diff --git a/apps/desktop/src/app/settings/model-settings.test.tsx b/apps/desktop/src/app/settings/model-settings.test.tsx
index a0b1afdc958..afe267b5fda 100644
--- a/apps/desktop/src/app/settings/model-settings.test.tsx
+++ b/apps/desktop/src/app/settings/model-settings.test.tsx
@@ -16,6 +16,8 @@ const getAuxiliaryModels = vi.fn()
 const setModelAssignment = vi.fn()
 const getRecommendedDefaultModel = vi.fn()
 const setEnvVar = vi.fn()
+const getHermesConfigRecord = vi.fn()
+const saveHermesConfig = vi.fn()
 const startManualProviderOAuth = vi.fn()
 
 vi.mock('@/hermes', () => ({
@@ -24,7 +26,9 @@ vi.mock('@/hermes', () => ({
   getAuxiliaryModels: () => getAuxiliaryModels(),
   setModelAssignment: (body: unknown) => setModelAssignment(body),
   getRecommendedDefaultModel: (slug: string) => getRecommendedDefaultModel(slug),
-  setEnvVar: (key: string, value: string) => setEnvVar(key, value)
+  setEnvVar: (key: string, value: string) => setEnvVar(key, value),
+  getHermesConfigRecord: () => getHermesConfigRecord(),
+  saveHermesConfig: (config: unknown) => saveHermesConfig(config)
 }))
 
 vi.mock('@/store/onboarding', () => ({
@@ -35,7 +39,13 @@ beforeEach(() => {
   getGlobalModelInfo.mockResolvedValue({ provider: 'nous', model: 'hermes-4' })
   getGlobalModelOptions.mockResolvedValue({
     providers: [
-      { name: 'Nous', slug: 'nous', models: ['hermes-4', 'hermes-4-mini'], authenticated: true },
+      {
+        name: 'Nous',
+        slug: 'nous',
+        models: ['hermes-4', 'hermes-4-mini'],
+        authenticated: true,
+        capabilities: { 'hermes-4': { reasoning: true, fast: true } }
+      },
       // An unconfigured api_key provider — surfaced by the full-universe payload.
       { name: 'DeepSeek', slug: 'deepseek', models: [], authenticated: false, auth_type: 'api_key', key_env: 'DEEPSEEK_API_KEY' }
     ]
@@ -47,6 +57,8 @@ beforeEach(() => {
   setModelAssignment.mockResolvedValue({ provider: 'nous', model: 'hermes-4', gateway_tools: [] })
   getRecommendedDefaultModel.mockResolvedValue({ provider: 'deepseek', model: 'deepseek-chat', free_tier: null })
   setEnvVar.mockResolvedValue({ ok: true })
+  getHermesConfigRecord.mockResolvedValue({ agent: { reasoning_effort: 'medium', service_tier: 'normal' } })
+  saveHermesConfig.mockResolvedValue({ ok: true })
 })
 
 afterEach(() => {
@@ -100,6 +112,31 @@ describe('ModelSettings', () => {
     await waitFor(() => expect(setEnvVar).toHaveBeenCalledWith('DEEPSEEK_API_KEY', 'sk-test-123'))
   })
 
+  it('writes the profile default speed (service_tier) when the fast switch is toggled', async () => {
+    await renderModelSettings()
+    await waitFor(() => expect(getHermesConfigRecord).toHaveBeenCalled())
+
+    const fastSwitch = await screen.findByRole('switch')
+    fireEvent.click(fastSwitch)
+
+    await waitFor(() =>
+      expect(saveHermesConfig).toHaveBeenCalledWith(
+        expect.objectContaining({ agent: expect.objectContaining({ service_tier: 'fast' }) })
+      )
+    )
+  })
+
+  it('hides the reasoning/speed defaults when the main model reports no capabilities', async () => {
+    getGlobalModelOptions.mockResolvedValueOnce({
+      providers: [{ name: 'Nous', slug: 'nous', models: ['hermes-4'], authenticated: true, capabilities: { 'hermes-4': { reasoning: false, fast: false } } }]
+    })
+
+    await renderModelSettings()
+    await waitFor(() => expect(getHermesConfigRecord).toHaveBeenCalled())
+
+    expect(screen.queryByRole('switch')).toBeNull()
+  })
+
   it('renders the auxiliary task rows', async () => {
     await renderModelSettings()
 
diff --git a/apps/desktop/src/app/settings/model-settings.tsx b/apps/desktop/src/app/settings/model-settings.tsx
index c55fa6b4773..e88938def06 100644
--- a/apps/desktop/src/app/settings/model-settings.tsx
+++ b/apps/desktop/src/app/settings/model-settings.tsx
@@ -3,11 +3,14 @@ import { useCallback, useEffect, useMemo, useState } from 'react'
 import { Button } from '@/components/ui/button'
 import { Input } from '@/components/ui/input'
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '@/components/ui/select'
+import { Switch } from '@/components/ui/switch'
 import {
   getAuxiliaryModels,
   getGlobalModelInfo,
   getGlobalModelOptions,
+  getHermesConfigRecord,
   getRecommendedDefaultModel,
+  saveHermesConfig,
   setEnvVar,
   setModelAssignment
 } from '@/hermes'
@@ -15,11 +18,26 @@ import type { AuxiliaryModelsResponse, ModelOptionProvider, StaleAuxAssignment }
 import { useI18n } from '@/i18n'
 import { AlertTriangle, Cpu, Loader2 } from '@/lib/icons'
 import { cn } from '@/lib/utils'
+import { notifyError } from '@/store/notifications'
 import { startManualLocalEndpoint, startManualProviderOAuth } from '@/store/onboarding'
+import type { HermesConfigRecord } from '@/types/hermes'
 
 import { CONTROL_TEXT } from './constants'
+import { getNested, setNested } from './helpers'
 import { ListRow, LoadingState, Pill, SectionHeading } from './primitives'
 
+// Hermes' reasoning levels (VALID_REASONING_EFFORTS); `none` = thinking off.
+// Empty config = Hermes default (medium), shown as Medium.
+const EFFORT_VALUES = ['none', 'minimal', 'low', 'medium', 'high', 'xhigh'] as const
+
+// agent.service_tier stores "fast"/"priority"/"on" for fast; anything else is
+// normal (mirrors tui_gateway _load_service_tier).
+const isFastTier = (tier: unknown): boolean =>
+  ['fast', 'priority', 'on'].includes(String(tier ?? '').trim().toLowerCase())
+
+// Reuse the composer's effort labels (`xhigh` shows as "Max", else 1:1).
+const effortLabelKey = (v: string) => (v === 'xhigh' ? 'max' : v) as 'high' | 'low' | 'max' | 'medium' | 'minimal'
+
 // A provider row is "ready" to pick a model from when it reports models. The
 // backend now surfaces the full `hermes model` universe (every canonical
 // provider), so unconfigured providers come back with `authenticated:false`
@@ -97,6 +115,9 @@ export function ModelSettings({ onMainModelChanged }: ModelSettingsProps) {
   const [selectedProvider, setSelectedProvider] = useState('')
   const [selectedModel, setSelectedModel] = useState('')
   const [auxiliary, setAuxiliary] = useState<AuxiliaryModelsResponse | null>(null)
+  // Full profile config, kept so the reasoning/speed defaults round-trip
+  // (read agent.* → write back the whole record) like the generic config page.
+  const [config, setConfig] = useState<HermesConfigRecord | null>(null)
   const [applying, setApplying] = useState(false)
   const [editingAuxTask, setEditingAuxTask] = useState<null | string>(null)
   const [auxDraft, setAuxDraft] = useState<{ model: string; provider: string }>({ model: '', provider: '' })
@@ -113,10 +134,11 @@ export function ModelSettings({ onMainModelChanged }: ModelSettingsProps) {
     setError('')
 
     try {
-      const [modelInfo, modelOptions, auxiliaryModels] = await Promise.all([
+      const [modelInfo, modelOptions, auxiliaryModels, cfg] = await Promise.all([
         getGlobalModelInfo(),
         getGlobalModelOptions(),
-        getAuxiliaryModels()
+        getAuxiliaryModels(),
+        getHermesConfigRecord()
       ])
 
       setMainModel({ model: modelInfo.model, provider: modelInfo.provider })
@@ -124,6 +146,7 @@ export function ModelSettings({ onMainModelChanged }: ModelSettingsProps) {
       setSelectedProvider(prev => prev || modelInfo.provider)
       setSelectedModel(prev => prev || modelInfo.model)
       setAuxiliary(auxiliaryModels)
+      setConfig(cfg)
     } catch (err) {
       setError(err instanceof Error ? err.message : String(err))
     } finally {
@@ -181,6 +204,42 @@ export function ModelSettings({ onMainModelChanged }: ModelSettingsProps) {
       .map(entry => ({ task: entry.task, provider: entry.provider, model: entry.model }))
   }, [auxiliary, mainModel])
 
+  // Capabilities of the APPLIED main model — gates the profile-default
+  // reasoning/speed controls the same way the composer picker gates per-model
+  // edits (reasoning defaults on, fast defaults off when unreported).
+  const mainCaps = useMemo(() => {
+    const row = providers.find(provider => provider.slug === mainModel?.provider)
+
+    return mainModel ? row?.capabilities?.[mainModel.model] : undefined
+  }, [providers, mainModel])
+
+  const reasoningSupported = mainCaps?.reasoning ?? true
+  const fastSupported = mainCaps?.fast ?? false
+  const effortValue = String(getNested(config ?? {}, 'agent.reasoning_effort') ?? '').trim().toLowerCase() || 'medium'
+  const fastOn = isFastTier(getNested(config ?? {}, 'agent.service_tier'))
+
+  // Persist a single agent.* default by round-tripping the whole config record
+  // (PUT /api/config replaces it) — optimistic, with rollback on failure.
+  const writeAgentDefault = useCallback(
+    async (key: string, value: string) => {
+      if (!config) {
+        return
+      }
+
+      const prev = config
+      const next = setNested(config, key, value)
+      setConfig(next)
+
+      try {
+        await saveHermesConfig(next)
+      } catch (err) {
+        setConfig(prev)
+        notifyError(err, m.defaultsFailed)
+      }
+    },
+    [config, m.defaultsFailed]
+  )
+
   // Paste an API key for the selected `api_key` provider, persist it, then
   // refresh so the now-authenticated provider's models populate. Auto-selects
   // the recommended default model so the user can Apply in one more click.
@@ -433,6 +492,38 @@ export function ModelSettings({ onMainModelChanged }: ModelSettingsProps) {
               : `${selectedProviderRow?.name} signs in through your browser — Hermes runs the flow for you.`}
           </p>
         )}
+        {config && mainModel && (reasoningSupported || fastSupported) && (
+          <div className="mt-3 flex flex-wrap items-center gap-x-6 gap-y-3">
+            <span className="text-xs text-muted-foreground">{m.defaultsLabel}</span>
+            {reasoningSupported && (
+              <div className="flex items-center gap-2 text-xs">
+                {m.reasoning}
+                <Select onValueChange={value => void writeAgentDefault('agent.reasoning_effort', value)} value={effortValue}>
+                  <SelectTrigger className={cn('min-w-28', CONTROL_TEXT)}>
+                    <SelectValue />
+                  </SelectTrigger>
+                  <SelectContent>
+                    {EFFORT_VALUES.map(value => (
+                      <SelectItem key={value} value={value}>
+                        {value === 'none' ? m.reasoningOff : t.shell.modelOptions[effortLabelKey(value)]}
+                      </SelectItem>
+                    ))}
+                  </SelectContent>
+                </Select>
+              </div>
+            )}
+            {fastSupported && (
+              <label className="flex items-center gap-2 text-xs">
+                {t.shell.modelOptions.fast}
+                <Switch
+                  checked={fastOn}
+                  onCheckedChange={checked => void writeAgentDefault('agent.service_tier', checked ? 'fast' : 'normal')}
+                  size="xs"
+                />
+              </label>
+            )}
+          </div>
+        )}
         {error && <div className="mt-2 text-xs text-destructive">{error}</div>}
         {switchStaleAux.length > 0 && (
           <div className="mt-2">
diff --git a/apps/desktop/src/app/shell/model-menu-panel.tsx b/apps/desktop/src/app/shell/model-menu-panel.tsx
index a9795564aab..c3d20ebd878 100644
--- a/apps/desktop/src/app/shell/model-menu-panel.tsx
+++ b/apps/desktop/src/app/shell/model-menu-panel.tsx
@@ -18,7 +18,7 @@ import { Skeleton } from '@/components/ui/skeleton'
 import type { HermesGateway } from '@/hermes'
 import { getGlobalModelOptions } from '@/hermes'
 import { useI18n } from '@/i18n'
-import { displayModelName, modelDisplayParts, reasoningEffortLabel } from '@/lib/model-status-label'
+import { currentPickerSelection, displayModelName, modelDisplayParts, reasoningEffortLabel } from '@/lib/model-status-label'
 import { cn } from '@/lib/utils'
 import { $modelPresets, applyModelPreset, modelPresetKey } from '@/store/model-presets'
 import {
@@ -84,8 +84,12 @@ export function ModelMenuPanel({ gateway, onSelectModel, requestGateway }: Model
     }
   })
 
-  const optionsModel = String(modelOptions.data?.model ?? currentModel ?? '')
-  const optionsProvider = String(modelOptions.data?.provider ?? currentProvider ?? '')
+  const { model: optionsModel, provider: optionsProvider } = currentPickerSelection(
+    !!activeSessionId,
+    { model: currentModel, provider: currentProvider },
+    modelOptions.data
+  )
+
   const loading = modelOptions.isPending && !modelOptions.data
 
   const error = modelOptions.error
diff --git a/apps/desktop/src/components/model-picker.tsx b/apps/desktop/src/components/model-picker.tsx
index be941e23d06..11c83f7f293 100644
--- a/apps/desktop/src/components/model-picker.tsx
+++ b/apps/desktop/src/components/model-picker.tsx
@@ -2,6 +2,7 @@ import { useQuery } from '@tanstack/react-query'
 import { useState } from 'react'
 
 import { useI18n } from '@/i18n'
+import { currentPickerSelection } from '@/lib/model-status-label'
 import type { ModelOptionProvider, ModelOptionsResponse, ModelPricing } from '@/types/hermes'
 
 import type { HermesGateway } from '../hermes'
@@ -66,8 +67,13 @@ export function ModelPickerDialog({
   })
 
   const providers = modelOptions.data?.providers ?? []
-  const optionsModel = String(modelOptions.data?.model ?? currentModel ?? '')
-  const optionsProvider = String(modelOptions.data?.provider ?? currentProvider ?? '')
+
+  const { model: optionsModel, provider: optionsProvider } = currentPickerSelection(
+    !!sessionId,
+    { model: currentModel, provider: currentProvider },
+    modelOptions.data
+  )
+
   const loading = modelOptions.isPending && !modelOptions.data
 
   const error = modelOptions.error
diff --git a/apps/desktop/src/i18n/en.ts b/apps/desktop/src/i18n/en.ts
index c1fbf90bcb7..fa6465c3388 100644
--- a/apps/desktop/src/i18n/en.ts
+++ b/apps/desktop/src/i18n/en.ts
@@ -538,6 +538,10 @@ export const en: Translations = {
       provider: 'Provider',
       model: 'Model',
       applying: 'Applying...',
+      defaultsLabel: 'Defaults',
+      reasoning: 'Reasoning',
+      reasoningOff: 'Off',
+      defaultsFailed: 'Failed to save model defaults',
       auxiliaryTitle: 'Auxiliary models',
       resetAllToMain: 'Reset all to main',
       auxiliaryDesc: 'Helper tasks run on the main model by default. Assign a dedicated model to any task to override.',
diff --git a/apps/desktop/src/i18n/types.ts b/apps/desktop/src/i18n/types.ts
index cc76b30d346..2e9cc76ab98 100644
--- a/apps/desktop/src/i18n/types.ts
+++ b/apps/desktop/src/i18n/types.ts
@@ -430,6 +430,10 @@ export interface Translations {
       provider: string
       model: string
       applying: string
+      defaultsLabel: string
+      reasoning: string
+      reasoningOff: string
+      defaultsFailed: string
       auxiliaryTitle: string
       resetAllToMain: string
       auxiliaryDesc: string
diff --git a/apps/desktop/src/i18n/zh.ts b/apps/desktop/src/i18n/zh.ts
index 0387a6be5bc..db13108d8f7 100644
--- a/apps/desktop/src/i18n/zh.ts
+++ b/apps/desktop/src/i18n/zh.ts
@@ -733,6 +733,10 @@ export const zh: Translations = {
       provider: '提供方',
       model: '模型',
       applying: '应用中...',
+      defaultsLabel: '默认值',
+      reasoning: '推理',
+      reasoningOff: '关闭',
+      defaultsFailed: '保存模型默认值失败',
       auxiliaryTitle: '辅助模型',
       resetAllToMain: '全部重置为主模型',
       auxiliaryDesc: '辅助任务默认使用主模型。你可以为任意任务指定专用模型。',
diff --git a/apps/desktop/src/lib/model-status-label.test.ts b/apps/desktop/src/lib/model-status-label.test.ts
index 78fe51492b1..f46282d00b2 100644
--- a/apps/desktop/src/lib/model-status-label.test.ts
+++ b/apps/desktop/src/lib/model-status-label.test.ts
@@ -1,6 +1,6 @@
 import { describe, expect, it } from 'vitest'
 
-import { displayModelName, formatModelStatusLabel, reasoningEffortLabel } from './model-status-label'
+import { currentPickerSelection, displayModelName, formatModelStatusLabel, reasoningEffortLabel } from './model-status-label'
 
 describe('model-status-label', () => {
   it('formats display names consistently', () => {
@@ -35,4 +35,25 @@ describe('model-status-label', () => {
   it('returns just the placeholder name when there is no model', () => {
     expect(formatModelStatusLabel('')).toBe('No model')
   })
+
+  describe('currentPickerSelection', () => {
+    const store = { model: 'opus', provider: 'anthropic' }
+    const options = { model: 'hermes-4', provider: 'nous' }
+
+    it('prefers the sticky composer pick over the profile default pre-session', () => {
+      expect(currentPickerSelection(false, store, options)).toEqual(store)
+    })
+
+    it('lets the live session model.options win when a session exists', () => {
+      expect(currentPickerSelection(true, store, options)).toEqual(options)
+    })
+
+    it('falls back to options when the store is empty', () => {
+      expect(currentPickerSelection(false, { model: '', provider: '' }, options)).toEqual(options)
+    })
+
+    it('falls back to the store while options are still loading', () => {
+      expect(currentPickerSelection(true, store, undefined)).toEqual(store)
+    })
+  })
 })
diff --git a/apps/desktop/src/lib/model-status-label.ts b/apps/desktop/src/lib/model-status-label.ts
index 60f0e81a959..9b0e8df7a64 100644
--- a/apps/desktop/src/lib/model-status-label.ts
+++ b/apps/desktop/src/lib/model-status-label.ts
@@ -17,6 +17,22 @@ export function reasoningEffortLabel(effort: string): string {
   return REASONING_LABELS[key] ?? effort
 }
 
+/** Which model/provider a picker should mark "current". With a live session the
+ *  gateway's `model.options` is authoritative; pre-session there is no server
+ *  "current", so the sticky composer pick wins over the profile default the
+ *  global options query returns — else the checkmark snaps back to the default
+ *  and the pick looks ignored. */
+export function currentPickerSelection(
+  hasSession: boolean,
+  store: { model: string; provider: string },
+  options?: { model?: string; provider?: string }
+): { model: string; provider: string } {
+  return {
+    model: String((hasSession && options?.model) || store.model || options?.model || ''),
+    provider: String((hasSession && options?.provider) || store.provider || options?.provider || '')
+  }
+}
+
 /** Strip provider prefix and normalize for display. */
 export function modelBaseId(model: string): string {
   const trimmed = model.trim()