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Version: Endpoint V2 Docs

LayerZero V2 Solidity Contract Standards

LayerZero enable seamless cross-chain messaging, configurations for security, and other quality of life improvements to simplify cross-chain development.

LayerZero Solidity Contract Standards​

OApp Standard

The base generic message passing standard, enabling cross-chain data transfer and external function calls.

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OFT Standard

Extension of OApp, combining the ERC20 token standard with core bridge logic to make Omnichain Fungible Tokens.

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ONFT Standard

Combines the ERC721 token standard with core bridge logic to make Omnichain Non-Fungible Tokens.

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LayerZero Solidity Protocol Configurations​

Configure Security Stack

Configure which decentralized verifier networks (DVNs) secure your messages.

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Configure Executor

Configure who executes your messages on the destination chain.

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Set Execution Options

Set the amount of gas to deliver to the destination chain.

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info

To find all of LayerZero's contracts visit the LayerZero V2 Protocol Repo.

Installation​

To start sending cross-chain messages with LayerZero, you can find install instructions for each contract package in OApp Quickstart, OFT Quickstart, or ONFT Quickstart.

LayerZero also provides create-lz-oapp, an all-in-one npx package that allows developers to create a project from any of the available omnichain standards in <4 minutes!

tip

Get started by running the following from your command line:

npx create-lz-oapp@latest

Usage​

Once installed, you can use the contracts in the library by importing them:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.22;

import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
import { OApp } from "@layerzerolabs/oapp-evm/contracts/oapp/OApp.sol";


contract MyOApp is OApp {
    constructor(address _endpoint, address _owner) OApp(_endpoint, _owner) Ownable(_owner) {}

    // ... rest of OApp interface functions
}

To keep your system secure, you should always use the installed code as-is, and neither copy-paste it from online sources, nor modify it directly.

Most of the LayerZero contracts are expected to be used via inheritance: you will inherit from them when writing your own contracts.

Tooling​

LayerZero also provides developer tooling to simplify the contract creation, testing, and deployment process:

  • LayerZero Scan: a comprehensive block explorer, search, API, and analytics platform for tracking and debugging your omnichain transactions.

  • TestHelper (Foundry): a suite of functions to simulate cross-chain transactions and validate the behavior of OApps locally in your Foundry unit tests.

You can also ask for help or follow development in the Discord.