Add MCP server indicator with plug emoji and modal

- Create McpServerModal component based on existing McpServers component
- Add plug emoji (🔌) indicator on right side, opposite to brain emoji
- Show '0' when no servers connected, '1 (N)' when connected with N tools
- Fullscreen modal with MCP server configuration UI
- Support for single MCP server connection (foundation for multiple servers)
- Integrate with existing MCP tools logic and useMcp hook
- Clean layout with brain emoji on left, plug emoji on right

examples/chat-ui/src/components/ConversationThread.tsx

@@ -9,6 +9,7 @@ import { type Tool } from 'use-mcp/react'
 import ChatMessage from './ChatMessage'
 import ChatInput from './ChatInput'
 import ModelSelectionModal from './ModelSelectionModal'
+import McpServerModal from './McpServerModal'
 import { useAutoscroll } from '../hooks/useAutoscroll'
 import { useStreamResponse } from '../hooks/useStreamResponse'
 import { setApiKey } from '../utils/apiKeys'
@@ -46,6 +47,7 @@ const ConversationThread: React.FC<ConversationThreadProps> = ({
     model: null,
   })
   const [modelSelectionModal, setModelSelectionModal] = useState(false)
+  const [mcpServerModal, setMcpServerModal] = useState(false)
 
   const { messagesEndRef, messagesContainerRef, scrollToBottom } = useAutoscroll()
 
@@ -220,8 +222,8 @@ const ConversationThread: React.FC<ConversationThreadProps> = ({
             messagesCount={currentConversation.messages.length}
           />
           
-          {/* Model selector indicator */}
-          <div className="flex items-center gap-2 mt-2">
+          {/* Model selector and MCP server indicators */}
+          <div className="flex items-center justify-between mt-2">
             <button
               onClick={() => setModelSelectionModal(true)}
               className="flex items-center gap-2 text-zinc-600 hover:text-zinc-900 transition-colors cursor-pointer"
@@ -235,6 +237,16 @@ const ConversationThread: React.FC<ConversationThreadProps> = ({
                 )}
               </span>
             </button>
+            
+            <button
+              onClick={() => setMcpServerModal(true)}
+              className="flex items-center gap-2 text-zinc-600 hover:text-zinc-900 transition-colors cursor-pointer"
+            >
+              <span className="text-lg">🔌</span>
+              <span className="text-sm text-zinc-500">
+                {mcpTools.length > 0 ? `1 (${mcpTools.length})` : "0"}
+              </span>
+            </button>
           </div>
         </div>
       </div>
@@ -253,6 +265,14 @@ const ConversationThread: React.FC<ConversationThreadProps> = ({
         onModelChange={onModelChange}
         apiKeyUpdateTrigger={apiKeyUpdateTrigger}
       />
+
+      <McpServerModal
+        isOpen={mcpServerModal}
+        onClose={() => setMcpServerModal(false)}
+        onToolsUpdate={(tools) => {
+          // This will be handled by the existing MCP tools logic in ChatApp
+        }}
+      />
     </div>
   )
 }

examples/chat-ui/src/components/McpServerModal.tsx

@@ -0,0 +1,367 @@
+import React, { useState, useRef, useEffect } from 'react'
+import { X, Info, Settings } from 'lucide-react'
+import { useMcp, type Tool } from 'use-mcp/react'
+
+// MCP Connection wrapper that only renders when active
+function McpConnection({
+  serverUrl,
+  onConnectionUpdate,
+}: {
+  serverUrl: string
+  onConnectionUpdate: (data: any) => void
+}) {
+  // Use the MCP hook with the server URL
+  const connection = useMcp({
+    url: serverUrl,
+    debug: true,
+    autoRetry: false,
+    popupFeatures: 'width=500,height=600,resizable=yes,scrollbars=yes',
+  })
+
+  // Update parent component with connection data
+  useEffect(() => {
+    onConnectionUpdate(connection)
+  }, [
+    connection.state,
+    connection.tools,
+    connection.error,
+    connection.log.length,
+    connection.authUrl,
+  ])
+
+  // Return null as this is just a hook wrapper
+  return null
+}
+
+interface McpServerModalProps {
+  isOpen: boolean
+  onClose: () => void
+  onToolsUpdate?: (tools: Tool[]) => void
+}
+
+const McpServerModal: React.FC<McpServerModalProps> = ({
+  isOpen,
+  onClose,
+  onToolsUpdate,
+}) => {
+  const [serverUrl, setServerUrl] = useState(() => {
+    return sessionStorage.getItem('mcpServerUrl') || ''
+  })
+  const [isActive, setIsActive] = useState(false)
+  const [showSettings, setShowSettings] = useState(false)
+  const [connectionData, setConnectionData] = useState<any>({
+    state: 'not-connected',
+    tools: [],
+    error: undefined,
+    log: [],
+    authUrl: undefined,
+    retry: () => {},
+    disconnect: () => {},
+    authenticate: () => Promise.resolve(undefined),
+    callTool: (_name: string, _args?: Record<string, unknown>) =>
+      Promise.resolve(undefined),
+    clearStorage: () => {},
+  })
+  const logRef = useRef<HTMLDivElement>(null)
+
+  // Extract connection properties
+  const { state, tools, error, log, authUrl, disconnect, authenticate } =
+    connectionData
+
+  // Notify parent component when tools change
+  useEffect(() => {
+    if (onToolsUpdate && tools.length > 0) {
+      onToolsUpdate(
+        tools.map((t: Tool) => ({
+          ...t,
+          callTool: (args: Record<string, unknown>) =>
+            connectionData.callTool(t.name, args),
+        })),
+      )
+    }
+  }, [tools, onToolsUpdate])
+
+  useEffect(() => {
+    if (isOpen) {
+      document.body.style.overflow = 'hidden'
+    } else {
+      document.body.style.overflow = 'unset'
+    }
+    
+    return () => {
+      document.body.style.overflow = 'unset'
+    }
+  }, [isOpen])
+
+  // Handle connection
+  const handleConnect = () => {
+    if (!serverUrl.trim()) return
+    setIsActive(true)
+  }
+
+  // Handle disconnection
+  const handleDisconnect = () => {
+    disconnect()
+    setIsActive(false)
+    setConnectionData({
+      state: 'not-connected',
+      tools: [],
+      error: undefined,
+      log: [],
+      authUrl: undefined,
+      retry: () => {},
+      disconnect: () => {},
+      authenticate: () => Promise.resolve(undefined),
+      callTool: (_name: string, _args?: Record<string, unknown>) =>
+        Promise.resolve(undefined),
+      clearStorage: () => {},
+    })
+  }
+
+  // Handle authentication if popup was blocked
+  const handleManualAuth = async () => {
+    try {
+      await authenticate()
+    } catch (err) {
+      console.error('Authentication error:', err)
+    }
+  }
+
+  // Auto-scroll log to bottom
+  useEffect(() => {
+    if (logRef.current) {
+      logRef.current.scrollTop = logRef.current.scrollHeight
+    }
+  }, [log])
+
+  // Generate status badge based on connection state
+  const getStatusBadge = () => {
+    const baseClasses = 'px-2 py-1 rounded-full text-xs font-medium'
+
+    switch (state) {
+      case 'discovering':
+        return (
+          <span className={`${baseClasses} bg-blue-100 text-blue-800`}>
+            Discovering
+          </span>
+        )
+      case 'authenticating':
+        return (
+          <span className={`${baseClasses} bg-purple-100 text-purple-800`}>
+            Authenticating
+          </span>
+        )
+      case 'connecting':
+        return (
+          <span className={`${baseClasses} bg-yellow-100 text-yellow-800`}>
+            Connecting
+          </span>
+        )
+      case 'loading':
+        return (
+          <span className={`${baseClasses} bg-orange-100 text-orange-800`}>
+            Loading
+          </span>
+        )
+      case 'ready':
+        return (
+          <span className={`${baseClasses} bg-green-100 text-green-800`}>
+            Connected
+          </span>
+        )
+      case 'failed':
+        return (
+          <span className={`${baseClasses} bg-red-100 text-red-800`}>
+            Failed
+          </span>
+        )
+      case 'not-connected':
+      default:
+        return (
+          <span className={`${baseClasses} bg-gray-100 text-gray-800`}>
+            Not Connected
+          </span>
+        )
+    }
+  }
+
+  if (!isOpen) return null
+
+  return (
+    <>
+      <div className="fixed inset-0 bg-black bg-opacity-50 z-50 flex items-center justify-center p-4">
+        <div className="bg-white rounded-lg shadow-xl w-full max-w-2xl max-h-[80vh] overflow-hidden">
+          <div className="flex items-center justify-between p-6 border-b border-zinc-200">
+            <h2 className="text-xl font-semibold text-zinc-900">MCP Servers</h2>
+            <button
+              onClick={onClose}
+              className="text-zinc-400 hover:text-zinc-600 p-1"
+            >
+              <X size={24} />
+            </button>
+          </div>
+          
+          <div className="p-6 overflow-y-auto">
+            <div className="flex items-center justify-between mb-4">
+              <div className="flex items-center">
+                <Info size={16} className="text-gray-400 mr-2" />
+                <span className="text-sm text-gray-600">
+                  Connect to Model Context Protocol (MCP) servers to access additional AI capabilities.
+                </span>
+              </div>
+              <button
+                className="rounded-md border border-gray-200 p-1 hover:bg-gray-50"
+                onClick={() => setShowSettings(!showSettings)}
+              >
+                <Settings size={16} className="text-gray-500" />
+              </button>
+            </div>
+
+            <div className="space-y-4">
+              <div className="flex items-center justify-between">
+                <label className="font-medium text-sm">Status:</label>
+                {getStatusBadge()}
+              </div>
+
+              {error && state === 'failed' && (
+                <div className="text-sm text-red-600 p-3 bg-red-50 rounded border">
+                  {error}
+                </div>
+              )}
+
+              <div className="space-y-3">
+                <input
+                  type="text"
+                  className="w-full p-3 border border-gray-200 rounded-lg text-sm placeholder-gray-400 focus:outline-none focus:ring-2 focus:ring-blue-500"
+                  placeholder="Enter MCP server URL"
+                  value={serverUrl}
+                  onChange={(e) => {
+                    const newValue = e.target.value
+                    setServerUrl(newValue)
+                    sessionStorage.setItem('mcpServerUrl', newValue)
+                  }}
+                  disabled={isActive && state !== 'failed'}
+                />
+                
+                {state === 'ready' ||
+                (isActive && state !== 'not-connected' && state !== 'failed') ? (
+                  <button
+                    className="w-full px-4 py-3 bg-orange-100 hover:bg-orange-200 text-orange-900 rounded-lg text-sm font-medium"
+                    onClick={handleDisconnect}
+                  >
+                    Disconnect
+                  </button>
+                ) : (
+                  <button
+                    className="w-full bg-blue-600 hover:bg-blue-700 text-white rounded-lg py-3 px-4 text-sm font-medium disabled:opacity-50"
+                    onClick={handleConnect}
+                    disabled={isActive || !serverUrl.trim()}
+                  >
+                    Connect
+                  </button>
+                )}
+              </div>
+
+              {/* Authentication Link if needed */}
+              {authUrl && (
+                <div className="p-4 bg-orange-50 border border-orange-200 rounded-lg">
+                  <p className="text-sm mb-2">
+                    Authentication required. Please click the link below:
+                  </p>
+                  <a
+                    href={authUrl}
+                    target="_blank"
+                    rel="noopener noreferrer"
+                    className="text-sm text-orange-700 hover:text-orange-800 underline"
+                    onClick={handleManualAuth}
+                  >
+                    Authenticate in new window
+                  </a>
+                </div>
+              )}
+
+              {/* Tools display when connected */}
+              {state === 'ready' && tools.length > 0 && (
+                <div>
+                  <h3 className="font-medium text-sm mb-3">
+                    Available Tools ({tools.length})
+                  </h3>
+                  <div className="border border-gray-200 rounded-lg p-3 bg-gray-50 max-h-40 overflow-y-auto space-y-3">
+                    {tools.map((tool: Tool, index: number) => (
+                      <div
+                        key={index}
+                        className="text-sm pb-3 border-b border-gray-200 last:border-b-0"
+                      >
+                        <span className="font-medium">{tool.name}</span>
+                        {tool.description && (
+                          <p className="text-gray-600 mt-1 text-sm">
+                            {tool.description}
+                          </p>
+                        )}
+                      </div>
+                    ))}
+                  </div>
+                </div>
+              )}
+
+              {/* Debug Log */}
+              {showSettings && (
+                <div>
+                  <label className="font-medium text-sm block mb-3">Debug Log</label>
+                  <div
+                    ref={logRef}
+                    className="border border-gray-200 rounded-lg p-3 bg-gray-50 h-40 overflow-y-auto font-mono text-xs"
+                  >
+                    {log.length > 0 ? (
+                      log.map((entry: any, index: number) => (
+                        <div
+                          key={index}
+                          className={`py-0.5 ${
+                            entry.level === 'debug'
+                              ? 'text-gray-500'
+                              : entry.level === 'info'
+                                ? 'text-blue-600'
+                                : entry.level === 'warn'
+                                  ? 'text-orange-600'
+                                  : 'text-red-600'
+                          }`}
+                        >
+                          [{entry.level}] {entry.message}
+                        </div>
+                      ))
+                    ) : (
+                      <div className="text-gray-400">No log entries yet</div>
+                    )}
+                  </div>
+                  {connectionData?.state !== 'not-connected' && (
+                    <button
+                      onClick={() => {
+                        connectionData?.clearStorage()
+                        if (isActive) {
+                          handleDisconnect()
+                        }
+                      }}
+                      className="text-sm text-orange-600 hover:text-orange-800 hover:underline mt-2"
+                    >
+                      Clear stored authentication
+                    </button>
+                  )}
+                </div>
+              )}
+            </div>
+          </div>
+        </div>
+      </div>
+
+      {/* Only render the actual MCP connection when active */}
+      {isActive && (
+        <McpConnection
+          serverUrl={serverUrl}
+          onConnectionUpdate={setConnectionData}
+        />
+      )}
+    </>
+  )
+}
+
+export default McpServerModal