Synthetic Stablecoin Design - $MADT

For educational purposes only.

Overview

This project serves as a proof-of-concept for a synthetic stablecoin pegged to the US Dollar. In this repository, we implement two key contracts: a Vault contract, which securely holds the collateral, and a MADT (Moroccan Dirham Token) contract, which is minted and distributed to users in exchange for a dollar-pegged stablecoin (USDT).

A previous version of this project used Hardhat as a development framework. I have migrated this codebase to use Foundry instead.

Prerequisites

• Foundry
• Install the dependencies: forge install
• Compile the contracts: forge build

How to run the project

• make fct-anvil: Launches a local Anvil node.
• make simulate-don: Launches the local DON simulator. Wait until the DON is ready.
• make deploy-all: Deploys all the contracts to a local node.

High-level Design

General architecture of the project:

Data provider architecture:

Architecture

This project uses Chainlink Functions in order to fetch the exchange rate of the Moroccan Dirham (MAD) to the US Dollar (USD).

Read about Chainlink Functions here.

Locally, we use a simulated DON environment to test the integration of the Chainlink Functions. We borrowed the implementation from the Chainlink Functions Toolkit repository.

Folder Structure

• src/: Contains the source code for the contracts.
• test/: Contains the test files for the Vault contract. I will add more tests soon.
• script/: Contains the script files to deploy MADT, a mock USDT stablecoin, and the Vault contract. It also contains a script to facilitate interactions with the Vault. This directory also contains a helper script to deploy the contracts to a local node.
• don-simulator/: Contains the implementation of the simulated DON environment. It also has the source code that is sent to the DON for fulfillment.

Contract Overview

MADT.sol

The MADT contract is a standard ERC20 contract that is used to represent the Moroccan Dirham Token.

Vault.sol

The Vault contract is a standard ERC20 contract that is used to hold the collateral for the stablecoin. It is used to mint MADT to users in exchange for (USDT).

DataProvider.sol

The DataProvider contract is a standard Chainlink Functions contract that is used to fetch the exchange rate of the Moroccan Dirham (MAD) to the US Dollar (USD). This contract is based on the Chainlink FunctionsClient contract.

MockUSDT.sol

The MockUSDT contract is a standard ERC20 contract that is used to represent the mock USDT stablecoin.

Easier interactions using Make

The project includes several make commands to simplify common development tasks:

• make simulate-don: Launches the local DON simulator.
• make deploy-all: Deploys all the contracts to a local node.
• make deploy-madt: Deploys the MADT contract to a local node.
• make deploy-usdt: Deploys the mock USDT contract to a local node.
• make deploy-vault: Deploys the Vault contract to a local node.
• make send-request: Sends a request to the DataProvider contract to fetch the exchange rate of the Moroccan Dirham (MAD) to the US Dollar (USD).
• make get-last-response: Gets the last response from the DataProvider contract.
• make get-last-error: Gets the last error from the DataProvider contract.
• make get-last-request-id: Gets the last request ID from the DataProvider contract.
• make deposit-collateral: Deposits collateral into the Vault contract.
• make redeem-collateral: Redeems collateral from the Vault contract.
• make rebase: Rebases the Vault contract.

To-do

• Add more tests for the Vault contract.
• Deploy to a testnet.