save refresh token

app/api/auth/refresh/route.ts

@@ -0,0 +1,56 @@
+import { NextResponse } from "next/server";
+
+export async function GET(req: Request) {
+  const cookie = req.headers.get("cookie");
+
+  const refreshToken = cookie
+    ?.split("; ")
+    .find((c) => c.startsWith("refresh_token="))
+    ?.split("=")[1];
+
+  if (!refreshToken) {
+    return NextResponse.json({ message: "No refresh token" }, { status: 401 });
+  }
+
+  try {
+    // Call your auth server (Keycloak or NestJS)
+    const res = await fetch("http://api.example.com/auth/refresh", {
+      method: "POST",
+      headers: {
+        "Content-Type": "application/json",
+      },
+      body: JSON.stringify({ refresh_token: refreshToken }),
+    });
+
+    if (!res.ok) {
+      throw new Error("Refresh failed");
+    }
+
+    const data = await res.json();
+
+    const response = NextResponse.json({ success: true });
+
+    // 🍪 Set new access token
+    response.cookies.set("access_token", data.access_token, {
+      httpOnly: true,
+      secure: true,
+      sameSite: "lax",
+      path: "/",
+      domain: ".example.com",
+      maxAge: data.expires_in,
+    });
+
+    response.cookies.set("refresh_token", data.refresh_token, {
+        httpOnly: true,
+        secure: true,
+        sameSite: "lax",
+        path: "/",
+        domain: ".example.com",
+        maxAge: data.expires_in,
+    });
+
+    return response;
+  } catch {
+    return NextResponse.json({ message: "Refresh failed" }, { status: 401 });
+  }
+}