Chainlink-CCIP-CNFT

Project Overview

The Chainlink-CCIP-CNFT project demonstrates minting and cross-chain transfer of NFTs using Chainlink's Cross-Chain Interoperability Protocol (CCIP). The project provides scripts to deploy the XNFT contract on test networks such as Ethereum Sepolia and Arbitrum Sepolia, and facilitate the cross-chain transfer of NFTs between these networks. Additionally, Chainlink Local is integrated to simulate cross-chain transactions on forked networks, running 2000x faster than on live test networks, significantly improving development and testing efficiency.

Directory Structure

.github/                   # GitHub configuration files
lib/                       # Project dependencies
  ├── ccip/                # Chainlink CCIP dependencies
  ├── chainlink/           # Chainlink contracts
  ├── chainlink-brownie-contracts/  # Chainlink Brownie contracts
  ├── chainlink-local/     # Chainlink Local simulator libraries
  ├── forge-std/           # Forge standard library
  ├── openzeppelin-contracts/ # OpenZeppelin contracts
out/                       # Contract compilation output
script/                    # Script files for deploying XNFT contracts
  ├── EncodeExtraArgs.s.sol   # Script to encode extra cross-chain transaction arguments
  ├── XNFTArbitrum.s.sol      # Script for deploying XNFT contract on Arbitrum Sepolia
  ├── XNFTSepolia.s.sol       # Script for deploying XNFT contract on Ethereum Sepolia
src/                       # Main contract files
  └── XNFT.sol              # XNFT main contract
test/                      # Test files
utils/                     # Utility contracts and test files
  ├── EncodeExtraArgs.sol   # Encoding utility contract
  ├── XNFTTest.t.sol        # Test file for XNFT contract
.env.example                # Environment variables file
.gitignore                 # Git ignore file
.gitmodules                # Git submodules configuration
foundry.toml               # Foundry configuration file
README.md                  # Project documentation

Features Overview

• NFT Minting and Deployment: Deploy and mint NFTs via the XNFT.sol contract on Ethereum Sepolia and Arbitrum Sepolia test networks.
• Cross-chain NFT Transfer: Using Chainlink's CCIP protocol, NFTs can be transferred between the Ethereum Sepolia and Arbitrum Sepolia test networks.
• Chainlink Local Simulator: Chainlink Local is integrated to simulate cross-chain transactions on forked networks, enabling faster testing and development.

Setup

Prerequisites

Ensure you have the following tools installed:

• Foundry: A Solidity development toolkit for testing, compiling, and deploying.

Clone the Project

First, clone this project locally:

git clone https://github.com/<your-repo>/chainlink-ccip-cnft.git
cd chainlink-ccip-cnft

Install Dependencies

Install the required dependencies:

forge install

Configure Environment Variables

Copy the .env.example file and rename it to .env, then fill in the following values:

ETHEREUM_SEPOLIA_RPC_URL=<your-ethereum-sepolia-rpc-url>
ARBITRUM_SEPOLIA_RPC_URL=<your-arbitrum-sepolia-rpc-url>
PRIVATE_KEY=<your-private-key>

Compile Contracts

Compile the smart contracts:

forge build

Usage: Minting NFTs and Cross-Chain Transfers

1. Deploy XNFT.sol on Ethereum Sepolia

Prepare the Chain Selector and CCIP Router & LINK Token contract addresses for the Ethereum Sepolia testnet. These can be obtained from Chainlink's CCIP Documentation.

Deploy the XNFT.sol contract using the following command:

forge create --rpc-url ethereumSepolia --private-key=$PRIVATE_KEY src/XNFT.sol:XNFT --constructor-args <CCIP_ROUTER_ETHEREUM_SEPOLIA> <LINK_TOKEN_ETHEREUM_SEPOLIA> <CHAIN_SELECTOR_ETHEREUM_SEPOLIA>

2. Deploy XNFT.sol on Arbitrum Sepolia

Deploy the XNFT.sol contract on the Arbitrum Sepolia testnet:

forge create --rpc-url arbitrumSepolia --private-key=$PRIVATE_KEY src/XNFT.sol:XNFT --constructor-args <CCIP_ROUTER_ARBITRUM_SEPOLIA> <LINK_TOKEN_ARBITRUM_SEPOLIA> <CHAIN_SELECTOR_ARBITRUM_SEPOLIA>

3. Enable Cross-Chain Transfer on Ethereum Sepolia

In the Ethereum Sepolia network, call the enableChain method:

cast send <XNFT_ADDRESS_ON_ETHEREUM_SEPOLIA> --rpc-url ethereumSepolia --private-key=$PRIVATE_KEY "enableChain(uint64,address,bytes)" <CHAIN_SELECTOR_ARBITRUM_SEPOLIA> <XNFT_ADDRESS_ON_ARBITRUM_SEPOLIA> 0x97a657c90000000000000000000000000000000000000000000000000000000000030d40

4. Enable Cross-Chain Transfer on Arbitrum Sepolia

In the Arbitrum Sepolia network, call the enableChain method:

cast send <XNFT_ADDRESS_ON_ARBITRUM_SEPOLIA> --rpc-url arbitrumSepolia --private-key=$PRIVATE_KEY "enableChain(uint64,address,bytes)" <CHAIN_SELECTOR_ETHEREUM_SEPOLIA> <XNFT_ADDRESS_ON_ETHEREUM_SEPOLIA> 0x97a657c90000000000000000000000000000000000000000000000000000000000030d40

5. Fund the XNFT Contract with LINK on Arbitrum Sepolia

Ensure that the XNFT contract on Arbitrum Sepolia is funded with LINK tokens to cover the CCIP transaction fees.

6. Mint a New xNFT on Arbitrum Sepolia

Mint a new xNFT on the Arbitrum Sepolia network:

cast send <XNFT_ADDRESS_ON_ARBITRUM_SEPOLIA> --rpc-url arbitrumSepolia --private-key=$PRIVATE_KEY "mint()"

7. Cross-Chain Transfer xNFT from Arbitrum Sepolia

To transfer the xNFT cross-chain, use the following command:

• from: Your EOA (Externally Owned Account) address
• to: The receiving address on the other chain (can be your own address)
• tokenId: The ID of the xNFT you wish to transfer
• destinationChainSelector: 16015286601757825753 (Ethereum Sepolia Chain Selector)
• payFeesIn: 1 (indicating that fees are paid in LINK)

cast send <XNFT_ADDRESS_ON_ARBITRUM_SEPOLIA> --rpc-url arbitrumSepolia --private-key=$PRIVATE_KEY "crossChainTransferFrom(address,address,uint256,uint64,uint8)" <YOUR_EOA_ADDRESS> <RECEIVER_ADDRESS> 0 16015286601757825753 1

Success! Go to metamask import your NFT and check it!