LayerZero Bridge Example dApp

An example LayerZero dApp built on top of next.js

Quick Start

The easiest way to create a dApp for your LayerZero tokens is to use our create-lz-app utility:

npx create-lz-app ./my-project-directory

This utility will walk you through the process of dApp configuration and will create a working Next.js application you can then deploy using e.g. Vercel or Netlify.

If want to contribute to the development of the shared packages, you can also clone this repository and run the example app (see the repository home page for more details):

# Clone the repository - this also includes reusable packages
git clone https://github.com/LayerZero-Labs/factory.git && cd factory

# Install required dependencies
yarn

# After a fresh clone, you'll need to run an initial build
yarn build

# To only run the example app (on port 3009)
yarn dev --filter=bridge-app

# To also make changes to the reusable packages
yarn dev

Project Structure

The example app is organized by feature. You’ll find verticals for the fungible token bridge and non-fungible token (ONFT) bridge in the features folder, along with core pieces used in each. Within each vertical folder you’ll find stores, components, and configuration specific to that use case.

bridge-app
├── README.md
├── node_modules
├── package.json
├── tsconfig.json
├── public
│   └── static
│        └── icons
└── src
    ├── config.ts
    ├── bootstrap.tsx
    ├── features
    |  ├──core
    |  ├──bridge
    |  └──onft
    └── pages
      ├── bridge.tsx
      ├── oft.tsx
      ├── onft.tsx
      └── _app.tsx

The config file defines and exports an object of type AppConfig. This will describe every token you want to support. The bootstrap file takes that config as an input and hydrates the stores with data and apis to handle bridging all the defined assets. If you are coming from create-lz-app, your config file will contain exactly what you configured in the cli steps, or the default configuration if you chose that option.

Your bridge will be fully functional out of the box for any bridge type. We have the following Next.js pages:

bridge: Transfer between any valid pair of registered tokens.
OFT: A simplified transfer form designed to swap just one type of OFT between supported networks.
ONFT: Transfer ONFTs across supported networks.

You can include or delete any of these pages to customize the exact application you want to build. For information on how to simplify your repo see the relevant section below.

Creating a Fungible Token Bridge

Your configuration should include some fungible tokens, either OFTs, wrapped assets, or tokens supported by our Aptos or Stargate contracts. In this case, your bootstrapping step will set up the bridgeStore with everything it needs, including access to the supported currencies and apis to execute transfers.

If you are not interested in including an ONFT bridge, you can completely remove the onft folder, as well as the /onft page. Next you will have to remove imports from the onft folder and refrences to the onftStore in bootstrap.ts, everything should be under the heading // ONFT ERC721 & ERC1155. Once that's done, feel free to remove dependencies related to the ONFT bridge, namely @layerzerolabs/ui-bridge-onft. You will also want to delete the ONFT tab from the AppHeader component in your layout.

By default we also include an OFT page. This uses the same bridgeStore as the full transfer form, so no code needs to be removed. You may remove the /oft page and OFT tab from the layout.

Creating a simple OFT Bridge

The OFT page is a simplified version of the full transfer form. This page uses the first oft from your AppConfig and is a good choice if you are only interested in transferring one token between its supported networks.

If you are only interested in this page you may remove the onft folder, as well as the /onft page. The same bridgeStore that supports the full transfer page is used in the OFT page so it should not be modified. Similar to above, you will have to remove imports from the onft folder and references to the onftStore in bootstrap.ts, and can remove the @layerzerolabs/ui-bridge-onft dependency.

Creating a Non-Fungible Token Bridge

If your AppConfig includes any items in the onft field, the bootstrapping step will automatically configure your onftStore to support transfers of all your collections across their respective supported networks. The scaffold will also include a store and UI for bridging fungible tokens, if you don't need this you can completely remove the bridge folder, as well as the Bridge and OFT tabs from the AppHeader component in your layout. You will then have to remove imports from the bridge folder and references to the bridgeStore from bootstrap.ts, and can remove all dependencies related to fungible token bridging.

ONFT Balances Providers

To read ONFT balances for your collection you will likely need to implement your own balance provider. We recommend using a third party indexing service like Alchemy, Infura, or Simple Hash.

Your custom provider should implement the ONFTBalanceProvider interface

interface OnftBalanceProvider {
  supports(contract: OnftContract): boolean;
  getAssets(contract: OnftContract, owner: string): Promise<OnftTokenAmount[]>;
}

Where supports returns true if the contract address belongs to your collection, and getAssets should request assets from your third party integration. Once implemented, you can swap the default balance provider in bootstrap.ts to complete your configuration.

Wallet Configuration

The example app ships with support for the following wallets

Petra
Fewcha
Martian
Wallet Connect
Metamask
Phantom
Coinbase Wallet
Core
Pontem
Brave
PhantomEvm
Solflare
Coinbase Wallet Solana

You can enable any combination of these in the createWallet helper by adding or removing from the wallets array.

RPC Provider

The core bootstrap is where we initialize a providerFactory. In this context we're referring to rpc node providers, and the factory maps a chainId to a FailoverProvider. See the ui-evm documentation for more details, in short we connect to RPC nodes based on a weighted score, and fallback to another option in case of multiple failures.

The providerFactory is used in some the the generic store providers and is sent to the app specific bootstrapping steps.

Disclaimer

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

DISCLAIMER: THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

zokyo-sec / Shimmer-Bridge

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