Server Configuration

The production server is a Fastify-based application defined in server.js at the project root.

Stack

Component	Package	Purpose
HTTP server	fastify	Core framework
Static files	@fastify/static	Serves the dist/ directory
Compression	@fastify/compress	gzip and brotli encoding
Rate limiting	@fastify/rate-limit	Request throttling

Static File Serving

The dist/ directory is served from the root path (/) with the following caching behavior:

File Type	Cache-Control	Rationale
Hashed assets (JS, CSS)	immutable, max-age=1y	Filenames include content hashes, so content changes produce a new URL
HTML files	public, max-age=3600, must-revalidate	HTML references hashed assets but must be rechecked periodically

Compression

@fastify/compress is registered to provide automatic gzip and brotli compression for text-based responses. This reduces network transfer size for HTML, CSS, and JavaScript files.

Rate Limiting

@fastify/rate-limit is configured with:

• Maximum: 100 requests per minute per client

This protects the server from abuse without affecting normal usage patterns.

SPA Fallback

Unmatched routes return index.html with a 200 status code. This enables client-side routing for URL parameter deep links (e.g., ?dna_dna=ATGC). Without this fallback, direct navigation to a URL with query parameters would result in a 404.

Port

The server listens on port 6001 by default. This can be overridden with the PORT environment variable:

PORT=3000 npm start

The server binds to :: (all IPv4 and IPv6 interfaces).

Reverse Proxy

For production deployments, a reverse proxy is recommended to provide HTTPS termination. Common choices include:

• Nginx -- configure as a reverse proxy with SSL certificates
• Cloudflare -- enable the proxy toggle on DNS records for automatic TLS

A typical Nginx configuration:

server {
    listen 443 ssl;
    server_name example.com;

    ssl_certificate     /path/to/cert.pem;
    ssl_certificate_key /path/to/key.pem;

    location / {
        proxy_pass http://127.0.0.1:6001;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }
}