OpenZeppelin Contracts 4.1

This new release introduces UUPS proxies as a cheaper alternative to Transparent proxies. Additionally, a new ERC20 extension allows easy creation of tokens with built-in flash minting, and a new small utility contract provides a function batching mechanism that requires no extra work to set up. Read on to learn more!

Introducing Contracts Wizard: An Interactive Contract Generator

Contracts Wizard is an interface to interactively build a contract out of components from OpenZeppelin Contracts. Select the kind of contract that you want (current support for ERC20 and ERC721), set your parameters and desired features (token name, symbol, premint amount, access control, etc.), and Wizard will generate all of the code necessary.

OpenZeppelin Contracts 4.0

Due to the new built-in overflow checks in Solidity 0.8, which mark the end of the `SafeMath` era, this release of OpenZeppelin Contracts is a new major version of the library.

OpenZeppelin Contracts 3.4

OpenZeppelin Contracts 3.4 includes an ERC777 security fix for potential reentrancy issues in custom ERC777 extension, virtual view functions, ERC20 permit in drafts, Beacon proxy, and a Minimal Proxy (Clones) library.

Reentrancy After Istanbul

How to protect your contracts against reentrancy after Ethereum’s Istanbul hard fork.

Announcing OpenZeppelin 2.0

A stable, audited, and fully tested package for smart contract development

Towards frictionless upgradeability

ZeppelinOS is all about making the technology of upgradeability into an accessible and frictionless tool for developers. Ideally, we want to enable a developer to create upgradeable instances...

Handling Crowdsale Funds Securely

When developing a crowdsale smart contract, there are several options for handling the collection of funds. In this post, we’ll analyze the most common approaches, and try to assess their degree of security and transparency.