Environment Setup

This guide walks through setting up the complete Dong Chain development environment.

1. Clone the Repository

git clone https://github.com/dongchain/dong-chain
cd dong-chain

# Install git submodules (Substrate, pallet-revive, etc.)
git submodule update --init --recursive

2. Environment Variables

Create a .env file in the project root:

cp .env.example .env

Edit .env:

# Bitcoin/OmniCore RPC
BITCOIN_RPC_URL=http://localhost:8332
BITCOIN_RPC_USER=dongchain
BITCOIN_RPC_PASS=<your-strong-password>

# Dong Chain Node
DONGCHAIN_RPC_URL=http://localhost:9944
DONGCHAIN_WS_URL=ws://localhost:9944

# Deployer keys (NEVER commit real keys)
DEPLOYER_PRIVATE_KEY=0x...  # testnet only
MPC_ALLOCATOR_ADDRESS=0x...

# Bundler
BUNDLER_PORT=3000
ENTRY_POINT_ADDRESS=0x...   # set after deployment

# ZK Prover (optional)
RISC_ZERO_API_KEY=           # for BONSAI cloud proving

3. Build the Dong Chain Node

# Build release binary (~15-20 min first time)
cargo build --release -p dong-chain-node

# Verify build
./target/release/dong-chain-node --version

4. resolc Toolchain Verification

# Verify resolc can compile OpenZeppelin contracts
cd examples/contracts

# Compile ERC-20
resolc --target polkavm \
       --optimization 3 \
       --output-dir artifacts \
       ERC20.sol

ls artifacts/
# ERC20.polkavm  ERC20.abi  ERC20.metadata

5. Foundry Project Setup

cd contracts

# Install dependencies
forge install

# Install OpenZeppelin (if not already)
forge install OpenZeppelin/openzeppelin-contracts

# Verify tests compile
forge build

# Run tests
forge test

foundry.toml:

[profile.default]
src = "src"
out = "out"
libs = ["lib"]
solc_version = "0.8.24"

[profile.polkavm]
src = "src"
out = "out-polkavm"
compiler = "resolc"

[rpc_endpoints]
dongchain = "${DONGCHAIN_RPC_URL}"

6. Hardhat Setup (Alternative)

cd contracts-hardhat
npm install

# Verify connection
npx hardhat compile

hardhat.config.js:

require("@nomicfoundation/hardhat-toolbox");
require("@parity/hardhat-revive");   // resolc plugin

module.exports = {
  solidity: {
    version: "0.8.24",
    settings: { optimizer: { enabled: true, runs: 200 } }
  },
  revive: {
    compiler: "resolc",
    version: "0.1.0",
    target: "polkavm",
    optimization: "3",
  },
  networks: {
    dongchain_local: {
      url: process.env.DONGCHAIN_RPC_URL,
      accounts: [process.env.DEPLOYER_PRIVATE_KEY],
      chainId: 1337,   // Update with actual Dong Chain chainId
    },
    dongchain_testnet: {
      url: "https://rpc.testnet.dongchain.io",
      accounts: [process.env.DEPLOYER_PRIVATE_KEY],
      chainId: 9999,   // Update with actual testnet chainId
    },
  },
};

7. Metamask Configuration

Connect Metamask to local Dong Chain node:

Field	Value
Network Name	Dong Chain Local
RPC URL	http://localhost:9944
Chain ID	1337 (or configured chainId)
Currency Symbol	DONG
Block Explorer	http://localhost:4000 (if running local explorer)

8. Run Local Development Stack

# Terminal 1: Start Dong Chain node (development mode)
./target/release/dong-chain-node \
  --dev \
  --rpc-port 9944 \
  --ws-port 9945 \
  --tmp

# Terminal 2: Start Bundler (ERC-4337)
cd bundler
npm start

# Terminal 3: (Optional) Start Bitcoin/OmniCore testnet
omnicored -testnet \
  -txindex=1 \
  -rpcuser=dongchain \
  -rpcpassword=test \
  -rpcport=18332

# Terminal 4: Deploy contracts
cd contracts
forge script script/Deploy.s.sol \
  --rpc-url http://localhost:9944 \
  --private-key $DEPLOYER_PRIVATE_KEY \
  --broadcast

9. Verify Full Stack

# Check node is running
cast block-number --rpc-url http://localhost:9944

# Check chain ID
cast chain-id --rpc-url http://localhost:9944

# Send test transaction
cast send \
  --rpc-url http://localhost:9944 \
  --private-key $DEPLOYER_PRIVATE_KEY \
  $RECIPIENT_ADDRESS \
  --value 1ether

# Deploy test ERC-20
forge create \
  --rpc-url http://localhost:9944 \
  --private-key $DEPLOYER_PRIVATE_KEY \
  src/tokens/TestERC20.sol:TestERC20

Common Issues

"OmniCore refused to start"

→ Check txindex=1 is set in bitcoin.conf. Re-index may be required.

"resolc: command not found"

→ Run cargo install resolc and ensure ~/.cargo/bin is in PATH.

"Substrate build fails on protobuf"

→ Install protobuf-compiler: sudo apt-get install protobuf-compiler

"Metamask not connecting"

→ Ensure node is running with --unsafe-rpc-external or binding to 0.0.0.0 for external access.

Next Steps

→ Node Setup — Production node configuration → Quickstart — Deploy your first contract