Smart Contracts

How to deploy smart contracts

Kiichain supports natively supports both CosmWasm and EVM smart contracts. Developers can choose between any of the two to create amazing dApps.

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Working with Cosmwasm

Prerequisites

• Install Rust and CosmWasm toolchain:

  rustup default stable
  rustup target add wasm32-unknown-unknown
  cargo install cargo-generate --features vendored-openssl
  cargo install cargo-run-script

• Create a new CosmWasm contract:

  cargo generate --git https://github.com/CosmWasm/cosmwasm-template.git --name my-contract
  cd my-contract

• Compile the contract:

  cargo wasm
  cargo schema

Upload and Instantiate the Contract

1. Store the Contract

   kiichaind wasmd tx wasm store artifacts/my_contract.wasm --from my-key --gas auto --gas-adjustment 1.2 --node <KIICHAIN_NODE> --chain-id <KIICHAIN_CHAIN_ID>

2. Instantiate the Contract

   kiichaind wasmd tx wasm instantiate <CONTRACT_CODE_ID> '{}' --from my-key --label "My Contract" --gas auto --gas-adjustment 1.2 --node <KIICHAIN_NODE> --chain-id <KIICHAIN_CHAIN_ID>

3. Execute the Contract

   kiichaind wasmd tx wasm execute <CONTRACT_ADDRESS> '{"your_method": {}}' --from my-key --gas auto --gas-adjustment 1.2 --node <KIICHAIN_NODE> --chain-id <KIICHAIN_CHAIN_ID>

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Working with EVM

Prerequisites

• Install Node.js and Hardhat:

  npm install -g hardhat
  mkdir my-evm-contract && cd my-evm-contract
  npx hardhat

• Install dependencies:

  npm install --save-dev @nomicfoundation/hardhat-toolbox

Write and Compile the Smart Contract

1. Create a Solidity file (MyContract.sol) in contracts/:

   // SPDX-License-Identifier: MIT
   pragma solidity ^0.8.19;
   
   contract MyContract {
       string public message;
   
       constructor(string memory _message) {
           message = _message;
       }
   
       function setMessage(string memory _newMessage) public {
           message = _newMessage;
       }
   }

2. Compile the contract:

   npx hardhat compile

Deploy the Smart Contract

1. Create a deployment script (scripts/deploy.js):

   const hre = require("hardhat");
   
   async function main() {
       const MyContract = await hre.ethers.getContractFactory("MyContract");
       const contract = await MyContract.deploy("Hello, Kiichain!");
       await contract.deployed();
       console.log("Contract deployed at:", contract.address);
   }
   
   main().catch((error) => {
       console.error(error);
       process.exitCode = 1;
   });

2. Deploy to Kiichain:

   npx hardhat run scripts/deploy.js --network kiichain

Interact with the Deployed Contract

• Using Hardhat Console:

  npx hardhat console --network kiichain

  const contract = await ethers.getContractAt("MyContract", "<DEPLOYED_CONTRACT_ADDRESS>");
  await contract.setMessage("New Message");

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References

• CosmWasm Documentation: CosmWasm Docs
• Ethereum Hardhat Guide: Hardhat Docs