Privy Authentication Implementation Guide

This document explains how to implement Privy authentication in a full-stack JavaScript application, including JWT verification and protected API endpoints.

Overview

The implementation consists of three main parts:

1. Client-side authentication with Privy
2. Server-side JWT verification
3. Protected API endpoints

Setup

Prerequisites

• Privy account and API credentials
• Node.js and npm
• SQLite for data storage

Environment Variables

Copy the .env.example file to .env and fill in the values.

Database

This example uses SQLite for simplicity. This can be replaced in production with MongoDB,

Starting up the server

1. Run npm install to install the dependencies.
2. Run npm run build to build the site.
3. Run node server.js to start the server.

Testing the server

1. Run npm run dev to start the development server.
2. Navigate to http://localhost:3000 in your browser.
3. Click the "Login" button to authenticate with Privy.
4. Once authenticated, you should see a random number and your user ID.
5. Click the "Open String Input Window" and enter a value.
6. Verify in the DB (or in the server logs) that the value was stored.

Example Flow with Screenshots

1. Initial Login Screen

User arrives at the application and sees the login button

2. Wallet Selection

User selects MetaMask as their authentication method

3. Post-Authentication View

After successful authentication, user sees their random number and user ID

4. String Input Window

User enters a string value in the popup window

5. Server Processing

Server logs showing successful string submission and processing