Use PYUSD in smart contracts

This guide is an introduction to "onchain" development with PYUSD, meaning integration into smart contracts.

The project

We will build a simple smart contract that accepts PYUSD as a fee to mint an ERC-721 NFT.

Full project is available on GitHub

Technology we'll cover

Foundry

Foundry is a toolkit for smart contract development. It provides a robust and flexible framework for building, testing, and deploying smart contracts. We will use the Foundry development toolkit to write, test, and deploy.

Solidity

Solidity is a programming language designed for developing special programs called "smart contracts" that run on the Ethereum Virtual Machine (EVM). If coming from a typical imperative programming background with languages like Java or C++, Solidity's syntax will feel familiar.

PYUSD

PYUSD is PayPal's stablecoin deployed on Ethereum as a smart contract that implements the ERC-20 standard. PYUSD represents a digital IOU for a US dollar, can be transferred among wallets, and can be used in smart contracts. PayPal users are able to mint and burn PYUSD tokens directly within the PayPal app.

Assumptions

We're going to assume a few starting points:

• We have git set up locally
• We're running on a Linux flavor or a Mac
• We are comfortable with some command line stuff
• We like tests and test coverage!

We won't assume:

• Any knowledge of Ethereum, Solidity, or Solidity tooling