Introduction to EVM Smart Contracts

What are EVM Smart Contracts?

Smart contracts on UOMI are programs that run on the Ethereum Virtual Machine (EVM). These self-executing contracts contain code and data that live at a specific address on the blockchain. Being EVM-compatible, UOMI supports the same smart contract functionality as Ethereum, allowing developers to write and deploy contracts using familiar tools and languages.

Programming Language

Smart contracts on UOMI are primarily written in Solidity, the most widely used programming language for EVM development. Solidity is:

• Object-oriented and high-level

• Specifically designed for smart contracts

• Similar to JavaScript/C++ in syntax

• Statically typed

💡 Note While Solidity is the most common choice, you can also use other EVM-compatible languages like Vyper.

Development Requirements

To start developing smart contracts on UOMI, you'll need:

1. MetaMask Wallet

• Browser extension for interacting with EVM chains

• Manages your accounts and transactions

• Connects dApps to the blockchain

2. UOMI Network Configuration

Network Name: UOMI Finney Testnet
RPC URL: https://finney.uomi.ai
Chain ID: 4386
Currency Symbol: UOMI

3. Development Tools

• Solidity Compiler: Converts Solidity code to EVM bytecode

• Development Framework: Hardhat, Truffle, or Foundry

• Code Editor: VS Code with Solidity extensions recommended

Smart Contract Basics

Contract Structure

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.19;

contract MyContract {
    // State variables
    uint256 public value;

    // Events
    event ValueChanged(uint256 newValue);

    // Constructor
    constructor() {
        value = 0;
    }

    // Functions
    function setValue(uint256 newValue) public {
        value = newValue;
        emit ValueChanged(newValue);
    }
}

Key Concepts

1. State Variables

   • Permanently stored in contract storage

   • Represent the contract's state

2. Functions

   • Execute contract logic

   • Can be public, private, internal, or external

   • Can modify state or be view/pure

3. Events

   • Log important changes

   • Can be monitored by applications

Interacting with Smart Contracts

You can interact with smart contracts through:

1. MetaMask

   • Send transactions

   • Manage accounts

   • Connect to dApps

2. Web3 Libraries

   • ethers.js

   • web3.js

3. Block Explorers

   • View transactions

   • Verify contracts

   • Monitor events

Getting Started

1. Set Up MetaMask

   • Install the extension

   • Create or import an account

   • Add UOMI network

2. Get Test Tokens

   • Use the testnet faucet

   • Required for deployment and testing

3. Choose Development Tools

   • Install development framework

   • Set up your IDE

   • Configure network settings

Next Steps

Ready to start developing? Check out:

• Your First Smart Contract

• HardHat