vercel__streamdown/apps/website/proxy.ts

import { createI18nMiddleware } from "fumadocs-core/i18n/middleware";
import { isMarkdownPreferred, rewritePath } from "fumadocs-core/negotiation";
import {
  type NextFetchEvent,
  type NextRequest,
  NextResponse,
} from "next/server";
import { i18n } from "@/lib/geistdocs/i18n";

const { rewrite: rewriteLLM } = rewritePath("/docs/*path", "/llms.mdx/*path");

const internationalizer = createI18nMiddleware(i18n);

const proxy = (request: NextRequest, context: NextFetchEvent) => {
  // First, handle Markdown preference rewrites
  if (isMarkdownPreferred(request)) {
    const result = rewriteLLM(request.nextUrl.pathname);
    if (result) {
      return NextResponse.rewrite(new URL(result, request.nextUrl));
    }
  }

  // Fallback to i18n middleware
  return internationalizer(request, context);
};

export const config = {
  // Matcher ignoring `/_next/`, `/api/`, static assets, favicon, sitemap, robots, etc.
  matcher: [
    "/((?!api|_next/static|_next/image|favicon.ico|sitemap.xml|robots.txt).*)",
  ],
};

export default proxy;