Partially Parametric Rules for ERC-721 Introduction This chapter is the final part (5/5) of the code walkthrough of OpenZeppelin’s ERC-721 CVL specification which formally verifies the following...

Mint and Burn Rules for ERC-721 Introduction ERC-721 is the Ethereum standard for non-fungible tokens, widely used to represent digital property. Like any form of property, it revolves around supply...

Invariants for ERC-721 Introduction In previous chapters, we explored how CVL invariants work: properties that must hold throughout all contract execution. Invariants can function as preconditions in...

Components Part 2: OpenZeppelin ERC-20 Tutorial In Component Part 1, we learned how to create and use a component within a single file. We built a from scratch and integrated its storage, events, and...

Cairo Storage Variable Types In Starknet, Contract Storage is the persistent memory where your smart contract's state lives. Unlike variables declared inside a function which disappear after...

ERC-20 Token on Starknet ERC-20 tokens on Starknet work the same way as on Ethereum. In fact, STRK (Starknet's fee token) is itself an ERC-20 token; there's no special "native" token at the protocol...

Solidity Coding Standards The purpose of this article is not to rehash the official Solidity Style Guide, which you should read. Rather, it is to document the common deviations from the style guide...

The staking algorithm of SushiSwap MasterChef and Synthetix The MasterChef and Synthetix staking algorithms distribute a fixed reward pool among stakers according to their time-weighted contributions...

Interest Bearing Token Part 1 The Token-2022 interest-bearing extension enables a token mint to automatically accrue interest on all token accounts for that specific mint. It uses an annual rate...

Interest Bearing Token Part 2 The interest-bearing extension adds the ability for a token mint to accrue interest over time. In our previous discussion of Token-2022, we introduced the...