LayerZero Executor Blueprint Template 🚀

A comprehensive template for creating LayerZero V2 Executors on Tangle Network

📚 Overview

This project provides a template for creating LayerZero Executor Blueprints on the Tangle Network. Executors are crucial components of the LayerZero protocol, responsible for committing and executing cross-chain messages, ensuring the reliability and efficiency of inter-blockchain communications.

Blueprints in Tangle are specifications for Actively Validated Services (AVS) that run arbitrary computations for a user-specified period. This template enables developers to create reusable Executor infrastructures, allowing them to participate in the LayerZero ecosystem and potentially monetize their work.

🛠️ Prerequisites

Before you begin, ensure you have the following software installed:

• Rust
• Forge
• Tangle

Install cargo-tangle, our CLI tool for creating and deploying Tangle Blueprints:

curl --proto '=https' --tlsv1.2 -LsSf https://github.com/tangle-network/gadget/releases/download/cargo-tangle-v0.1.2/cargo-tangle-installer.sh | sh

Or, install from crates.io:

cargo install cargo-tangle --force

🚀 Getting Started

1. Create a new project using the Executor blueprint template:

cargo tangle blueprint create --name my-executor-blueprint --repo https://github.com/tangle-network/layerzero-executor-blueprint-template

2. Navigate to your project directory:

cd my-executor-blueprint

3. Implement your offchain Executor logic in src/lib.rs and onchain Executor in contracts/src/, building upon the provided template functions.

4. Build your project:

cargo build

5. Deploy your Executor blueprint to the Tangle network:

cargo tangle blueprint deploy

📖 Understanding the Template

The Executor has two main off-chain workflows:

Committer Workflow

1. Listen for the PacketSent event.
2. Wait for the ExecutorFeePaid event to confirm assignment.
3. Listen for the PacketVerified event.
4. Perform an idempotency check using ULN.verifiable().
5. Based on the VerificationState, either wait, call commitVerification(), or terminate.
6. Perform a final idempotency check to confirm workflow completion.

Executor Workflow

1. Listen for the PacketSent event.
2. Wait for the ExecutorFeePaid event to confirm assignment.
3. Listen for the PacketVerified event.
4. Perform an idempotency check using endpoint.executable().
5. Based on the ExecutionState, either wait, call endpoint.lzReceive(), or terminate.
6. Perform a final idempotency check to confirm workflow completion.

💼 Implementing the Executor Contract

Your Executor contract must implement the ILayerZeroExecutor interface:

interface ILayerZeroExecutor {
   function assignJob(
       uint32 _dstEid,
       address _sender,
       uint256 _calldataSize,
       bytes calldata _options
   ) external payable returns (uint256 price);

   function getFee(
       uint32 _dstEid,
       address _sender,
       uint256 _calldataSize,
       bytes calldata _options
   ) external view returns (uint256 price);
}

• assignJob: Called as part of _lzSend.
• getFee: Used by applications to estimate fees before sending a packet.

🔍 Key Events to Monitor

• PacketSent(bytes encodedPacket, bytes options, address sendLibrary)
• ExecutorFeePaid(address executor, uint256 fee)
• PayloadVerified(address dvn, bytes header, uint256 confirmations, bytes32 proofHash)

📚 Resources

• LayerZero V2 Documentation
• Tangle Network Documentation

📬 Feedback and Support

If you encounter any issues or have questions, please open an issue on our GitHub repository.

📜 License

This project is licensed under the MIT License. See the LICENSE file for details.

🤝 Contributing

We welcome contributions! Please see our Contributing Guidelines for more information on how to get involved.

🙏 Acknowledgements

Special thanks to the LayerZero team for their support and contributions to this project.