bench: replay feat(mcp-clients) — MCP client subsystem with Smithery registry + UI

app/src/components/channels/ChannelConfigPanel.tsx

@@ -1,6 +1,7 @@
 import type { ChannelDefinition, ChannelType } from '../../types/channels';
 import ChannelCapabilities from './ChannelCapabilities';
 import DiscordConfig from './DiscordConfig';
+import McpServersTab from './mcp/McpServersTab';
 import TelegramConfig from './TelegramConfig';
 import WebChannelConfig from './WebChannelConfig';
 
@@ -10,6 +11,25 @@ interface ChannelConfigPanelProps {
 }
 
 const ChannelConfigPanel = ({ selectedChannel, definitions }: ChannelConfigPanelProps) => {
+  // MCP is a virtual tab — not backed by a ChannelDefinition from the core.
+  if (selectedChannel === 'mcp') {
+    return (
+      <div className="space-y-4">
+        <section className="rounded-xl border border-stone-200 dark:border-neutral-800 bg-white dark:bg-neutral-900 p-4 space-y-3">
+          <div>
+            <h3 className="text-base font-semibold text-stone-900 dark:text-neutral-100">
+              MCP Servers
+            </h3>
+            <p className="text-xs text-stone-500 dark:text-neutral-400 mt-1">
+              Browse and manage Model Context Protocol servers that extend the AI with new tools.
+            </p>
+          </div>
+          <McpServersTab />
+        </section>
+      </div>
+    );
+  }
+
   const definition = definitions.find(d => d.id === selectedChannel);
   if (!definition) return null;
 

app/src/components/channels/ChannelSelector.tsx

@@ -12,7 +12,17 @@ interface ChannelSelectorProps {
   onSelectChannel: (channel: ChannelType) => void;
 }
 
-const CHANNEL_ICONS: Record<string, string> = { telegram: '✈️', discord: '🎮', web: '🌐' };
+const CHANNEL_ICONS: Record<string, string> = {
+  telegram: '✈️',
+  discord: '🎮',
+  web: '🌐',
+  mcp: '🔌',
+};
+
+/** Virtual (static) tabs that are not backed by a ChannelDefinition from the core. */
+const VIRTUAL_TABS: { id: ChannelType; display_name: string }[] = [
+  { id: 'mcp', display_name: 'MCP Servers' },
+];
 const CHANNEL_STATUS_PRIORITY: ChannelConnectionStatus[] = [
   'connected',
   'connecting',
@@ -48,7 +58,7 @@ const ChannelSelector = ({
         </p>
       </div>
 
-      <div className="flex gap-2">
+      <div className="flex gap-2 flex-wrap">
         {definitions.map(def => {
           const channelId = def.id as ChannelType;
           const isSelected = selectedChannel === channelId;
@@ -81,6 +91,25 @@ const ChannelSelector = ({
             </button>
           );
         })}
+
+        {/* Virtual tabs — not backed by a ChannelDefinition from the core */}
+        {VIRTUAL_TABS.map(tab => {
+          const isSelected = selectedChannel === tab.id;
+          return (
+            <button
+              key={tab.id}
+              type="button"
+              onClick={() => onSelectChannel(tab.id)}
+              className={`flex-1 flex items-center gap-2 rounded-lg border px-4 py-3 text-sm transition-colors ${
+                isSelected
+                  ? 'border-primary-500/60 bg-primary-50 dark:bg-primary-500/15 text-primary-600 dark:text-primary-300'
+                  : 'border-stone-200 dark:border-neutral-800 bg-stone-50 dark:bg-neutral-800/60 text-stone-600 dark:text-neutral-300 hover:border-stone-300 dark:hover:border-neutral-700'
+              }`}>
+              <span className="text-base">{CHANNEL_ICONS[tab.id] ?? ''}</span>
+              <span className="font-medium">{tab.display_name}</span>
+            </button>
+          );
+        })}
       </div>
     </section>
   );

app/src/components/channels/mcp/ConfigAssistantPanel.test.tsx

@@ -0,0 +1,135 @@
+import { act, fireEvent, render, screen, waitFor } from '@testing-library/react';
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+
+import ConfigAssistantPanel from './ConfigAssistantPanel';
+
+const mockConfigAssist = vi.fn();
+
+vi.mock('../../../services/api/mcpClientsApi', () => ({
+  mcpClientsApi: { configAssist: (...args: unknown[]) => mockConfigAssist(...args) },
+}));
+
+describe('ConfigAssistantPanel', () => {
+  beforeEach(() => {
+    mockConfigAssist.mockReset();
+  });
+
+  it('renders the input textarea and Send button', () => {
+    render(<ConfigAssistantPanel qualifiedName="acme/test" />);
+    expect(screen.getByPlaceholderText(/ask a question/i)).toBeInTheDocument();
+    expect(screen.getByRole('button', { name: 'Send' })).toBeInTheDocument();
+  });
+
+  it('send button is disabled when input is empty', () => {
+    render(<ConfigAssistantPanel qualifiedName="acme/test" />);
+    expect(screen.getByRole('button', { name: 'Send' })).toBeDisabled();
+  });
+
+  it('enables send button when input has text', () => {
+    render(<ConfigAssistantPanel qualifiedName="acme/test" />);
+    fireEvent.change(screen.getByPlaceholderText(/ask a question/i), {
+      target: { value: 'What env vars do I need?' },
+    });
+    expect(screen.getByRole('button', { name: 'Send' })).not.toBeDisabled();
+  });
+
+  it('sends message and renders assistant reply', async () => {
+    mockConfigAssist.mockResolvedValue({ reply: 'You need an API_KEY env var.' });
+    render(<ConfigAssistantPanel qualifiedName="acme/test" />);
+
+    fireEvent.change(screen.getByPlaceholderText(/ask a question/i), {
+      target: { value: 'What do I need?' },
+    });
+
+    await act(async () => {
+      fireEvent.click(screen.getByRole('button', { name: 'Send' }));
+    });
+
+    await waitFor(() => {
+      expect(screen.getByText('You need an API_KEY env var.')).toBeInTheDocument();
+    });
+
+    expect(mockConfigAssist).toHaveBeenCalledWith({
+      qualified_name: 'acme/test',
+      user_message: 'What do I need?',
+      history: [{ role: 'user', content: 'What do I need?' }],
+    });
+  });
+
+  it('shows suggested_env values and Apply button', async () => {
+    mockConfigAssist.mockResolvedValue({
+      reply: 'Here are suggested values',
+      suggested_env: { API_KEY: 'abc123' },
+    });
+
+    const onApply = vi.fn();
+    render(<ConfigAssistantPanel qualifiedName="acme/test" onApplySuggestedEnv={onApply} />);
+
+    fireEvent.change(screen.getByPlaceholderText(/ask a question/i), {
+      target: { value: 'Help me configure' },
+    });
+
+    await act(async () => {
+      fireEvent.click(screen.getByRole('button', { name: 'Send' }));
+    });
+
+    await waitFor(() => {
+      expect(screen.getByText('Here are suggested values')).toBeInTheDocument();
+    });
+
+    // Shows key name (the colon is in the same text node with whitespace)
+    expect(screen.getByText(/API_KEY:/)).toBeInTheDocument();
+
+    // Apply button exists and calls the callback
+    const applyBtn = screen.getByRole('button', { name: 'Apply suggested values' });
+    fireEvent.click(applyBtn);
+    expect(onApply).toHaveBeenCalledWith({ API_KEY: 'abc123' });
+  });
+
+  it('shows error on failed request', async () => {
+    mockConfigAssist.mockRejectedValue(new Error('AI service unavailable'));
+    render(<ConfigAssistantPanel qualifiedName="acme/test" />);
+
+    fireEvent.change(screen.getByPlaceholderText(/ask a question/i), {
+      target: { value: 'Hello' },
+    });
+
+    await act(async () => {
+      fireEvent.click(screen.getByRole('button', { name: 'Send' }));
+    });
+
+    await waitFor(() => {
+      expect(screen.getByText('AI service unavailable')).toBeInTheDocument();
+    });
+  });
+
+  it('clears input after sending', async () => {
+    mockConfigAssist.mockResolvedValue({ reply: 'OK' });
+    render(<ConfigAssistantPanel qualifiedName="acme/test" />);
+
+    const textarea = screen.getByPlaceholderText(/ask a question/i) as HTMLTextAreaElement;
+    fireEvent.change(textarea, { target: { value: 'Question?' } });
+
+    await act(async () => {
+      fireEvent.click(screen.getByRole('button', { name: 'Send' }));
+    });
+
+    expect(textarea.value).toBe('');
+  });
+
+  it('sends on Enter key press', async () => {
+    mockConfigAssist.mockResolvedValue({ reply: 'reply' });
+    render(<ConfigAssistantPanel qualifiedName="acme/test" />);
+
+    const textarea = screen.getByPlaceholderText(/ask a question/i);
+    fireEvent.change(textarea, { target: { value: 'test message' } });
+
+    await act(async () => {
+      fireEvent.keyDown(textarea, { key: 'Enter', shiftKey: false });
+    });
+
+    await waitFor(() => {
+      expect(mockConfigAssist).toHaveBeenCalledTimes(1);
+    });
+  });
+});