Smart contracts are the main foundation of blockchain development and serve as the backbone of such solutions as DeFi protocols, NFT marketplaces, and many others. However, what do you do when you need to invoke the same contract many times with varying parameters, and you have to keep forking over an expensive gas fee?
That’s where cloning a smart contract comes in. This blog will guide you through how to clone a smart contract efficiently using the factory pattern, ERC-116, and tools like Foundry, a blazing-fast smart contract development toolkit.
Why Clone a Smart Contract?
Assume that you are developing an on-chain application where a contract instance (such as a reserved Foundation contract to manage treasury, votes, or NFTs) would be created by each user or DAO. Deploying each of the contracts separately would cost you a full gas fee per invocation. That’s wasteful and expensive.
By cloning contracts, you can deploy lightweight proxy contracts that point to a single implementation. It dramatically reduces deployment costs and simplifies upgrades.
Key Concepts You Need to Know
Before jumping into the code, here are a few technical concepts you’ll encounter:
1. Factory Pattern
The factory pattern is a common object-oriented programming design pattern that allows one contract (the factory) to deploy or “spawn” many copies of another contract (the product).
2. ERC-1167 Minimal Proxy
This is the official EIP that standardizes contract cloning. It uses the low-level CREATE opcode to deploy lightweight proxies that delegate calls to a logic contract. It’s the backbone of many on-chain applications that need scalable contract instantiation.
3. Ethereum JSON-RP
When deploying or interacting with smart contracts, your client (like Foundry or Hardhat) communicates with a local node or public endpoint via the Ethereum JSON-RPC protocol.
Cloning a Smart Contract Using ERC-1167
Let’s walk through how to clone a smart contract on the Ethereum blockchain using Foundry. You can also do this on other EVM-compatible chains like Polygon and Arbitrum blockchain.
Step 1: Install Foundry
Foundry is an extremely fast, Rust-powered Ethereum smart contract development framework. First, you will be required to install it through a simple command in the terminal. It also features such tools as forge to test and deploy, and cast to send transactions or call contracts. It is recommended to make sure that Git and a recent version of Rust are installed prior to use.
Step 2: Create a Simple Logic Contract
Next, you’ll write the main contract that will serve as the logic or implementation contract. This is the contract you’ll be cloning later. It should include any core functions your clones will use, along with an initialize function to set parameters like the owner. Remember, constructors aren’t called in clones, so initialization must be done manually.
Step 3: Write the Clone Factory
Now, create a factory contract that will handle the deployment of clone instances. This contract uses the ERC-1167 minimal proxy pattern to deploy lightweight clones pointing to the original logic contract. You’ll typically use a library like OpenZeppelin’s Clones to simplify this process. The factory will also include a createFoundation function to initialize each clone with custom parameters like the owner.
Step 4: Deploy and Test
With both the logic and factory contracts ready, it’s time to deploy them to your desired blockchain, whether a testnet or local node. Use Foundry’s forge commands to deploy the factory, then call its createFoundation function to generate new clones. After deployment, test the clones to ensure they’re initialized correctly and function as expected. This step confirms your clone factory is working reliably.
Gas Cost Comparison
Cloning using ERC-1167 typically costs 90% less gas than deploying full contracts. That’s a massive improvement for apps like NFT minting factories, DAOs, or DeFi vaults that deploy frequently. Since clones share the same logic contract, they save storage space on-chain and reduce execution overhead. This efficiency not only lowers deployment costs but also enhances scalability for high-volume dApps.
Real-World Use Cases
Many major protocols use the clone factory pattern, including:
- Uniswap V3 is for deploying multiple liquidity pools with custom parameters.
- OpenZeppelin Defender automates deployment and upgrade processes using minimal proxies.
- Juicebox Protocol for creating DAO treasuries that can be customized per project.
- Gnosis Safe uses clones to deploy secure multisig wallets at scale with minimal gas costs.
- Zora Protocol for minting NFT drops through a standardized logic contract, cloned per artist or collection.
Whether you’re on Ethereum or another EVM-compatible chain, cloning lets you scale faster, cheaper, and more securely.
Source Code Access & Analysis
Would you like to experiment or audit the above? One can find an open-source example in GitHub by searching for ERC-1167 clone factory or traversing the source code of protocols that apply the factory pattern.
Moreover, you may want to run source code analysis tooling such as MythX to verify that your contracts are not vulnerable before deployment. Such tools can track more typical flaws like reentrancy, uninitialized storage pointers, or access control. It is also very important to regularly audit your implementation as well as factory logic, particularly when you are dealing with financial or DAO-based smart contracts.
Final Thoughts
Cloning smart contracts using ERC-1167 is a powerful technique for efficient, scalable blockchain development. It reduces gas fees, simplifies upgrades, and enables complex on-chain applications to scale easily.
Now that you understand how it works, you can integrate clones into your dApp architecture, deploy thousands of contract instances with minimal cost, and even build your protocol factories.
This pattern is especially valuable for developers building user-generated contract platforms, modular DeFi tools, and NFT drop engines. By combining the factory pattern with proper initialization logic and access controls, you can ensure your clones remain both secure and customizable.
