SimpleVault Smart Contract

A basic Solidity vault system demonstrating inheritance patterns with secure deposit and withdrawal functionality using OpenZeppelin's SafeCast library.

Overview

This project consists of two contracts:

• VaultBase: Foundation contract handling asset storage and balance tracking
• VaultManager: Inherited contract implementing deposit/withdrawal logic

Features

• ✅ Inheritance Pattern: Clean separation of base functionality and management logic
• ✅ Balance Tracking: Individual user balance mapping with total deposits counter
• ✅ SafeCast Integration: OpenZeppelin library for secure mathematical operations
• ✅ Event Logging: Deposit and withdrawal events for transparency
• ✅ Input Validation: Prevents zero-amount transactions and insufficient balance withdrawals
• ✅ Immutable Asset: Asset address cannot be changed after deployment

Contract Structure

VaultBase

• Stores the asset address (immutable)
• Maintains user balance mappings
• Provides balance query functionality

VaultManager

• Inherits from VaultBase
• Implements deposit and withdrawal functions
• Tracks total deposited amount
• Emits transaction events

Installation

Prerequisites

• Solidity ^0.8.24
• OpenZeppelin Contracts

Using Remix IDE

1. Create a new workspace in Remix
2. Install OpenZeppelin contracts:

   npm install @openzeppelin/contracts

3. Copy the contract code into a new .sol file
4. Compile and deploy

Usage

Deployment

Deploy the VaultManager contract with the target asset address:

VaultManager vault = new VaultManager(0x1234...); // Asset contract address

Interacting with the Contract

Deposit Tokens

vault.deposit(1000); // Deposit 1000 tokens

Withdraw Tokens

vault.withdraw(500); // Withdraw 500 tokens

Check Balance

uint256 balance = vault.getBalance(userAddress);
uint256 myBalance = vault.balances(msg.sender);

View Total Deposits

uint256 total = vault.totalDeposited();

Functions

Function	Description	Visibility
deposit(uint256)	Deposit tokens to vault	Public
withdraw(uint256)	Withdraw tokens from vault	Public
getBalance(address)	Get user's balance	Public View
balances(address)	Direct balance mapping access	Public View
totalDeposited()	Get total amount deposited	Public View
asset()	Get asset contract address	Public View

Events

event Deposit(address indexed user, uint256 amount);
event Withdraw(address indexed user, uint256 amount);

Security Features

• Input validation prevents zero-amount transactions
• Balance checks prevent overdrafts
• SafeCast library provides overflow protection
• Immutable asset prevents asset switching after deployment

Important Notes

⚠️ This is a basic educational contract and lacks several production features:

• No actual ERC-20 token transfers (interface calls missing)
• No access controls or admin functions
• No pause/emergency mechanisms
• No fee structures
• No reentrancy guards

Development

Testing

Test the contract thoroughly on testnets before mainnet deployment.

Gas Optimization

• Consider using uint128 for balances to pack storage
• Implement batch operations for multiple transactions

License

MIT License - see LICENSE file for details.

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests
5. Submit a pull request

Disclaimer

This contract is for educational purposes. Use at your own risk and conduct thorough audits before deploying to mainnet with real funds.