Transceivers Contracts Reference (EVM)＃

The NTT Transceiver contracts are responsible for sending and receiving messages between chains as part of the NTT protocol. They support multiple verification methods and operate alongside the NTT Manager to enable cross-chain token transfers.

Structure Overview＃

The NTT Transceiver system is built using a layered inheritance structure with the base Transceiver contract providing common functionality and specific implementations like WormholeTransceiver adding protocol-specific features.

WormholeTransceiver.sol
├── IWormholeTransceiver.sol
├── IWormholeReceiver.sol
└── WormholeTransceiverState.sol
    ├── IWormholeTransceiverState.sol
    └── Transceiver.sol
        ├── ITransceiver.sol
        ├── PausableOwnable.sol
        ├── ReentrancyGuardUpgradeable.sol
        └── Implementation.sol

Key Components:

Transceiver.sol: Base abstract contract providing common transceiver functionality including message transmission, ownership management, and upgrade capabilities.
WormholeTransceiver.sol: Concrete implementation for Wormhole protocol, handling message verification through Wormhole Core and supporting multiple delivery methods (standard relaying, custom relaying, manual).
WormholeTransceiverState.sol: State management contract for Wormhole-specific storage including peer registration, relaying configuration, and VAA consumption tracking.
PausableOwnable.sol: Provides ownership and emergency pause functionality.
ReentrancyGuardUpgradeable.sol: Protects against reentrancy attacks in an upgradeable context.
Implementation.sol: Handles proxy implementation logic for upgradeable contracts.

State Variables＃

Core Identification＃

nttManager address: Immutable address of the NTT Manager that this transceiver is tied to.
nttManagerToken address: Immutable address of the token associated with the NTT deployment.
deployer address: Immutable address of the contract deployer.

Version＃

WORMHOLE_TRANSCEIVER_VERSION string: Version string of the WormholeTransceiver implementation.

Messaging and Relaying Configuration＃

consistencyLevel uint8: Immutable Wormhole consistency level for message finality.
wormhole IWormhole: Immutable reference to the Wormhole Core bridge contract.
wormholeRelayer IWormholeRelayer: Immutable reference to the Wormhole Relayer contract.
specialRelayer ISpecialRelayer: Immutable reference to a custom relayer contract.
gasLimit uint256: Immutable gas limit for cross-chain message delivery.

Peer Configuration and Replay Protection＃

WORMHOLE_CONSUMED_VAAS_SLOT mapping(bytes32 ⇒ bool): Tracks consumed VAA hashes for replay protection. Exposed via isVAAConsumed.
WORMHOLE_PEERS_SLOT mapping(uint16 ⇒ bytes32): Wormhole chain ID → peer transceiver address. Exposed via getWormholePeer.
WORMHOLE_RELAYING_ENABLED_CHAINS_SLOT mapping(uint16 ⇒ BooleanFlag): Per-chain flag for enabling standard relaying. Exposed via isWormholeRelayingEnabled.
SPECIAL_RELAYING_ENABLED_CHAINS_SLOT mapping(uint16 ⇒ BooleanFlag): Per-chain flag for enabling special relaying. Exposed via isSpecialRelayingEnabled.
WORMHOLE_EVM_CHAIN_IDS mapping(uint16 ⇒ BooleanFlag): Per-chain EVM-compatibility flag used to choose the relaying path. Exposed via isWormholeEvmChain.

Events＃

NotPaused＃

Emitted when the contract is unpaused. (Defined in PausableUpgradeable.sol)

event NotPaused(bool notPaused)

Parameters

notPaused bool

Whether the contract is not paused.

OwnershipTransferred＃

Emitted when ownership is transferred. (Defined in OwnableUpgradeable.sol)

event OwnershipTransferred(address indexed previousOwner, address indexed newOwner)

Parameters

previousOwner address

The address of the previous owner.

newOwner address

The address of the new owner.

Paused＃

Emitted when the contract is paused. (Defined in PausableUpgradeable.sol)

event Paused(bool paused)

Parameters

paused bool

Whether the contract is paused.

PauserTransferred＃

Emitted when the pauser capability is transferred. (Defined in PausableUpgradeable.sol)

event PauserTransferred(address indexed oldPauser, address indexed newPauser)

Parameters

oldPauser address

The address of the previous pauser.

newPauser address

The address of the new pauser.

ReceivedMessage＃

Emitted when a message is received. (Defined in IWormholeTransceiver.sol)

event ReceivedMessage(
    bytes32 digest,
    uint16 emitterChainId,
    bytes32 emitterAddress,
    uint64 sequence
)

Parameters

digest bytes32

The digest of the message.

emitterChainId uint16

The chain ID of the emitter.

emitterAddress bytes32

The address of the emitter.

sequence uint64

The sequence of the message.

ReceivedRelayedMessage＃

Emitted when a relayed message is received. (Defined in IWormholeTransceiver.sol)

event ReceivedRelayedMessage(
    bytes32 digest,
    uint16 emitterChainId,
    bytes32 emitterAddress
)

Parameters

digest bytes32

The digest of the message.

emitterChainId uint16

The chain ID of the emitter.

emitterAddress bytes32

The address of the emitter.

RelayingInfo＃

Emitted when a message is sent from the transceiver. (Defined in IWormholeTransceiverState.sol)

event RelayingInfo(
    uint8 relayingType,
    bytes32 refundAddress,
    uint256 deliveryPayment
)

Parameters

relayingType uint8

The type of relaying.

refundAddress bytes32

The refund address for unused gas.

deliveryPayment uint256

The amount of ether sent along with the tx to cover the delivery fee.

SendTransceiverMessage＃

Emitted when a message is sent from the transceiver. (Defined in IWormholeTransceiver.sol)

event SendTransceiverMessage(
    uint16 recipientChain,
    TransceiverStructs.TransceiverMessage message
)

Parameters

recipientChain uint16

The chain ID of the recipient.

message TransceiverStructs.TransceiverMessage

The message.

TransceiverMessage type

sourceNttManagerAddress bytes32

The address of the source NTT Manager.

recipientNttManagerAddress bytes32

The address of the recipient NTT Manager.

nttManagerPayload bytes

The NTT Manager payload.

transceiverPayload bytes

The transceiver-specific payload.

SetIsSpecialRelayingEnabled＃

Emitted when special relaying is enabled for the given chain. (Defined in IWormholeTransceiverState.sol)

event SetIsSpecialRelayingEnabled(uint16 chainId, bool isRelayingEnabled)

Parameters

chainId uint16

The chain ID to set.

isRelayingEnabled bool

A boolean indicating whether special relaying is enabled.

SetIsWormholeEvmChain＃

Emitted when the EVM-compatibility flag is set for a chain. (Defined in IWormholeTransceiverState.sol)

event SetIsWormholeEvmChain(uint16 chainId, bool isEvm)

Parameters

chainId uint16

The chain ID to set.

isEvm bool

A boolean indicating whether relaying is enabled.

SetIsWormholeRelayingEnabled＃

Emitted when relaying is enabled for the given chain. (Defined in IWormholeTransceiverState.sol)

event SetIsWormholeRelayingEnabled(uint16 chainId, bool isRelayingEnabled)

Parameters

chainId uint16

The chain ID to set.

isRelayingEnabled bool

A boolean indicating whether relaying is enabled.

SetWormholePeer＃

Emitted when a peer transceiver is set. (Defined in IWormholeTransceiverState.sol)

event SetWormholePeer(uint16 chainId, bytes32 peerContract)

Parameters

chainId uint16

The chain ID of the peer.

peerContract bytes32

The address of the peer contract.

Functions＃

encodeWormholeTransceiverInstruction＃

Encodes the WormholeTransceiverInstruction into a byte array. (Defined in WormholeTransceiver.sol)

function encodeWormholeTransceiverInstruction(
    WormholeTransceiverInstruction memory instruction
) public pure returns (bytes memory)

Parameters

instruction WormholeTransceiverInstruction

The WormholeTransceiverInstruction to encode.

WormholeTransceiverInstruction type

shouldSkipRelayerSend bool

Whether to skip delivery via the relayer.

Returns

encoded bytes

The encoded instruction.

getMigratesImmutables＃

Returns whether the contract migrates immutables during upgrades. (Defined in Implementation.sol)

function getMigratesImmutables() public view returns (bool)

Returns

migratesImmutables bool

Whether the contract migrates immutables.

getNttManagerOwner＃

Returns the owner address of the NTT Manager that this transceiver is related to. (Defined in Transceiver.sol)

function getNttManagerOwner() public view returns (address)

Returns

owner address

The owner address of the NTT Manager.

getNttManagerToken＃

Returns the address of the token associated with this NTT deployment. (Defined in Transceiver.sol)

function getNttManagerToken() public view virtual returns (address)

Returns

token address

The address of the token.

getTransceiverType＃

Returns the string type of the transceiver. (Defined in WormholeTransceiver.sol)

function getTransceiverType() external pure returns (string memory)

Returns

transceiverType string

The type of the transceiver (e.g., "wormhole").

getWormholePeer＃

Returns the peer contract address for a given chain. (Defined in WormholeTransceiverState.sol)

function getWormholePeer(uint16 chainId) public view returns (bytes32)

Parameters

chainId uint16

The chain ID to query.

Returns

peerContract bytes32

The address of the peer contract on the given chain.

initialize＃

Initializes the contract implementation. Only callable through a delegate call. (Defined in Implementation.sol)

function initialize() external payable

isPaused＃

Returns whether the contract is currently paused. (Defined in PausableUpgradeable.sol)

function isPaused() public view returns (bool)

Returns

paused bool

Whether the contract is paused.

isSpecialRelayingEnabled＃

Returns whether special relaying is enabled for a given chain. (Defined in WormholeTransceiverState.sol)

function isSpecialRelayingEnabled(uint16 chainId) public view returns (bool)

Parameters

chainId uint16

The chain ID to query.

Returns

isEnabled bool

Whether special relaying is enabled.

isVAAConsumed＃

Returns whether a VAA has been consumed. (Defined in WormholeTransceiverState.sol)

function isVAAConsumed(bytes32 hash) public view returns (bool)

Parameters

hash bytes32

The hash of the VAA.

Returns

consumed bool

Whether the VAA has been consumed.

isWormholeEvmChain＃

Returns whether a chain is EVM compatible. (Defined in WormholeTransceiverState.sol)

function isWormholeEvmChain(uint16 chainId) public view returns (bool)

Parameters

chainId uint16

The chain ID to query.

Returns

isEvm bool

Whether the chain is EVM compatible.

isWormholeRelayingEnabled＃

Returns whether relaying is enabled for a given chain. (Defined in WormholeTransceiverState.sol)

function isWormholeRelayingEnabled(uint16 chainId) public view returns (bool)

Parameters

chainId uint16

The chain ID to query.

Returns

isEnabled bool

Whether relaying is enabled.

migrate＃

Migrates the contract to a new implementation. Only callable during upgrades through a delegate call. (Defined in Implementation.sol)

function migrate() external

parseWormholeTransceiverInstruction＃

Parses the encoded instruction and returns the instruction struct. (Defined in WormholeTransceiver.sol)

function parseWormholeTransceiverInstruction(
    bytes memory encoded
) public pure returns (WormholeTransceiverInstruction memory instruction)

Parameters

encoded bytes

The encoded instruction.

Returns

instruction WormholeTransceiverInstruction

The parsed WormholeTransceiverInstruction.

WormholeTransceiverInstruction type

shouldSkipRelayerSend bool

Whether to skip delivery via the relayer.

quoteDeliveryPrice＃

Fetches the delivery price for a given recipient chain transfer. (Defined in Transceiver.sol)

function quoteDeliveryPrice(
    uint16 recipientChain,
    TransceiverStructs.TransceiverInstruction memory instruction
) external view returns (uint256)

Parameters

recipientChain uint16

The Wormhole chain ID of the target chain.

instruction TransceiverStructs.TransceiverInstruction

An additional Instruction provided by the Transceiver to be executed on the recipient chain.

TransceiverInstruction type

index uint8

The index of the transceiver.

payload bytes

The instruction payload.

Returns

deliveryPrice uint256

The cost of delivering a message to the recipient chain, in this chain's native token.

owner＃

Returns the address of the current owner. (Defined in OwnableUpgradeable.sol)

function owner() public view returns (address)

Returns

owner address

The address of the current owner.

pauser＃

Returns the address of the current pauser. (Defined in PausableUpgradeable.sol)

function pauser() public view returns (address)

Returns

pauser address

The address of the current pauser.

receiveMessage＃

Receives an attested message from the verification layer. (Defined in WormholeTransceiver.sol)

function receiveMessage(bytes memory encodedMessage) external

Parameters

encodedMessage bytes

The attested message.

Emits: ReceivedMessage

receiveWormholeMessages＃

Receives and processes Wormhole messages via the relayer. Only callable by the relayer. (Defined in WormholeTransceiver.sol)

function receiveWormholeMessages(
    bytes memory payload,
    bytes[] memory additionalMessages,
    bytes32 sourceAddress,
    uint16 sourceChain,
    bytes32 deliveryHash
) external payable

Parameters

payload bytes

The message payload.

additionalMessages bytes[]

Additional messages array.

sourceAddress bytes32

The source address of the message.

sourceChain uint16

The source chain ID.

deliveryHash bytes32

The delivery hash.

Emits: ReceivedRelayedMessage

sendMessage＃

Sends a message to another chain. (Defined in Transceiver.sol)

function sendMessage(
    uint16 recipientChain,
    TransceiverStructs.TransceiverInstruction memory instruction,
    bytes memory nttManagerMessage,
    bytes32 recipientNttManagerAddress,
    bytes32 refundAddress
) external payable

Parameters

recipientChain uint16

The Wormhole chain ID of the recipient.

instruction TransceiverStructs.TransceiverInstruction

An additional Instruction provided by the Transceiver to be executed on the recipient chain.

TransceiverInstruction type

index uint8

The index of the transceiver.

payload bytes

The instruction payload.

nttManagerMessage bytes

A message to be sent to the nttManager on the recipient chain.

recipientNttManagerAddress bytes32

The Wormhole formatted address of the peer NTT Manager on the recipient chain.

refundAddress bytes32

The Wormhole formatted address of the refund recipient.

Emits: SendTransceiverMessage, RelayingInfo

setIsSpecialRelayingEnabled＃

Sets whether special relaying is enabled for the given chain. (Defined in WormholeTransceiverState.sol)

function setIsSpecialRelayingEnabled(uint16 chainId, bool isRelayingEnabled) external

Parameters

chainId uint16

The Wormhole chain ID to set.

isRelayingEnabled bool

A boolean indicating whether special relaying is enabled.

Emits: SetIsSpecialRelayingEnabled

setIsWormholeEvmChain＃

Sets whether the chain is EVM compatible. (Defined in WormholeTransceiverState.sol)

function setIsWormholeEvmChain(uint16 chainId, bool isEvm) external

Parameters

chainId uint16

The Wormhole chain ID to set.

isEvm bool

A boolean indicating whether the chain is an EVM chain.

Emits: SetIsWormholeEvmChain

setIsWormholeRelayingEnabled＃

Sets whether Wormhole relaying is enabled for the given chain. (Defined in WormholeTransceiverState.sol)

function setIsWormholeRelayingEnabled(uint16 chainId, bool isRelayingEnabled) external

Parameters

chainId uint16

The Wormhole chain ID to set.

isRelayingEnabled bool

A boolean indicating whether relaying is enabled.

Emits: SetIsWormholeRelayingEnabled

setWormholePeer＃

Sets the Wormhole peer contract for the given chain. (Defined in WormholeTransceiverState.sol)

function setWormholePeer(uint16 chainId, bytes32 peerContract) external payable

Parameters

chainId uint16

The Wormhole chain ID of the peer to set.

peerContract bytes32

The address of the peer contract on the given chain.

Emits: SetWormholePeer

transferOwnership＃

Transfers ownership of the contract to a new account. Can only be called by the current owner. (Defined in OwnableUpgradeable.sol)

function transferOwnership(address newOwner) public

Parameters

newOwner address

The address of the new owner.

Emits: OwnershipTransferred

transferPauserCapability＃

Transfers the ability to pause to a new account. (Defined in PausableOwnable.sol)

function transferPauserCapability(address newPauser) public

Parameters

newPauser address

The address of the new pauser.

Emits: PauserTransferred

transferTransceiverOwnership＃

Transfers the ownership of the transceiver to a new address. (Defined in Transceiver.sol)

function transferTransceiverOwnership(address newOwner) external

Parameters

newOwner address

The address of the new owner.

Emits: OwnershipTransferred

upgrade＃

Upgrades the transceiver to a new implementation. (Defined in Transceiver.sol)

function upgrade(address newImplementation) external

Parameters

newImplementation address

The address of the new implementation contract.

Errors＃

CallerNotNttManager＃

The caller is not the NttManager. (Defined in ITransceiver.sol)

error CallerNotNttManager(address caller);

Parameters

caller address

The address of the caller.

CallerNotRelayer＃

The caller is not the relayer. (Defined in IWormholeTransceiverState.sol)

error CallerNotRelayer(address caller);

Parameters

caller address

The caller.

CannotRenounceTransceiverOwnership＃

Error when trying renounce transceiver ownership. (Defined in ITransceiver.sol)

error CannotRenounceTransceiverOwnership(address currentOwner);

Parameters

currentOwner address

The current owner of the transceiver.

CannotTransferTransceiverOwnership＃

Error when trying to transfer transceiver ownership. (Defined in ITransceiver.sol)

error CannotTransferTransceiverOwnership(address currentOwner, address newOwner);

Parameters

currentOwner address

The current owner of the transceiver.

newOwner address

The new owner of the transceiver.

InvalidPauser＃

The pauser is not a valid pauser account. (Defined in PausableUpgradeable.sol)

error InvalidPauser(address account);

Parameters

account address

The invalid pauser account.

InvalidRelayingConfig＃

Error when the relaying configuration is invalid. (Defined in IWormholeTransceiver.sol)

error InvalidRelayingConfig(uint16 chainId);

Parameters

chainId uint16

The chain ID that is invalid.

InvalidVaa＃

Error if the VAA is invalid. (Defined in IWormholeTransceiverState.sol)

error InvalidVaa(string reason);

Parameters

reason string

The reason the VAA is invalid.

InvalidWormholeChainIdZero＃

The chain ID cannot be zero. (Defined in IWormholeTransceiverState.sol)

error InvalidWormholeChainIdZero();

InvalidWormholePeer＃

Error when the peer transceiver is invalid. (Defined in IWormholeTransceiver.sol)

error InvalidWormholePeer(uint16 chainId, bytes32 peerAddress);

Parameters

chainId uint16

The chain ID of the peer.

peerAddress bytes32

The address of the invalid peer.

InvalidWormholePeerZeroAddress＃

Error the peer contract cannot be the zero address. (Defined in IWormholeTransceiverState.sol)

error InvalidWormholePeerZeroAddress();

NotMigrating＃

The contract is not currently migrating. (Defined in Implementation.sol)

error NotMigrating();

OnlyDelegateCall＃

Function can only be called through delegate call. (Defined in Implementation.sol)

error OnlyDelegateCall();

OwnableInvalidOwner＃

The owner is not a valid owner account. (Defined in OwnableUpgradeable.sol)

error OwnableInvalidOwner(address owner);

Parameters

owner address

The invalid owner address.

OwnableUnauthorizedAccount＃

The caller account is not authorized to perform an operation. (Defined in OwnableUpgradeable.sol)

error OwnableUnauthorizedAccount(address account);

Parameters

account address

The unauthorized account.

RequireContractIsNotPaused＃

Contract is not paused, functionality is unblocked. (Defined in PausableUpgradeable.sol)

error RequireContractIsNotPaused();

RequireContractIsPaused＃

Contract state is paused, blocking functionality. (Defined in PausableUpgradeable.sol)

error RequireContractIsPaused();

PeerAlreadySet＃

Error if the peer has already been set. (Defined in IWormholeTransceiverState.sol)

error PeerAlreadySet(uint16 chainId, bytes32 peerAddress);

Parameters

chainId uint16

The chain ID of the peer.

peerAddress bytes32

The address of the peer.

UnexpectedAdditionalMessages＃

Additional messages are not allowed. (Defined in IWormholeTransceiverState.sol)

error UnexpectedAdditionalMessages();

TransferAlreadyCompleted＃

The transfer has already been completed. (Defined in IWormholeTransceiverState.sol)

error TransferAlreadyCompleted(bytes32 digest);

Parameters

digest bytes32

The digest of the completed transfer message.

UnexpectedRecipientNttManagerAddress＃

The recipient NTT Manager address in the message does not match this transceiver’s NTT Manager. (Defined in IWormholeTransceiverState.sol)

error UnexpectedRecipientNttManagerAddress(bytes32 recipientNttManagerAddress);

Parameters

recipientNttManagerAddress bytes32

The unexpected NTT Manager address from the message.

InvalidFork＃

The current EVM chain ID does not match the stored chain ID, indicating a possible fork. (Defined in IWormholeTransceiverState.sol)

error InvalidFork(uint256 expectedChainId, uint256 actualChainId);

Parameters

expectedChainId uint256

The chain ID stored at deployment.

actualChainId uint256

The chain ID returned by the current network.