LayerZero Message Passing Explained: How Omnichain Apps Work (v2, ULN, Oracles & Relayers) ∙ Kolo

How Layer-Zero Message Passing Enables Truly Cross-Chain Apps

LayerZero cross chain message in 2025: Check out core features, how it works, and why it can skyrocket the modern-day DApps.
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Let's not rush out of the gate and start with understanding the term LayerZero cross-chain messaging. What is meant here is a blockchain messaging protocol that enables apps to unlock communication across more than 70 networks.

Plain English for that? The protocol allows for direct interaction between chains through an advanced security model and modular architecture capabilities. Official stats indicate that in 2024, the solution was involved in transactions exceeding $25 billion.

Today's article will guide you through all the intricacies of cross chain messaging, how it works, and its use cases in the world of Web3 apps.

Key Takeaways

We're already aware that LayerZero solves key cross-chain challenges through a relatively lightweight and secure architecture. Below, you'll find the fundamental features that describe the tool, its usage stats, and practical aspects:

It enables native messaging between 70+ blockchains
Uses Ultra Light Nodes for cost-efficient messaging
Supports custom security via Decentralized Verifier Networks
OFTs maintain unified token supply across chains
No wrapped tokens or asset custody required
Over $25B in cross-chain volume processed
Stargate and Radiant use the protocol for liquidity
Message flow includes oracles, relayers, endpoints, and executors

Each of the above features has a direct connection to the LayerZero ecosystem, complementing and improving the solution. The following sections will detail its core purpose and design, which are actively used in the Web3 space.

What Is LayerZero?

Okay, let's make haste slowly and take a minute to answer "What is Layer Zero?" for a start. This is nothing less than a cross-chain messaging protocol. Its aim? Lies in allowing dApps (decentralized applications) to interact with different blockchains natively. In fact, it all goes around solving the so-called interoperability challenges without the need to use wrapped tokens, custodians, or any third-party bridges.

LayerZero message passing eliminates all the flaws of manually bridging assets or duplicating token supply. Instead, it lets smart contracts send direct messages and execute their conditions across chains.

As a result, developers gain broad opportunities to create apps that function as a holistic ecosystem. The solution has already proven its worth on over 70 supported networks, including Ethereum, Arbitrum, Optimism, Solana, BNB Chain, and beyond.

Here are the core features of the protocol to keep in mind:

Connects 70+ blockchains directly
Uses lightweight Ultra Light Nodes
Noncustodial and immutable protocol
Supports secure omnichain token transfers
Customizable security via verifier networks
Trusted by major DeFi and LST protocols

Key takeaway: The technology provides a secure method for exchanging messages between smart contracts. It enables the seamless operation of cross-chain dApps without the need for extra means, such as bridges or wrapped assets.

Why Cross-Chain Interoperability Matters

Now, let's explore how the protocol can work favorably for users and developers. Most retailers interact with blockchain networks, such as Ethereum and Solana, as isolated ecosystems. LayerZero expands the horizons of possibilities by uniting networks into a single, seamless interface.

Need more arguments for it? See the table below:


Reason	Why It Matters
Unified liquidity	Reduces slippage and improves trading depth
Cross-chain DeFi strategies	Enables borrowing and lending across chains
Better dApp UX	No bridging or wallet switching needed
Native asset transfers	Avoids wrapped tokens and third-party risks
Inter-chain composability	Apps interact across chains as one network
Developer flexibility	Deploy once, reach many ecosystems
Scalability	Distribute app logic across fast chains
Protocol expansion	Easy to grow into new environments

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“The protocol is key to boosting liquidity, gaining quick access, and enjoying utility across well-known blockchains.”

How LayerZero Works

No worries, it's not rocket science anyway. The mechanism revolves around secure messaging between smart contracts on different blockchains. Due to the architecture, message exchange is separated into independent components.

This approach aims to reduce costs, increase flexibility, and maintain trust assumptions. In real-world contexts, each message undergoes thorough verification by multiple parties before delivery to the final recipient.

LayerZero scan uses five key building blocks to ensure seamless message flow between blockchains. It's time to discover these core components, their features, and use cases.

Ultra Light Node (ULN)

ULN is an advanced alternative to full blockchain nodes, providing cost efficiency. Judge for yourself. It doesn't store all the information in communication, but brings only the necessary block data.

Here are the fundamental features of ULNs to remember:

Offloads storage to reduce fees
Retrieves block headers on demand
No full node replication required
Enables real-time verification
Runs efficiently on any chain

In straightforward terms, ULNs reduce gas and complexity. The result? They minimize the time and resources needed to maintain verification trust.

Oracles

Oracles are third-party services that provide instant delivery of block headers to the destination information chain. This verifies that the message was received from a valid chain source.

Here are the features and objectives of oracles in omnichain interoperability:

Retracts source chain header data
Delivers headers to the destination contract
Used once per message flow
Works with decentralized oracle networks
Enables trust-minimized communication

Summing up all of the above, oracles act as a guarantee that the destination chain receives the correct data before final processing.

Endpoint

The endpoint is another core element that serves as the interface contract, handling all messages between chains. Essentially, its purpose is to abstract away the technical layers for developers. Being the core component of the ecosystem, the LayerZero endpoint:

Unifies contracts per chain
Handles sending and receiving logic
Manages gas estimation and fees
Supports retries and error recovery
Connects to LayerZero SDKs

Endpoints simplify omnichain development at all stages. This also significantly reduces the time required for integration.

Relayers

Relayers perform the function of confirming transactions from the source to the destination chain. Moreover, they work in tandem with oracles in data delivery, adding a vital layer of proof to the process.

Their core metrics to keep in mind:

Delivers transaction proof
Operates independently of oracles
Can be picked by each DApp (decentralized app)
Can be third-party or in-house solutions
Triggers execution once verified

In summary, the tool enhances message security with an additional verification layer.

Message Lifecycle

Finally, we're getting to the fifth element. Here, you'll learn how messaging works in omnichain apps. The process follows a well-structured path from start to finish. Meanwhile, delivery requires verification from two core sources, namely, the oracle and the relayer components.

Here's how the flow looks step-by-step:

The source chain contract sends the data
Oracle delivers the header to the destination
Relayer submits transaction proofs
The destination contract verifies both
Triggers target function execution

Key takeaway: LayerZero breaks message transmission into several modules or so-called verifiable stages. This approach ensures increased security while being easy to implement in various ecosystems.

LayerZero v2: Security Model

Control over trust assumptions, proof flow, and message validation paths is critical for developers. Therefore, LayerZero v2 offers a modular system that runs on an app-defined security model. Below, you'll find a comparison table that highlights the differences between v1 and v2:

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The module-based approach enables developers to control messages at security, verification, and routing levels across multiple chains.

Key Components & Principles

V2 has a clear separation of message responsibilities, while the architecture enables apps to choose components that suit their needs. Here are the key elements and their functions to get the whole picture:


Feature	v2	v3
Security Model	Fixed oracle and relayer combo	App-level configurable trust model
Validator Permissions	Limited and centralized	Permissionless, open participation
Customization	Minimal	Full modular architecture
Replay Protection	Basic	Built-in for all messages
Oracle and Relayer Coupling	Tightly coupled	Decoupled for flexibility
Message Routing	Static endpoints only	Dynamic paths and custom hops
Supported Use Cases	Basic token transfers	Complex app logic and crosschain state

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This modular approach is excellent for builders, enabling them to replace necessary components for varying levels of trust, performance, or cost.

Key takeaway: The v2 version utilizes customizable components in the system to provide considerable room for securing cross-chain apps.

Omnichain Tokens & OApps

How can data move freely between chains without relying on wrapped assets or bridges? Here's where omnichain tokens and applications come into play. The protocol facilitates this transition through a system of standards that sets the terms for how tokens operate and communicate across chains.

Below, you'll learn about two fundamental components that make this possible.

OFT (Omnichain Fungible Token) Standard

OFT chain is a widely accepted standard that developers use for deploying tokens across multiple chains. This eliminates the need for minting, burning, bridging, or duplication of supply.

Key features of omnichain fungible tokens:

Native transfers across supported chains
Supply tracked only on the source chain
Compatible with standard ERC-20 tokens
Built-in support for chain messaging
Secure, noncustodial transfers
Core component for protocols like Stargate and Radiant

Using a standardized approach with the OFT chain reduces fragmentation. Additionally, it enables tokens to scale across ecosystems without undue complexity.

OFT Adapters

There are times when using tokens implies more complex behavior. For example, this could apply to scenarios such as integrating yield-bearing tokens or liquidity staking. In these cases, OFT Adapters expand the core standard by adapting the logic to meet the needs of the ecosystem.

The tool's features:

Flexible architecture for new token types
Supports real-world token mechanics
Ecosystem-specific customization
No need to change the OFT base
Maintains omnichain compatibility

Key takeaway: Omnichain tokens utilize OFT standards and adapters, offering more advanced capabilities. They enable free movement across chains without the need to fall back on wrapping.

Use Cases

The Layer Zero bridge architecture is used in a wide range of real-world applications. Typically, these projects utilize on-chain messages for three primary purposes:

Unify liquidity
Simplify bridging
Improve user experience

Now, let's move on to two real-world examples where the solution has successfully integrated cases.

Stargate Finance

This is a well-known liquidity transport protocol that utilizes LayerZero capabilities as its foundation. It allows users to deposit funds on one chain and withdraw them to another without resorting to the well-established approach called wrapped tokens.

A few things to bear in mind on how the solution works for Stargate Finance:

Instant guaranteed finality
Unified liquidity pools
No wrapped tokens or synthetic assets
Supports ETH, ARB, BNB, OP chains, and more
Built-in message routing
Used by protocols like Curve and Sushi

Stargate has proven that using the v2 can provide a seamless user experience across ecosystems.

Radiant Capital

This is another equally well-known money market protocol that provides cross-chain borrowing and lending. It lets users deposit collateral on one chain and borrow on another. The best part? There's no need for bridges or manual fund moves.

Core options and features today:

Omnichain money market design
Single collateral base for multiple chains
Borrow and repay across supported networks
LayerZero governs messaging and state sync
Lower gas costs compared to traditional bridge-based lending
Expands to new chains like zkSync and Base

Key takeaway: Stargate and Radiant set the protocol to provide users with quick and seamless omnichain access. This resulted in improved liquidity, a better user experience, and scalability with no additional bridges required.

Risks & Limitations

Hardly anyone can find a protocol architecture devoid of risks for the end user. Here is a list of the most obvious exposures inherent to cross-chain DApps:


Component:	Purpose:
Endpoint	Main interface for sending and receiving cross-chain messages
Oracle	Delivers block headers to the destination chain
Relayer	Supplies proof of source-chain transaction
OApp Framework	Standardizes how apps send, receive, and process messages
Modules	Pluggable functions for routing, quoting, and execution
Config Layer	Stores app-specific security and routing preferences
Replay Protection	Prevents duplicate or malicious message execution
Path Customization	Enables developers to define specific chain routes

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Key takeaway: The protocol is a powerful tool, but it has several drawbacks that are worth keeping in mind.

Conclusion

The send layer solution has already processed over 100 million cross-chain messages and connected more than 70 blockchains. Its primary goal is to facilitate the real-time movement of liquidity, NFTs, and data. The protocol significantly improved security and trust standards by eliminating the use of wrapped tokens or centralized custodians.

It supports multiple OFTs, NFTs (ONFTs), and full OApps. These formats are ideal for decentralized applications to operate seamlessly across blockchains without duplicating logic or deploying isolated contracts.

FAQ

What is LayerZero?

It is a cross-chain messaging protocol that has united over 70 blockchains. It enables DApps to exchange messages between smart contracts and transfer assets across different blockchains.

How Do I Send a Cross-Chain Message?

Use the lzSend() function from a LayerZero-powered contract to route the message to the target chain via oracles and relayers.

What is an Endpoint?

In plain terms, this is an on-chain contract that controls message routing, verification, and delivery functions.

What Are the 3 Core LayerZero Principles?

These are modular security, application-level configuration, and trustless cross-chain messaging.


Risks	Explanation
Message failure	Oracles or relayers can fail, blocking delivery
Trust assumptions	Security depends on the selected oracle-relayer combo
Higher gas cost	Cross-chain messaging needs more on-chain transactions
Configuration risk	A wrong setup can expose routes to spoofing or failure
Partial decentralization	Oracle or relayer centralization can reduce trust
Chain onboarding delay	New chains need LayerZero to integrate them manually