👷 Setting up your development environment

In order to write smart contracts on Frame, you'll need to set up Foundry (opens in a new tab).

Foundry is a suite of tools that makes it easy to write, test, and deploy smart contracts. With Foundry, we can locally develop and test our smart contracts before launching them on testnet or mainnet.

🛠 Install Foundry

Note: We recommend downloading the Solidity extension for VSCode which gives nice syntax highlighting.

Installing Foundry is as simple as going into your terminal and typing in the following:

curl -L https://foundry.paradigm.xyz | bash

Afterwards, you should see the following screen:

If you see any problems or errors appear, you can read more about the installation process in this guide (opens in a new tab) from the Foundry docs.

Now, simply run the following to install the latest workingversion of Foundry:

foundryup --version ca67d15

You should see the following:

Finally, let's make a new directory for our project.

cd <preferred_directory>
forge init my-first-frame-nft
cd my-first-frame-nft

forge init my-first-frame-nft creates a new directory called my-first-frame-nft and initializes it with a sample project.

Inside the directory, there's 4 folders: lib, script, src, and test.

These folders each have a specific purpose:

• lib contains the smart contracts we'll write
• script contains scripts that we can run to interact with our smart contracts
• src contains the front-end code for our dapp
• test contains tests for our smart contracts

In this tutorial, we'll be interacting with src and test in order to create and deploy our NFT set.

Setup Solidity version

Because Frame is a rollup, it's not always up to date with the latest EVM changes. The latest Solidity version, 0.8.21, contains a new opcode that isn't supported on Frame yet. To make sure our compiler is generating valid code, we need to add this line to our foundry.toml file:

evm_version = "paris"

This tells the Solidity compiler to compile our code against an older version of the EVM (which doesn't include the new opcode).

🔨 Run tests on Foundry

To make sure that our Foundry install worked, let's build and run the tests on our sample project.

forge build
forge test

If it works, you should see the following:

If you're seeing this, you're just about ready to start writing your NFT smart contract! The above means that the two written sample tests both passed after you built the project using forge build.

Note: We will not be using the existing files in src/ or test/ for the rest of this tutorial. These files are only meant for reference.