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Overview

Watch N Chill uses environment variables to configure Redis connections, CORS settings, rate limiting, and server behavior. All variables are optional with sensible defaults for local development.

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Redis Configuration

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REDIS_URL
string
default:"redis://localhost:6379"
Redis connection URL for room state, chat history, and rate limiting.Local development:
REDIS_URL=redis://localhost:6379
Upstash Redis (production):
REDIS_URL=rediss://default:<password>@<your-subdomain>.upstash.io:6379
The application automatically detects Upstash URLs (containing upstash.io) and configures TLS accordingly.

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Server Configuration

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NODE_ENV
string
default:"development"
Node.js environment mode. Set to production for production deployments.
NODE_ENV=production
Rate limiting is only enforced when NODE_ENV=production. Development mode disables rate limiting for easier testing.
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PORT
number
default:"3000"
HTTP server port for the application.
PORT=3000
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HOSTNAME
string
default:"localhost (dev) | 0.0.0.0 (prod)"
Hostname the server binds to. Automatically set based on NODE_ENV.
HOSTNAME=0.0.0.0

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CORS Configuration

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ALLOWED_ORIGINS
string
default:"http://localhost:3000 (dev)"
Comma-separated list of allowed origins for Socket.IO CORS.Required in production to enable cross-origin Socket.IO connections.
ALLOWED_ORIGINS=https://watchnchill.app,https://www.watchnchill.app
In development mode, http://localhost:3000 is automatically allowed. In production, you must explicitly set this variable.

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Rate Limiting

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RATE_LIMIT_WINDOW_MS
number
default:"60000"
Time window in milliseconds for HTTP rate limiting (1 minute default).
RATE_LIMIT_WINDOW_MS=60000
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RATE_LIMIT_MAX_REQUESTS
number
default:"360"
Maximum HTTP requests allowed per IP within the rate limit window.
RATE_LIMIT_MAX_REQUESTS=360
Default allows 360 requests per minute (6 requests per second).
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RATE_LIMIT_SOCKET_MAX_PER_IP
number
default:"10"
Maximum concurrent Socket.IO connections allowed per IP address.
RATE_LIMIT_SOCKET_MAX_PER_IP=10

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Next.js Configuration

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NEXT_TELEMETRY_DISABLED
boolean
default:"false"
Disable Next.js telemetry collection.
NEXT_TELEMETRY_DISABLED=1

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Complete Examples

# Redis - local instance
REDIS_URL=redis://localhost:6379

# Server configuration
NODE_ENV=development
PORT=3000

# CORS (auto-configured for localhost in dev)
# ALLOWED_ORIGINS not needed for local development

# Rate limiting (disabled in development)
RATE_LIMIT_WINDOW_MS=60000
RATE_LIMIT_MAX_REQUESTS=360
RATE_LIMIT_SOCKET_MAX_PER_IP=10

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Environment Variable Loading

The application loads environment variables in the following order:
  1. System environment variables
  2. .env.local (local development, gitignored)
  3. .env.production (production builds)
  4. .env (committed defaults)
Never commit .env.local or any file containing production credentials to version control.

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Validation

The application validates critical environment variables at startup:
  • REDIS_URL: Automatically tested on connection. Logs errors if Redis is unavailable.
  • Rate limiting: Falls back to in-memory rate limiting if Redis connection fails.
  • CORS: Defaults to localhost in development, requires explicit configuration in production.
Check the server logs on startup to verify your configuration: 
> Initializing Redis connection...
> Redis connected successfully
> Redis ready for commands
> Ready on http://0.0.0.0:3000
> Socket.IO server running on path: /api/socket/io

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