Compress middleware

server/middleware/compress.ts

@@ -0,0 +1,17 @@
+import { defineEventHandler, setResponseHeader } from 'h3';
+
+export default defineEventHandler(async (event) => {
+    const acceptEncoding = event.headers.get('accept-encoding') || '';
+    if (!acceptEncoding.includes('zstd')) return;
+
+    const _end = event.node.res.end;
+    //@ts-expect-error
+    event.node.res.end = async (body: any, ...args: any[]) => {
+        const buffer = typeof body === "string" ? new TextEncoder().encode(body) : body;
+
+        setResponseHeader(event, "Content-Encoding", "zstd");
+        setResponseHeader(event, "Vary", "Accept-Encoding");
+        //@ts-expect-error
+        _end.call(event.node.res, await Bun.zstdCompress(buffer), ...args);
+    };
+});