Bartosz

[bartosz0718]

Pull Request: Web3 Message Signer & Verifier (Take-Home Task)
📌 Overview

This PR implements the Decentralized Masters Test Task, delivering a full-stack Web3 application that allows users to:

Authenticate with Dynamic.xyz headless email OTP (no widget)

Automatically create & connect an embedded non-custodial wallet

Sign custom user messages with the wallet

Verify signatures server-side using ethers.js

Maintain a local signing history for transparency

The project is split into two workspaces:

frontend/ → React (CRA + TypeScript + Tailwind)

backend/ → Node.js + Express + ethers v6

🔑 Features Implemented
Frontend (frontend/)

Authentication: Headless Dynamic email login with OTP input (react-otp-input) styled via Tailwind

Embedded Wallet: Automatic creation and connection for new users

UI/UX:

Clean, responsive Tailwind interface

Pixel-perfect OTP flow similar to Privy/Dynamic

Clear error and loading states

Message Signing:

Enter custom message → sign with wallet

Submit { message, signature } to backend

History:

Persist signed message history in localStorage

Display signer, message, signature, and timestamp

Backend (backend/)

API Endpoint: POST /verify-signature

Input: { message, signature }

Verification via ethers.verifyMessage

Returns { isValid, signer, originalMessage }

Security & Structure:

Express middleware setup (CORS, JSON body parser)

Configurable via .env

Testing:

Added tests with Vitest + Supertest for valid & invalid signatures

🛠️ Tech Stack

Frontend: React 18, TypeScript, TailwindCSS, Dynamic SDK (headless), Axios

Backend: Node.js, Express, ethers.js v6, Vitest, Supertest

Tooling: GitHub Actions (CI), ESLint, Prettier

Storage: LocalStorage (client), in-memory (server; no DB per requirements)

📖 Setup Instructions

Detailed setup instructions are included in:

frontend/README.md

backend/README.md

Quick start:

Backend

cd backend && cp .env.example .env && npm i && npm run dev

Frontend

cd frontend && cp .env.example .env && npm i && npm start

🚀 Improvements & Next Steps

Add EIP-712 typed data signing support

Implement headless MFA (Dynamic) for stronger security

Add persistent DB layer for server-side audit logs

Deploy to Vercel (frontend) + Render/Fly (backend) for demo

✅ Deliverables Checklist

Frontend: headless auth + wallet + signing + history

Backend: verify signature endpoint (ethers.js)

Tests included (frontend & backend)

README setup docs

Code structured & styled with Tailwind

👉 This PR delivers the full test assignment implementation as described.