Location via proxy:   
[Report a bug]   [Manage cookies]                

The standard for secure onchain applications at any scale

Build and operate with OpenZeppelin's open-source tools and Defender Cloud Services across 30+ networks. Secure your code with our smart contracts audit.

Trusted by the world’s leading projects

Uniswap
ANZ
Coinbase
AAVE
Compound
Ethereum Foundation
Lens Protocol
Polkadot
Uniswap
ANZ-Logo-2009 1-1
Coinbase-1
aaveLogoWhite 1-1
Group-2
Ethereum Foundation-1
Lens Protocol
Polkadot
Uniswap
ANZ-Logo-2009 1-1
Coinbase-1
aaveLogoWhite 1-1
Group-2
Ethereum Foundation-1
Lens Protocol
Polkadot

Total value transferred
via OpenZeppelin Contracts

Dune
Explore Dune Dashboard

$6,398,582,627,181T

Dune
Explore Dune Dashboard
OpenZeppelin Stack

Build

“OpenZeppelin's contract library continues to be one of the best things to have happened for security in this space.”

Daniel Von Fange

Security Lead, Origin

Contract Libraries

Speed up development process and minimize risk. The battle-tested industry standard for Solidity and other languages.

Use Cases

Tokens Icon Tokens
Asset Tokenization Icon Asset Tokenization
DeFi Icon DeFi
Governance Icon Governance
Stablecoins Icon Stablecoins
Gaming Icon Gaming
NFTs Icon NFTs
Bridges Icon Bridges
Create your smart contract now
pragma solidity ^0.8.20;
          
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
          
contract MyToken is ERC20 {
    constructor() ERC20("MyToken", "MTK") {
        _mint(msg.sender, 5 * 10 ** decimals());
    }
}
pragma solidity ^0.8.20;
    
import "@openzeppelin/contracts/governance/Governor.sol"; 
import "@openzeppelin/contracts/governance/extensions/GovernorCountingSimple.sol"; 
import "@openzeppelin/contracts/governance/extensions/GovernorVotes.sol"; 
import "@openzeppelin/contracts/governance/extensions/GovernorVotesQuorumFraction.sol"; 
    
contract MyGovernor is Governor, GovernorCountingSimple, GovernorVotes, GovernorVotesQuorumFraction {
    constructor(IVotes _token)
        Governor("MyGovernor")
        GovernorVotes(_token)
        GovernorVotesQuorumFraction(4)
    {}
    
    function votingDelay() public pure override returns (uint256) {
        return 7200; // 1 day 
    }
    
    function votingPeriod() public pure override returns (uint256) {
        return 50400; // 1 week 
    }
    
    // The following functions are overrides required by Solidity.
    
    function quorum(uint256 blockNumber)
        public
        view
        override(Governor, GovernorVotesQuorumFraction)
        returns (uint256)
    {
        return super.quorum(blockNumber);
    }
}
pragma solidity ^0.8.20;
          
contract MyContract {
}
AI Assistant
#[starknet::contract]
mod MyToken {
    
    use openzeppelin::token::erc20::ERC20Component;
    use openzeppelin::token::erc20::ERC20HooksEmptyImpl;
          
    component!(path: ERC20Component, storage: erc20, event: ERC20Event);
    
    #[abi(embed_v0)]
    impl ERC20MixinImpl = ERC20Component::ERC20MixinImpl<ContractState>;
          
    impl ERC20InternalImpl = ERC20Component::InternalImpl<ContractState>;
          
    #[storage]
    struct Storage {
        #[substorage(v0)]
        erc20: ERC20Component::Storage,
        
    }
          
    #[event]
    #[derive(Drop, starknet::Event)]
    enum Event {
        #[flat]
        ERC20Event: ERC20Component::Event,
        
    }
          
    #[constructor]
    fn constructor(ref self: ContractState) {
        self.erc20.initializer("MyToken", "MTK");
        self.erc20.mint(recipient, 0000000000000000000);
    }
}
          
#[starknet::contract]
mod MyContract {
    #[storage]
    struct Storage {
    }
}
                  
AI Assistant

“OpenZeppelin's contract library continues to be one of the best things to have happened for security in this space.”

Daniel Von Fange

Security Lead, Origin

Secure

“Collaborating with OpenZeppelin on our security audit was a positive experience. We appreciated their thoroughness and attention to detail.”

Yoav Weiss

Security, Ethereum Foundation

Gold Standard Audits

Our Security Researchers set the industry standard in code review. Securing cutting-edge implementations in multiple types of audits including Smart Contract, ZKP, and Infrastructure.

Audit Report illustration
Audit Report illustration

1K+

Critical and High vulnerabilities uncovered

$50B

in Total Value Locked (TVL) secured

+1M

Lines of code
reviewed
We protect decentralized systems in different languages.

“Collaborating with OpenZeppelin on our security audit was a positive experience. We appreciated their thoroughness and attention to detail.”

Yoav Weiss

Security, Ethereum Foundation

Operate

“Defender is the perfect companion for operating with a protocol transparently and securely.”

Ariel Barmat

Lead Engineer, Edge & Node

Defender Cloud Services

Operate, Monitor, and Automate applications from testnet to mainnet, at any scale. Reliable and efficient relayers for high volume transactions across 30+ networks.

Defender Services illustration Defender Services illustration

+50M

Transactions processed via Defender relayers

+29M

Monitors alerts triggered

+3K

Deployed contracts
+30 mainnet and testnet networks supported.

“Defender is the perfect companion for operating with a protocol transparently and securely.”

Ariel Barmat

Lead Engineer, Edge & Node

Community Public Goods

Your success is our passion

Our mission is to create and protect the Open Economy.
Our industry-standard development and tooling resources are public, good – and free.

Ethereum logo
Authoring and co-authoring numerous EIPs and ERCs

Notable contributions include Account Abstraction (ERC-1271), Upgradeability (ERC-7201, ERC-1967), and Metatransactions (ERC-2771).

Supporting top protocols to Build, Secure & Operate onchain

Build
Secure
Operate
Matterlabs

Securing all releases and reducing response time

Build
TransparentProxy ProxyAdmin Ownable2Step Math ERC20Permit
Secure

Smart Contract Security Audits

ZKP Security Audits

Security Advisory

Operate

Defender Monitors

Arbitrum

Ensuring seamless upgrades and accelerating its developer ecosystem

Build
ERC20 Ownable Proxy Address StorageSlot Pausable TransparentProxy Initializable

Contracts library implementation for Stylus

Secure

Smart Contract Security Audits

DAO Security Proposal reviews

Operate

Defender Deploy, Relayers, Monitors & Actions support for Arbitrum One, Arbitrum Nova & Arbitrum Sepolia

Compound

Securing all DAO governance proposals and incidents

Build
Math ECDSA ERC20 ERC4626 SafeERC20
Secure

Smart Contract Security Audits

Security Advisory

Security Council Incident Response

DAO Security Proposal Reviews

Operate

Defender Monitors, Relayers, Actions

Polkadot

Accelerating their ecosystem with the OpenZeppelin Stack

Build

Parachain runtimes library

Secure

Smart Contract Security Audits

Security Advisory

Operate

Defender Monitors

Starkware

Accelerating their ecosystem with the OpenZeppelin Stack

Build

Contracts library implementation for Cairo

Secure

Smart Contract Security Audits

Sandbox

Building and expanding its virtual world securely

Build
Initializable Ownable SafeERC20 Address AccessControlEnumerable ECDSA BeaconProxy
Secure

Smart Contract Security Audits

Security Advisory

Operate

Defender Monitors, Actions, Transaction Proposals, Code Inspector

View more View more