🗿 fix: Static Cache Headers

.env.example

@@ -18,3 +18,21 @@ SESSION_SECRET=
 
 # Session idle timeout in milliseconds (default: 30 minutes)
 # ADMIN_SESSION_IDLE_TIMEOUT_MS=1800000
+
+# ── Cache Control ────────────────────────────────────────────
+# These mirror LibreChat's cache env vars. ADMIN_PANEL_* variants
+# take precedence, falling back to the shared LibreChat equivalents.
+
+# Static asset caching (hashed files in /assets/)
+# STATIC_CACHE_MAX_AGE=172800        # browser max-age in seconds (default: 2 days)
+# STATIC_CACHE_S_MAX_AGE=86400       # CDN s-maxage in seconds (default: 1 day)
+# ADMIN_PANEL_STATIC_CACHE_MAX_AGE=  # overrides STATIC_CACHE_MAX_AGE for admin panel
+# ADMIN_PANEL_STATIC_CACHE_S_MAX_AGE= # overrides STATIC_CACHE_S_MAX_AGE for admin panel
+
+# HTML / index response caching
+# INDEX_CACHE_CONTROL=no-cache, no-store, must-revalidate
+# INDEX_PRAGMA=no-cache
+# INDEX_EXPIRES=0
+# ADMIN_PANEL_INDEX_CACHE_CONTROL=   # overrides INDEX_CACHE_CONTROL for admin panel
+# ADMIN_PANEL_INDEX_PRAGMA=          # overrides INDEX_PRAGMA for admin panel
+# ADMIN_PANEL_INDEX_EXPIRES=         # overrides INDEX_EXPIRES for admin panel

package.json

@@ -31,6 +31,7 @@
     "@tanstack/react-router-ssr-query": "^1.166.10",
     "@tanstack/react-start": "^1.167.16",
     "@tanstack/router-plugin": "^1.167.12",
+    "@types/bun": "^1.3.11",
     "clsx": "^2.1.1",
     "cmdk": "^1.1.1",
     "date-fns": "^4.1.0",

server.ts

@@ -4,6 +4,31 @@ import { join } from 'node:path';
 const CLIENT_DIR = join(import.meta.dir, 'dist', 'client');
 const SERVER_ENTRY = new URL('./dist/server/server.js', import.meta.url);
 
+const env = process.env;
+
+const ONE_DAY = 86400;
+const maxAge = Number(env.ADMIN_PANEL_STATIC_CACHE_MAX_AGE ?? env.STATIC_CACHE_MAX_AGE) || ONE_DAY * 2;
+const sMaxAge = Number(env.ADMIN_PANEL_STATIC_CACHE_S_MAX_AGE ?? env.STATIC_CACHE_S_MAX_AGE) || ONE_DAY;
+
+const NO_CACHE: Record<string, string> = {
+  'Cache-Control': env.ADMIN_PANEL_INDEX_CACHE_CONTROL ?? env.INDEX_CACHE_CONTROL ?? 'no-cache, no-store, must-revalidate',
+  Pragma: env.ADMIN_PANEL_INDEX_PRAGMA ?? env.INDEX_PRAGMA ?? 'no-cache',
+  Expires: env.ADMIN_PANEL_INDEX_EXPIRES ?? env.INDEX_EXPIRES ?? '0',
+};
+
+const LONG_CACHE: Record<string, string> = {
+  'Cache-Control': `public, max-age=${maxAge}, s-maxage=${sMaxAge}`,
+};
+
+const NEVER_CACHE = new Set(['manifest.json', 'sw.js', 'robots.txt']);
+
+function getCacheHeaders(filePath: string): Record<string, string> {
+  const fileName = filePath.split('/').pop() ?? '';
+  if (NEVER_CACHE.has(fileName)) return NO_CACHE;
+  if (filePath.startsWith('assets/')) return LONG_CACHE;
+  return {};
+}
+
 type Handler = { default: { fetch: (req: Request) => Promise<Response> } };
 
 const { default: handler } = (await import(SERVER_ENTRY.href)) as Handler;
@@ -12,7 +37,9 @@ async function buildStaticRoutes(): Promise<Record<string, () => Response>> {
   const routes: Record<string, () => Response> = {};
   for await (const path of new Glob('**/*').scan(CLIENT_DIR)) {
     const file = Bun.file(`${CLIENT_DIR}/${path}`);
-    routes[`/${path}`] = () => new Response(file, { headers: { 'Content-Type': file.type } });
+    const cache = getCacheHeaders(path);
+    routes[`/${path}`] = () =>
+      new Response(file, { headers: { 'Content-Type': file.type, ...cache } });
   }
   return routes;
 }
@@ -21,7 +48,14 @@ Bun.serve({
   port: Number(process.env.PORT ?? 3000),
   routes: {
     ...(await buildStaticRoutes()),
-    '/*': (req) => handler.fetch(req),
+    '/*': async (req) => {
+      const res = await handler.fetch(req);
+      const patched = new Response(res.body, res);
+      for (const [k, v] of Object.entries(NO_CACHE)) {
+        patched.headers.set(k, v);
+      }
+      return patched;
+    },
   },
 });