Index: frontend/src/lib/admin-api.ts
===================================================================
--- frontend/src/lib/admin-api.ts	(revision b8093a091d45f33bab33deb8ff2fffc4734972c0)
+++ frontend/src/lib/admin-api.ts	(revision b8093a091d45f33bab33deb8ff2fffc4734972c0)
@@ -0,0 +1,90 @@
+import { apiUrl } from "@/lib/api";
+import { getAccessToken } from "@/lib/auth";
+
+export type AdminResult = { ok: boolean; message?: string; id?: number | null };
+
+export type SubjectRef = { id: number; name?: string; code?: string | null };
+
+export type SubjectMajor = {
+  majorId: number;
+  majorName?: string;
+  mandatorySemester: number;
+};
+
+export type AdminSubject = {
+  id: number;
+  name?: string;
+  code?: string;
+  awardedCredits: number;
+  dependencyCredit?: number | null;
+  majors: SubjectMajor[];
+  prerequisites: SubjectRef[];
+  enrolledCount: number;
+};
+
+export type AdminSemester = {
+  id: number;
+  year: number;
+  type?: string;
+  name?: string;
+  enrolmentCount: number;
+  uncoveredSubjects: SubjectRef[];
+};
+
+export type ScheduleRow = {
+  subjectId: number;
+  subjectName?: string;
+  subjectCode?: string;
+  professorId: number;
+  professorName?: string;
+};
+
+export type ProfessorLoad = {
+  professorId: number;
+  professorName?: string;
+  subjects: number;
+};
+
+export type Schedule = {
+  semesterId: number;
+  semesterName?: string;
+  assignments: ScheduleRow[];
+  load: ProfessorLoad[];
+  uncoveredSubjects: SubjectRef[];
+  allSubjects: SubjectRef[];
+  professors: { id: number; name?: string }[];
+};
+
+function authHeaders(): Record<string, string> {
+  const token = getAccessToken();
+  if (!token) throw new Error("You are not signed in.");
+  return { Authorization: `Bearer ${token}`, "Content-Type": "application/json" };
+}
+
+/** GET that throws with the server message rather than a bare status code. */
+export async function adminGet<T>(path: string): Promise<T> {
+  const res = await fetch(apiUrl(path), { cache: "no-store", headers: authHeaders() });
+  if (!res.ok) {
+    const body = await res.json().catch(() => null);
+    throw new Error(body?.message || `Request failed (${res.status})`);
+  }
+  return (await res.json()) as T;
+}
+
+/** POST/PUT/DELETE returning the standard {ok, message} envelope. */
+export async function adminSend(
+  path: string,
+  method: "POST" | "PUT" | "DELETE",
+  body?: unknown,
+): Promise<AdminResult> {
+  const res = await fetch(apiUrl(path), {
+    method,
+    headers: authHeaders(),
+    body: body === undefined ? undefined : JSON.stringify(body),
+  });
+  const result = (await res.json().catch(() => null)) as AdminResult | null;
+  if (!res.ok || !result?.ok) {
+    throw new Error(result?.message || `Request failed (${res.status})`);
+  }
+  return result;
+}