How to Run Vercel CDN in Front of Discourse

Vercel CDN can act as a proxy not only for applications deployed directly on the Vercel platform, but also in front of external platforms such as Discourse or WordPress. This makes it easy to add firewall protection, DDoS mitigation, and observability features without fully migrating an existing application.

Using Vercel as a proxy provides the following benefits:

• Web Analytics: Provides anonymized data on user traffic and behavior
• Firewall: Prevents DDoS attacks and strengthens security
• Bot Management: Blocks malicious scrapers while allowing trusted crawlers to index

The implementation requires two domains: the Inner host, the actual hosting server, and the Outer host, the Vercel domain that users access. vercel.ts is used to rewrite traffic to the Inner host, and for security, the x-proxy-secret header is used to verify traffic, blocking direct external access to the Inner host.

Additionally, Vercel Microfrontends can be used to extend functionality by mounting a Next.js app on a specific path. This is useful for creating pages that are difficult to implement as CMS plugins, overwriting existing pages, and maintaining authentication via Sign in with Vercel. This approach enables incremental modernization instead of large-scale refactoring.