diff --git a/desktop/src/api/plugins.ts b/desktop/src/api/plugins.ts
index 56bddc8b..4708c847 100644
--- a/desktop/src/api/plugins.ts
+++ b/desktop/src/api/plugins.ts
@@ -3,6 +3,7 @@ import type {
   PluginDetail,
   PluginListResponse,
   PluginReloadSummary,
+  PluginSessionReloadSummary,
   PluginScope,
 } from '../types/plugin'
 
@@ -36,10 +37,17 @@ export const pluginsApi = {
   uninstall: (payload: PluginActionPayload) =>
     api.post<{ ok: true; message: string }>('/api/plugins/uninstall', payload),
 
-  reload: (cwd?: string) => {
-    const query = cwd ? `?cwd=${encodeURIComponent(cwd)}` : ''
-    return api.post<{ ok: true; summary: PluginReloadSummary }>(
-      `/api/plugins/reload${query}`,
+  reload: (cwd?: string, sessionId?: string) => {
+    const query = new URLSearchParams()
+    if (cwd) query.set('cwd', cwd)
+    if (sessionId) query.set('sessionId', sessionId)
+    const suffix = query.size > 0 ? `?${query.toString()}` : ''
+    return api.post<{
+      ok: true
+      summary: PluginReloadSummary
+      session?: PluginSessionReloadSummary
+    }>(
+      `/api/plugins/reload${suffix}`,
       undefined,
       { timeout: 120_000 },
     )
diff --git a/desktop/src/components/plugins/PluginDetail.tsx b/desktop/src/components/plugins/PluginDetail.tsx
index 14c0d897..abe9f5d6 100644
--- a/desktop/src/components/plugins/PluginDetail.tsx
+++ b/desktop/src/components/plugins/PluginDetail.tsx
@@ -82,7 +82,7 @@ export function PluginDetail() {
   const handleReload = async () => {
     setActionKey('reload')
     try {
-      const summary = await reloadPlugins(currentWorkDir)
+      const summary = await reloadPlugins(currentWorkDir, activeSessionId || undefined)
       addToast({
         type: summary.errors > 0 ? 'warning' : 'success',
         message: t('settings.plugins.reloadToast', {
@@ -247,7 +247,7 @@ export function PluginDetail() {
                 variant="secondary"
                 size="sm"
                 loading={isApplying && actionKey === 'disable'}
-                onClick={() => void runAction('disable', () => disablePlugin(selectedPlugin.id, selectedPlugin.scope, currentWorkDir))}
+                onClick={() => void runAction('disable', () => disablePlugin(selectedPlugin.id, selectedPlugin.scope, currentWorkDir, activeSessionId || undefined))}
               >
                 {t('settings.plugins.disable')}
               </Button>
@@ -255,7 +255,7 @@ export function PluginDetail() {
               <Button
                 size="sm"
                 loading={isApplying && actionKey === 'enable'}
-                onClick={() => void runAction('enable', () => enablePlugin(selectedPlugin.id, selectedPlugin.scope, currentWorkDir))}
+                onClick={() => void runAction('enable', () => enablePlugin(selectedPlugin.id, selectedPlugin.scope, currentWorkDir, activeSessionId || undefined))}
               >
                 {t('settings.plugins.enable')}
               </Button>
@@ -267,7 +267,7 @@ export function PluginDetail() {
               variant="secondary"
               size="sm"
               loading={isApplying && actionKey === 'update'}
-              onClick={() => void runAction('update', () => updatePlugin(selectedPlugin.id, selectedPlugin.scope, currentWorkDir))}
+              onClick={() => void runAction('update', () => updatePlugin(selectedPlugin.id, selectedPlugin.scope, currentWorkDir, activeSessionId || undefined))}
             >
               {t('settings.plugins.update')}
             </Button>
@@ -489,7 +489,7 @@ export function PluginDetail() {
         }}
         onConfirm={async () => {
           setShowUninstallDialog(false)
-          await runAction('uninstall', () => uninstallPlugin(selectedPlugin.id, selectedPlugin.scope, false, currentWorkDir))
+          await runAction('uninstall', () => uninstallPlugin(selectedPlugin.id, selectedPlugin.scope, false, currentWorkDir, activeSessionId || undefined))
         }}
         title={t('settings.plugins.uninstall')}
         body={t('settings.plugins.confirmUninstall', { name: selectedPlugin.name })}
diff --git a/desktop/src/components/plugins/PluginList.tsx b/desktop/src/components/plugins/PluginList.tsx
index 7d8df76a..e7b5d4a0 100644
--- a/desktop/src/components/plugins/PluginList.tsx
+++ b/desktop/src/components/plugins/PluginList.tsx
@@ -54,7 +54,7 @@ export function PluginList() {
 
   const handleReload = async () => {
     try {
-      const reloadSummary = await reloadPlugins(currentWorkDir)
+      const reloadSummary = await reloadPlugins(currentWorkDir, activeSessionId || undefined)
       addToast({
         type: reloadSummary.errors > 0 ? 'warning' : 'success',
         message: t('settings.plugins.reloadToast', {
diff --git a/desktop/src/pages/EmptySession.test.tsx b/desktop/src/pages/EmptySession.test.tsx
index 7c24562b..dfa90160 100644
--- a/desktop/src/pages/EmptySession.test.tsx
+++ b/desktop/src/pages/EmptySession.test.tsx
@@ -1,4 +1,4 @@
-import { cleanup, fireEvent, render, screen, waitFor } from '@testing-library/react'
+import { act, cleanup, fireEvent, render, screen, waitFor } from '@testing-library/react'
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
 import '@testing-library/jest-dom'
 
@@ -98,6 +98,7 @@ import { useSessionStore } from '../stores/sessionStore'
 import { useSettingsStore } from '../stores/settingsStore'
 import { useTabStore } from '../stores/tabStore'
 import { useUIStore } from '../stores/uiStore'
+import { usePluginStore } from '../stores/pluginStore'
 import type { RepositoryContextResult } from '../api/sessions'
 
 function okRepositoryContext(overrides: Partial<RepositoryContextResult> = {}): RepositoryContextResult {
@@ -146,6 +147,7 @@ describe('EmptySession', () => {
   const initialTabState = useTabStore.getInitialState()
   const initialRuntimeState = useSessionRuntimeStore.getInitialState()
   const initialUiState = useUIStore.getInitialState()
+  const initialPluginState = usePluginStore.getInitialState()
 
   beforeEach(() => {
     vi.clearAllMocks()
@@ -157,6 +159,7 @@ describe('EmptySession', () => {
     useTabStore.setState(initialTabState, true)
     useSessionRuntimeStore.setState(initialRuntimeState, true)
     useUIStore.setState(initialUiState, true)
+    usePluginStore.setState(initialPluginState, true)
 
     mocks.createSession.mockResolvedValue({ sessionId: 'draft-session' })
     mocks.getRepositoryContext.mockResolvedValue(okRepositoryContext())
@@ -187,6 +190,7 @@ describe('EmptySession', () => {
     useTabStore.setState(initialTabState, true)
     useSessionRuntimeStore.setState(initialRuntimeState, true)
     useUIStore.setState(initialUiState, true)
+    usePluginStore.setState(initialPluginState, true)
   })
 
   it('uses compact composer controls on phone-sized H5 browsers', async () => {
@@ -203,6 +207,45 @@ describe('EmptySession', () => {
     expect(screen.getByTestId('empty-session-composer-panel')).toHaveClass('rounded-2xl')
   })
 
+  it('refreshes empty-session slash commands after plugin reloads', async () => {
+    mocks.listSkills
+      .mockResolvedValueOnce({ skills: [] })
+      .mockResolvedValueOnce({
+        skills: [
+          {
+            name: 'draw:render',
+            description: 'Render with the drawing plugin.',
+            userInvocable: true,
+          },
+        ],
+      })
+
+    render(<EmptySession />)
+
+    await waitFor(() => {
+      expect(mocks.listSkills).toHaveBeenCalledTimes(1)
+    })
+
+    act(() => {
+      usePluginStore.setState({
+        lastReloadSummary: {
+          enabled: 1,
+          disabled: 0,
+          skills: 1,
+          agents: 0,
+          hooks: 0,
+          mcpServers: 0,
+          lspServers: 0,
+          errors: 0,
+        },
+      })
+    })
+
+    await waitFor(() => {
+      expect(mocks.listSkills).toHaveBeenCalledTimes(2)
+    })
+  })
+
   it('integrates repository launch controls into the desktop composer panel', async () => {
     render(<EmptySession />)
 
diff --git a/desktop/src/pages/EmptySession.tsx b/desktop/src/pages/EmptySession.tsx
index b1618838..64e02fd1 100644
--- a/desktop/src/pages/EmptySession.tsx
+++ b/desktop/src/pages/EmptySession.tsx
@@ -4,6 +4,7 @@ import { skillsApi } from '../api/skills'
 import { useTranslation } from '../i18n'
 import { useSessionStore } from '../stores/sessionStore'
 import { useChatStore } from '../stores/chatStore'
+import { usePluginStore } from '../stores/pluginStore'
 import { useSessionRuntimeStore, DRAFT_RUNTIME_SELECTION_KEY } from '../stores/sessionRuntimeStore'
 import { useSettingsStore } from '../stores/settingsStore'
 import { useUIStore } from '../stores/uiStore'
@@ -103,6 +104,7 @@ export function EmptySession() {
   const setActiveView = useUIStore((state) => state.setActiveView)
   const addToast = useUIStore((state) => state.addToast)
   const currentModel = useSettingsStore((state) => state.currentModel)
+  const lastPluginReloadSummary = usePluginStore((state) => state.lastReloadSummary)
   const draftRuntimeSelection = useSessionRuntimeStore((state) => state.selections[DRAFT_RUNTIME_SELECTION_KEY])
   const draftRuntimeSelectionKey = draftRuntimeSelection
     ? `${draftRuntimeSelection.providerId ?? 'official'}:${draftRuntimeSelection.modelId}`
@@ -198,7 +200,7 @@ export function EmptySession() {
     return () => {
       cancelled = true
     }
-  }, [workDir])
+  }, [workDir, lastPluginReloadSummary])
 
   const allSlashCommands = useMemo(
     () => mergeSlashCommands(slashCommands, FALLBACK_SLASH_COMMANDS),
diff --git a/desktop/src/stores/pluginStore.test.ts b/desktop/src/stores/pluginStore.test.ts
new file mode 100644
index 00000000..1a6be4b8
--- /dev/null
+++ b/desktop/src/stores/pluginStore.test.ts
@@ -0,0 +1,91 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { usePluginStore } from './pluginStore'
+import { pluginsApi } from '../api/plugins'
+
+vi.mock('../api/plugins', () => ({
+  pluginsApi: {
+    list: vi.fn(),
+    detail: vi.fn(),
+    enable: vi.fn(),
+    disable: vi.fn(),
+    update: vi.fn(),
+    uninstall: vi.fn(),
+    reload: vi.fn(),
+  },
+}))
+
+const mockedPluginsApi = vi.mocked(pluginsApi)
+
+describe('pluginStore', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mockedPluginsApi.list.mockResolvedValue({
+      plugins: [],
+      marketplaces: [],
+      summary: { total: 0, enabled: 0, errorCount: 0, marketplaceCount: 0 },
+    })
+    mockedPluginsApi.reload.mockResolvedValue({
+      ok: true,
+      summary: {
+        enabled: 1,
+        disabled: 0,
+        skills: 1,
+        agents: 0,
+        hooks: 0,
+        mcpServers: 0,
+        lspServers: 0,
+        errors: 0,
+      },
+      session: {
+        applied: true,
+        commands: 1,
+        agents: 0,
+        plugins: 1,
+        mcpServers: 0,
+        errors: 0,
+      },
+    })
+    usePluginStore.setState({
+      plugins: [],
+      marketplaces: [],
+      summary: null,
+      selectedPlugin: null,
+      lastReloadSummary: null,
+      isLoading: false,
+      isDetailLoading: false,
+      isApplying: false,
+      error: null,
+    })
+  })
+
+  it('reloads the active CLI session after enabling a plugin', async () => {
+    mockedPluginsApi.enable.mockResolvedValue({
+      ok: true,
+      message: 'enabled',
+    })
+
+    const message = await usePluginStore
+      .getState()
+      .enablePlugin('draw@test', 'user', '/workspace/project', 'session-1')
+
+    expect(message).toBe('enabled')
+    expect(mockedPluginsApi.enable).toHaveBeenCalledWith({
+      id: 'draw@test',
+      scope: 'user',
+    })
+    expect(mockedPluginsApi.reload).toHaveBeenCalledWith(
+      '/workspace/project',
+      'session-1',
+    )
+    expect(usePluginStore.getState().lastReloadSummary).toEqual({
+      enabled: 1,
+      disabled: 0,
+      skills: 1,
+      agents: 0,
+      hooks: 0,
+      mcpServers: 0,
+      lspServers: 0,
+      errors: 0,
+    })
+  })
+})
diff --git a/desktop/src/stores/pluginStore.ts b/desktop/src/stores/pluginStore.ts
index 5fb39637..9c70b9ba 100644
--- a/desktop/src/stores/pluginStore.ts
+++ b/desktop/src/stores/pluginStore.ts
@@ -20,11 +20,11 @@ type PluginStore = {
   error: string | null
   fetchPlugins: (cwd?: string) => Promise<void>
   fetchPluginDetail: (id: string, cwd?: string) => Promise<void>
-  reloadPlugins: (cwd?: string) => Promise<PluginReloadSummary>
-  enablePlugin: (id: string, scope?: PluginScope, cwd?: string) => Promise<string>
-  disablePlugin: (id: string, scope?: PluginScope, cwd?: string) => Promise<string>
-  updatePlugin: (id: string, scope?: PluginScope, cwd?: string) => Promise<string>
-  uninstallPlugin: (id: string, scope?: PluginScope, keepData?: boolean, cwd?: string) => Promise<string>
+  reloadPlugins: (cwd?: string, sessionId?: string) => Promise<PluginReloadSummary>
+  enablePlugin: (id: string, scope?: PluginScope, cwd?: string, sessionId?: string) => Promise<string>
+  disablePlugin: (id: string, scope?: PluginScope, cwd?: string, sessionId?: string) => Promise<string>
+  updatePlugin: (id: string, scope?: PluginScope, cwd?: string, sessionId?: string) => Promise<string>
+  uninstallPlugin: (id: string, scope?: PluginScope, keepData?: boolean, cwd?: string, sessionId?: string) => Promise<string>
   clearSelection: () => void
 }
 
@@ -70,10 +70,10 @@ export const usePluginStore = create<PluginStore>((set, get) => ({
     }
   },
 
-  reloadPlugins: async (cwd) => {
+  reloadPlugins: async (cwd, sessionId) => {
     set({ isApplying: true, error: null })
     try {
-      const { summary } = await pluginsApi.reload(cwd)
+      const { summary } = await pluginsApi.reload(cwd, sessionId)
       await get().fetchPlugins(cwd)
       const selected = get().selectedPlugin
       if (selected) {
@@ -88,39 +88,43 @@ export const usePluginStore = create<PluginStore>((set, get) => ({
     }
   },
 
-  enablePlugin: async (id, scope, cwd) => {
+  enablePlugin: async (id, scope, cwd, sessionId) => {
     return runAction(
       () => pluginsApi.enable({ id, scope }),
       set,
       get,
       cwd,
+      sessionId,
     )
   },
 
-  disablePlugin: async (id, scope, cwd) => {
+  disablePlugin: async (id, scope, cwd, sessionId) => {
     return runAction(
       () => pluginsApi.disable({ id, scope }),
       set,
       get,
       cwd,
+      sessionId,
     )
   },
 
-  updatePlugin: async (id, scope, cwd) => {
+  updatePlugin: async (id, scope, cwd, sessionId) => {
     return runAction(
       () => pluginsApi.update({ id, scope }),
       set,
       get,
       cwd,
+      sessionId,
     )
   },
 
-  uninstallPlugin: async (id, scope, keepData = false, cwd) => {
+  uninstallPlugin: async (id, scope, keepData = false, cwd, sessionId) => {
     return runAction(
       () => pluginsApi.uninstall({ id, scope, keepData }),
       set,
       get,
       cwd,
+      sessionId,
       true,
     )
   },
@@ -133,11 +137,13 @@ async function runAction(
   set: (updater: Partial<PluginStore>) => void,
   get: () => PluginStore,
   cwd?: string,
+  sessionId?: string,
   clearSelection = false,
 ): Promise<string> {
   set({ isApplying: true, error: null })
   try {
     const { message } = await action()
+    const { summary } = await pluginsApi.reload(cwd, sessionId)
     await get().fetchPlugins(cwd)
     const selected = get().selectedPlugin
     if (clearSelection) {
@@ -145,7 +151,7 @@ async function runAction(
     } else if (selected) {
       await get().fetchPluginDetail(selected.id, cwd)
     }
-    set({ isApplying: false })
+    set({ isApplying: false, lastReloadSummary: summary })
     return message
   } catch (err) {
     set({
diff --git a/desktop/src/types/plugin.ts b/desktop/src/types/plugin.ts
index eb948b9a..266ae2a2 100644
--- a/desktop/src/types/plugin.ts
+++ b/desktop/src/types/plugin.ts
@@ -99,3 +99,14 @@ export type PluginReloadSummary = {
   lspServers: number
   errors: number
 }
+
+export type PluginSessionReloadSummary = {
+  applied: boolean
+  reason?: 'not_running' | 'failed'
+  commands: number
+  agents: number
+  plugins: number
+  mcpServers: number
+  errors: number
+  error?: string
+}
diff --git a/src/server/__tests__/plugins.test.ts b/src/server/__tests__/plugins.test.ts
index 8fbcf452..31694ce3 100644
--- a/src/server/__tests__/plugins.test.ts
+++ b/src/server/__tests__/plugins.test.ts
@@ -7,9 +7,13 @@ import { clearInstalledPluginsCache } from '../../utils/plugins/installedPlugins
 import { clearPluginCache, loadAllPluginsCacheOnly } from '../../utils/plugins/pluginLoader.js'
 import { resetSettingsCache } from '../../utils/settings/settingsCache.js'
 import { handlePluginsApi } from '../api/plugins.js'
+import { conversationService } from '../services/conversationService.js'
+import { __resetWebSocketHandlerStateForTests, getSlashCommands } from '../ws/handler.js'
 
 let tmpDir: string
 let originalConfigDir: string | undefined
+let originalHasSession: typeof conversationService.hasSession
+let originalRequestControl: typeof conversationService.requestControl
 
 function makeRequest(
   method: string,
@@ -38,9 +42,15 @@ describe('Plugins API', () => {
     clearInstalledPluginsCache()
     clearPluginCache('plugins-api-test-setup')
     resetSettingsCache()
+    __resetWebSocketHandlerStateForTests()
+    originalHasSession = conversationService.hasSession.bind(conversationService)
+    originalRequestControl = conversationService.requestControl.bind(conversationService)
   })
 
   afterEach(async () => {
+    conversationService.hasSession = originalHasSession
+    conversationService.requestControl = originalRequestControl
+    __resetWebSocketHandlerStateForTests()
     clearInstalledPluginsCache()
     clearPluginCache('plugins-api-test-teardown')
     resetSettingsCache()
@@ -166,4 +176,69 @@ describe('Plugins API', () => {
     expect(typeof body.summary.skills).toBe('number')
     expect(typeof body.summary.errors).toBe('number')
   })
+
+  it('POST /api/plugins/reload hot-reloads an active CLI session and updates slash commands', async () => {
+    const controlRequests: Array<{ sessionId: string; request: Record<string, unknown> }> = []
+    conversationService.hasSession = ((sessionId: string) => sessionId === 'session-plugins') as typeof conversationService.hasSession
+    conversationService.requestControl = (async (
+      sessionId: string,
+      request: Record<string, unknown>,
+    ) => {
+      controlRequests.push({ sessionId, request })
+      return {
+        commands: [
+          {
+            name: 'draw:render',
+            description: 'Render a drawing.',
+            argumentHint: '<prompt>',
+          },
+        ],
+        agents: [{ name: 'draw-agent' }],
+        plugins: [{ name: 'draw', path: '/tmp/draw', source: 'draw@test' }],
+        mcpServers: [{ name: 'plugin:draw:server', type: 'connected' }],
+        error_count: 0,
+      }
+    }) as typeof conversationService.requestControl
+
+    const { req, url, segments } = makeRequest(
+      'POST',
+      '/api/plugins/reload?sessionId=session-plugins',
+      {},
+    )
+    const res = await handlePluginsApi(req, url, segments)
+
+    expect(res.status).toBe(200)
+    const body = await res.json() as {
+      session: {
+        applied: boolean
+        commands: number
+        agents: number
+        plugins: number
+        mcpServers: number
+        errors: number
+      }
+    }
+
+    expect(controlRequests).toEqual([
+      {
+        sessionId: 'session-plugins',
+        request: { subtype: 'reload_plugins' },
+      },
+    ])
+    expect(body.session).toEqual({
+      applied: true,
+      commands: 1,
+      agents: 1,
+      plugins: 1,
+      mcpServers: 1,
+      errors: 0,
+    })
+    expect(getSlashCommands('session-plugins')).toEqual([
+      {
+        name: 'draw:render',
+        description: 'Render a drawing.',
+        argumentHint: '<prompt>',
+      },
+    ])
+  })
 })
diff --git a/src/server/api/plugins.ts b/src/server/api/plugins.ts
index 7a6f9794..1ed6602f 100644
--- a/src/server/api/plugins.ts
+++ b/src/server/api/plugins.ts
@@ -1,9 +1,22 @@
 import type { PluginScope } from '../../utils/plugins/schemas.js'
 import { ApiError, errorResponse } from '../middleware/errorHandler.js'
 import { PluginService } from '../services/pluginService.js'
+import { conversationService } from '../services/conversationService.js'
+import { updateSessionSlashCommands } from '../ws/handler.js'
 
 const pluginService = new PluginService()
 
+type PluginSessionReloadSummary = {
+  applied: boolean
+  reason?: 'not_running' | 'failed'
+  commands: number
+  agents: number
+  plugins: number
+  mcpServers: number
+  errors: number
+  error?: string
+}
+
 export async function handlePluginsApi(
   req: Request,
   url: URL,
@@ -29,7 +42,16 @@ export async function handlePluginsApi(
     }
 
     if (method === 'POST' && sub === 'reload') {
-      return Response.json(await pluginService.reloadPlugins(cwd))
+      const sessionId = url.searchParams.get('sessionId') || undefined
+      const response = await pluginService.reloadPlugins(cwd)
+      if (!sessionId) {
+        return Response.json(response)
+      }
+
+      return Response.json({
+        ...response,
+        session: await reloadSessionPlugins(sessionId),
+      })
     }
 
     if (method === 'POST' && sub) {
@@ -73,6 +95,52 @@ export async function handlePluginsApi(
   }
 }
 
+async function reloadSessionPlugins(
+  sessionId: string,
+): Promise<PluginSessionReloadSummary> {
+  if (!conversationService.hasSession(sessionId)) {
+    return {
+      applied: false,
+      reason: 'not_running',
+      commands: 0,
+      agents: 0,
+      plugins: 0,
+      mcpServers: 0,
+      errors: 0,
+    }
+  }
+
+  try {
+    const response = await conversationService.requestControl(
+      sessionId,
+      { subtype: 'reload_plugins' },
+      120_000,
+    )
+    const commands = Array.isArray(response.commands) ? response.commands : []
+    const normalizedCommands = updateSessionSlashCommands(sessionId, commands)
+
+    return {
+      applied: true,
+      commands: normalizedCommands.length,
+      agents: Array.isArray(response.agents) ? response.agents.length : 0,
+      plugins: Array.isArray(response.plugins) ? response.plugins.length : 0,
+      mcpServers: Array.isArray(response.mcpServers) ? response.mcpServers.length : 0,
+      errors: typeof response.error_count === 'number' ? response.error_count : 0,
+    }
+  } catch (error) {
+    return {
+      applied: false,
+      reason: 'failed',
+      commands: 0,
+      agents: 0,
+      plugins: 0,
+      mcpServers: 0,
+      errors: 0,
+      error: error instanceof Error ? error.message : String(error),
+    }
+  }
+}
+
 async function parseJsonBody(req: Request): Promise<Record<string, unknown>> {
   try {
     return (await req.json()) as Record<string, unknown>
diff --git a/src/server/ws/handler.ts b/src/server/ws/handler.ts
index dc798417..553b8b43 100644
--- a/src/server/ws/handler.ts
+++ b/src/server/ws/handler.ts
@@ -32,7 +32,13 @@ const providerService = new ProviderService()
 /**
  * Cache slash commands from CLI init messages, keyed by sessionId.
  */
-const sessionSlashCommands = new Map<string, Array<{ name: string; description: string }>>()
+export type SessionSlashCommand = {
+  name: string
+  description: string
+  argumentHint?: string
+}
+
+const sessionSlashCommands = new Map<string, SessionSlashCommand[]>()
 
 /**
  * Timers for delayed session cleanup after client disconnect.
@@ -86,7 +92,7 @@ async function sendRepositoryStartupStatus(
   }
 }
 
-export function getSlashCommands(sessionId: string): Array<{ name: string; description: string }> {
+export function getSlashCommands(sessionId: string): SessionSlashCommand[] {
   return sessionSlashCommands.get(sessionId) || []
 }
 
@@ -785,10 +791,7 @@ function cacheSessionInitMetadata(sessionId: string, cliMsg: any) {
     })()
   }
   if (cliMsg.slash_commands && Array.isArray(cliMsg.slash_commands)) {
-    sessionSlashCommands.set(sessionId, cliMsg.slash_commands.map((cmd: any) => ({
-      name: typeof cmd === 'string' ? cmd : (cmd.name || cmd.command || ''),
-      description: typeof cmd === 'string' ? '' : (cmd.description || ''),
-    })))
+    updateSessionSlashCommands(sessionId, cliMsg.slash_commands, { notifyClient: false })
   }
 }
 
@@ -1575,6 +1578,55 @@ export function sendToSession(sessionId: string, message: ServerMessage): boolea
   return true
 }
 
+export function updateSessionSlashCommands(
+  sessionId: string,
+  commands: unknown[],
+  options: { notifyClient?: boolean } = {},
+): SessionSlashCommand[] {
+  const normalized = commands
+    .map(normalizeSessionSlashCommand)
+    .filter((command): command is SessionSlashCommand => command !== null)
+
+  sessionSlashCommands.set(sessionId, normalized)
+
+  if (options.notifyClient !== false) {
+    sendToSession(sessionId, {
+      type: 'system_notification',
+      subtype: 'slash_commands',
+      data: normalized,
+    })
+  }
+
+  return normalized
+}
+
+function normalizeSessionSlashCommand(command: unknown): SessionSlashCommand | null {
+  if (typeof command === 'string') {
+    return command.trim() ? { name: command, description: '' } : null
+  }
+  if (!command || typeof command !== 'object') return null
+
+  const record = command as {
+    name?: unknown
+    command?: unknown
+    description?: unknown
+    argumentHint?: unknown
+  }
+  const name =
+    typeof record.name === 'string'
+      ? record.name
+      : typeof record.command === 'string'
+        ? record.command
+        : ''
+  if (!name.trim()) return null
+
+  return {
+    name,
+    description: typeof record.description === 'string' ? record.description : '',
+    ...(typeof record.argumentHint === 'string' ? { argumentHint: record.argumentHint } : {}),
+  }
+}
+
 export function closeSessionConnection(sessionId: string, reason = 'session closed'): boolean {
   const cleanupTimer = sessionCleanupTimers.get(sessionId)
   if (cleanupTimer) {