## Understanding Factory Contracts in Solidity

### Introduction

Today at **Blockfuse Labs**, I learned about the **Factory Pattern** in Solidity a concept that allows one contract to **deploy and manage other contracts**.
It’s a simple but powerful pattern used in **DeFi protocols, NFT collections, DAOs,** and **launchpads**, where you need to create many similar smart contracts automatically.

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### The Factory Concept

A **Factory Contract** acts like a manager that produces multiple instances of another contract.
Instead of deploying contracts manually, you can deploy them programmatically through the factory using the `new` keyword.

Example (very short):

pragma solidity ^0.8.20;

contract Product {
    string public name;
    constructor(string memory _name) { name = _name; }
}

contract Factory {
    address[] public products;
    function create(string memory _name) public {
        Product p = new Product(_name);
        products.push(address(p));
    }
}

Each time you call `create("ClemProduct")`, the factory automatically deploys a new **Product contract** and stores its address.

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### Scripting with Foundry

After writing the contracts, we use **Foundry scripting** to deploy and interact with them easily.
Scripting in Foundry is done with `.s.sol` files inside the **`script/`** directory.
A script is just a Solidity contract that uses Foundry’s special cheat codes to perform blockchain actions like deployment or interaction.

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### Example Script

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
import "forge-std/Script.sol";
import "../src/Factory.sol";

contract FactoryScript is Script {
    function run() external {
        vm.startBroadcast(); // start sending transactions

        Factory factory = new Factory(); // deploy factory
        factory.create("ClemProduct");   // deploy new product through factory

        vm.stopBroadcast(); // stop broadcasting transactions
    }
}

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### Explanation of the Script

Here’s what happens step-by-step:

1. **`import "forge-std/Script.sol";`**

* This gives access to Foundry’s scripting tools like `vm.startBroadcast()` and `vm.stopBroadcast()`.

2. **`vm.startBroadcast()`**

* Tells Foundry to start sending real transactions to the network using your wallet’s private key.

3. **`new Factory()`**

* Deploys the **Factory** contract on the blockchain.

4. **`factory.create("ClemProduct")`**

* Uses the Factory to create a new **Product** contract.

5. **`vm.stopBroadcast()`**

* Ends the transaction broadcast.

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### Running the Script

To run your script, use:

forge script script/Factory.s.sol --rpc-url <your_rpc_url> --private-key <your_private_key> --broadcast

This command will:

* Compile your code
* Deploy the **Factory** contract
* Automatically call the `create()` function
* Broadcast everything to the network (local, testnet, or mainnet)

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