live_chat_app

Live chat app with Express, SocketIO and Next.js A highly scalable real-time chat ecosystem, structured as a monorepo to facilitate type sharing and service orchestration.

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🛠️ Tech Stack

Layer	Technology
Runtime Ecosystem	Node.js
Language	TypeScript (Strict Mode)
Backend (API)	Express.js
Real-time	Socket.IO
Frontend	Next.js
ORM	Prisma
Package Manager	PNPM (Workspaces)

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📂 Folder Architecture

live_chat_app/
├── apps/
│   ├── api/      # Backend – REST API with Express Server
│   ├── socket/   # Backend – WebSocket Server (Socket.IO)
│   └── web/      # Frontend – Client-side Application (Next.js)
├── pnpm-workspace.yaml
├── package.json
└── turbo.json

The project uses PNPM Workspaces and Turborepo for orchestration::

• pnpm-workspace.yaml:Defines the location of packages and applications within the monorepo, allowing PNPM to manage dependencies in a shared and efficient way.
• package.json (Root): Manages global commands and monorepo dependencies.
• turbo.json: Configures the execution pipeline and task caching.

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⚙️ System Requirements

Make sure you have the following installed on your machine:

• Node.js
• pnpm (Essential for monorepo management)
• npm + npx (For running Prisma scripts)

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🚀 Installation and Initial Setup

At the project root, install all dependencies:

pnpm install

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🔧 6. Backend (API) Configuration

6.1 Integration Credentials

The API requires credentials so the Socket Server and Web Client can communicate securely.

6.1.1 Configure the Socket Server

Generate the credentials:

pnpm generate-app-credentials:socket

In apps/api/.env, save the returned credential values:

SOCKET_IO_APP_NAME=SocketIO Server
SOCKET_IO_APP_ID=<returned_app_id>
SOCKET_IO_APP_API_KEY_HASH=<returned_app_hash>

In apps/socket/.env, save the key:

API_KEY=<returned_API_key>

6.1.2 Configure the Web Client

Generate the credentials:

pnpm generate-app-credentials:web

In apps/api/.env, add:

WEB_APP_NAME=Web Client
WEB_APP_ID=<returned_app_id>
WEB_APP_API_KEY_HASH=<returned_app_hash>

In apps/web/.env, add:

API_KEY=<returned_API_key>

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6.2 Database Configuration (Prisma)

The project is natively configured for MySQL.

Set the connection variables in apps/api/.env:

DATABASE_URL="mysql://username:password@localhost:3306/mydb"
DATABASE_USER="username"
DATABASE_PASSWORD="password"
DATABASE_NAME="mydb"
DATABASE_HOST="localhost"
DATABASE_PORT=3306

PostgreSQL note: If you prefer Postgres, replace the adapter:

pnpm remove --filter ./apps/api @prisma/adapter-mariadb
pnpm add --filter ./apps/api @prisma/adapter-pg pg

Update the connection in: apps/api/src/infra/database/prisma.js.

Run the migrations and seed:

cd apps/api
npx prisma migrate dev --name init
npx prisma generate
npx prisma db seed

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6.3 Authentication Key Generation (JWT PKCS#8)

Use OpenSSL to generate the signing and verification keys.

Generate RSA private key (PKCS#8):

openssl genpkey -algorithm RSA -out private_key.pem -pkeyopt rsa_keygen_bits:2048

Extract the public key:

openssl rsa -pubout -in private_key.pem -out public_key.pem

Key distribution:

• Move private_key.pem and public_key.pem to apps/api/secrets/
• Move public_key.pem to apps/socket/secrets/

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6.4 Additional API Variables

In apps/api/.env, set the port and the "pepper" (secret value for hashing):

SERVER_PORT=3000
API_KEY_PEPPER=<secret_pepper_value>

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🔌 7. Socket Server Configuration

In apps/socket/.env, configure the API integration:

API_KEY=<API_KEY_generated_in_step_6.1.1>
SERVER_PORT=3001

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💻 8. Web Client (Frontend) Configuration

In apps/web/.env, add the environment definitions:

API_KEY=<API_KEY_generated_in_step_6.1.2>
COOKIE_LOGGED_USER=<uuid_for_cookie_identification>
API_BASE_URL=http://localhost:3000
NEXT_PUBLIC_SOCKET_BASE_URL=http://localhost:3001
NODE_ENV=development

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🚀 9. Running the Project

Development Mode (All services)

pnpm dev

Individual Commands (Dev)

Service	Command
API	pnpm dev:api
Web	pnpm dev:web
Socket	pnpm dev:socket

Build and Production

Action	Command
Build All	pnpm build
Start All	pnpm start
Build API	pnpm build:api
Build Web	pnpm build:web
Build Socket	pnpm build:socket
Start API	pnpm start:api
Start Web	pnpm start:web
Start Socket	pnpm start:socket