Chirpy

Chirpy is a robust backend API for a social network application similar to Twitter. This project demonstrates the implementation of a scalable web server using TypeScript and modern Node.js practices, focusing on type safety, database management and secure authentication.

Tech Stack

• Language: TypeScript
• Runtime: Node.js
• Framework: Express.js
• Database: PostgreSQL
• ORM: Drizzle ORM (with drizzle-kit for migrations)
• Authentication: JWT, Argon2
• Testing: Vitest
• Tooling: npm

Features

• User Authentication: Secure signup and login flows using Argon2 for password hashing and JWTs (JSON Web Tokens) for session management. Includes refresh token rotation and revocation strategies.
• Chirps (Posts): Full CRUD (Create, Read, Update, Delete) capabilities for user posts, known as "chirps".
• Membership Tiering: Integration with webhooks to handle premium user upgrades ("Chirpy Red").
• Admin Tools: Dedicated endpoints for system metrics and database management (reset functionality for development).
• Database Management: Utilizes PostgreSQL with Drizzle ORM for type-safe database interactions and schema migrations.
• Middleware: Custom middleware for request logging, error handling, and metric tracking.

Achievements & Key Learnings

Building Chirpy provided deep insights into backend development:

• Architecting a RESTful API: Designed and implemented a clean, RESTful API structure separating concerns between routing, controllers, and database logic.
• TypeScript Mastery: Leveraged TypeScript's static typing to catch errors early and ensure type safety across the entire application, from database models to API responses.
• Database Integration: Gained hands-on experience with PostgreSQL and Drizzle ORM, including defining schemas, running migrations, and writing complex queries.
• Security Best Practices: Implemented industry-standard security measures, including password hashing with Argon2 and stateless authentication using JWTs.
• Webhook Integration: Handled external events via webhooks to simulate real-world payment processing and user status updates.
• Testing: Wrote comprehensive unit and integration tests using Vitest to ensure code reliability and prevent regressions.

Getting Started

Prerequisites

• Node.js (v20+ recommended)
• npm
• PostgreSQL database

Installation

1. Clone the repository:

   git clone https://github.com/yourusername/chirpy.git
   cd chirpy

2. Install dependencies:

   npm install

3. Set up environment variables: Create a .env file in the root directory with the following variables:

   PORT=8080
   PLATFORM=dev
   DB_URL=postgres://user:password@localhost:5432/chirpy
   SECRET=your_jwt_secret_key
   POLKA_KEY=your_mock_payment_api_key

4. Run database migrations:

   npm run migrate

Running the Server

• Development Mode (with hot reload):

  npm run dev

• Production Build:

  npm run build
  npm start

• Run Tests:

  npm test

API Endpoints

Auth & Users

• POST /api/login: Authenticate a user.
• POST /api/users: Create a new user.
• PUT /api/users: Update user details.
• POST /api/refresh: Refresh an access token.
• POST /api/revoke: Revoke a refresh token.

Chirps

• GET /api/chirps: Retrieve all chirps (optional sorting).
• GET /api/chirps/:chirpId: Retrieve a specific chirp.
• POST /api/chirps: Create a new chirp.
• DELETE /api/chirps/:chirpId: Delete a chirp.

Webhooks

• POST /api/polka/webhooks: Handle events from Polka (payment provider).

Admin

• GET /admin/metrics: View server metrics.
• POST /admin/reset: Reset the database (dev only).

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This project was built as part of the backend engineering curriculum at Boot.dev.