FileHost/docs-site/en/guide/reverse-proxy.md

Reverse proxy

In production, terminate HTTPS with Nginx, Caddy, NPM (Nginx Proxy Manager), or your NAS proxy and forward to PicHost on port 6892.

Basics

• Upstream: http://127.0.0.1:6892 (or host IP)
• Forward: Host, X-Forwarded-Proto (and X-Forwarded-For as needed)
• Body size: Nginx client_max_body_size 12m or larger
• Use HTTPS on the public edge

Single domain (Nginx)

Admin, API, and images on one hostname:

server {
  server_name pic.example.com;
  location / {
    proxy_pass http://127.0.0.1:6892;
    proxy_set_header Host $host;
    proxy_set_header X-Forwarded-Proto $scheme;
    client_max_body_size 12m;
  }
}

Optional:

IMAGE_BASE_URL=https://pic.example.com

Without IMAGE_BASE_URL, PicHost infers the public URL from forwarded headers.

Dual domains

Both hostnames can fully proxy to the same port; isolation is enforced in PicHost middleware.

See Dual-domain separation.

Cloudflare orange cloud

See Cloudflare deployment.

Practice	Notes
Proxied DNS	Both admin and image hostnames → origin proxy to 6892, SSL Full (strict)
Preferred edge IPs	Compatible; keep admin → admin, img → img on origin
R2	Object storage backend in Storage; not the same as hosting the app on Pages
Origin firewall	Allow only Cloudflare IPs; do not expose 6892 publicly

Avoid:

• Cloudflare Pages (*.pages.dev) or Workers (*.workers.dev) as a full-site reverse proxy, or chaining the image host to fetch(admin…) — rewrites Host and bypasses dual-domain isolation (guide)
• “Create Worker” from Git on this repo — node-server preset is not Workers-ready

Origin hardening (dual-domain)

PicHost middleware does not reject unlisted Host values. Complement with:

1. server_name allowlist — site + image hosts only; default_server blocks bare IP and unknown Host
2. Do not expose 6892 on the public Internet — only local reverse proxy; public 80/443 only
3. Orange cloud — origin firewall limited to Cloudflare IP ranges

Caddy

pic.example.com {
  reverse_proxy 127.0.0.1:6892
}

Add a second site block for the second hostname with the same upstream.

Caching

Image 404/403 and domain-isolation 404 responses are no-cache to avoid sticky CDN errors. Be careful caching API paths behind a CDN.

See also

• Environment variables
• Quick start