fix(desktop): apply active provider before first prompt (#844)

Materialize the active provider runtime for empty-session first prompts before the WebSocket prewarm and user message are sent. This keeps a clean install that adds a MiniMax provider from starting the first turn without the selected provider runtime.

Tested: bun test src/server/__tests__/conversations.test.ts -t "MiniMax provider turn"
Tested: bun test src/server/__tests__/websocket-handler.test.ts src/server/__tests__/conversations.test.ts -t "prewarm|active provider id|MiniMax provider turn|first-turn runtime synchronization"
Tested: cd desktop && bun run test -- --run src/pages/EmptySession.test.tsx -t "draft runtime|active provider runtime|creates a new session"
Tested: cd desktop && bun run test -- --run src/components/controls/ModelSelector.test.tsx -t "defaults blank provider-scoped runtime selections|selects provider-scoped runtime models"
Tested: cd desktop && bun run lint
Tested: cd desktop && bun run build
Not-tested: bun run check:desktop, unrelated full-suite failures in MessageList timestamp formatting and TabBar AbortSignal cleanup blocked the gate.
Confidence: medium
Scope-risk: narrow

desktop/src/components/controls/ModelSelector.tsx

@@ -1,8 +1,7 @@
 import { forwardRef, useCallback, useEffect, useImperativeHandle, useLayoutEffect, useMemo, useRef, useState } from 'react'
 import { createPortal } from 'react-dom'
-import { OFFICIAL_DEFAULT_MODEL_ID, OFFICIAL_MODELS } from '../../constants/modelCatalog'
+import { OFFICIAL_MODELS } from '../../constants/modelCatalog'
 import {
-  OPENAI_OFFICIAL_DEFAULT_MODEL_ID,
   OPENAI_OFFICIAL_MODELS,
   OPENAI_OFFICIAL_PROVIDER_ID,
 } from '../../constants/openaiOfficialProvider'
@@ -16,6 +15,7 @@ import type { RuntimeSelection } from '../../types/runtime'
 import type { EffortLevel, ModelInfo } from '../../types/settings'
 import { useMobileViewport } from '../../hooks/useMobileViewport'
 import { isDesktopRuntime } from '../../lib/desktopRuntime'
+import { resolveDefaultRuntimeSelection } from '../../lib/runtimeSelection'
 import { useHahaOAuthStore } from '../../stores/hahaOAuthStore'
 import { useHahaOpenAIOAuthStore } from '../../stores/hahaOpenAIOAuthStore'
 import { MobileBottomSheet } from '../shared/MobileBottomSheet'
@@ -144,30 +144,6 @@ function buildProviderChoices(
   return choices
 }
 
-function resolveDefaultRuntimeSelection(
-  activeId: string | null,
-  activeProviderName: string | null,
-  providers: SavedProvider[],
-  currentModelId: string | undefined,
-): RuntimeSelection {
-  const activeProvider = activeId
-    ? providers.find((provider) => provider.id === activeId)
-    : activeProviderName
-      ? providers.find((provider) => provider.name === activeProviderName)
-      : undefined
-  const inferredProviderId = activeId ?? activeProvider?.id ?? null
-  const providerMainModelId = activeProvider?.models.main.trim()
-
-  return {
-    providerId: inferredProviderId,
-    modelId: providerMainModelId || currentModelId || (
-      inferredProviderId === OPENAI_OFFICIAL_PROVIDER_ID
-        ? OPENAI_OFFICIAL_DEFAULT_MODEL_ID
-        : OFFICIAL_DEFAULT_MODEL_ID
-    ),
-  }
-}
-
 export const ModelSelector = forwardRef<ModelSelectorHandle, Props>(function ModelSelector({
   value,
   onChange,

desktop/src/lib/runtimeSelection.ts

@@ -0,0 +1,50 @@
+import { OFFICIAL_DEFAULT_MODEL_ID } from '../constants/modelCatalog'
+import {
+  OPENAI_OFFICIAL_DEFAULT_MODEL_ID,
+  OPENAI_OFFICIAL_PROVIDER_ID,
+} from '../constants/openaiOfficialProvider'
+import type { SavedProvider } from '../types/provider'
+import type { RuntimeSelection } from '../types/runtime'
+
+export function resolveActiveProviderRuntimeSelection(
+  activeId: string | null,
+  activeProviderName: string | null,
+  providers: SavedProvider[],
+  currentModelId: string | undefined,
+): RuntimeSelection | null {
+  const activeProvider = activeId
+    ? providers.find((provider) => provider.id === activeId)
+    : activeProviderName
+      ? providers.find((provider) => provider.name === activeProviderName)
+      : undefined
+  const inferredProviderId = activeId ?? activeProvider?.id ?? null
+  if (!inferredProviderId) return null
+
+  const providerMainModelId = activeProvider?.models.main.trim()
+
+  return {
+    providerId: inferredProviderId,
+    modelId: providerMainModelId || currentModelId || (
+      inferredProviderId === OPENAI_OFFICIAL_PROVIDER_ID
+        ? OPENAI_OFFICIAL_DEFAULT_MODEL_ID
+        : OFFICIAL_DEFAULT_MODEL_ID
+    ),
+  }
+}
+
+export function resolveDefaultRuntimeSelection(
+  activeId: string | null,
+  activeProviderName: string | null,
+  providers: SavedProvider[],
+  currentModelId: string | undefined,
+): RuntimeSelection {
+  return resolveActiveProviderRuntimeSelection(
+    activeId,
+    activeProviderName,
+    providers,
+    currentModelId,
+  ) ?? {
+    providerId: null,
+    modelId: currentModelId || OFFICIAL_DEFAULT_MODEL_ID,
+  }
+}

desktop/src/pages/EmptySession.test.tsx

@@ -131,6 +131,7 @@ vi.mock('../components/controls/ModelSelector', async () => {
 import { EmptySession } from './EmptySession'
 import { ApiError } from '../api/client'
 import { useChatStore } from '../stores/chatStore'
+import { useProviderStore } from '../stores/providerStore'
 import { useSessionRuntimeStore } from '../stores/sessionRuntimeStore'
 import { useSessionStore } from '../stores/sessionStore'
 import { useSettingsStore } from '../stores/settingsStore'
@@ -186,6 +187,7 @@ describe('EmptySession', () => {
   const initialRuntimeState = useSessionRuntimeStore.getInitialState()
   const initialUiState = useUIStore.getInitialState()
   const initialPluginState = usePluginStore.getInitialState()
+  const initialProviderState = useProviderStore.getInitialState()
 
   beforeEach(() => {
     vi.clearAllMocks()
@@ -199,6 +201,7 @@ describe('EmptySession', () => {
     useSessionRuntimeStore.setState(initialRuntimeState, true)
     useUIStore.setState(initialUiState, true)
     usePluginStore.setState(initialPluginState, true)
+    useProviderStore.setState(initialProviderState, true)
 
     mocks.createSession.mockResolvedValue({ sessionId: 'draft-session' })
     mocks.getRepositoryContext.mockResolvedValue(okRepositoryContext())
@@ -238,6 +241,7 @@ describe('EmptySession', () => {
     useSessionRuntimeStore.setState(initialRuntimeState, true)
     useUIStore.setState(initialUiState, true)
     usePluginStore.setState(initialPluginState, true)
+    useProviderStore.setState(initialProviderState, true)
   })
 
   it('uses compact composer controls on phone-sized H5 browsers', async () => {
@@ -527,6 +531,66 @@ describe('EmptySession', () => {
     ])
   })
 
+  it('materializes the active provider runtime before the first draft message', async () => {
+    useProviderStore.setState({
+      providers: [{
+        id: 'provider-minimax',
+        presetId: 'minimax',
+        name: 'MiniMax',
+        apiKey: 'sk-minimax',
+        baseUrl: 'https://api.minimaxi.com/anthropic',
+        apiFormat: 'anthropic',
+        runtimeKind: 'anthropic_compatible',
+        models: {
+          main: 'MiniMax-M3[1m]',
+          haiku: 'MiniMax-M3[1m]',
+          sonnet: 'MiniMax-M3[1m]',
+          opus: 'MiniMax-M3[1m]',
+        },
+        toolSearchEnabled: true,
+      }],
+      activeId: 'provider-minimax',
+      providerOrder: ['provider-minimax', 'claude-official', 'openai-official'],
+      hasLoadedProviders: true,
+    })
+
+    render(<EmptySession />)
+
+    fireEvent.change(screen.getByRole('textbox'), {
+      target: { value: 'draft question', selectionStart: 14 },
+    })
+
+    fireEvent.click(screen.getByRole('button', { name: /Run/i }))
+
+    await waitFor(() => {
+      expect(mocks.createSession).toHaveBeenCalledWith({ permissionMode: 'default' })
+    })
+
+    expect(useSessionRuntimeStore.getState().selections['draft-session']).toEqual({
+      providerId: 'provider-minimax',
+      modelId: 'MiniMax-M3[1m]',
+    })
+    expect(mocks.wsSend.mock.calls.slice(0, 3)).toEqual([
+      [
+        'draft-session',
+        {
+          type: 'set_runtime_config',
+          providerId: 'provider-minimax',
+          modelId: 'MiniMax-M3[1m]',
+        },
+      ],
+      ['draft-session', { type: 'prewarm_session' }],
+      [
+        'draft-session',
+        {
+          type: 'user_message',
+          content: 'draft question',
+          attachments: [],
+        },
+      ],
+    ])
+  })
+
   it('uses native desktop file paths for draft attachments', async () => {
     mocks.isTauriRuntime = true
     window.desktopHost = {

desktop/src/pages/EmptySession.tsx

@@ -6,6 +6,7 @@ import { useTranslation } from '../i18n'
 import { useSessionStore } from '../stores/sessionStore'
 import { useChatStore } from '../stores/chatStore'
 import { usePluginStore } from '../stores/pluginStore'
+import { useProviderStore } from '../stores/providerStore'
 import { useSessionRuntimeStore, DRAFT_RUNTIME_SELECTION_KEY } from '../stores/sessionRuntimeStore'
 import { useSettingsStore } from '../stores/settingsStore'
 import { useUIStore } from '../stores/uiStore'
@@ -21,6 +22,7 @@ import { LocalSlashCommandPanel, type LocalSlashCommandName } from '../component
 import { useMobileViewport } from '../hooks/useMobileViewport'
 import { isDesktopRuntime } from '../lib/desktopRuntime'
 import { publicAssetPath } from '../lib/publicAsset'
+import { resolveActiveProviderRuntimeSelection } from '../lib/runtimeSelection'
 import {
   filesToComposerAttachments,
   selectNativeFileAttachments,
@@ -116,8 +118,11 @@ export function EmptySession() {
   const setActiveView = useUIStore((state) => state.setActiveView)
   const addToast = useUIStore((state) => state.addToast)
   const currentModel = useSettingsStore((state) => state.currentModel)
+  const activeProviderName = useSettingsStore((state) => state.activeProviderName)
   const chatSendBehavior = useSettingsStore((state) => state.chatSendBehavior)
   const defaultPermissionMode = useSettingsStore((state) => state.permissionMode)
+  const providers = useProviderStore((state) => state.providers)
+  const activeProviderId = useProviderStore((state) => state.activeId)
   const [draftPermissionMode, setDraftPermissionMode] = useState<PermissionMode>(defaultPermissionMode)
   const lastPluginReloadSummary = usePluginStore((state) => state.lastReloadSummary)
   const draftRuntimeSelection = useSessionRuntimeStore((state) => state.selections[DRAFT_RUNTIME_SELECTION_KEY])
@@ -315,7 +320,17 @@ export function EmptySession() {
 
     setIsSubmitting(true)
     try {
-      const explicitDraftSelection = useSessionRuntimeStore.getState().selections[DRAFT_RUNTIME_SELECTION_KEY]
+      const runtimeStore = useSessionRuntimeStore.getState()
+      const explicitDraftSelection = runtimeStore.selections[DRAFT_RUNTIME_SELECTION_KEY]
+      const defaultActiveProviderSelection = explicitDraftSelection
+        ? null
+        : resolveActiveProviderRuntimeSelection(
+          activeProviderId,
+          activeProviderName,
+          providers,
+          currentModel?.id,
+        )
+      const runtimeSelection = explicitDraftSelection ?? defaultActiveProviderSelection ?? undefined
       const sessionId = await createSession(
         workDir || undefined,
         {
@@ -325,9 +340,11 @@ export function EmptySession() {
           permissionMode: draftPermissionMode,
         },
       )
-      if (explicitDraftSelection) {
+      if (runtimeSelection) {
-        useSessionRuntimeStore.getState().setSelection(sessionId, explicitDraftSelection)
+        runtimeStore.setSelection(sessionId, runtimeSelection)
-        useSessionRuntimeStore.getState().clearSelection(DRAFT_RUNTIME_SELECTION_KEY)
+        if (explicitDraftSelection) {
+          runtimeStore.clearSelection(DRAFT_RUNTIME_SELECTION_KEY)
+        }
       }
       setActiveView('code')
       useTabStore.getState().openTab(sessionId, 'New Session')

src/server/__tests__/conversations.test.ts

@@ -2192,6 +2192,111 @@ describe('WebSocket Chat Integration', () => {
     }
   }, 20_000)
 
+  it('does not strand the first MiniMax provider turn when prewarm and user message flush together (#844)', async () => {
+    const providerService = new ProviderService()
+    const provider = await providerService.addProvider({
+      presetId: 'minimax',
+      name: 'MiniMax first-turn race',
+      apiKey: 'key-minimax-first-turn-race',
+      baseUrl: 'https://api.minimaxi.com/anthropic',
+      apiFormat: 'anthropic',
+      models: {
+        main: 'MiniMax-M3',
+        haiku: 'MiniMax-M3',
+        sonnet: 'MiniMax-M3',
+        opus: 'MiniMax-M3',
+      },
+      model1mSupport: {
+        main: true,
+        haiku: true,
+        sonnet: true,
+        opus: true,
+      },
+    })
+    await providerService.activateProvider(provider.id)
+
+    const createRes = await fetch(`${baseUrl}/api/sessions`, {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ workDir: process.cwd() }),
+    })
+    expect(createRes.status).toBe(201)
+    const { sessionId } = await createRes.json() as { sessionId: string }
+
+    const originalStartSession = conversationService.startSession.bind(conversationService)
+    const startCalls: Array<{
+      sessionId: string
+      options: { providerId?: string | null } | undefined
+    }> = []
+
+    conversationService.startSession = (async function patchedStartSession(
+      sid: string,
+      workDir: string,
+      sdkUrl: string,
+      options?: { permissionMode?: string; model?: string; effort?: string; thinking?: 'enabled' | 'adaptive' | 'disabled'; providerId?: string | null },
+    ) {
+      startCalls.push({ sessionId: sid, options })
+      return originalStartSession(sid, workDir, sdkUrl, options)
+    }) as typeof conversationService.startSession
+
+    const messages: any[] = []
+    const ws = new WebSocket(`${wsUrl}/ws/${sessionId}`)
+
+    try {
+      await new Promise<void>((resolve, reject) => {
+        const timeout = setTimeout(() => {
+          ws.close()
+          reject(new Error(`Timed out waiting for first MiniMax provider turn for session ${sessionId}`))
+        }, 10_000)
+
+        ws.onmessage = (event) => {
+          const msg = JSON.parse(event.data as string)
+          messages.push(msg)
+
+          if (msg.type === 'connected') {
+            ws.send(JSON.stringify({ type: 'prewarm_session' }))
+            ws.send(JSON.stringify({ type: 'user_message', content: 'first turn without provider test' }))
+            return
+          }
+
+          if (msg.type === 'error') {
+            clearTimeout(timeout)
+            ws.close()
+            reject(new Error(msg.message))
+            return
+          }
+
+          if (msg.type === 'message_complete') {
+            clearTimeout(timeout)
+            ws.close()
+            resolve()
+          }
+        }
+
+        ws.onerror = () => {
+          clearTimeout(timeout)
+          ws.close()
+          reject(new Error(`WebSocket error for first MiniMax provider turn ${sessionId}`))
+        }
+      })
+
+      expect(startCalls).toHaveLength(1)
+      expect(startCalls[0]).toMatchObject({
+        sessionId,
+        options: {
+          providerId: provider.id,
+        },
+      })
+      expect(messages.some((msg) => msg.type === 'content_delta')).toBe(true)
+      expect(messages.some((msg) => msg.type === 'message_complete')).toBe(true)
+      expect(messages.some((msg) => msg.type === 'error')).toBe(false)
+    } finally {
+      ws.close()
+      conversationService.startSession = originalStartSession
+      conversationService.stopSession(sessionId)
+    }
+  }, 20_000)
+
   it('should pass the active provider id into default desktop sessions', async () => {
     const providerService = new ProviderService()
     const provider = await providerService.addProvider({