diff --git a/src/app/[locale]/admin/clubs/[club_id]/slot-definitions/GenerateSlotDefinitionsModal.tsx b/src/app/[locale]/admin/clubs/[club_id]/slot-definitions/GenerateSlotDefinitionsModal.tsx
index 3a63142..eee68c8 100644
--- a/src/app/[locale]/admin/clubs/[club_id]/slot-definitions/GenerateSlotDefinitionsModal.tsx
+++ b/src/app/[locale]/admin/clubs/[club_id]/slot-definitions/GenerateSlotDefinitionsModal.tsx
@@ -1,16 +1,17 @@
 'use client';
 
-import { useState } from 'react';
+import { useState, useEffect } from 'react';
 import { X, Loader2, AlertCircle, ChevronDown, ChevronUp } from 'lucide-react';
-import { generateSlotDefinitions } from '@/src/lib/api/slot-definitions';
+import { generateSlotDefinitions, getSlotDefinitionPresets } from '@/src/lib/api/slot-definitions';
 import type { Court } from '@/src/types/courts';
 import type {
   SlotDefinitionPreset,
   GenerateSlotDefinitionsRequest,
   PatternOverrides,
   DayOfWeek,
+  PresetInfo,
 } from '@/src/types/slot-definitions';
-import { PRESET_OPTIONS, DAY_NAMES } from '@/src/types/slot-definitions';
+import { DAY_NAMES } from '@/src/types/slot-definitions';
 
 interface GenerateSlotDefinitionsModalProps {
   clubId: number;
@@ -25,6 +26,10 @@ export default function GenerateSlotDefinitionsModal({
   onClose,
   onSuccess,
 }: GenerateSlotDefinitionsModalProps) {
+  // Preset data
+  const [presets, setPresets] = useState<PresetInfo[]>([]);
+  const [loadingPresets, setLoadingPresets] = useState(true);
+
   // Form state
   const [preset, setPreset] = useState<SlotDefinitionPreset>('workday_standard');
   const [selectedCourtIds, setSelectedCourtIds] = useState<number[]>([]);
@@ -44,6 +49,21 @@ export default function GenerateSlotDefinitionsModal({
   const [loading, setLoading] = useState(false);
   const [error, setError] = useState<string | null>(null);
 
+  // Fetch presets on mount
+  useEffect(() => {
+    async function loadPresets() {
+      const result = await getSlotDefinitionPresets();
+      if (result.success) {
+        setPresets(result.data.data.presets);
+        setLoadingPresets(false);
+      } else {
+        setError('Failed to load presets');
+        setLoadingPresets(false);
+      }
+    }
+    loadPresets();
+  }, []);
+
   function handleSelectAllCourts() {
     if (selectedCourtIds.length === courts.length) {
       setSelectedCourtIds([]);
@@ -113,7 +133,7 @@ export default function GenerateSlotDefinitionsModal({
     setLoading(false);
   }
 
-  const selectedPreset = PRESET_OPTIONS.find(p => p.id === preset);
+  const selectedPreset = presets.find((p) => p.key === preset);
 
   return (
     <div className="fixed inset-0 bg-black bg-opacity-50 flex items-center justify-center z-50 p-4">
@@ -131,30 +151,43 @@ export default function GenerateSlotDefinitionsModal({
 
         {/* Body */}
         <div className="p-6 space-y-6">
+          {/* Loading State */}
+          {loadingPresets && (
+            <div className="flex items-center justify-center py-8">
+              <Loader2 className="w-8 h-8 text-slate-900 animate-spin" />
+              <span className="ml-3 text-slate-600">Loading presets...</span>
+            </div>
+          )}
+
           {/* Preset Selection */}
-          <div>
-            <label className="block text-sm font-semibold text-slate-700 mb-2">
-              Preset Schedule
-            </label>
-            <select
-              value={preset}
-              onChange={(e) => setPreset(e.target.value as SlotDefinitionPreset)}
-              className="w-full px-4 py-3 border-2 border-slate-200 rounded-lg focus:outline-none focus:border-slate-900 font-medium"
-            >
-              {PRESET_OPTIONS.map(opt => (
-                <option key={opt.id} value={opt.id}>
-                  {opt.name} ({opt.days}, {opt.hours}, {opt.duration})
-                </option>
-              ))}
-            </select>
-            {selectedPreset && (
-              <p className="mt-2 text-sm text-slate-600">{selectedPreset.description}</p>
-            )}
-          </div>
+          {!loadingPresets && presets.length > 0 && (
+            <div>
+              <label className="block text-sm font-semibold text-slate-700 mb-2">
+                Preset Schedule
+              </label>
+              <select
+                value={preset}
+                onChange={(e) => setPreset(e.target.value as SlotDefinitionPreset)}
+                className="w-full px-4 py-3 border-2 border-slate-200 rounded-lg focus:outline-none focus:border-slate-900 font-medium"
+              >
+                {presets.map((p) => (
+                  <option key={p.key} value={p.key}>
+                    {p.title}
+                  </option>
+                ))}
+              </select>
+              {selectedPreset && (
+                <p className="mt-2 text-sm text-slate-600">{selectedPreset.description}</p>
+              )}
+            </div>
+          )}
 
-          {/* Court Selection */}
-          <div>
-            <div className="flex items-center justify-between mb-2">
+          {/* Form Elements */}
+          {!loadingPresets && (
+            <>
+              {/* Court Selection */}
+              <div>
+                <div className="flex items-center justify-between mb-2">
               <label className="block text-sm font-semibold text-slate-700">
                 Select Courts
               </label>
@@ -323,6 +356,8 @@ export default function GenerateSlotDefinitionsModal({
               </div>
             )}
           </div>
+            </>
+          )}
 
           {/* Error Message */}
           {error && (
@@ -343,7 +378,7 @@ export default function GenerateSlotDefinitionsModal({
           </button>
           <button
             onClick={handleSubmit}
-            disabled={loading || selectedCourtIds.length === 0}
+            disabled={loading || loadingPresets || selectedCourtIds.length === 0}
             className="px-6 py-2 bg-slate-900 text-white font-semibold rounded-lg hover:bg-slate-800 transition-colors disabled:opacity-50 disabled:cursor-not-allowed flex items-center space-x-2"
           >
             {loading ? (
diff --git a/src/lib/api/admin-clubs.ts b/src/lib/api/admin-clubs.ts
index 80b485f..abb35fb 100644
--- a/src/lib/api/admin-clubs.ts
+++ b/src/lib/api/admin-clubs.ts
@@ -13,6 +13,7 @@ import type {
   AdminApiResult,
   AdminApiError,
 } from '@/src/types/admin-api';
+import { getPathnameLocale } from '@/src/utils/getLocale';
 
 // ============================================================================
 // Configuration
@@ -24,6 +25,26 @@ if (!API_BASE_URL) {
   throw new Error('NEXT_PUBLIC_PYTHON_API_URL environment variable is not set');
 }
 
+// ============================================================================
+// Helpers
+// ============================================================================
+
+/**
+ * Add locale and timezone headers to requests
+ */
+function getLocaleHeaders(): Record<string, string> {
+  const locale = typeof window !== 'undefined'
+    ? getPathnameLocale(window.location.pathname) || 'en-US'
+    : 'en-US';
+
+  const timezone = Intl.DateTimeFormat().resolvedOptions().timeZone;
+
+  return {
+    'X-Locale': locale,
+    'X-Timezone': timezone,
+  };
+}
+
 // ============================================================================
 // Error Handling
 // ============================================================================
@@ -69,6 +90,7 @@ export async function getAdminClubs(cookieHeader?: string): Promise<AdminApiResu
   try {
     const headers: Record<string, string> = {
       'Content-Type': 'application/json',
+      ...getLocaleHeaders(),
     };
 
     // Forward cookies for server-side rendering
@@ -113,6 +135,7 @@ export async function getAdminClubDetail(
   try {
     const headers: Record<string, string> = {
       'Content-Type': 'application/json',
+      ...getLocaleHeaders(),
     };
 
     // Forward cookies for server-side rendering
diff --git a/src/lib/api/booking-admin.ts b/src/lib/api/booking-admin.ts
index e6ebdcc..10984d5 100644
--- a/src/lib/api/booking-admin.ts
+++ b/src/lib/api/booking-admin.ts
@@ -17,12 +17,7 @@ import type {
   BookingAdminError,
   BookingApiResult,
 } from '@/src/types/booking-admin';
-
-const API_BASE_URL = process.env.NEXT_PUBLIC_PYTHON_API_URL;
-
-if (!API_BASE_URL) {
-  throw new Error('NEXT_PUBLIC_PYTHON_API_URL environment variable is not defined');
-}
+import apiFetch from '@/src/utils/apiFetch';
 
 // ============================================================================
 // Helper Functions
@@ -92,11 +87,10 @@ export async function getBookingDetail(
     }
 
     const queryString = params.toString();
-    const url = `${API_BASE_URL}/admin/bookings/${bookingId}${queryString ? `?${queryString}` : ''}`;
+    const endpoint = `/admin/bookings/${bookingId}${queryString ? `?${queryString}` : ''}`;
 
-    const response = await fetch(url, {
+    const response = await apiFetch(endpoint, {
       method: 'GET',
-      credentials: 'include',
       headers: {
         'Content-Type': 'application/json',
       },
@@ -144,9 +138,8 @@ export async function cancelBooking(
       headers['X-Idempotency-Key'] = options.idempotencyKey;
     }
 
-    const response = await fetch(`${API_BASE_URL}/admin/bookings/${bookingId}`, {
+    const response = await apiFetch(`/admin/bookings/${bookingId}`, {
       method: 'PATCH',
-      credentials: 'include',
       headers,
       body: JSON.stringify(request),
     });
@@ -194,9 +187,8 @@ export async function moveBooking(
       headers['X-Idempotency-Key'] = options.idempotencyKey;
     }
 
-    const response = await fetch(`${API_BASE_URL}/admin/bookings/${bookingId}/move`, {
+    const response = await apiFetch(`/admin/bookings/${bookingId}/move`, {
       method: 'PATCH',
-      credentials: 'include',
       headers,
       body: JSON.stringify(request),
     });
@@ -243,9 +235,8 @@ export async function updateAttendees(
       headers['X-Idempotency-Key'] = options.idempotencyKey;
     }
 
-    const response = await fetch(`${API_BASE_URL}/admin/bookings/${bookingId}/attendees`, {
+    const response = await apiFetch(`/admin/bookings/${bookingId}/attendees`, {
       method: 'PATCH',
-      credentials: 'include',
       headers,
       body: JSON.stringify(request),
     });
diff --git a/src/lib/api/courts.ts b/src/lib/api/courts.ts
index e0a6bb7..c32bfca 100644
--- a/src/lib/api/courts.ts
+++ b/src/lib/api/courts.ts
@@ -2,7 +2,6 @@
  * Court Management API Client
  *
  * Handles club profile and court inventory CRUD operations.
- * Uses mock data until backend endpoints are ready.
  */
 
 import type {
@@ -14,12 +13,7 @@ import type {
   CourtError,
   SportsResponse,
 } from '@/src/types/courts';
-
-const API_BASE_URL = process.env.NEXT_PUBLIC_PYTHON_API_URL;
-
-if (!API_BASE_URL) {
-  throw new Error('NEXT_PUBLIC_PYTHON_API_URL environment variable is not defined');
-}
+import apiFetch from '@/src/utils/apiFetch';
 
 type ApiResult<T> =
   | { success: true; data: T }
@@ -30,9 +24,8 @@ type ApiResult<T> =
  */
 export async function getClubProfile(clubId: number): Promise<ApiResult<ClubProfile>> {
   try {
-    const response = await fetch(`${API_BASE_URL}/admin/clubs/${clubId}`, {
+    const response = await apiFetch(`/admin/clubs/${clubId}`, {
       method: 'GET',
-      credentials: 'include',
       headers: {
         'Content-Type': 'application/json',
       },
@@ -70,9 +63,8 @@ export async function updateClubProfile(
   request: ClubProfileUpdateRequest
 ): Promise<ApiResult<ClubProfile>> {
   try {
-    const response = await fetch(`${API_BASE_URL}/admin/clubs/${clubId}`, {
+    const response = await apiFetch(`/admin/clubs/${clubId}`, {
       method: 'PATCH',
-      credentials: 'include',
       headers: {
         'Content-Type': 'application/json',
       },
@@ -105,9 +97,8 @@ export async function updateClubProfile(
  */
 export async function getCourts(clubId: number): Promise<ApiResult<Court[]>> {
   try {
-    const response = await fetch(`${API_BASE_URL}/admin/clubs/${clubId}/courts`, {
+    const response = await apiFetch(`/admin/clubs/${clubId}/courts`, {
       method: 'GET',
-      credentials: 'include',
       headers: {
         'Content-Type': 'application/json',
       },
@@ -142,9 +133,8 @@ export async function createCourt(
   request: CourtRequest
 ): Promise<ApiResult<Court>> {
   try {
-    const response = await fetch(`${API_BASE_URL}/admin/clubs/${clubId}/courts`, {
+    const response = await apiFetch(`/admin/clubs/${clubId}/courts`, {
       method: 'POST',
-      credentials: 'include',
       headers: {
         'Content-Type': 'application/json',
       },
@@ -181,9 +171,8 @@ export async function updateCourt(
   request: CourtRequest
 ): Promise<ApiResult<Court>> {
   try {
-    const response = await fetch(`${API_BASE_URL}/admin/clubs/${clubId}/courts/${courtId}`, {
+    const response = await apiFetch(`/admin/clubs/${clubId}/courts/${courtId}`, {
       method: 'PATCH',
-      credentials: 'include',
       headers: {
         'Content-Type': 'application/json',
       },
@@ -219,9 +208,8 @@ export async function getCourtDependencies(
   courtId: number
 ): Promise<ApiResult<CourtDependencies>> {
   try {
-    const response = await fetch(`${API_BASE_URL}/admin/clubs/${clubId}/courts/${courtId}/dependencies`, {
+    const response = await apiFetch(`/admin/clubs/${clubId}/courts/${courtId}/dependencies`, {
       method: 'GET',
-      credentials: 'include',
       headers: {
         'Content-Type': 'application/json',
       },
@@ -256,9 +244,8 @@ export async function deleteCourt(
   courtId: number
 ): Promise<ApiResult<void>> {
   try {
-    const response = await fetch(`${API_BASE_URL}/admin/clubs/${clubId}/courts/${courtId}`, {
+    const response = await apiFetch(`/admin/clubs/${clubId}/courts/${courtId}`, {
       method: 'DELETE',
-      credentials: 'include',
       headers: {
         'Content-Type': 'application/json',
       },
@@ -289,9 +276,8 @@ export async function deleteCourt(
  */
 export async function getSports(): Promise<ApiResult<SportsResponse>> {
   try {
-    const response = await fetch(`${API_BASE_URL}/admin/sports`, {
+    const response = await apiFetch(`/admin/sports`, {
       method: 'GET',
-      credentials: 'include',
       headers: {
         'Content-Type': 'application/json',
       },
diff --git a/src/lib/api/materialisation.ts b/src/lib/api/materialisation.ts
index 18a2a6c..104ece1 100644
--- a/src/lib/api/materialisation.ts
+++ b/src/lib/api/materialisation.ts
@@ -2,7 +2,6 @@
  * Materialisation API Client
  *
  * Handles slot materialisation status polling and manual trigger requests.
- * Uses mock data until backend endpoints are ready.
  */
 
 import type {
@@ -11,12 +10,7 @@ import type {
   MaterialisationTriggerResponse,
   MaterialisationError,
 } from '@/src/types/materialisation';
-
-const API_BASE_URL = process.env.NEXT_PUBLIC_PYTHON_API_URL;
-
-if (!API_BASE_URL) {
-  throw new Error('NEXT_PUBLIC_PYTHON_API_URL environment variable is not defined');
-}
+import apiFetch from '@/src/utils/apiFetch';
 
 type ApiResult<T> =
   | { success: true; data: T }
@@ -29,9 +23,8 @@ export async function getMaterialisationStatus(
   clubId: number
 ): Promise<ApiResult<MaterialisationStatus>> {
   try {
-    const response = await fetch(`${API_BASE_URL}/admin/clubs/${clubId}/materialisation-status`, {
+    const response = await apiFetch(`/admin/clubs/${clubId}/materialisation-status`, {
       method: 'GET',
-      credentials: 'include',
       headers: {
         'Content-Type': 'application/json',
       },
@@ -66,9 +59,8 @@ export async function triggerMaterialisation(
   request: MaterialisationTriggerRequest
 ): Promise<ApiResult<MaterialisationTriggerResponse>> {
   try {
-    const response = await fetch(`${API_BASE_URL}/admin/clubs/${clubId}/slot-materialize`, {
+    const response = await apiFetch(`/admin/clubs/${clubId}/slot-materialize`, {
       method: 'POST',
-      credentials: 'include',
       headers: {
         'Content-Type': 'application/json',
       },
diff --git a/src/lib/api/slot-definitions.ts b/src/lib/api/slot-definitions.ts
index 2c6494c..3df224c 100644
--- a/src/lib/api/slot-definitions.ts
+++ b/src/lib/api/slot-definitions.ts
@@ -6,13 +6,9 @@ import type {
   GenerateSlotDefinitionsResponse,
   CloneSlotDefinitionRequest,
   CloneSlotDefinitionResponse,
+  GetPresetsResponse,
 } from '@/src/types/slot-definitions';
-
-const API_BASE_URL = process.env.NEXT_PUBLIC_PYTHON_API_URL;
-
-if (!API_BASE_URL) {
-  throw new Error('NEXT_PUBLIC_PYTHON_API_URL environment variable is not defined');
-}
+import apiFetch from '@/src/utils/apiFetch';
 
 type ApiResult<T> =
   | { success: true; data: T }
@@ -29,11 +25,10 @@ export async function getSlotDefinitions(
     if (filters?.active_on) params.append('active_on', filters.active_on);
 
     const queryString = params.toString();
-    const url = `${API_BASE_URL}/admin/clubs/${clubId}/slot-definitions${queryString ? `?${queryString}` : ''}`;
+    const endpoint = `/admin/clubs/${clubId}/slot-definitions${queryString ? `?${queryString}` : ''}`;
 
-    const response = await fetch(url, {
+    const response = await apiFetch(endpoint, {
       method: 'GET',
-      credentials: 'include',
       headers: {
         'Content-Type': 'application/json',
       },
@@ -66,9 +61,8 @@ export async function createSlotDefinition(
   request: SlotDefinitionRequest
 ): Promise<ApiResult<SlotDefinition>> {
   try {
-    const response = await fetch(`${API_BASE_URL}/admin/clubs/${clubId}/slot-definitions`, {
+    const response = await apiFetch(`/admin/clubs/${clubId}/slot-definitions`, {
       method: 'POST',
-      credentials: 'include',
       headers: {
         'Content-Type': 'application/json',
       },
@@ -103,11 +97,10 @@ export async function updateSlotDefinition(
   request: Partial<SlotDefinitionRequest>
 ): Promise<ApiResult<SlotDefinition>> {
   try {
-    const response = await fetch(
-      `${API_BASE_URL}/admin/clubs/${clubId}/slot-definitions/${slotDefinitionId}`,
+    const response = await apiFetch(
+      `/admin/clubs/${clubId}/slot-definitions/${slotDefinitionId}`,
       {
         method: 'PATCH',
-        credentials: 'include',
         headers: {
           'Content-Type': 'application/json',
         },
@@ -142,11 +135,10 @@ export async function deleteSlotDefinition(
   slotDefinitionId: number
 ): Promise<ApiResult<void>> {
   try {
-    const response = await fetch(
-      `${API_BASE_URL}/admin/clubs/${clubId}/slot-definitions/${slotDefinitionId}`,
+    const response = await apiFetch(
+      `/admin/clubs/${clubId}/slot-definitions/${slotDefinitionId}`,
       {
         method: 'DELETE',
-        credentials: 'include',
       }
     );
 
@@ -170,15 +162,42 @@ export async function deleteSlotDefinition(
   }
 }
 
+// GET /admin/slot-definition-presets
+export async function getSlotDefinitionPresets(): Promise<ApiResult<GetPresetsResponse>> {
+  try {
+    const response = await apiFetch('/admin/slot-definition-presets', {
+      method: 'GET',
+    });
+
+    if (!response.ok) {
+      const error: SlotDefinitionError = await response.json();
+      return { success: false, error };
+    }
+
+    const data: GetPresetsResponse = await response.json();
+    return { success: true, data };
+  } catch (error) {
+    return {
+      success: false,
+      error: {
+        type: 'about:blank',
+        title: 'Network Error',
+        status: 0,
+        detail: 'Failed to fetch slot definition presets. Please check your connection.',
+        code: 'network_error',
+      },
+    };
+  }
+}
+
 // POST /admin/clubs/{club_id}/slot-definitions/generate
 export async function generateSlotDefinitions(
   clubId: number,
   request: GenerateSlotDefinitionsRequest
 ): Promise<ApiResult<GenerateSlotDefinitionsResponse>> {
   try {
-    const response = await fetch(`${API_BASE_URL}/admin/clubs/${clubId}/slot-definitions/generate`, {
+    const response = await apiFetch(`/admin/clubs/${clubId}/slot-definitions/generate`, {
       method: 'POST',
-      credentials: 'include',
       headers: {
         'Content-Type': 'application/json',
       },
@@ -213,11 +232,10 @@ export async function cloneSlotDefinition(
   request: CloneSlotDefinitionRequest
 ): Promise<ApiResult<CloneSlotDefinitionResponse>> {
   try {
-    const response = await fetch(
-      `${API_BASE_URL}/admin/clubs/${clubId}/slot-definitions/${slotDefinitionId}/clone`,
+    const response = await apiFetch(
+      `/admin/clubs/${clubId}/slot-definitions/${slotDefinitionId}/clone`,
       {
         method: 'POST',
-        credentials: 'include',
         headers: {
           'Content-Type': 'application/json',
         },
diff --git a/src/types/slot-definitions.ts b/src/types/slot-definitions.ts
index 7e73938..9e4340c 100644
--- a/src/types/slot-definitions.ts
+++ b/src/types/slot-definitions.ts
@@ -99,51 +99,37 @@ export type SlotDefinitionPreset =
   | 'hourly_daytime';     // Mon-Fri, 9am-6pm, 60min
 
 /**
- * Preset metadata for UI display
+ * Pattern details from preset
+ */
+export interface PresetPattern {
+  days: DayOfWeek[];
+  start_time: string; // HH:MM:SS
+  end_time: string; // HH:MM:SS
+  duration_minutes: number;
+  interval_minutes: number;
+  capacity: number;
+}
+
+/**
+ * Preset info from API (localized)
  */
 export interface PresetInfo {
-  id: SlotDefinitionPreset;
-  name: string;
-  description: string;
-  days: string;
-  hours: string;
-  duration: string;
-}
-
-export const PRESET_OPTIONS: PresetInfo[] = [
-  {
-    id: 'workday_standard',
-    name: 'Weekday Standard',
-    description: 'Standard weekday operations',
-    days: 'Mon-Fri',
-    hours: '8am-10pm',
-    duration: '90min slots',
-  },
-  {
-    id: 'weekend_extended',
-    name: 'Weekend Extended',
-    description: 'Weekend with early/late slots',
-    days: 'Sat-Sun',
-    hours: '7am-11pm',
-    duration: '90min slots',
-  },
-  {
-    id: 'all_week_uniform',
-    name: 'All Week Uniform',
-    description: 'Uniform schedule year-round',
-    days: 'Every day',
-    hours: '8am-10pm',
-    duration: '90min slots',
-  },
-  {
-    id: 'hourly_daytime',
-    name: 'Hourly Daytime',
-    description: 'Short slots for busy periods',
-    days: 'Mon-Fri',
-    hours: '9am-6pm',
-    duration: '60min slots',
-  },
-];
+  key: SlotDefinitionPreset;
+  title: string; // Localized title
+  description: string; // Localized description
+  pattern: PresetPattern;
+}
+
+/**
+ * Get presets endpoint response
+ */
+export interface GetPresetsResponse {
+  status: 'success';
+  data: {
+    locale: string;
+    presets: PresetInfo[];
+  };
+}
 
 /**
  * Pattern overrides for customizing presets