diff --git a/ui/src/api/queries/admin/admin-api.ts b/ui/src/api/queries/admin/admin-api.ts
new file mode 100644
index 00000000..20c71eb7
--- /dev/null
+++ b/ui/src/api/queries/admin/admin-api.ts
@@ -0,0 +1,22 @@
+import { config } from '../../../config';
+import { useAuthStore } from '../../../auth/auth-store';
+
+export async function adminFetch<T>(path: string, options?: RequestInit): Promise<T> {
+  const token = useAuthStore.getState().accessToken;
+  const res = await fetch(`${config.apiBaseUrl}/admin${path}`, {
+    ...options,
+    headers: {
+      'Content-Type': 'application/json',
+      ...(token ? { Authorization: `Bearer ${token}` } : {}),
+      'X-Cameleer-Protocol-Version': '1',
+      ...options?.headers,
+    },
+  });
+  if (res.status === 401 || res.status === 403) {
+    useAuthStore.getState().logout();
+    throw new Error('Unauthorized');
+  }
+  if (!res.ok) throw new Error(`API error: ${res.status}`);
+  if (res.status === 204) return undefined as T;
+  return res.json();
+}
diff --git a/ui/src/api/queries/admin/audit.ts b/ui/src/api/queries/admin/audit.ts
new file mode 100644
index 00000000..2ea3399a
--- /dev/null
+++ b/ui/src/api/queries/admin/audit.ts
@@ -0,0 +1,45 @@
+import { useQuery } from '@tanstack/react-query';
+import { adminFetch } from './admin-api';
+
+export interface AuditEvent {
+  id: string;
+  timestamp: string;
+  username: string;
+  category: string;
+  action: string;
+  target: string;
+  result: string;
+  detail: Record<string, unknown>;
+}
+
+export interface AuditLogParams {
+  from?: string;
+  to?: string;
+  username?: string;
+  category?: string;
+  search?: string;
+  page?: number;
+  size?: number;
+}
+
+export interface AuditLogResponse {
+  events: AuditEvent[];
+  total: number;
+}
+
+export function useAuditLog(params: AuditLogParams) {
+  const query = new URLSearchParams();
+  if (params.from) query.set('from', params.from);
+  if (params.to) query.set('to', params.to);
+  if (params.username) query.set('username', params.username);
+  if (params.category) query.set('category', params.category);
+  if (params.search) query.set('search', params.search);
+  if (params.page !== undefined) query.set('page', String(params.page));
+  if (params.size !== undefined) query.set('size', String(params.size));
+  const qs = query.toString();
+
+  return useQuery({
+    queryKey: ['admin', 'audit', params],
+    queryFn: () => adminFetch<AuditLogResponse>(`/audit${qs ? `?${qs}` : ''}`),
+  });
+}
diff --git a/ui/src/api/queries/admin/database.ts b/ui/src/api/queries/admin/database.ts
new file mode 100644
index 00000000..b83eb7bf
--- /dev/null
+++ b/ui/src/api/queries/admin/database.ts
@@ -0,0 +1,71 @@
+import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
+import { adminFetch } from './admin-api';
+
+export interface DatabaseStatus {
+  connected: boolean;
+  version: string;
+  host: string;
+  schema: string;
+}
+
+export interface PoolStats {
+  activeConnections: number;
+  idleConnections: number;
+  pendingConnections: number;
+  maxConnections: number;
+  maxWaitMillis: number;
+}
+
+export interface TableInfo {
+  tableName: string;
+  rowEstimate: number;
+  dataSize: string;
+  indexSize: string;
+}
+
+export interface ActiveQuery {
+  pid: number;
+  durationMs: number;
+  state: string;
+  query: string;
+}
+
+export function useDatabaseStatus() {
+  return useQuery({
+    queryKey: ['admin', 'database', 'status'],
+    queryFn: () => adminFetch<DatabaseStatus>('/database/status'),
+  });
+}
+
+export function useDatabasePool() {
+  return useQuery({
+    queryKey: ['admin', 'database', 'pool'],
+    queryFn: () => adminFetch<PoolStats>('/database/pool'),
+    refetchInterval: 15000,
+  });
+}
+
+export function useDatabaseTables() {
+  return useQuery({
+    queryKey: ['admin', 'database', 'tables'],
+    queryFn: () => adminFetch<TableInfo[]>('/database/tables'),
+  });
+}
+
+export function useDatabaseQueries() {
+  return useQuery({
+    queryKey: ['admin', 'database', 'queries'],
+    queryFn: () => adminFetch<ActiveQuery[]>('/database/queries'),
+    refetchInterval: 15000,
+  });
+}
+
+export function useKillQuery() {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: async (pid: number) => {
+      await adminFetch<void>(`/database/queries/${pid}`, { method: 'DELETE' });
+    },
+    onSuccess: () => qc.invalidateQueries({ queryKey: ['admin', 'database', 'queries'] }),
+  });
+}
diff --git a/ui/src/api/queries/admin/opensearch.ts b/ui/src/api/queries/admin/opensearch.ts
new file mode 100644
index 00000000..15b5133b
--- /dev/null
+++ b/ui/src/api/queries/admin/opensearch.ts
@@ -0,0 +1,102 @@
+import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
+import { adminFetch } from './admin-api';
+
+export interface OpenSearchStatus {
+  connected: boolean;
+  clusterName: string;
+  clusterHealth: string;
+  version: string;
+  numberOfNodes: number;
+  host: string;
+}
+
+export interface PipelineStats {
+  queueDepth: number;
+  maxQueueSize: number;
+  totalIndexed: number;
+  totalFailed: number;
+  avgLatencyMs: number;
+}
+
+export interface IndexInfo {
+  name: string;
+  health: string;
+  status: string;
+  docsCount: number;
+  storeSize: string;
+  primaryShards: number;
+  replicas: number;
+}
+
+export interface PerformanceStats {
+  queryCacheHitRate: number;
+  requestCacheHitRate: number;
+  avgQueryLatencyMs: number;
+  avgIndexLatencyMs: number;
+  jvmHeapUsedPercent: number;
+  jvmHeapUsedBytes: number;
+  jvmHeapMaxBytes: number;
+}
+
+export interface IndicesParams {
+  search?: string;
+  health?: string;
+  sortBy?: string;
+  sortDir?: 'asc' | 'desc';
+  page?: number;
+  size?: number;
+}
+
+export function useOpenSearchStatus() {
+  return useQuery({
+    queryKey: ['admin', 'opensearch', 'status'],
+    queryFn: () => adminFetch<OpenSearchStatus>('/opensearch/status'),
+  });
+}
+
+export function usePipelineStats() {
+  return useQuery({
+    queryKey: ['admin', 'opensearch', 'pipeline'],
+    queryFn: () => adminFetch<PipelineStats>('/opensearch/pipeline'),
+    refetchInterval: 15000,
+  });
+}
+
+export function useIndices(params: IndicesParams) {
+  const query = new URLSearchParams();
+  if (params.search) query.set('search', params.search);
+  if (params.health) query.set('health', params.health);
+  if (params.sortBy) query.set('sortBy', params.sortBy);
+  if (params.sortDir) query.set('sortDir', params.sortDir);
+  if (params.page !== undefined) query.set('page', String(params.page));
+  if (params.size !== undefined) query.set('size', String(params.size));
+  const qs = query.toString();
+
+  return useQuery({
+    queryKey: ['admin', 'opensearch', 'indices', params],
+    queryFn: () =>
+      adminFetch<{ indices: IndexInfo[]; total: number }>(
+        `/opensearch/indices${qs ? `?${qs}` : ''}`,
+      ),
+  });
+}
+
+export function usePerformanceStats() {
+  return useQuery({
+    queryKey: ['admin', 'opensearch', 'performance'],
+    queryFn: () => adminFetch<PerformanceStats>('/opensearch/performance'),
+    refetchInterval: 15000,
+  });
+}
+
+export function useDeleteIndex() {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: async (indexName: string) => {
+      await adminFetch<void>(`/opensearch/indices/${encodeURIComponent(indexName)}`, {
+        method: 'DELETE',
+      });
+    },
+    onSuccess: () => qc.invalidateQueries({ queryKey: ['admin', 'opensearch', 'indices'] }),
+  });
+}
diff --git a/ui/src/api/queries/admin/thresholds.ts b/ui/src/api/queries/admin/thresholds.ts
new file mode 100644
index 00000000..ffcc09eb
--- /dev/null
+++ b/ui/src/api/queries/admin/thresholds.ts
@@ -0,0 +1,33 @@
+import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
+import { adminFetch } from './admin-api';
+
+export interface Thresholds {
+  poolWarningPercent: number;
+  poolCriticalPercent: number;
+  queryDurationWarningSeconds: number;
+  queryDurationCriticalSeconds: number;
+  osQueueWarningPercent: number;
+  osQueueCriticalPercent: number;
+  osHeapWarningPercent: number;
+  osHeapCriticalPercent: number;
+}
+
+export function useThresholds() {
+  return useQuery({
+    queryKey: ['admin', 'thresholds'],
+    queryFn: () => adminFetch<Thresholds>('/thresholds'),
+  });
+}
+
+export function useSaveThresholds() {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: async (body: Thresholds) => {
+      await adminFetch<Thresholds>('/thresholds', {
+        method: 'PUT',
+        body: JSON.stringify(body),
+      });
+    },
+    onSuccess: () => qc.invalidateQueries({ queryKey: ['admin', 'thresholds'] }),
+  });
+}