# 💰 StakeBank – Simple Ethereum Staking Smart Contract

StakeBank is a basic staking smart contract written in Solidity. It allows users to lock ETH for 7 days and earn a fixed interest rate (default 5%). The goal is to demonstrate fundamental smart contract patterns such as staking, access control, time locks, and events.

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## 🚀 Features

- 🔐 Stake ETH with a 7-day lock period
- 📈 Fixed interest (default 5%)
- 🧾 Withdraw after lock time with interest
- 👑 Admin function to update interest rate
- 👀 View balance and unlock time
- 🧠 Emits events for every deposit/withdrawal
- ⚡ Written and tested on Ethereum (Remix + MetaMask)

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## 🛠️ How to Deploy

1. Open [Remix IDE](https://remix.ethereum.org)
2. Create a new file called `StakeBank.sol`
3. Paste the contract code
4. Compile with Solidity version ^0.8.0
5. Deploy using **Injected Web3** (MetaMask)
6. Choose a network like Goerli/Sepolia or Mainnet (at your own risk)
7. Interact with contract through Remix or Web3 frontend

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## 📄 Contract Overview

### deposit()
```solidity
function deposit() external payable
Allows a user to stake ETH. The deposit must be > 0. Each user can only stake once at a time.

withdraw()

function withdraw() external
Lets a user withdraw their original deposit + interest after the 7-day lock period.

increestate(uint newRate)

function increestate(uint newRate) external onlyOwner
Owner-only function to change the interest rate.

getBalance(address user)

function getBalance(address user) external view returns (uint)
Returns the amount deposited by a user.

getUnlockTime(address user)
function getUnlockTime(address user) external view returns (uint)
Returns the unlock timestamp (UNIX) for a user’s stake.

receive()
Contract is able to receive ETH directly (used to accept transfers if needed).

Events

event Deposited(address indexed user, uint amount);
event Withdrawn(address indexed user, uint amount, uint interest);
You can view emitted events in Remix → Terminal → Logs or through a block explorer (like Etherscan).

🔐 Access Control
Only the contract owner (deployer) can update the interest rate.

modifier onlyOwner {
    require(msg.sender == owner, "Not owner!");
    _;
}
💻 Example UI (optional)
If you want to build a frontend, consider:

React + ethers.js or viem

MetaMask wallet integration

Basic dashboard: balance, deposit form, withdraw button, unlock countdown

🧠 Learnings
This project demonstrates:

Solidity basics

Mappings and structs

Modifiers

Safe ETH transfer

Time locking logic

Emitting and listening to events

👨‍💻 Author
Developed by Zero – Web3 beginner with big plans.

📄 License
MIT License

Free to use, fork, and build on.