieving

executors

mapping(address => mapping(uint32 => address)) executors

defaultExecutors

mapping(uint32 => address) defaultExecutors

PacketDelivered

event PacketDelivered(struct Origin origin, address receiver)

InvalidDst

event InvalidDst(uint16 srcChainId, bytes32 srcAddress, address dstAddress, uint64 nonce, bytes32 payloadHash)

DefaultExecutorsSet

event DefaultExecutorsSet(struct SetDefaultExecutorParam[] params)

ExecutorSet

event ExecutorSet(address oapp, uint32 eid, address executor)

LZ_MessageLib_InvalidExecutor

error LZ_MessageLib_InvalidExecutor()

LZ_MessageLib_OnlyExecutor

error LZ_MessageLib_OnlyExecutor()

constructor

constructor(address _endpoint, uint32 _localEid) internal

setDefaultExecutors

function setDefaultExecutors(struct SetDefaultExecutorParam[] _params) external

getExecutor

function getExecutor(address _oapp, uint32 _remoteEid) public view returns (address)

_setExecutor

function _setExecutor(uint32 _remoteEid, address _oapp, address _executor) internal

_execute

function _execute(uint16 _srcEid, bytes32 _sender, address _receiver, uint64 _nonce, bytes _message, uint256 _gasLimit) internal

this function change pack the path as required for EndpointV1

ReceiveUln301

ULN301 will be deployed on EndpointV1 and is for backward compatibility with ULN302 on EndpointV2. 301 can talk to both 301 and 302 This is a gluing contract. It simply parses the requests and forward to the super.impl() accordingly. In this case, it combines the logic of ReceiveUlnBase and ReceiveLibBaseE1

CONFIG_TYPE_EXECUTOR

uint256 CONFIG_TYPE_EXECUTOR

CONFIG_TYPE_ULN

uint256 CONFIG_TYPE_ULN

LZ_ULN_InvalidConfigType

error LZ_ULN_InvalidConfigType(uint256 configType)

constructor

constructor(address _endpoint, uint32 _localEid) public

setConfig

function setConfig(uint16 _eid, address _oapp, uint256 _configType, bytes _config) external

commitVerification

function commitVerification(bytes _packet, uint256 _gasLimit) external

in 301, this is equivalent to execution as in Endpoint V2 dont need to check endpoint verifiable here to save gas, as it will reverts if not verifiable.

verify

function verify(bytes _packetHeader, bytes32 _payloadHash, uint64 _confirmations) external

getConfig

function getConfig(uint16 _eid, address _oapp, uint256 _configType) external view returns (bytes)

version

function version() external pure returns (uint64 major, uint8 minor, uint8 endpointVersion)

VerificationState

enum VerificationState {
  Verifying,
  Verifiable,
  Verified
}

IReceiveUln301

assertHeader

function assertHeader(bytes _packetHeader, uint32 _localEid) external pure

addressSizes

function addressSizes(uint32 _dstEid) external view returns (uint256)

endpoint

function endpoint() external view returns (address)

verifiable

function verifiable(struct UlnConfig _config, bytes32 _headerHash, bytes32 _payloadHash) external view returns (bool)

getUlnConfig

function getUlnConfig(address _oapp, uint32 _remoteEid) external view returns (struct UlnConfig rtnConfig)

ReceiveUln301View

endpoint

contract ILayerZeroEndpoint endpoint

receiveUln301

contract IReceiveUln301 receiveUln301

localEid

uint32 localEid

initialize

function initialize(address _endpoint, uint32 _localEid, address _receiveUln301) external

executable

function executable(bytes _packetHeader, bytes32 _payloadHash) public view returns (enum ExecutionState)

verifiable

function verifiable(bytes _packetHeader, bytes32 _payloadHash) external view returns (enum VerificationState)

keeping the same interface as 302 a verifiable message requires it to be ULN verifiable only, excluding the endpoint verifiable check

SendLibBaseE1

send-side message library base contract on endpoint v1. design: 1/ it enforces the path definition on V1 and interacts with the nonce contract 2/ quote: first executor, then verifier (e.g. DVNs), then treasury 3/ send: first executor, then verifier (e.g. DVNs), then treasury. the treasury pay much be DoS-proof

nonceContract

contract INonceContract nonceContract

treasuryFeeHandler

contract ITreasuryFeeHandler treasuryFeeHandler

lzToken

address lzToken

PacketSent

event PacketSent(bytes encodedPayload, bytes options, uint256 nativeFee, uint256 lzTokenFee)

NativeFeeWithdrawn

event NativeFeeWithdrawn(address user, address receiver, uint256 amount)

LzTokenSet

event LzTokenSet(address token)

constructor

constructor(address _endpoint, uint256 _treasuryGasLimit, uint256 _treasuryNativeFeeCap, address _nonceContract, uint32 _localEid, address _treasuryFeeHandler) internal

send

function send(address _sender, uint64, uint16 _dstEid, bytes _path, bytes _message, address payable _refundAddress, address _lzTokenPaymentAddress, bytes _options) external payable

the abstract process for send() is: 1/ pay workers, which includes the executor and the validation workers 2/ pay treasury 3/ in EndpointV1, here we handle the fees and refunds

setLzToken

function setLzToken(address _lzToken) external

setTreasury

function setTreasury(address _treasury) external

withdrawFee

function withdrawFee(address _to, uint256 _amount) external

estimateFees

function estimateFees(uint16 _dstEid, address _sender, bytes _message, bool _payInLzToken, bytes _options) external view returns (uint256 nativeFee, uint256 lzTokenFee)

_assertPath

function _assertPath(address _sender, bytes _path, uint256 remoteAddressSize) internal pure

path = remoteAddress + localAddress.

_payLzTokenFee

function _payLzTokenFee(address _sender, uint256 _lzTokenFee) internal

_outbound

function _outbound(address _sender, uint16 _dstEid, bytes _path, bytes _message) internal returns (struct Packet packet)

_outbound does three things

asserts path
increments the nonce
assemble packet_

Return Values

Name	Type	Description
packet	struct Packet	to be sent to workers

_payWorkers

function _payWorkers(address _sender, uint16 _dstEid, bytes _path, bytes _message, bytes _options) internal returns (bytes encodedPacket, uint256 totalNativeFee)

1/ handle executor 2/ handle other workers

_payVerifier

function _payVerifier(struct Packet _packet, struct WorkerOptions[] _options) internal virtual returns (uint256 otherWorkerFees, bytes encodedPacket)

SendUln301

CONFIG_TYPE_EXECUTOR

uint256 CONFIG_TYPE_EXECUTOR

CONFIG_TYPE_ULN

uint256 CONFIG_TYPE_ULN

LZ_ULN_InvalidConfigType

error LZ_ULN_InvalidConfigType(uint256 configType)

constructor

constructor(address _endpoint, uint256 _treasuryGasLimit, uint256 _treasuryGasForFeeCap, address _nonceContract, uint32 _localEid, address _treasuryFeeHandler) public

setConfig

function setConfig(uint16 _eid, address _oapp, uint256 _configType, bytes _config) external

getConfig

function getConfig(uint16 _eid, address _oapp, uint256 _configType) external view returns (bytes)

version

function version() external pure returns (uint64 major, uint8 minor, uint8 endpointVersion)

isSupportedEid

function isSupportedEid(uint32 _eid) external view returns (bool)

_quoteVerifier

function _quoteVerifier(address _sender, uint32 _dstEid, struct WorkerOptions[] _options) internal view returns (uint256)

_payVerifier

function _payVerifier(struct Packet _packet, struct WorkerOptions[] _options) internal virtual returns (uint256 otherWorkerFees, bytes encodedPacket)

_splitOptions

function _splitOptions(bytes _options) internal pure returns (bytes, struct WorkerOptions[])

this function will split the options into executorOptions and validationOptions

TreasuryFeeHandler

endpoint

contract ILayerZeroEndpoint endpoint

LZ_TreasuryFeeHandler_OnlySendLibrary

error LZ_TreasuryFeeHandler_OnlySendLibrary()

LZ_TreasuryFeeHandler_OnlyOnSending

error LZ_TreasuryFeeHandler_OnlyOnSending()

LZ_TreasuryFeeHandler_InvalidAmount

error LZ_TreasuryFeeHandler_InvalidAmount(uint256 required, uint256 supplied)

constructor

constructor(address _endpoint) public

payFee

function payFee(address _lzToken, address _sender, uint256 _required, uint256 _supplied, address _treasury) external

IMessageLibE1

extends ILayerZeroMessagingLibrary instead of ILayerZeroMessagingLibraryV2 for reducing the contract size

LZ_MessageLib_InvalidPath

error LZ_MessageLib_InvalidPath()

LZ_MessageLib_InvalidSender

error LZ_MessageLib_InvalidSender()

LZ_MessageLib_InsufficientMsgValue

error LZ_MessageLib_InsufficientMsgValue()

LZ_MessageLib_LzTokenPaymentAddressMustBeSender

error LZ_MessageLib_LzTokenPaymentAddressMustBeSender()

setLzToken

function setLzToken(address _lzToken) external

setTreasury

function setTreasury(address _treasury) external

withdrawFee

function withdrawFee(address _to, uint256 _amount) external

version

function version() external view returns (uint64 major, uint8 minor, uint8 endpointVersion)

INonceContract

increment

function increment(uint16 _chainId, address _ua, bytes _path) external returns (uint64)

ITreasuryFeeHandler

payFee

function payFee(address _lzToken, address _sender, uint256 _required, uint256 _supplied, address _treasury) external

IUltraLightNode301

commitVerification

function commitVerification(bytes _packet, uint256 _gasLimit) external

NonceContractMock

OnlySendLibrary

error OnlySendLibrary()

endpoint

contract ILayerZeroEndpoint endpoint

outboundNonce

mapping(uint16 => mapping(bytes => uint64)) outboundNonce

constructor

constructor(address _endpoint) public

increment

function increment(uint16 _chainId, address _ua, bytes _path) external returns (uint64)

ReceiveUln302

This is a gluing contract. It simply parses the requests and forward to the super.impl() accordingly. In this case, it combines the logic of ReceiveUlnBase and ReceiveLibBaseE2

CONFIG_TYPE_ULN

uint32 CONFIG_TYPE_ULN

CONFIG_TYPE_ULN=2 here to align with SendUln302/ReceiveUln302/ReceiveUln301

LZ_ULN_InvalidConfigType

error LZ_ULN_InvalidConfigType(uint32 configType)

constructor

constructor(address _endpoint) public

supportsInterface

function supportsInterface(bytes4 _interfaceId) public view returns (bool)

setConfig

function setConfig(address _oapp, struct SetConfigParam[] _params) external

commitVerification

function commitVerification(bytes _packetHeader, bytes32 _payloadHash) external

dont need to check endpoint verifiable here to save gas, as it will reverts if not verifiable.

verify

function verify(bytes _packetHeader, bytes32 _payloadHash, uint64 _confirmations) external

for dvn to verify the payload

getConfig

function getConfig(uint32 _eid, address _oapp, uint32 _configType) external view returns (bytes)

isSupportedEid

function isSupportedEid(uint32 _eid) external view returns (bool)

version

function version() external pure returns (uint64 major, uint8 minor, uint8 endpointVersion)

VerificationState

enum VerificationState {
  Verifying,
  Verifiable,
  Verified,
  NotInitializable
}

IReceiveUln302

assertHeader

function assertHeader(bytes _packetHeader, uint32 _localEid) external pure

verifiable

function verifiable(struct UlnConfig _config, bytes32 _headerHash, bytes32 _payloadHash) external view returns (bool)

getUlnConfig

function getUlnConfig(address _oapp, uint32 _remoteEid) external view returns (struct UlnConfig rtnConfig)

ReceiveUln302View

receiveUln302

contract IReceiveUln302 receiveUln302

localEid

uint32 localEid

initialize

function initialize(address _endpoint, address _receiveUln302) external

verifiable

function verifiable(bytes _packetHeader, bytes32 _payloadHash) external view returns (enum VerificationState)

a ULN verifiable requires it to be endpoint verifiable and committable

_endpointVerifiable

function _endpointVerifiable(struct Origin origin, address _receiver, bytes32 _payloadHash) internal view returns (bool)

checks for endpoint verifiable and endpoint has payload hash

SendUln302

This is a gluing contract. It simply parses the requests and forward to the super.impl() accordingly. In this case, it combines the logic of SendUlnBase and SendLibBaseE2

CONFIG_TYPE_EXECUTOR

uint32 CONFIG_TYPE_EXECUTOR

CONFIG_TYPE_ULN

uint32 CONFIG_TYPE_ULN

LZ_ULN_InvalidConfigType

error LZ_ULN_InvalidConfigType(uint32 configType)

constructor

constructor(address _endpoint, uint256 _treasuryGasLimit, uint256 _treasuryGasForFeeCap) public

setConfig

function setConfig(address _oapp, struct SetConfigParam[] _params) external

getConfig

function getConfig(uint32 _eid, address _oapp, uint32 _configType) external view returns (bytes)

version

function version() external pure returns (uint64 major, uint8 minor, uint8 endpointVersion)

isSupportedEid

function isSupportedEid(uint32 _eid) external view returns (bool)

_quoteVerifier

function _quoteVerifier(address _sender, uint32 _dstEid, struct WorkerOptions[] _options) internal view returns (uint256)

_payVerifier

function _payVerifier(struct Packet _packet, struct WorkerOptions[] _options) internal returns (uint256 otherWorkerFees, bytes encodedPacket)

_splitOptions

function _splitOptions(bytes _options) internal pure returns (bytes, struct WorkerOptions[])

this function will split the options into executorOptions and validationOptions

WorkerUpgradeable

MESSAGE_LIB_ROLE

bytes32 MESSAGE_LIB_ROLE

ALLOWLIST

bytes32 ALLOWLIST

DENYLIST

bytes32 DENYLIST

ADMIN_ROLE

bytes32 ADMIN_ROLE

workerFeeLib

address workerFeeLib

allowlistSize

uint64 allowlistSize

defaultMultiplierBps

uint16 defaultMultiplierBps

priceFeed

address priceFeed

supportedOptionTypes

mapping(uint32 => uint8[]) supportedOptionTypes

__Worker_init

function __Worker_init(address[] _messageLibs, address _priceFeed, uint16 _defaultMultiplierBps, address _roleAdmin, address[] _admins) internal

Parameters

Name	Type	Description
_messageLibs	address[]	array of message lib addresses that are granted the MESSAGE_LIB_ROLE
_priceFeed	address	price feed address
_defaultMultiplierBps	uint16	default multiplier for worker fee
_roleAdmin	address	address that is granted the DEFAULT_ADMIN_ROLE (can grant and revoke all roles)
_admins	address[]	array of admin addresses that are granted the ADMIN_ROLE

__Worker_init_unchained

function __Worker_init_unchained(address[] _messageLibs, address _priceFeed, uint16 _defaultMultiplierBps, address _roleAdmin, address[] _admins) internal

onlyAcl

modifier onlyAcl(address _sender)

hasAcl

function hasAcl(address _sender) public view returns (bool)

_Access control list using allowlist and denylist

if one address is in the denylist -> deny
else if address in the allowlist OR allowlist is empty (allows everyone)-> allow
else deny_

Parameters

Name	Type	Description
_sender	address	address to check

setPaused

function setPaused(bool _paused) external

flag to pause execution of workers (if used with whenNotPaused modifier)

Parameters

Name	Type	Description
_paused	bool	true to pause, false to unpause

setPriceFeed

function setPriceFeed(address _priceFeed) external

Parameters

Name	Type	Description
_priceFeed	address	price feed address

setWorkerFeeLib

function setWorkerFeeLib(address _workerFeeLib) external

Parameters

Name	Type	Description
_workerFeeLib	address	worker fee lib address

setDefaultMultiplierBps

function setDefaultMultiplierBps(uint16 _multiplierBps) external

Parameters

Name	Type	Description
_multiplierBps	uint16	default multiplier for worker fee

withdrawFee

function withdrawFee(address _lib, address _to, uint256 _amount) external

supports withdrawing fee from ULN301, ULN302 and more

Parameters

Name	Type	Description
_lib	address	message lib address
_to	address	address to withdraw fee to
_amount	uint256	amount to withdraw

withdrawToken

function withdrawToken(address _token, address _to, uint256 _amount) external

supports withdrawing token from the contract

Parameters

Name	Type	Description
_token	address	token address
_to	address	address to withdraw token to
_amount	uint256	amount to withdraw

setSupportedOptionTypes

function setSupportedOptionTypes(uint32 _eid, uint8[] _optionTypes) external

getSupportedOptionTypes

function getSupportedOptionTypes(uint32 _eid) external view returns (uint8[])

_grantRole

function _grantRole(bytes32 _role, address _account) internal

overrides AccessControl to allow for counting of allowlistSize

Parameters

Name	Type	Description
_role	bytes32	role to grant
_account	address	address to grant role to

_revokeRole

function _revokeRole(bytes32 _role, address _account) internal

overrides AccessControl to allow for counting of allowlistSize

Parameters

Name	Type	Description
_role	bytes32	role to revoke
_account	address	address to revoke role from

renounceRole

function renounceRole(bytes32, address) public pure

overrides AccessControl to disable renouncing of roles

LayerZero for EVM

Contract Standards

Technical Reference

Troubleshooting

Resources

​EndpointV2

​lzToken

​delegates

​constructor

​Parameters

​quote

​Parameters

​send

​Parameters

​_send

​Parameters

​verify

​Parameters

​lzReceive

​Parameters

​lzReceiveAlert

​Parameters

​clear

​Parameters

​setLzToken

​Parameters

​recoverToken

​Parameters

​_payToken

​Parameters

​_payNative

​Parameters

​_suppliedLzToken

​_suppliedNative

​_assertMessagingFee

​nativeToken

​Return Values

​setDelegate

​_initializable

​_verifiable

​_assertAuthorized

​initializable

​verifiable

​EndpointV2Alt

​LZ_OnlyAltToken

​nativeErc20

​constructor

​_payNative

​Parameters

​_suppliedNative

​setLzToken

​nativeToken

​Return Values

​EndpointV2View

​initialize

​ExecutionState

​EndpointV2ViewUpgradeable

​EMPTY_PAYLOAD_HASH

​NIL_PAYLOAD_HASH

​endpoint

​__EndpointV2View_init

​__EndpointV2View_init_unchained

​initializable

​verifiable

​executable

​Return Values

​MessageLibManager

​blockedLibrary

​registeredLibraries

​isRegisteredLibrary

​sendLibrary

​receiveLibrary

​receiveLibraryTimeout

​defaultSendLibrary

​defaultReceiveLibrary

​defaultReceiveLibraryTimeout

​constructor

​onlyRegistered

​isSendLib

​isReceiveLib

EndpointV2

lzToken

delegates

constructor

Parameters

quote

Parameters

send

Parameters

_send

Parameters

verify

Parameters

lzReceive

Parameters

lzReceiveAlert

Parameters

clear

Parameters

setLzToken

Parameters

recoverToken

Parameters

_payToken

Parameters

_payNative

Parameters

_suppliedLzToken

_suppliedNative

_assertMessagingFee

nativeToken

Return Values

setDelegate

_initializable

_verifiable

_assertAuthorized

initializable

verifiable

EndpointV2Alt

LZ_OnlyAltToken

nativeErc20

constructor

_payNative

Parameters

_suppliedNative

setLzToken

nativeToken

Return Values

EndpointV2View

initialize

ExecutionState

EndpointV2ViewUpgradeable

EMPTY_PAYLOAD_HASH

NIL_PAYLOAD_HASH

endpoint

__EndpointV2View_init

__EndpointV2View_init_unchained

initializable

verifiable

executable

Return Values

MessageLibManager

blockedLibrary

registeredLibraries

isRegisteredLibrary

sendLibrary

receiveLibrary

receiveLibraryTimeout

defaultSendLibrary

defaultReceiveLibrary

defaultReceiveLibraryTimeout

constructor

onlyRegistered

isSendLib

isReceiveLib

onlyRegisteredOrDefault

onlySupportedEid

getRegisteredLibraries

getSendLibrary

Parameters