LayerZero Glossary

The native blockchain identifier assigned by the network. This is distinct from LayerZero's Endpoint ID (EID), which is the protocol's internal identifier used to route messages between chains.

A dedicated message pathway in LayerZero defined by four specific components: the sender OApp (source application contract), the source endpoint ID, the destination endpoint ID, and the receiver OApp (destination application contract).

The ability to combine multiple cross-chain operations into a single transaction. Composition allows for complex cross-chain interactions while maintaining transaction integrity across multiple chains.

A Composer is the smart contract that is responsible for executing a compose message.

An escrow account is a financial arrangement where a third party, holds funds or assets on behalf of another until specific conditions are met.

The traditional form of smart contract composability, where multiple function calls are stacked within a single transaction. In vertical composability, all operations must succeed together or the entire transaction reverts, providing atomic execution.

LayerZero’s horizontal cross-chain composability allows a receiving contract to break execution into independent atomic steps using endpoint.sendCompose and ILayerZeroComposer, where each step can succeed or fail independently rather than requiring all-or-nothing execution. This enables flexible cross-chain workflows that can continue despite partial failures.

A CPI in Solana is when one program calls the instruction of another program.

The blockchain network that receives and processes a LayerZero message. The destination chain hosts the contract that will execute the received message's instructions through its lzReceive function.

A network of independent verifiers that validate message integrity between chains. DVNs are part of LayerZero's modular security model, allowing applications to configure multiple verification schemes for their messages.

A placeholder DVN used when the default LayerZero configuration is inactive for a specific pathway. Dead DVNs appear when new chains are added before default providers support every pathway. They function as null addresses - no verification will match, and messages will be blocked until the Dead DVN is replaced with a functional DVN.

The core, immutable smart contract deployed on each blockchain that serves as the entry and exit point for LayerZero messages. The Endpoint provides standardized interfaces for sending, receiving, and configuring messages.

A variant of the LayerZero Endpoint (EndpointV2Alt) designed for blockchains where an ERC20 token serves as the de facto native currency for fee payments. While the standard Endpoint processes fees via the chain's native token sent as msg.value, Endpoint Alt accepts fees exclusively through ERC20 token transfers. This enables LayerZero to support chains where the native token has no economic value.

Endpoint ID (EID) is LayerZero's internal identifier used to route messages between chains. Each Endpoint contract has a unique EID for determining which chain's endpoint to send to or receive messages from.

A committer (also referred to as the Sealer in some API responses) is an off-chain process that monitors a cross-chain message and, once it receives the required confirmations from the configured DVNs, submits a commit transaction to the destination chain.

An off-chain, permissionless service that monitors message verification and ensures seamless execution of omnichain messages on the destination chain, following the OApp owner’s instructions and handling gas and delivery when all required DVNs have verified the message.

A unique identifier generated for each LayerZero message that combines the message's nonce, source chain, destination chain, and participating contracts. GUIDs ensure messages can be tracked across the network and prevent replay attacks.

A mechanism that tracks the highest consecutively delivered message number for a channel. All messages before lazyNonce have been verified, and messages are executed sequentially from lazyNonce. This ensures lossless delivery while allowing parallel verification.

The file that declares an OApp’s configuration, including pathways, DVNs, and more. By default named layerzero.config.ts, its name can be arbitrary. The LayerZero CLI references it via the --oapp-config flag when needed.

A function that enables horizontal composition by allowing a received message to trigger additional cross-chain messages. These composed messages are processed sequentially, creating chains of cross-chain operations.

Allows an OApp to request, receive and compute data from another blockchain by specifying the target chain and the block from which the state needs to be retrieved (including all historical data).

The standard function implemented by LayerZero-compatible contracts to process incoming messages. When a message is delivered, the destination chain's Endpoint calls lzReceive on the target contract with the decoded message data.

The primary function used by the sender OApp to send messages through LayerZero. OApps call endpoint.send() on their local Endpoint, providing the destination details and message payload. The function initiates the cross-chain messaging process.

LayerZero's network topology where every supported blockchain can directly communicate with every other supported blockchain. This creates a fully connected network without requiring intermediate chains or bridges.

Smart contracts that pack messages on the source chain and verify them on the destination chain. MessageLibs are immutable and append-only, letting protocols add new verification methods without altering existing ones. The Ultra-Light Node (ULN) is the default MessageLib.

A required parameter in LayerZero transactions that specifies how messages should be handled on the destination chain.

OApp-level options that must be included on every message to enforce minimum gas limits for a pathway, combined with per-transaction options during sends

Per transaction options passed in send. Merged with enforced options to adjust gas/behavior or supply msg.value.

A unique identifier for the message within specific messaging channel. Prevents replay attacks and censorship by defining a strong gapless ordering between all nonces in each channel. Each channel maintains its own independent nonce counter.

A Message Option that lets the sender drop a specified amount of native tokens to a receiver on the destination chain, providing gas for transactions. The amount is specified in the chain’s smallest unit and sent directly to the receiver during message execution.

A smart contract that implements LayerZero's messaging interface for cross-chain communication. The base contract type for building omnichain applications.

OFT is a token standard that extends existing fungible token standards with LayerZero messaging, enabling seamless transfers across blockchains while maintaining a unified total supply. Tokens are debited (burned or locked) on the source chain and credited (minted or unlocked) on the destination chain.

An OFT Adapter enables an existing token (e.g. ERC-20, SPL token) to function as an OFT. The OFT Adapter contract serves as a lockbox for the original token.

The core protocol that enables secure cross-chain communication. An OMP provides the fundamental messaging capabilities that higher-level applications build upon.

Omnichain Non-Fungible Token - A token standard that extends ERC721 with LayerZero's messaging capabilities, enabling NFT transfers across different blockchains while maintaining their unique properties and ownership history.

The standardized formatted data structure for messages in LayerZero, containing the message payload along with routing and verification information. Packets include fields like nonce, source chain, destination chain and the actual message data.

The actual data being sent in a cross-chain LayerZero message. This could be token transfer information, function calls, or any other data the application needs to transmit between chains.

A pathway is a configured route between two OApp deployments on different chains that enables cross-chain messaging. It is directional, defined by the source and destination OApps and their chains, and can have its own security configuration.

A peer is a trusted OApp address on another blockchain for a specific pathway, authorized to send messages to your OApp. Incoming messages are validated against the configured peer for the source chain.

A PDA is a Solana account owned by a program and derived using seeds.

The combination of MessageLib, DVNs, and other security parameters that an application configures for its cross-chain messages. Each application can (and should) customize its security stack to balance security, cost, and performance.

The blockchain from which a cross-chain message is being sent.

The default MessageLib in LayerZero that implements a flexible verification system using configurable DVN sets. ULN allows applications to specify required and optional verifiers along with confirmation thresholds.

"Wiring" in LayerZero is the process of connecting OApps across blockchains to enable cross-chain communication by setting peers, configuring DVNs, and message execution settings via transactions on each chain.

A general term for offchain or onchain components that perform specific tasks in the LayerZero network, including executors and DVNs.

A configurable security model pattern where: • X: Number of required DVNs—specific verifiers that must always verify a message. • Y: Total DVNs needed for a message to be verified, including required DVNs (X) plus a threshold of optional, fungible DVNs. • N: Total pool of available DVNs for verification, including both required and optional DVNs.

An address that an Omnichain Application (OApp) authorizes to act on its behalf within LayerZero's protocol. Specifically, Authorization and Permissions

The "lowest common denominator" of decimal precision across all chains in the OFT system. It limits how many decimal places can be reliably represented when moving tokens cross chain. Default is 6, but total supply exceeds (2⁶⁴–1) / 10^6, you can override sharedDecimals().

A composable cross-chain liquidity transport protocol built on LayerZero V2 that enables seamless asset transfers through unified liquidity pools.

The number of decimal places a token natively supports on the source chain. Tokens on different VMs may use different integer sizes (e.g. uint256 vs uint64), so local decimals capture each chain's native precision.

The scaling factor used to "clean" a local decimal token amount down to the shared decimal precision before cross chain transfer, and to scale it back on the destination chain.

The tiny remainder that gets dropped when you scale a token amount down to the shared decimal precision. In other words, any fractional units smaller than 1 / rate (where rate = 10^(localDecimals – sharedDecimals)) become "dust."