Use Cloudflare Cache API for actual edge caching

src/routes/-worker-entry.ts

@@ -309,36 +309,53 @@ async function handleIconProxy(request: Request): Promise<Response> {
 
 // ─── Worker Entry ───────────────────────────────────────────────────
 
+const cache = (caches as unknown as { default: Cache }).default;
+
 export default {
 	async fetch(request: Request, _env: Env): Promise<Response> {
 		const url = new URL(request.url);
 		const { pathname } = url;
 
-		// robots.txt
-		if (pathname === "/robots.txt") {
-			return robotsTxt();
-		}
-
-		// Sitemaps
-		const sitemapHandler = sitemapHandlers[pathname];
-		if (sitemapHandler) {
-			return sitemapHandler();
+		// robots.txt + sitemaps — serve from edge cache
+		if (pathname === "/robots.txt" || sitemapHandlers[pathname]) {
+			const cacheKey = new Request(url.toString(), { method: "GET" });
+			const cached = await cache.match(cacheKey);
+			if (cached) return cached;
+
+			const response =
+				pathname === "/robots.txt"
+					? robotsTxt()
+					: await sitemapHandlers[pathname]();
+			cache.put(cacheKey, response.clone()).catch(() => {});
+			return response;
 		}
 
 		// Icon proxy
 		if (pathname === "/icon") {
 			return handleIconProxy(request);
 		}
 
+		// Determine if this route is cacheable
+		const cacheHeader = getCacheHeader(pathname);
+
+		// Check edge cache for cacheable GET requests
+		if (cacheHeader && request.method === "GET") {
+			const cacheKey = new Request(url.toString(), { method: "GET" });
+			const cached = await cache.match(cacheKey);
+			if (cached) return cached;
+		}
+
 		// Pass through to TanStack Start
 		const response = await tanstackFetch(request);
 
-		// Apply cache headers
-		const cacheHeader = getCacheHeader(pathname);
-		if (cacheHeader && response.status === 200) {
-			const newResponse = new Response(response.body, response);
-			newResponse.headers.set("Cache-Control", cacheHeader);
-			return newResponse;
+		// Store cacheable responses in edge cache
+		if (cacheHeader && response.status === 200 && request.method === "GET") {
+			const cacheKey = new Request(url.toString(), { method: "GET" });
+			const cacheable = new Response(response.body, response);
+			cacheable.headers.set("Cache-Control", cacheHeader);
+			// Fire-and-forget cache write
+			cache.put(cacheKey, cacheable.clone()).catch(() => {});
+			return cacheable;
 		}
 
 		return response;