endpoint

XDC Zero Endpoint

The XDC Zero Endpoint is a foundational cross-chain contract that enables seamless reception and dispatch of data packets across diverse blockchain networks.

Table of Contents

• Overview
• Contract Development and Deployment
• Additional Commands

Overview

• Initialization: Set the chainId for the current blockchain.
• Register Chain: Introduce a new blockchain, providing its unique identifier, checkpoint contract, and endpoint contract.
• Send Packet: Dispatch a data packet to a specified receiving chain.
• Validate Transaction Proof:
  • Monitor payload event data via a relayer from the sending chain's Zero Endpoint contract.
  • Deduce the rid (receiver's chainId).
  • Execute the validateTransactionProof method on the recipient chain, authenticating and archiving the transaction payload.
• Retrieve Payload: Applications, identified by ra, can easily access the cross-chain payload from the Zero Endpoint contract.

Workflow

Contract Development and Deployment

Environment Setup

1. Install Dependencies:

   yarn

2. Compile & Test:

   npx hardhat test

Contract Configuration

1. Configuration Files:

endpointconfig.json - Defining Network Details:

• xdcparentnet: Contains parameters for deploying the parentnet endpoint.

• xdcsubnet: Contains parameters for deploying the subnet endpoint.

  • endpoint: Current address of the chain endpoint.

  • registers: Parameters for registering specific details.

    • csc: Checkpoint smart contract address within this chain.
    • chainId: Identifies the Chain ID of the corresponding chain. (e.g., if set in xdcparentnet, the other side refers to the subnet).
    • endpoint: Address of the endpoint for the register chain.

  • applications: Parameters for application specific details.

    • rid: receive chain id
    • rua: receive chain user application
    • sua: send chain user application

network.config.json - Specifying Network Details:

• xdcparentnet: RPC URL for the parentnet.
• xdcsubnet: RPC URL for the subnet.

2. Environment Variables:
   • Set up a .env file based on .env.sample and provide a valid private key.

Deployment

To begin deployment, start with the subnet endpoint:

npx hardhat run scripts/endpointdeploy.js --network xdcsubnet

Also start the parentnet endpoint:

npx hardhat run scripts/endpointdeploy.js --network xdcparentnet

Next, configure the registration parameters in the endpointconfig.json file for the chain:

npx hardhat run scripts/registerchain.js --network xdcsubnet

Also register on the parentnet:

npx hardhat run scripts/registerchain.js --network xdcparentnet

After setting the application parameters in endpointconfig.json, proceed to register the user application (check applications/subswap for an example on deploying application):

npx hardhat run scripts/registerapplications.js --network xdcsubnet

npx hardhat run scripts/registerapplications.js --network xdcparentnet

Additional Commands

For comprehensive functionalities or deeper insights, refer to the command list below:

npx hardhat accounts
npx hardhat compile
npx hardhat clean
npx hardhat test
npx hardhat node
npx hardhat help
REPORT_GAS=true npx hardhat test
npx prettier '**/*.{js,json,sol,md}' --check
npx prettier '**/*.{js,json,sol,md}' --write
npx solhint 'contracts/**/*.sol'
npx solhint 'contracts/**/*.sol' --fix