feat: surface MCP server status in System Status page

Add per-tool in-memory call counters to the MCP module and a
GET /api/v1/status/mcp endpoint that joins them with the live tool
registry and endpoint config, then render it as a new card on the
System Status page with a one-click client-config copy button.

- app/mcp/stats.py: lock-guarded MCPStatsTracker (the mcp SDK runs sync
  tool bodies via anyio.to_thread.run_sync, so this is genuinely
  multi-threaded, unlike the async REST routes)
- app/mcp/server.py: instrument search_regulations, add get_mcp_status()
- app/config/settings.py: optional MCP_PUBLIC_URL override, required
  because the Vite proxy and reverse proxies rewrite the Host header
- StatusPage.tsx: MCP Server card, joins the existing parallel fetch

Counters are process-local by design; token usage is already persisted
by ModelUsageTracker since MCP calls route through ask().

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

frontend/src/api/index.ts

@@ -333,4 +333,22 @@ export interface ModelUsageResponse {
   models: ModelUsageEntry[];
 }
 
+/** One tool advertised by the MCP server, joined with its in-memory call counters. */
+export interface MCPToolEntry {
+  name: string;
+  description: string;
+  calls: number;
+  errors: number;
+  /** null when the tool has never been called — distinct from an average of 0. */
+  avg_duration_ms: number | null;
+  last_called_at: string | null;
+}
+
+export interface MCPStatusResponse {
+  endpoint_url: string;
+  auth_required: boolean;
+  allowed_hosts: string[];
+  tools: MCPToolEntry[];
+}
+
 export { API_BASE_URL };

frontend/src/api/status.ts

@@ -1,4 +1,4 @@
-import { fetchAPI, type ModelUsageResponse, type SystemConfig, type SystemHealth, type SystemStats } from './index';
+import { fetchAPI, type MCPStatusResponse, type ModelUsageResponse, type SystemConfig, type SystemHealth, type SystemStats } from './index';
 
 export async function getSystemStats(): Promise<SystemStats> {
   return fetchAPI<SystemStats>('/status/stats');
@@ -22,4 +22,9 @@ export async function pingModelConnections(): Promise<ModelUsageResponse> {
   return fetchAPI<ModelUsageResponse>('/status/models/ping', { method: 'POST' });
 }
 
-export type { ModelUsageResponse, SystemConfig, SystemHealth, SystemStats };
+/** MCP endpoint config, advertised tools, and per-tool call counters. */
+export async function getMCPStatus(): Promise<MCPStatusResponse> {
+  return fetchAPI<MCPStatusResponse>('/status/mcp');
+}
+
+export type { MCPStatusResponse, ModelUsageResponse, SystemConfig, SystemHealth, SystemStats };

frontend/src/locales/en.ts

@@ -143,6 +143,19 @@ export interface Translations {
     modelStatusDisabled: string;
     sharesUsageWithMain: string;
     lastCalledNever: string;
+    cardMcp: string;
+    mcpEndpoint: string;
+    mcpAuthRequired: string;
+    mcpAuthDisabled: string;
+    mcpAllowedHosts: string;
+    mcpCopyConfig: string;
+    mcpCopied: string;
+    mcpCopyFailed: string;
+    mcpCalls: string;
+    mcpErrors: string;
+    mcpAvgDuration: string;
+    mcpNoTools: string;
+    mcpUnavailable: string;
   };
   docs: {
     topbarTitle: string;
@@ -415,6 +428,19 @@ export const en: Translations = {
     modelStatusDisabled: 'Disabled',
     sharesUsageWithMain: 'Shares usage with main LLM',
     lastCalledNever: 'Never',
+    cardMcp: 'MCP Server',
+    mcpEndpoint: 'Endpoint',
+    mcpAuthRequired: 'Auth required',
+    mcpAuthDisabled: 'No auth',
+    mcpAllowedHosts: 'Allowed hosts',
+    mcpCopyConfig: 'Copy client config',
+    mcpCopied: 'Copied',
+    mcpCopyFailed: 'Copy failed',
+    mcpCalls: 'calls',
+    mcpErrors: 'errors',
+    mcpAvgDuration: 'avg',
+    mcpNoTools: 'No MCP tools registered',
+    mcpUnavailable: 'MCP status endpoint unavailable',
   },
   docs: {
     topbarTitle: 'Document Management',

frontend/src/locales/zh.ts

@@ -144,6 +144,19 @@ export const zh: Translations = {
     modelStatusDisabled: '已禁用',
     sharesUsageWithMain: '与主 LLM 共用统计',
     lastCalledNever: '从未',
+    cardMcp: 'MCP 服务',
+    mcpEndpoint: '接入端点',
+    mcpAuthRequired: '需鉴权',
+    mcpAuthDisabled: '未鉴权',
+    mcpAllowedHosts: 'Host 白名单',
+    mcpCopyConfig: '复制接入配置',
+    mcpCopied: '已复制',
+    mcpCopyFailed: '复制失败',
+    mcpCalls: '调用',
+    mcpErrors: '失败',
+    mcpAvgDuration: '平均',
+    mcpNoTools: '未注册任何 MCP 工具',
+    mcpUnavailable: 'MCP 状态接口不可用',
   },
   docs: {
     topbarTitle: '文档管理',

frontend/src/pages/Status/StatusPage.tsx

@@ -1,10 +1,10 @@
 import { useState, useEffect } from 'react';
 import { Topbar } from '../../components/layout/Topbar';
-import { Search, Upload, Download, RefreshCw, CheckCircle, XCircle, AlertTriangle, Info } from 'lucide-react';
+import { Search, Upload, Download, RefreshCw, CheckCircle, XCircle, AlertTriangle, Info, Copy } from 'lucide-react';
 import { UploadModal } from '../Docs/UploadModal';
 import { useLanguage } from '../../contexts/LanguageContext';
-import { getModelUsage, pingModelConnections } from '../../api/status';
-import type { ModelUsageEntry } from '../../api/index';
+import { getMCPStatus, getModelUsage, pingModelConnections } from '../../api/status';
+import type { MCPStatusResponse, ModelUsageEntry } from '../../api/index';
 
 const TOKEN_KEY = 'auth_token';
 function authHeader(): Record<string, string> {
@@ -90,11 +90,15 @@ export function StatusPage() {
   const [lastRefresh, setLastRefresh] = useState<Date | null>(null);
   const [modelUsage, setModelUsage] = useState<ModelUsageEntry[] | null>(null);
   const [pinging, setPinging] = useState(false);
+  const [mcp, setMcp] = useState<MCPStatusResponse | null>(null);
+  const [mcpLoading, setMcpLoading] = useState(true);
+  const [copyState, setCopyState] = useState<'idle' | 'ok' | 'fail'>('idle');
 
   useEffect(() => {
     setLoading(true);
     setHealthLoading(true);
     setModelsLoading(true);
+    setMcpLoading(true);
 
     // Fetch all endpoints in parallel. The first three use raw fetch() (legacy
     // pattern already established in this file); model usage uses the typed
@@ -104,7 +108,8 @@ export function StatusPage() {
       fetch('/api/v1/status/health', { headers: authHeader() }).then(r => r.json()),
       fetch('/api/v1/status/config', { headers: authHeader() }).then(r => r.json()),
       getModelUsage(),
-    ]).then(([statsRes, healthRes, configRes, modelsRes]) => {
+      getMCPStatus(),
+    ]).then(([statsRes, healthRes, configRes, modelsRes, mcpRes]) => {
       if (statsRes.status === 'fulfilled') setStats(statsRes.value);
       else setStats({ documents_total: 0, documents_indexed: 0, documents_failed: 0, chunks_total: 0 });
 
@@ -112,10 +117,13 @@ export function StatusPage() {
       if (configRes.status === 'fulfilled') setConfig(configRes.value);
       if (modelsRes.status === 'fulfilled') setModelUsage(modelsRes.value.models);
       else setModelUsage(null);
+      // A failing MCP endpoint must degrade to a muted card, never blank the page.
+      setMcp(mcpRes.status === 'fulfilled' ? mcpRes.value : null);
 
       setLoading(false);
       setHealthLoading(false);
       setModelsLoading(false);
+      setMcpLoading(false);
       setLastRefresh(new Date());
     });
   }, [refreshKey]);
@@ -140,7 +148,7 @@ export function StatusPage() {
 
   // ── Export ───────────────────────────────────────────────────────────────
   function handleExport() {
-    const data = { stats, health, config, exportedAt: new Date().toISOString() };
+    const data = { stats, health, config, mcp, exportedAt: new Date().toISOString() };
     const blob = new Blob([JSON.stringify(data, null, 2)], { type: 'application/json' });
     const url = URL.createObjectURL(blob);
     const a = document.createElement('a');
@@ -180,6 +188,34 @@ export function StatusPage() {
     return new Date(entry.last_called_at).toLocaleTimeString(undefined, { hour: '2-digit', minute: '2-digit' });
   }
 
+  /** Build the mcpServers block Claude Desktop / Cursor accept for a Streamable HTTP server. */
+  function buildMCPClientConfig(status: MCPStatusResponse): string {
+    const token = localStorage.getItem(TOKEN_KEY);
+    const server: Record<string, unknown> = { url: status.endpoint_url };
+    // Omit the header entirely when the backend runs unauthenticated, so the
+    // pasted config never carries a stale "Bearer null".
+    if (status.auth_required && token) server.headers = { Authorization: `Bearer ${token}` };
+    return JSON.stringify({ mcpServers: { 'ai-regulations': server } }, null, 2);
+  }
+
+  async function handleCopyMCPConfig() {
+    if (!mcp) return;
+    try {
+      await navigator.clipboard.writeText(buildMCPClientConfig(mcp));
+      setCopyState('ok');
+    } catch {
+      // clipboard.writeText rejects on insecure origins and denied permissions.
+      // Surface it: a silent no-op would leave the operator pasting stale data.
+      setCopyState('fail');
+    }
+    setTimeout(() => setCopyState('idle'), 2000);
+  }
+
+  function mcpDurationLabel(ms: number | null): string {
+    if (ms === null) return '—';
+    return ms >= 1000 ? `${(ms / 1000).toFixed(1)}s` : `${Math.round(ms)}ms`;
+  }
+
   return (
     <div className="status-page">
       <Topbar
@@ -344,6 +380,65 @@ export function StatusPage() {
               )}
             </div>
 
+            {/* MCP server — endpoint config + advertised tools + call counters */}
+            <div className="card">
+              <div className="card-header" style={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between' }}>
+                <span>{t.status.cardMcp}</span>
+                <button className="btn sm" onClick={handleCopyMCPConfig} disabled={!mcp}>
+                  <Copy size={13} />
+                  {copyState === 'ok' ? t.status.mcpCopied : copyState === 'fail' ? t.status.mcpCopyFailed : t.status.mcpCopyConfig}
+                </button>
+              </div>
+
+              {mcpLoading ? (
+                <div style={{ padding: '12px 0', display: 'flex', flexDirection: 'column', gap: 10 }}>
+                  {[1, 2].map(i => <div key={i} className="loading-shimmer" style={{ height: 28, borderRadius: 6 }} />)}
+                </div>
+              ) : mcp ? (
+                <>
+                  <div className="service-row">
+                    <StatusIcon status="ok" />
+                    <span className="service-name" style={{ marginLeft: 8 }}>{t.status.mcpEndpoint}</span>
+                    <span style={{ fontSize: 11, color: 'var(--muted)', marginLeft: 6, fontFamily: 'var(--font-mono)', wordBreak: 'break-all' }}>
+                      {mcp.endpoint_url}
+                    </span>
+                    <span className={`status ${mcp.auth_required ? 'ok' : 'warn'}`} style={{ marginLeft: 'auto' }}>
+                      {mcp.auth_required ? t.status.mcpAuthRequired : t.status.mcpAuthDisabled}
+                    </span>
+                  </div>
+
+                  <div className="service-row">
+                    <StatusIcon status="info" />
+                    <span className="service-name" style={{ marginLeft: 8 }}>{t.status.mcpAllowedHosts}</span>
+                    <span style={{ fontSize: 11, color: 'var(--muted)', marginLeft: 6, fontFamily: 'var(--font-mono)', wordBreak: 'break-all' }}>
+                      {mcp.allowed_hosts.join(', ') || '—'}
+                    </span>
+                  </div>
+
+                  {mcp.tools.length === 0 ? (
+                    <div style={{ padding: '12px 0', color: 'var(--muted)', fontSize: 13 }}>{t.status.mcpNoTools}</div>
+                  ) : mcp.tools.map(tool => (
+                    <div className="service-row" key={tool.name}>
+                      <StatusIcon status={tool.errors > 0 ? 'warn' : tool.calls > 0 ? 'ok' : 'info'} />
+                      <span className="service-name" style={{ marginLeft: 8, fontFamily: 'var(--font-mono)' }}>{tool.name}</span>
+                      <span style={{ fontSize: 11, color: 'var(--muted)', marginLeft: 6 }}>
+                        {`${t.status.mcpCalls} ${tool.calls}`}
+                        {tool.errors > 0 && ` · ${t.status.mcpErrors} ${tool.errors}`}
+                        {` · ${t.status.mcpAvgDuration} ${mcpDurationLabel(tool.avg_duration_ms)}`}
+                      </span>
+                      <span style={{ marginLeft: 'auto', fontFamily: 'var(--font-mono)', fontSize: 11, color: 'var(--muted)' }}>
+                        {tool.last_called_at
+                          ? new Date(tool.last_called_at).toLocaleTimeString(undefined, { hour: '2-digit', minute: '2-digit' })
+                          : t.status.lastCalledNever}
+                      </span>
+                    </div>
+                  ))}
+                </>
+              ) : (
+                <div style={{ padding: '12px 0', color: 'var(--muted)', fontSize: 13 }}>{t.status.mcpUnavailable}</div>
+              )}
+            </div>
+
             {/* System config (collapsible) */}
             <div className="card">
               <button