feat(mcp): add reconnect button to evict stale MCP connections

When MCP servers update their tools externally, the gateway keeps
stale cached connections. Add POST /v1/mcp/servers/{id}/reconnect
endpoint that evicts the pooled connection, forcing re-discovery
on next agent use. Exposed via reconnect button on both web and
desktop MCP management pages.

internal/http/mcp.go

@@ -61,6 +61,9 @@ func (h *MCPHandler) RegisterRoutes(mux *http.ServeMux) {
 	// Test connection (no save)
 	mux.HandleFunc("POST /v1/mcp/servers/test", h.auth(h.handleTestConnection))
 
+	// Reconnect (evict pooled connection so next use re-discovers tools)
+	mux.HandleFunc("POST /v1/mcp/servers/{id}/reconnect", h.auth(h.handleReconnectServer))
+
 	// Server tools (runtime-discovered)
 	mux.HandleFunc("GET /v1/mcp/servers/{id}/tools", h.auth(h.handleListServerTools))
 
@@ -231,3 +234,28 @@ func (h *MCPHandler) handleDeleteServer(w http.ResponseWriter, r *http.Request)
 	emitAudit(h.msgBus, r, "mcp_server.deleted", "mcp_server", id.String())
 	writeJSON(w, http.StatusOK, map[string]string{"status": "deleted"})
 }
+
+func (h *MCPHandler) handleReconnectServer(w http.ResponseWriter, r *http.Request) {
+	locale := store.LocaleFromContext(r.Context())
+	id, err := uuid.Parse(r.PathValue("id"))
+	if err != nil {
+		writeJSON(w, http.StatusBadRequest, map[string]string{"error": i18n.T(locale, i18n.MsgInvalidID, "server")})
+		return
+	}
+
+	srv, err := h.store.GetServer(r.Context(), id)
+	if err != nil {
+		writeJSON(w, http.StatusNotFound, map[string]string{"error": i18n.T(locale, i18n.MsgNotFound, "server", id.String())})
+		return
+	}
+
+	if h.poolEvictor != nil {
+		tid := store.TenantIDFromContext(r.Context())
+		h.poolEvictor.Evict(tid, srv.Name)
+	}
+
+	h.emitCacheInvalidate()
+	emitAudit(h.msgBus, r, "mcp_server.reconnected", "mcp_server", id.String())
+	slog.Info("mcp.server.reconnect_requested", "server", srv.Name, "id", id)
+	writeJSON(w, http.StatusOK, map[string]string{"status": "reconnected"})
+}

ui/desktop/frontend/src/components/settings/mcp/McpServerList.tsx

@@ -14,7 +14,7 @@ export function McpServerList() {
   const {
     servers, loading, atLimit,
     fetchServers, createServer, updateServer, deleteServer,
-    testConnection, listServerTools,
+    testConnection, reconnectServer, listServerTools,
     listGrants, grantAgent, revokeAgent,
   } = useMcpServers()
   const { agents } = useAgentCrud()
@@ -24,6 +24,7 @@ export function McpServerList() {
   const [deleteTarget, setDeleteTarget] = useState<MCPServerData | null>(null)
   const [grantsServer, setGrantsServer] = useState<MCPServerData | null>(null)
   const [toolsServer, setToolsServer] = useState<MCPServerData | null>(null)
+  const [reconnectingId, setReconnectingId] = useState<string | null>(null)
 
   function openCreate() {
     setEditServer(null)
@@ -163,6 +164,19 @@ export function McpServerList() {
                   {/* Actions */}
                   <td className="px-4 py-3 text-right">
                     <div className="flex items-center justify-end gap-1">
+                      <button
+                        disabled={reconnectingId === s.id}
+                        onClick={async () => {
+                          setReconnectingId(s.id)
+                          try { await reconnectServer(s.id) } finally { setReconnectingId(null) }
+                        }}
+                        className="p-1 text-text-muted hover:text-text-primary transition-colors disabled:opacity-50"
+                        title={t('reconnect')}
+                      >
+                        <svg className={`h-3.5 w-3.5${reconnectingId === s.id ? ' animate-spin' : ''}`} viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth={2} strokeLinecap="round" strokeLinejoin="round">
+                          <path d="M21 12a9 9 0 1 1-9-9c2.52 0 4.93 1 6.74 2.74L21 8" /><path d="M21 3v5h-5" />
+                        </svg>
+                      </button>
                       <button onClick={() => openEdit(s)} className="p-1 text-text-muted hover:text-text-primary transition-colors" title="Edit">
                         <svg className="h-3.5 w-3.5" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth={2} strokeLinecap="round" strokeLinejoin="round">
                           <path d="M21.174 6.812a1 1 0 0 0-3.986-3.987L3.842 16.174a2 2 0 0 0-.5.83l-1.321 4.352a.5.5 0 0 0 .623.622l4.353-1.32a2 2 0 0 0 .83-.497z" />

ui/desktop/frontend/src/hooks/use-mcp-servers.ts

@@ -68,6 +68,16 @@ export function useMcpServers() {
     return getApiClient().post<MCPTestResult>('/v1/mcp/servers/test', data)
   }, [])
 
+  const reconnectServer = useCallback(async (id: string) => {
+    try {
+      await getApiClient().post(`/v1/mcp/servers/${id}/reconnect`, {})
+      toast.success('Connection reset')
+    } catch (err) {
+      toast.error('Failed to reconnect', (err as Error).message)
+      throw err
+    }
+  }, [])
+
   const listServerTools = useCallback(async (serverId: string) => {
     const res = await getApiClient().get<{ tools: MCPToolInfo[] | null }>(`/v1/mcp/servers/${serverId}/tools`)
     return res.tools ?? []
@@ -93,7 +103,7 @@ export function useMcpServers() {
   return {
     servers, loading, atLimit,
     fetchServers, createServer, updateServer, deleteServer,
-    testConnection, listServerTools,
+    testConnection, reconnectServer, listServerTools,
     listGrants, grantAgent, revokeAgent,
   }
 }

ui/desktop/frontend/src/i18n/locales/en/mcp.json

@@ -18,6 +18,7 @@
   },
   "viewTools": "View tools",
   "manageGrants": "Manage grants",
+  "reconnect": "Reconnect",
   "delete": {
     "title": "Delete MCP Server",
     "description": "Are you sure you want to delete \"{{name}}\"? This will also remove all associated grants.",

ui/desktop/frontend/src/i18n/locales/vi/mcp.json

@@ -18,6 +18,7 @@
   },
   "viewTools": "Xem công cụ",
   "manageGrants": "Quản lý quyền",
+  "reconnect": "Kết nối lại",
   "delete": {
     "title": "Xóa MCP Server",
     "description": "Bạn có chắc muốn xóa \"{{name}}\"? Tất cả quyền liên quan cũng sẽ bị xóa.",

ui/desktop/frontend/src/i18n/locales/zh/mcp.json

@@ -18,6 +18,7 @@
   },
   "viewTools": "查看工具",
   "manageGrants": "管理授权",
+  "reconnect": "重新连接",
   "delete": {
     "title": "删除 MCP 服务器",
     "description": "确定要删除「{{name}}」吗？这将同时移除所有相关授权。",

ui/web/src/i18n/locales/en/mcp.json

@@ -18,6 +18,7 @@
   },
   "viewTools": "View tools",
   "manageGrants": "Manage grants",
+  "reconnect": "Reconnect",
   "delete": {
     "title": "Delete MCP Server",
     "description": "Are you sure you want to delete \"{{name}}\"? This will also remove all associated grants.",
@@ -98,7 +99,9 @@
     "deleted": "MCP server deleted",
     "failedCreate": "Failed to create MCP server",
     "failedUpdate": "Failed to update MCP server",
-    "failedDelete": "Failed to delete MCP server"
+    "failedDelete": "Failed to delete MCP server",
+    "reconnected": "MCP server connection reset",
+    "failedReconnect": "Failed to reconnect MCP server"
   },
   "userCredentials": {
     "title": "My Credentials",

ui/web/src/i18n/locales/vi/mcp.json

@@ -18,6 +18,7 @@
   },
   "viewTools": "Xem công cụ",
   "manageGrants": "Quản lý quyền",
+  "reconnect": "Kết nối lại",
   "delete": {
     "title": "Xóa MCP Server",
     "description": "Bạn có chắc muốn xóa \"{{name}}\"? Tất cả quyền liên quan cũng sẽ bị xóa.",
@@ -98,7 +99,9 @@
     "deleted": "Đã xóa MCP server",
     "failedCreate": "Không thể tạo MCP server",
     "failedUpdate": "Không thể cập nhật MCP server",
-    "failedDelete": "Không thể xóa MCP server"
+    "failedDelete": "Không thể xóa MCP server",
+    "reconnected": "Đã reset kết nối MCP server",
+    "failedReconnect": "Không thể kết nối lại MCP server"
   },
   "userCredentials": {
     "title": "Thông tin xác thực",

ui/web/src/i18n/locales/zh/mcp.json

@@ -18,6 +18,7 @@
   },
   "viewTools": "查看工具",
   "manageGrants": "管理授权",
+  "reconnect": "重新连接",
   "delete": {
     "title": "删除 MCP 服务器",
     "description": "确定要删除「{{name}}」吗？这将同时移除所有相关授权。",
@@ -98,7 +99,9 @@
     "deleted": "MCP 服务器已删除",
     "failedCreate": "创建 MCP 服务器失败",
     "failedUpdate": "更新 MCP 服务器失败",
-    "failedDelete": "删除 MCP 服务器失败"
+    "failedDelete": "删除 MCP 服务器失败",
+    "reconnected": "MCP 服务器连接已重置",
+    "failedReconnect": "重新连接 MCP 服务器失败"
   },
   "userCredentials": {
     "title": "我的凭证",

ui/web/src/pages/mcp/hooks/use-mcp.ts

@@ -109,6 +109,19 @@ export function useMCP() {
     [http],
   );
 
+  const reconnectServer = useCallback(
+    async (id: string) => {
+      try {
+        await http.post(`/v1/mcp/servers/${id}/reconnect`, {});
+        toast.success(i18next.t("mcp:toast.reconnected"));
+      } catch (err) {
+        toast.error(i18next.t("mcp:toast.failedReconnect"), err instanceof Error ? err.message : "");
+        throw err;
+      }
+    },
+    [http],
+  );
+
   const listServerTools = useCallback(
     async (serverId: string) => {
       const res = await http.get<{ tools: MCPToolInfo[] }>(`/v1/mcp/servers/${serverId}/tools`);
@@ -153,6 +166,7 @@ export function useMCP() {
     revokeAgent,
     listGrantsByAgent,
     testConnection,
+    reconnectServer,
     listServerTools,
     getUserCredentials,
     setUserCredentials,

ui/web/src/pages/mcp/mcp-page.tsx

@@ -1,6 +1,6 @@
 import { useState, useEffect } from "react";
 import { useTranslation } from "react-i18next";
-import { Plug, Plus, RefreshCw, Pencil, Trash2, Users, Wrench, KeyRound } from "lucide-react";
+import { Plug, Plus, RefreshCw, RotateCcw, Pencil, Trash2, Users, Wrench, KeyRound } from "lucide-react";
 import { Button } from "@/components/ui/button";
 import { Badge } from "@/components/ui/badge";
 import { PageHeader } from "@/components/shared/page-header";
@@ -27,7 +27,7 @@ const transportBadge: Record<string, string> = {
 export function MCPPage() {
   const { t } = useTranslation("mcp");
   const { t: tc } = useTranslation("common");
-  const { servers, loading, refresh, createServer, updateServer, deleteServer, grantAgent, revokeAgent, listAgentGrants, testConnection, listServerTools, getUserCredentials, setUserCredentials, deleteUserCredentials } = useMCP();
+  const { servers, loading, refresh, createServer, updateServer, deleteServer, grantAgent, revokeAgent, listAgentGrants, testConnection, reconnectServer, listServerTools, getUserCredentials, setUserCredentials, deleteUserCredentials } = useMCP();
   const spinning = useMinLoading(loading);
   const showSkeleton = useDeferredLoading(loading && servers.length === 0);
   const [search, setSearch] = useState("");
@@ -38,6 +38,7 @@ export function MCPPage() {
   const [deleteTarget, setDeleteTarget] = useState<MCPServerData | null>(null);
   const [deleteLoading, setDeleteLoading] = useState(false);
   const [credentialsServer, setCredentialsServer] = useState<MCPServerData | null>(null);
+  const [reconnectingId, setReconnectingId] = useState<string | null>(null);
 
   const filtered = servers.filter(
     (s) =>
@@ -163,6 +164,18 @@ export function MCPPage() {
                     <td className="px-4 py-3 text-muted-foreground">{srv.created_by || "-"}</td>
                     <td className="px-4 py-3 text-right">
                       <div className="flex items-center justify-end gap-1">
+                        <Button
+                          variant="ghost"
+                          size="sm"
+                          disabled={reconnectingId === srv.id}
+                          onClick={async () => {
+                            setReconnectingId(srv.id);
+                            try { await reconnectServer(srv.id); } finally { setReconnectingId(null); }
+                          }}
+                          title={t("reconnect")}
+                        >
+                          <RotateCcw className={"h-3.5 w-3.5" + (reconnectingId === srv.id ? " animate-spin" : "")} />
+                        </Button>
                         <Button
                           variant="ghost"
                           size="sm"