What does the fastly error message mean when trying to host a component of my site (/en/privacy-policy) on Webflow using an nginx reverse proxy?

You're seeing a Fastly error message because Webflow uses Fastly as its CDN and security layer, and the request from your NGINX reverse proxy isn’t compliant with what Fastly/CDN expects from web traffic. This typically happens when there are improper headers, missing host info, or SSL/TLS issues.

1. Understand What Fastly Is Doing

• Fastly is Webflow’s CDN and application firewall, sitting between your site and the world.
• If a request appears suspicious, malformed, or improperly routed, Fastly will return a standard error page (often a 503 or 403 Forbidden).
• Issues often arise when requests are proxied from servers like NGINX, which may strip or modify headers critical to Fastly.

2. Check Your NGINX Reverse Proxy Configuration

• Make sure your proxy passes the correct headers, especially:
• Host: Should exactly match your Webflow domain (e.g., www.example.com)
• X-Forwarded-For, X-Forwarded-Proto: Often expected by CDN/firewall layers.
• Your NGINX config should include:
• 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;

3. Avoid Path-Level Routing When Using Webflow Hosting

• Webflow does not support hosting only portions of a site (e.g., just /en/privacy-policy) directly.
• If you're proxying only that sub-route through NGINX into Webflow, Fastly may reject the traffic since your domain/routing doesn't match Webflow’s expectations.
• Webflow expects the entire site to be under one root domain that it manages via DNS or full proxy.

4. Use a Custom Domain Pointed Fully to Webflow (If Hosting Pages There)

• You should either:
• Point a full domain (e.g., privacy.example.com) to Webflow using the correct A records (75.2.70.75, 99.83.190.102) or
• Let Webflow manage routing for all sub-pages under one domain.
• Attempting to serve just certain URLs (like /en/privacy-policy) through a reverse proxy bypasses Webflow’s domain validation and can trigger Fastly security errors.

5. Consider Using Static Redirects or Proxy Alternatives

• If your goal is to preserve paths like /en/privacy-policy:
• Use 301 redirects at the root domain level to a Webflow-managed subdomain.
• Or serve Webflow content under a subdomain (webflow.example.com), and link directly rather than reverse-proxying.

Summary

The Fastly error likely means your NGINX reverse proxy is sending malformed or incomplete requests to Webflow’s CDN, which blocks them for security. Webflow doesn't support segment-only routing like /en/privacy-policy through a reverse proxy. Instead, route a full domain or subdomain properly to Webflow and avoid path-by-path proxying.