add otp swagger

app/api/openapi/route.ts

@@ -1,11 +1,39 @@
-import { NextResponse } from "next/server";
+import { NextRequest, NextResponse } from "next/server";
 import { openApiSpec } from "@/lib/openapi";
 
-export async function GET() {
-  return NextResponse.json(openApiSpec, {
+function getRequestOrigin(req: NextRequest) {
+  const forwardedProto = req.headers.get("x-forwarded-proto")?.split(",")[0]?.trim();
+  const forwardedHost = req.headers.get("x-forwarded-host")?.split(",")[0]?.trim();
+  const host = forwardedHost ?? req.headers.get("host");
+  const proto = forwardedProto ?? req.nextUrl.protocol.replace(":", "");
+  const origin = host ? `${proto}://${host}` : req.nextUrl.origin;
+
+  try {
+    const url = new URL(origin);
+    if (url.protocol === "http:" || url.protocol === "https:") return url.origin;
+  } catch {
+    // Fall through to the same-origin server below.
+  }
+
+  return "/";
+}
+
+export async function GET(req: NextRequest) {
+  return NextResponse.json({
+    ...openApiSpec,
+    servers: [
+      {
+        url: getRequestOrigin(req),
+        description: "Current request origin",
+      },
+      {
+        url: "/",
+        description: "Same-origin fallback",
+      },
+    ],
+  }, {
     headers: {
       "Cache-Control": "no-store",
     },
   });
 }
-