Pulse Chat

Pulse Chat is a production-oriented, real-time chat application built with React, Express, Socket.io, MongoDB, JWT, and Docker.

Architecture

• client/: Vite, React, TypeScript, and Tailwind responsive web application.
• server/: Express API, MongoDB models, JWT auth, Socket.io gateway, validated image uploads.
• MongoDB stores users, direct/group conversations, messages, and read receipts.
• Socket.io delivers messages, presence, typing state, and seen receipts in real time.

Included capabilities

• Register, sign in, persistent JWT sessions, and protected API routes.
• Direct conversations and group creation.
• Realtime text/image messages with optimistic delivery feedback.
• Presence indicators, typing indicators, unread counts, and seen receipts.
• JPEG, PNG, GIF, and WebP uploads with MIME and file-signature validation.
• Responsive dark-mode interface, test coverage for client utilities and server security helpers.

Local development

1. Copy server/.env.example to server/.env and set a unique JWT secret of at least 32 characters.
2. Run npm install.
3. Start MongoDB locally, then run npm run dev.
4. Open http://localhost:5173.

The API is available at http://localhost:4000, with GET /health for a health check.

Validation

• npm run build type-checks and builds both applications.
• npm run lint runs static checks.
• npm test runs unit tests.

Docker

Set a strong JWT_SECRET in your environment, then run docker compose up --build. The web client is served at http://localhost:8080; the API is exposed on port 4000. Uploads and MongoDB data use named Docker volumes.

Security notes

Passwords are bcrypt-hashed. Auth is JWT-based, routes and socket connections validate tokens, inputs use Zod, errors avoid leaking production internals, requests are rate limited, security headers are enabled, and uploads are size-, MIME-, and signature-checked. Use HTTPS and a managed MongoDB deployment in production.