diff --git a/apps/desktop/src/app/agents/index.tsx b/apps/desktop/src/app/agents/index.tsx
index e84458877a..480efe444b 100644
--- a/apps/desktop/src/app/agents/index.tsx
+++ b/apps/desktop/src/app/agents/index.tsx
@@ -1,3 +1,4 @@
+import { compactNumber } from '@hermes/shared'
 import { useStore } from '@nanostores/react'
 import { type ReactNode, useEffect, useMemo, useState } from 'react'
 
@@ -8,7 +9,6 @@ import { Codicon } from '@/components/ui/codicon'
 import { FadeText } from '@/components/ui/fade-text'
 import { GlyphSpinner } from '@/components/ui/glyph-spinner'
 import { type Translations, useI18n } from '@/i18n'
-import { compactNumber } from '@/lib/format'
 import { AlertCircle, CheckCircle2 } from '@/lib/icons'
 import { useEnterAnimation } from '@/lib/use-enter-animation'
 import { cn } from '@/lib/utils'
diff --git a/apps/desktop/src/app/chat/composer/reasoning-pill.tsx b/apps/desktop/src/app/chat/composer/reasoning-pill.tsx
index 6df4a81535..d13700ced1 100644
--- a/apps/desktop/src/app/chat/composer/reasoning-pill.tsx
+++ b/apps/desktop/src/app/chat/composer/reasoning-pill.tsx
@@ -1,3 +1,4 @@
+import { DEFAULT_REASONING_EFFORT } from '@hermes/shared'
 import { useStore } from '@nanostores/react'
 import { useState } from 'react'
 
@@ -9,7 +10,7 @@ import { releaseTypingFocus } from '@/components/ui/keyboard-first'
 import { Tip } from '@/components/ui/tooltip'
 import { useI18n } from '@/i18n'
 import { ChevronDown } from '@/lib/icons'
-import { DEFAULT_REASONING_EFFORT, reasoningEffortLabel } from '@/lib/reasoning-effort'
+import { reasoningEffortLabel } from '@/lib/reasoning-effort'
 import { cn } from '@/lib/utils'
 import { $defaultReasoningEffort } from '@/store/session'
 
diff --git a/apps/desktop/src/app/chat/sidebar/chrome.tsx b/apps/desktop/src/app/chat/sidebar/chrome.tsx
index 1bcb2117c8..aad36a0878 100644
--- a/apps/desktop/src/app/chat/sidebar/chrome.tsx
+++ b/apps/desktop/src/app/chat/sidebar/chrome.tsx
@@ -1,3 +1,4 @@
+import { compactNumber } from '@hermes/shared'
 import { useStore } from '@nanostores/react'
 import type * as React from 'react'
 
@@ -7,7 +8,6 @@ import { Codicon } from '@/components/ui/codicon'
 import { DisclosureCaret } from '@/components/ui/disclosure-caret'
 import { RowButton } from '@/components/ui/row-button'
 import { Tip } from '@/components/ui/tooltip'
-import { compactNumber } from '@/lib/format'
 import { cn } from '@/lib/utils'
 import { $sidebarRowMeta } from '@/store/layout'
 import type { TileDock } from '@/store/session-states'
diff --git a/apps/desktop/src/app/chat/sidebar/session-row.tsx b/apps/desktop/src/app/chat/sidebar/session-row.tsx
index 41aa0abc2c..cfe2076fb2 100644
--- a/apps/desktop/src/app/chat/sidebar/session-row.tsx
+++ b/apps/desktop/src/app/chat/sidebar/session-row.tsx
@@ -1,3 +1,4 @@
+import { compactNumber } from '@hermes/shared'
 import { useStore } from '@nanostores/react'
 import { memo } from 'react'
 import type * as React from 'react'
@@ -15,7 +16,6 @@ import type { SessionInfo } from '@/hermes'
 import { type Translations, useI18n } from '@/i18n'
 import { sessionTitle } from '@/lib/chat-runtime'
 import { pathLeaf } from '@/lib/display-path'
-import { compactNumber } from '@/lib/format'
 import { triggerHaptic } from '@/lib/haptics'
 import { middleClickHandlers } from '@/lib/middle-click'
 import { displayModelName } from '@/lib/model-status-label'
diff --git a/apps/desktop/src/app/command-center/index.tsx b/apps/desktop/src/app/command-center/index.tsx
index f2d9830172..2192ec1b84 100644
--- a/apps/desktop/src/app/command-center/index.tsx
+++ b/apps/desktop/src/app/command-center/index.tsx
@@ -1,3 +1,4 @@
+import { compactNumber } from '@hermes/shared'
 import { type MouseEvent, type ReactNode, useCallback, useEffect, useMemo, useRef, useState } from 'react'
 
 import { LogTail } from '@/components/chat/log-tail'
@@ -12,7 +13,6 @@ import { getActionStatus, getLogs, getStatus, getUsageAnalytics, restartGateway,
 import type { ActionStatusResponse, AnalyticsResponse, SessionInfo, StatusResponse } from '@/hermes'
 import { useI18n } from '@/i18n'
 import { sessionTitle } from '@/lib/chat-runtime'
-import { compactNumber } from '@/lib/format'
 import {
   Activity,
   AlertCircle,
diff --git a/apps/desktop/src/app/settings/constants.ts b/apps/desktop/src/app/settings/constants.ts
index 46142dda84..70ac9ab455 100644
--- a/apps/desktop/src/app/settings/constants.ts
+++ b/apps/desktop/src/app/settings/constants.ts
@@ -1,3 +1,5 @@
+import { REASONING_EFFORTS } from '@hermes/shared'
+
 import {
   Box,
   Brain,
@@ -12,7 +14,6 @@ import {
   Sun,
   Wrench
 } from '@/lib/icons'
-import { REASONING_EFFORTS } from '@/lib/reasoning-effort'
 import type { ThemeMode } from '@/themes/context'
 
 // Single source of truth for built-in personality names lives in
diff --git a/apps/desktop/src/app/settings/model-settings.tsx b/apps/desktop/src/app/settings/model-settings.tsx
index 8c169070db..1b2dd71e40 100644
--- a/apps/desktop/src/app/settings/model-settings.tsx
+++ b/apps/desktop/src/app/settings/model-settings.tsx
@@ -1,4 +1,5 @@
 import type { ModelOptionProvider } from '@hermes/shared'
+import { DEFAULT_REASONING_EFFORT, REASONING_EFFORT_VALUES } from '@hermes/shared'
 import { useCallback, useEffect, useMemo, useRef, useState } from 'react'
 
 import { Button } from '@/components/ui/button'
@@ -27,7 +28,6 @@ import type {
 import { useI18n } from '@/i18n'
 import { isCodeSkewRestartRequired } from '@/lib/code-skew-error'
 import { AlertTriangle, Cpu, Loader2 } from '@/lib/icons'
-import { DEFAULT_REASONING_EFFORT, REASONING_EFFORT_VALUES } from '@/lib/reasoning-effort'
 import { cn } from '@/lib/utils'
 import { setMainModelAssignment } from '@/store/cron-model-impact'
 import { notifyError, readableError } from '@/store/notifications'
diff --git a/apps/desktop/src/app/shell/context-usage-panel.tsx b/apps/desktop/src/app/shell/context-usage-panel.tsx
index d98517fb20..f604193536 100644
--- a/apps/desktop/src/app/shell/context-usage-panel.tsx
+++ b/apps/desktop/src/app/shell/context-usage-panel.tsx
@@ -1,7 +1,7 @@
+import { compactNumber } from '@hermes/shared'
 import { useMemo } from 'react'
 
 import { useI18n } from '@/i18n'
-import { compactNumber } from '@/lib/format'
 import { cn } from '@/lib/utils'
 import type { ContextBreakdown, ContextUsageCategory, UsageStats } from '@/types/hermes'
 
diff --git a/apps/desktop/src/app/shell/model-catalog-menu.tsx b/apps/desktop/src/app/shell/model-catalog-menu.tsx
index 58d836e0f5..d99ff8a421 100644
--- a/apps/desktop/src/app/shell/model-catalog-menu.tsx
+++ b/apps/desktop/src/app/shell/model-catalog-menu.tsx
@@ -1,4 +1,5 @@
 import type { ModelOptionProvider, ModelOptionsResponse } from '@hermes/shared'
+import { DEFAULT_REASONING_EFFORT } from '@hermes/shared'
 import { useStore } from '@nanostores/react'
 import { useQuery } from '@tanstack/react-query'
 import { createContext, type ReactNode, useContext, useEffect, useMemo, useRef, useState } from 'react'
@@ -24,7 +25,7 @@ import { getLocalModelsStatus } from '@/hermes'
 import { useI18n } from '@/i18n'
 import { catalogProviderMatches, modelOptionsQueryKey, requestModelOptions } from '@/lib/model-options'
 import { displayModelName, modelDisplayParts } from '@/lib/model-status-label'
-import { DEFAULT_REASONING_EFFORT, reasoningEffortLabel } from '@/lib/reasoning-effort'
+import { reasoningEffortLabel } from '@/lib/reasoning-effort'
 import { foldIncludes, normalize } from '@/lib/text'
 import { useStoreSelector } from '@/lib/use-session-slice'
 import { cn } from '@/lib/utils'
diff --git a/apps/desktop/src/app/shell/model-edit-submenu.tsx b/apps/desktop/src/app/shell/model-edit-submenu.tsx
index cafc938876..9b77c081fb 100644
--- a/apps/desktop/src/app/shell/model-edit-submenu.tsx
+++ b/apps/desktop/src/app/shell/model-edit-submenu.tsx
@@ -1,3 +1,5 @@
+import { REASONING_EFFORTS } from '@hermes/shared'
+
 import {
   DropdownMenuItem,
   DropdownMenuLabel,
@@ -10,7 +12,7 @@ import {
 } from '@/components/ui/dropdown-menu'
 import { Switch } from '@/components/ui/switch'
 import { useI18n } from '@/i18n'
-import { isThinkingEnabled, REASONING_EFFORTS, resolveReasoningEffort } from '@/lib/reasoning-effort'
+import { isThinkingEnabled, resolveReasoningEffort } from '@/lib/reasoning-effort'
 
 // Hermes' real reasoning levels live in lib/reasoning-effort; `none` is owned
 // by the Thinking toggle, not the radio.
diff --git a/apps/desktop/src/app/shell/titlebar-controls.tsx b/apps/desktop/src/app/shell/titlebar-controls.tsx
index 023e4e32d4..203cef0923 100644
--- a/apps/desktop/src/app/shell/titlebar-controls.tsx
+++ b/apps/desktop/src/app/shell/titlebar-controls.tsx
@@ -1,3 +1,4 @@
+import { compactNumber } from '@hermes/shared'
 import { useStore } from '@nanostores/react'
 import { type ComponentProps, type MouseEvent, type ReactNode, useEffect, useState } from 'react'
 import { useLocation, useNavigate } from 'react-router'
@@ -11,7 +12,6 @@ import { Tip, TipKeybindLabel } from '@/components/ui/tooltip'
 import { Slot } from '@/contrib/react/slot'
 import { useContributions } from '@/contrib/react/use-contributions'
 import { useI18n } from '@/i18n'
-import { compactNumber } from '@/lib/format'
 import { triggerHaptic } from '@/lib/haptics'
 import { formatModifierToken } from '@/lib/keybinds/combo'
 import { cn } from '@/lib/utils'
diff --git a/apps/desktop/src/app/shell/use-model-menu-controller.ts b/apps/desktop/src/app/shell/use-model-menu-controller.ts
index c8bb3e951c..e49e44fec1 100644
--- a/apps/desktop/src/app/shell/use-model-menu-controller.ts
+++ b/apps/desktop/src/app/shell/use-model-menu-controller.ts
@@ -1,4 +1,4 @@
-import type { ModelOptionsResponse } from '@hermes/shared'
+import { DEFAULT_REASONING_EFFORT, type ModelOptionsResponse } from '@hermes/shared'
 import { useStore } from '@nanostores/react'
 import { useQuery } from '@tanstack/react-query'
 
@@ -7,7 +7,6 @@ import type { HermesGateway } from '@/hermes'
 import { useI18n } from '@/i18n'
 import { modelOptionsQueryKey, requestModelOptions } from '@/lib/model-options'
 import { currentPickerSelection } from '@/lib/model-status-label'
-import { DEFAULT_REASONING_EFFORT } from '@/lib/reasoning-effort'
 import { $modelPresets, applyModelPreset, modelPresetKey, setModelPreset } from '@/store/model-presets'
 import { notifyError } from '@/store/notifications'
 import {
diff --git a/apps/desktop/src/app/skills/index.tsx b/apps/desktop/src/app/skills/index.tsx
index 3a17f97b62..f98e548f8a 100644
--- a/apps/desktop/src/app/skills/index.tsx
+++ b/apps/desktop/src/app/skills/index.tsx
@@ -1,3 +1,4 @@
+import { compactNumber } from '@hermes/shared'
 import { useStore } from '@nanostores/react'
 import { useQuery } from '@tanstack/react-query'
 import type * as React from 'react'
@@ -29,7 +30,6 @@ import {
 } from '@/hermes'
 import { useI18n } from '@/i18n'
 import { isDesktopToolsetVisible } from '@/lib/desktop-toolsets'
-import { compactNumber } from '@/lib/format'
 import { Loader2 } from '@/lib/icons'
 import { queryClient } from '@/lib/query-client'
 import { invalidateSlashCompletions } from '@/lib/slash-completion-cache'
diff --git a/apps/desktop/src/app/skills/mcp-tab.tsx b/apps/desktop/src/app/skills/mcp-tab.tsx
index 020d3e8e2a..830165b7ee 100644
--- a/apps/desktop/src/app/skills/mcp-tab.tsx
+++ b/apps/desktop/src/app/skills/mcp-tab.tsx
@@ -1,3 +1,4 @@
+import { compactNumber } from '@hermes/shared'
 import { useStore } from '@nanostores/react'
 import { useQuery } from '@tanstack/react-query'
 import { useEffect, useMemo, useRef, useState } from 'react'
@@ -32,7 +33,6 @@ import {
 } from '@/hermes'
 import { type Translations, useI18n } from '@/i18n'
 import { startCompletionPoll } from '@/lib/completion-poll'
-import { compactNumber } from '@/lib/format'
 import { brandFor } from '@/lib/mcp-brands'
 import { estimateServerTokens, serverUsageCount } from '@/lib/mcp-cost'
 import { completeMcpDesktopOAuth } from '@/lib/mcp-dashboard-oauth'
diff --git a/apps/desktop/src/components/ui/tab-dropdown.tsx b/apps/desktop/src/components/ui/tab-dropdown.tsx
index 83a5d68ebf..9c670f34a4 100644
--- a/apps/desktop/src/components/ui/tab-dropdown.tsx
+++ b/apps/desktop/src/components/ui/tab-dropdown.tsx
@@ -1,3 +1,4 @@
+import { compactNumber } from '@hermes/shared'
 import { Fragment } from 'react'
 
 import { Codicon } from '@/components/ui/codicon'
@@ -10,7 +11,6 @@ import {
 } from '@/components/ui/dropdown-menu'
 import { CountSkeleton } from '@/components/ui/skeleton'
 import { TextTab, TextTabMeta } from '@/components/ui/text-tab'
-import { compactNumber } from '@/lib/format'
 import type { IconComponent } from '@/lib/icons'
 import { cn } from '@/lib/utils'
 
diff --git a/apps/desktop/src/lib/reasoning-effort.test.ts b/apps/desktop/src/lib/reasoning-effort.test.ts
index bc61b91fb9..1bbecd8a5e 100644
--- a/apps/desktop/src/lib/reasoning-effort.test.ts
+++ b/apps/desktop/src/lib/reasoning-effort.test.ts
@@ -1,22 +1,9 @@
+import { DEFAULT_REASONING_EFFORT, REASONING_EFFORT_VALUES } from '@hermes/shared'
 import { describe, expect, it } from 'vitest'
 
-import {
-  DEFAULT_REASONING_EFFORT,
-  isReasoningEffort,
-  isThinkingEnabled,
-  REASONING_EFFORT_VALUES,
-  REASONING_EFFORTS,
-  reasoningEffortLabel,
-  resolveReasoningEffort
-} from './reasoning-effort'
+import { isThinkingEnabled, reasoningEffortLabel, resolveReasoningEffort } from './reasoning-effort'
 
 describe('reasoning-effort', () => {
-  it('keeps the scale ascending and `none` off it', () => {
-    expect(REASONING_EFFORTS).not.toContain('none')
-    expect(REASONING_EFFORT_VALUES[0]).toBe('none')
-    expect(REASONING_EFFORT_VALUES).toHaveLength(REASONING_EFFORTS.length + 1)
-  })
-
   it('labels every level it claims to support', () => {
     for (const effort of REASONING_EFFORT_VALUES) {
       expect(reasoningEffortLabel(effort)).not.toBe('')
@@ -27,13 +14,6 @@ describe('reasoning-effort', () => {
     expect(reasoningEffortLabel('bogus')).toBe('bogus')
   })
 
-  it('recognizes only real scale levels', () => {
-    expect(isReasoningEffort(DEFAULT_REASONING_EFFORT)).toBe(true)
-    expect(isReasoningEffort('HIGH')).toBe(true)
-    expect(isReasoningEffort('none')).toBe(false)
-    expect(isReasoningEffort('bogus')).toBe(false)
-  })
-
   it('treats empty as inherit and only `none` as off', () => {
     expect(isThinkingEnabled('none')).toBe(false)
     expect(isThinkingEnabled('high')).toBe(true)
diff --git a/apps/desktop/src/lib/reasoning-effort.ts b/apps/desktop/src/lib/reasoning-effort.ts
index 5d3e17afd0..87e968ff4c 100644
--- a/apps/desktop/src/lib/reasoning-effort.ts
+++ b/apps/desktop/src/lib/reasoning-effort.ts
@@ -1,19 +1,7 @@
+import { DEFAULT_REASONING_EFFORT, isReasoningEffort } from '@hermes/shared'
+
 import { normalize } from '@/lib/text'
 
-/** Hermes' reasoning levels, in ascending order — mirrors the backend's
- *  VALID_REASONING_EFFORTS (hermes_constants.py). `none` is not a level: it's
- *  thinking disabled, owned by the Thinking toggle rather than the scale. */
-export const REASONING_EFFORTS = ['minimal', 'low', 'medium', 'high', 'xhigh', 'max', 'ultra'] as const
-
-export type ReasoningEffort = (typeof REASONING_EFFORTS)[number]
-
-/** The scale plus the off state — the full set a config value may hold. */
-export const REASONING_EFFORT_VALUES = ['none', ...REASONING_EFFORTS] as const
-
-/** Hermes' built-in level when neither the surface nor the profile config
- *  specifies one (mirrors the backend's own fallback). */
-export const DEFAULT_REASONING_EFFORT: ReasoningEffort = 'medium'
-
 /** Compact labels for chrome where space is tight (pill, picker rows). Menus
  *  and settings use the translated `shell.modelOptions` strings instead. */
 const SHORT_LABELS: Record<string, string> = {
@@ -33,9 +21,6 @@ export function reasoningEffortLabel(effort: string): string {
   return key ? (SHORT_LABELS[key] ?? effort) : ''
 }
 
-export const isReasoningEffort = (value: string): value is ReasoningEffort =>
-  REASONING_EFFORTS.includes(normalize(value) as ReasoningEffort)
-
 /** Thinking is on unless a level explicitly says otherwise; an empty value
  *  means "inherit", so it resolves through `fallback` first. */
 export const isThinkingEnabled = (effort: string, fallback: string = DEFAULT_REASONING_EFFORT): boolean =>
diff --git a/apps/desktop/src/lib/statusbar.tsx b/apps/desktop/src/lib/statusbar.tsx
index 4f875fa90e..b12e6056c2 100644
--- a/apps/desktop/src/lib/statusbar.tsx
+++ b/apps/desktop/src/lib/statusbar.tsx
@@ -1,8 +1,8 @@
+import { compactNumber } from '@hermes/shared'
 import { useState } from 'react'
 
 import { StableText } from '@/components/chat/stable-text'
 import { useViewedInterval } from '@/hooks/use-viewed-interval'
-import { compactNumber } from '@/lib/format'
 import type { UsageStats } from '@/types/hermes'
 
 export function formatDuration(elapsedMs: number): string {
diff --git a/apps/desktop/src/sdk/index.ts b/apps/desktop/src/sdk/index.ts
index 5720b09008..e1880bc8ef 100644
--- a/apps/desktop/src/sdk/index.ts
+++ b/apps/desktop/src/sdk/index.ts
@@ -1669,9 +1669,6 @@ export { type BudgetedLoop, type BudgetedLoopOptions, createBudgetedLoop } from
 /** The blank transcript as a contribution area: claim the sessions you own and
  *  render what stands in the gap. Core's own splash keeps a fresh draft. */
 export { CHAT_EMPTY_AREA, type ChatEmptyContribution, type ChatEmptyProps } from '@/lib/chat-empty'
-/** THE compact-number formatter — every user-facing count/token figure goes
- *  through here (1230 → "1.2k", 1_500_000 → "1.5M"). Don't hand-roll `/1000`. */
-export { compactNumber } from '@/lib/format'
 /** THE confirm flow for guarded model switches — when a gateway model-switch
  *  RPC answers `confirm_required` (data-policy / expensive-model guard),
  *  route it through this shared applier instead of forking a per-surface
@@ -1703,17 +1700,11 @@ export { PROFILE_SWATCHES, profileColor, profileColorSoft } from '@/lib/profile-
  *  `ctx.socket` frame invalidating a query). Inside components keep using
  *  `useQueryClient`. */
 export { queryClient } from '@/lib/query-client'
+/** Compact labels for the reasoning levels exported from @hermes/shared, so a
+ *  plugin surfacing a thinking depth uses the same spelling as the app. */
+export { reasoningEffortLabel } from '@/lib/reasoning-effort'
 
 export const PANES_AREA = 'panes'
-/** Hermes' reasoning levels + their compact labels, so a plugin surfacing a
- *  thinking depth uses the same scale and spelling as the rest of the app. */
-export {
-  DEFAULT_REASONING_EFFORT,
-  REASONING_EFFORT_VALUES,
-  REASONING_EFFORTS,
-  type ReasoningEffort,
-  reasoningEffortLabel
-} from '@/lib/reasoning-effort'
 export const STATUSBAR_AREAS = { left: 'statusBar.left', right: 'statusBar.right' } as const
 export const TITLEBAR_AREAS = { center: 'titleBar.center', left: 'titleBar.left', right: 'titleBar.right' } as const
 
@@ -1783,6 +1774,17 @@ export { THEMES_AREA } from '@/themes/user-themes'
 export type { StatusResponse } from '@/types/hermes'
 /** Public SDK name for the shared gateway wire event; kept stable for plugins. */
 export type { GatewayEvent as RpcEvent } from '@hermes/shared'
+/** THE compact-number formatter — every user-facing count/token figure goes
+ *  through here (1230 → "1.2k", 1_500_000 → "1.5M"). Don't hand-roll `/1000`. */
+export { compactNumber } from '@hermes/shared'
+/** Hermes' reasoning levels, so a plugin surfacing a thinking depth uses the
+ *  same scale as the rest of the app (labels: `reasoningEffortLabel`). */
+export {
+  DEFAULT_REASONING_EFFORT,
+  REASONING_EFFORT_VALUES,
+  REASONING_EFFORTS,
+  type ReasoningEffort
+} from '@hermes/shared'
 /** Subscribe a component to a `host.state` atom. */
 export { useStore as useValue } from '@nanostores/react'
 /** The app's data-fetching layer. Plugins share the ONE QueryClient mounted at
diff --git a/apps/shared/package.json b/apps/shared/package.json
index b610261962..a12c8c1dfe 100644
--- a/apps/shared/package.json
+++ b/apps/shared/package.json
@@ -8,11 +8,16 @@
     "./billing": "./src/billing-types.ts",
     "./billing-policy": "./src/billing-policy.ts",
     "./charge-settlement": "./src/charge-settlement.ts",
+    "./format": "./src/format.ts",
     "./fuzzy": "./src/fuzzy.ts",
     "./gateway-events": "./src/gateway-events.ts",
     "./json-rpc-channel": "./src/json-rpc-channel.ts",
     "./model-search-text": "./src/model-search-text.ts",
+<<<<<<< HEAD
     "./reconnect-backoff": "./src/reconnect-backoff.ts",
+=======
+    "./reasoning-effort": "./src/reasoning-effort.ts",
+>>>>>>> 914084147a68 (refactor(ts): one compactNumber and one reasoning-effort value set in @hermes/shared)
     "./skin": "./src/skin.ts"
   },
   "types": "./src/index.ts",
diff --git a/apps/shared/src/format.test.ts b/apps/shared/src/format.test.ts
new file mode 100644
index 0000000000..b2820fc032
--- /dev/null
+++ b/apps/shared/src/format.test.ts
@@ -0,0 +1,27 @@
+import { describe, expect, it } from 'vitest'
+
+import { compactNumber } from './format'
+
+describe('compactNumber', () => {
+  it.each([
+    [0, '0'],
+    [999, '999'],
+    [1000, '1k'],
+    [1500, '1.5k'],
+    [128_000, '128k'],
+    // Promotion guard: a value that would round to "1000k" promotes to M.
+    [999_949, '999.9k'],
+    [999_999, '1M'],
+    [1_000_000, '1M'],
+    [1_500_000, '1.5M'],
+    [1_000_000_000, '1000M']
+  ])('%d → %s', (value, expected) => {
+    expect(compactNumber(value)).toBe(expected)
+  })
+
+  it('never emits a unit-boundary artifact like "1000k" or "1000"', () => {
+    for (const value of [999.5, 999.9, 999_950, 999_999.4]) {
+      expect(compactNumber(value)).not.toMatch(/^1000(\.\d)?k?$/)
+    }
+  })
+})
diff --git a/apps/desktop/src/lib/format.ts b/apps/shared/src/format.ts
similarity index 100%
rename from apps/desktop/src/lib/format.ts
rename to apps/shared/src/format.ts
diff --git a/apps/shared/src/index.ts b/apps/shared/src/index.ts
index 44ff583105..ea0da12a0f 100644
--- a/apps/shared/src/index.ts
+++ b/apps/shared/src/index.ts
@@ -46,6 +46,7 @@ export {
   DATA_URL_READ_MAX_MAX_MB,
   DATA_URL_READ_MIN_MAX_MB
 } from './data-url-read-max'
+export { compactNumber } from './format'
 export { type FuzzyMatch, fuzzyRank, fuzzyScore, fuzzyScoreMulti, type RankedItem } from './fuzzy'
 export {
   type ApprovalRequestPayload,
@@ -113,6 +114,14 @@ export {
 } from './json-rpc-gateway'
 export { reconnectBackoffDelayMs, type ReconnectBackoffOptions } from './reconnect-backoff'
 export { modelSearchText } from './model-search-text'
+export {
+  DEFAULT_REASONING_EFFORT,
+  isReasoningEffort,
+  REASONING_EFFORT_VALUES,
+  REASONING_EFFORTS,
+  type ReasoningEffort,
+  type ReasoningEffortValue
+} from './reasoning-effort'
 export { skillInvocationText } from './skill-scaffold'
 export {
   type HermesSkin,
diff --git a/apps/shared/src/reasoning-effort.test.ts b/apps/shared/src/reasoning-effort.test.ts
new file mode 100644
index 0000000000..b4afc83ad3
--- /dev/null
+++ b/apps/shared/src/reasoning-effort.test.ts
@@ -0,0 +1,20 @@
+import { describe, expect, it } from 'vitest'
+
+import {
+  DEFAULT_REASONING_EFFORT,
+  isReasoningEffort,
+  REASONING_EFFORT_VALUES,
+  REASONING_EFFORTS
+} from './reasoning-effort'
+
+describe('reasoning-effort', () => {
+  it('is one duplicate-free value set with `none` as the only non-level', () => {
+    expect(new Set(REASONING_EFFORT_VALUES).size).toBe(REASONING_EFFORT_VALUES.length)
+    expect(REASONING_EFFORT_VALUES.filter(v => !isReasoningEffort(v))).toEqual(['none'])
+  })
+
+  it('defaults to a real level and recognizes it case-insensitively', () => {
+    expect(REASONING_EFFORTS).toContain(DEFAULT_REASONING_EFFORT)
+    expect(isReasoningEffort(DEFAULT_REASONING_EFFORT.toUpperCase())).toBe(true)
+  })
+})
diff --git a/apps/shared/src/reasoning-effort.ts b/apps/shared/src/reasoning-effort.ts
new file mode 100644
index 0000000000..e92adf3a19
--- /dev/null
+++ b/apps/shared/src/reasoning-effort.ts
@@ -0,0 +1,19 @@
+/** Hermes' reasoning levels, in ascending order — mirrors the backend's
+ *  VALID_REASONING_EFFORTS (hermes_constants.py). `none` is not a level: it's
+ *  thinking disabled. */
+export const REASONING_EFFORTS = ['minimal', 'low', 'medium', 'high', 'xhigh', 'max', 'ultra'] as const
+
+export type ReasoningEffort = (typeof REASONING_EFFORTS)[number]
+
+/** The scale plus the off state — the full set a config value may hold. */
+export const REASONING_EFFORT_VALUES = ['none', ...REASONING_EFFORTS] as const
+
+export type ReasoningEffortValue = (typeof REASONING_EFFORT_VALUES)[number]
+
+/** Hermes' built-in level when neither the surface nor the profile config
+ *  specifies one (mirrors the backend's own fallback). */
+export const DEFAULT_REASONING_EFFORT: ReasoningEffort = 'medium'
+
+/** True for a real level (case-insensitive, trimmed); `none` is not a level. */
+export const isReasoningEffort = (value: string): value is ReasoningEffort =>
+  REASONING_EFFORTS.includes(value.trim().toLowerCase() as ReasoningEffort)
diff --git a/ui-tui/src/__tests__/text.test.ts b/ui-tui/src/__tests__/text.test.ts
index 707ad227ec..fba3109299 100644
--- a/ui-tui/src/__tests__/text.test.ts
+++ b/ui-tui/src/__tests__/text.test.ts
@@ -7,7 +7,6 @@ import {
   edgePreview,
   estimateRows,
   estimateTokensRough,
-  fmtK,
   hasAnsi,
   isToolTrailResultLine,
   lastCotTrailIndex,
@@ -118,22 +117,6 @@ describe('sameToolTrailGroup', () => {
   })
 })
 
-describe('fmtK', () => {
-  it('keeps small numbers plain', () => {
-    expect(fmtK(999)).toBe('999')
-  })
-
-  it('formats thousands as lowercase k', () => {
-    expect(fmtK(1000)).toBe('1k')
-    expect(fmtK(1500)).toBe('1.5k')
-  })
-
-  it('formats millions and billions with lowercase suffixes', () => {
-    expect(fmtK(1_000_000)).toBe('1m')
-    expect(fmtK(1_000_000_000)).toBe('1b')
-  })
-})
-
 describe('estimateTokensRough', () => {
   it('uses 4 chars per token rounding up', () => {
     expect(estimateTokensRough('')).toBe(0)
diff --git a/ui-tui/src/app/slash/commands/session.ts b/ui-tui/src/app/slash/commands/session.ts
index 5367b5a1b9..502fd21524 100644
--- a/ui-tui/src/app/slash/commands/session.ts
+++ b/ui-tui/src/app/slash/commands/session.ts
@@ -1,3 +1,5 @@
+import { compactNumber } from '@hermes/shared/format'
+
 import { usageBarsText } from '../../../components/overlayPrimitives.js'
 import { introMsg, toTranscriptMessages } from '../../../domain/messages.js'
 import { sessionScopedModelArg, TUI_SESSION_MODEL_FLAG } from '../../../domain/slash.js'
@@ -12,7 +14,6 @@ import type {
   VoiceToggleResponse
 } from '../../../gatewayTypes.js'
 import { formatVoiceRecordKey, parseVoiceRecordKey } from '../../../lib/platform.js'
-import { fmtK } from '../../../lib/text.js'
 import type { PanelSection } from '../../../types.js'
 import { applyConfiguredTuiTheme } from '../../createGatewayEventHandler.js'
 import { DEFAULT_INDICATOR_STYLE, INDICATOR_STYLES, type IndicatorStyle } from '../../interfaces.js'
@@ -281,7 +282,7 @@ export const sessionCommands: SlashCommand[] = [
             }
 
             ctx.transcript.sys(
-              `compressed ${r.removed} messages${r.usage?.total ? ` · ${fmtK(r.usage.total)} tok` : ''}`
+              `compressed ${r.removed} messages${r.usage?.total ? ` · ${compactNumber(r.usage.total)} tok` : ''}`
             )
           })
         )
diff --git a/ui-tui/src/components/appChrome.tsx b/ui-tui/src/components/appChrome.tsx
index 4deef2c9bb..2a5de7ce85 100644
--- a/ui-tui/src/components/appChrome.tsx
+++ b/ui-tui/src/components/appChrome.tsx
@@ -1,5 +1,6 @@
 import { Box, type ScrollBoxHandle, stringWidth, Text } from '@hermes/ink'
 import type { Usage } from '@hermes/shared/gateway-events'
+import { compactNumber } from '@hermes/shared/format'
 import { useStore } from '@nanostores/react'
 import { type ReactNode, type RefObject, useEffect, useMemo, useRef, useState } from 'react'
 import unicodeSpinners from 'unicode-animations'
@@ -14,7 +15,6 @@ import { VERBS } from '../content/verbs.js'
 import { fmtDuration } from '../domain/messages.js'
 import { stickyPromptFromViewport } from '../domain/viewport.js'
 import { buildSubagentTree, treeTotals, widthByDepth } from '../lib/subagentTree.js'
-import { fmtK } from '../lib/text.js'
 import { useScrollbarSnapshot, useViewportSnapshot } from '../lib/viewportStore.js'
 import type { Theme } from '../theme.js'
 import type { Msg } from '../types.js'
@@ -525,10 +525,10 @@ export function StatusRule({
     ok('context_detail') || ok('context_pct')
       ? usage.context_max
         ? segs.compactCtx
-          ? `${contextMark}${fmtK(usage.context_used ?? 0)} tok`
-          : `${contextMark}${fmtK(usage.context_used ?? 0)}/${fmtK(usage.context_max)}`
+          ? `${contextMark}${compactNumber(usage.context_used ?? 0)} tok`
+          : `${contextMark}${compactNumber(usage.context_used ?? 0)}/${compactNumber(usage.context_max)}`
         : usage.total > 0
-          ? `${fmtK(usage.total)} tok`
+          ? `${compactNumber(usage.total)} tok`
           : ''
       : ''
 
diff --git a/ui-tui/src/components/thinking.tsx b/ui-tui/src/components/thinking.tsx
index da484a0fa6..222b8a0a15 100644
--- a/ui-tui/src/components/thinking.tsx
+++ b/ui-tui/src/components/thinking.tsx
@@ -1,4 +1,5 @@
 import { Box, NoSelect, Text } from '@hermes/ink'
+import { compactNumber } from '@hermes/shared/format'
 import { memo, type ReactNode, useEffect, useMemo, useRef, useState } from 'react'
 import spinners, { type BrailleSpinnerName } from 'unicode-animations'
 
@@ -18,7 +19,6 @@ import {
   boundedLiveRenderText,
   compactPreview,
   estimateTokensRough,
-  fmtK,
   formatToolCall,
   parseToolTrailResultLine,
   pick,
@@ -934,11 +934,12 @@ export const ToolTrail = memo(function ToolTrail({
 
   const toolTokenCount = toolTokens ?? 0
   const totalTokenCount = tokenCount + toolTokenCount
-  const thinkingTokensLabel = tokenCount > 0 ? `~${fmtK(tokenCount)} tokens` : null
+  const thinkingTokensLabel = tokenCount > 0 ? `~${compactNumber(tokenCount)} tokens` : null
 
-  const toolTokensLabel = toolTokens !== undefined && toolTokens > 0 ? `~${fmtK(toolTokens)} tokens` : undefined
+  const toolTokensLabel =
+    toolTokens !== undefined && toolTokens > 0 ? `~${compactNumber(toolTokens)} tokens` : undefined
 
-  const totalTokensLabel = tokenCount > 0 && toolTokenCount > 0 ? `~${fmtK(totalTokenCount)} total` : null
+  const totalTokensLabel = tokenCount > 0 && toolTokenCount > 0 ? `~${compactNumber(totalTokenCount)} total` : null
   const delegateGroups = groups.filter(g => g.label.startsWith('Delegate Task'))
   const inlineDelegateKey = hasSubagents && delegateGroups.length === 1 ? delegateGroups[0]!.key : null
 
diff --git a/ui-tui/src/lib/text.ts b/ui-tui/src/lib/text.ts
index 003930dbe2..18c11d8263 100644
--- a/ui-tui/src/lib/text.ts
+++ b/ui-tui/src/lib/text.ts
@@ -1,3 +1,5 @@
+import { compactNumber } from '@hermes/shared/format'
+
 import {
   LIVE_RENDER_MAX_CHARS,
   LIVE_RENDER_MAX_LINES,
@@ -96,14 +98,14 @@ export const pasteTokenLabel = (text: string, lineCount: number) => {
   const preview = edgePreview(text)
 
   if (!preview) {
-    return `[[ [${fmtK(lineCount)} lines] ]]`
+    return `[[ [${compactNumber(lineCount)} lines] ]]`
   }
 
   const [head = preview, tail = ''] = preview.split('.. ', 2)
 
   return tail
-    ? `[[ ${head.trimEnd()}.. [${fmtK(lineCount)} lines] .. ${tail.trimStart()} ]]`
-    : `[[ ${preview} [${fmtK(lineCount)} lines] ]]`
+    ? `[[ ${head.trimEnd()}.. [${compactNumber(lineCount)} lines] .. ${tail.trimStart()} ]]`
+    : `[[ ${preview} [${compactNumber(lineCount)} lines] ]]`
 }
 
 const THINKING_STATUS_RE = new RegExp(`^(?:${VERBS.join('|')})\\.{0,3}$`, 'i')
@@ -177,8 +179,8 @@ const boundedRenderText = (
 
   const label =
     omittedLines > 0
-      ? `[${labelPrefix}; omitted ${fmtK(omittedLines)} lines / ${fmtK(omittedChars)} chars]\n`
-      : `[${labelPrefix}; omitted ${fmtK(omittedChars)} chars]\n`
+      ? `[${labelPrefix}; omitted ${compactNumber(omittedLines)} lines / ${compactNumber(omittedChars)} chars]\n`
+      : `[${labelPrefix}; omitted ${compactNumber(omittedChars)} chars]\n`
 
   return `${label}${tail}`
 }
@@ -410,10 +412,6 @@ export const clarifyBatchRevisitState = (
 
 export const flat = (r: Record<string, string[]>) => Object.values(r).flat()
 
-const COMPACT_NUMBER = new Intl.NumberFormat('en-US', { maximumFractionDigits: 1, notation: 'compact' })
-
-export const fmtK = (n: number) => COMPACT_NUMBER.format(n).replace(/[KMBT]$/, s => s.toLowerCase())
-
 export const pick = <T>(a: T[]) => a[Math.floor(Math.random() * a.length)]!
 
 export const isPasteBackedText = (text: string) =>
diff --git a/web/src/components/ModelInfoCard.tsx b/web/src/components/ModelInfoCard.tsx
index 6feb6113df..389f2a5c3c 100644
--- a/web/src/components/ModelInfoCard.tsx
+++ b/web/src/components/ModelInfoCard.tsx
@@ -3,7 +3,7 @@ import { Brain, Eye, Gauge, Lightbulb, Wrench } from "lucide-react";
 import { Spinner } from "@nous-research/ui/ui/components/spinner";
 import { api } from "@/lib/api";
 import type { ModelInfoResponse } from "@/lib/api";
-import { formatTokenCount } from "@/lib/format";
+import { compactNumber } from "@hermes/shared";
 
 interface ModelInfoCardProps {
   /** Current model string from config state — used to detect changes */
@@ -57,11 +57,11 @@ export function ModelInfoCard({
         </div>
         <div className="flex items-center gap-2">
           <span className="font-mono font-semibold text-foreground">
-            {formatTokenCount(info.effective_context_length)}
+            {compactNumber(info.effective_context_length)}
           </span>
           {info.config_context_length > 0 ? (
             <span className="text-amber-500 text-xs">
-              (override — auto: {formatTokenCount(info.auto_context_length)})
+              (override — auto: {compactNumber(info.auto_context_length)})
             </span>
           ) : (
             <span className="text-text-tertiary text-xs">
@@ -78,7 +78,7 @@ export function ModelInfoCard({
             <span className="font-medium">Max Output</span>
           </div>
           <span className="font-mono font-semibold text-foreground">
-            {formatTokenCount(caps.max_output_tokens)}
+            {compactNumber(caps.max_output_tokens)}
           </span>
         </div>
       )}
diff --git a/web/src/lib/format.ts b/web/src/lib/format.ts
deleted file mode 100644
index f5e373ca6b..0000000000
--- a/web/src/lib/format.ts
+++ /dev/null
@@ -1,9 +0,0 @@
-/**
- * Format a token count as a human-readable string (e.g. 1M, 128K, 4096).
- * Strips trailing ".0" for clean round numbers.
- */
-export function formatTokenCount(n: number): string {
-  if (n >= 1_000_000) return `${(n / 1_000_000).toFixed(n % 1_000_000 === 0 ? 0 : 1)}M`;
-  if (n >= 1_000) return `${(n / 1_000).toFixed(n % 1_000 === 0 ? 0 : 1)}K`;
-  return String(n);
-}
diff --git a/web/src/lib/reasoning-effort.ts b/web/src/lib/reasoning-effort.ts
index 2d5fecd312..55bc303baa 100644
--- a/web/src/lib/reasoning-effort.ts
+++ b/web/src/lib/reasoning-effort.ts
@@ -1,12 +1,18 @@
+import {
+  DEFAULT_REASONING_EFFORT,
+  REASONING_EFFORT_VALUES,
+  type ReasoningEffortValue,
+} from "@hermes/shared";
+
 /**
  * Pure reasoning-effort helpers shared by the dashboard ReasoningPicker.
  *
  * Kept DOM-free so the node-environment vitest harness can cover the
  * resolution logic without loading React or the UI kit.
  *
- * Values mirror hermes_constants.VALID_REASONING_EFFORTS plus `none`
- * (thinking-off). An empty/unset config value means the Hermes default,
- * which is `medium`.
+ * Values come from @hermes/shared (hermes_constants.VALID_REASONING_EFFORTS
+ * plus `none`, thinking-off). An empty/unset config value means the Hermes
+ * default.
  */
 
 export interface EffortOption {
@@ -14,25 +20,28 @@ export interface EffortOption {
   label: string;
 }
 
-export const EFFORT_OPTIONS: ReadonlyArray<EffortOption> = [
-  { value: "none", label: "Off (no thinking)" },
-  { value: "minimal", label: "Minimal" },
-  { value: "low", label: "Low" },
-  { value: "medium", label: "Medium" },
-  { value: "high", label: "High" },
-  { value: "xhigh", label: "Extra High" },
-  { value: "max", label: "Max" },
-  { value: "ultra", label: "Ultra" },
-];
+const EFFORT_LABELS: Record<ReasoningEffortValue, string> = {
+  none: "Off (no thinking)",
+  minimal: "Minimal",
+  low: "Low",
+  medium: "Medium",
+  high: "High",
+  xhigh: "Extra High",
+  max: "Max",
+  ultra: "Ultra",
+};
 
-export const VALID_EFFORTS: ReadonlySet<string> = new Set(
-  EFFORT_OPTIONS.map((o) => o.value),
+/** `none` first, then the seven levels ascending — the shared value order. */
+export const EFFORT_OPTIONS: ReadonlyArray<EffortOption> = REASONING_EFFORT_VALUES.map(
+  (value) => ({ value, label: EFFORT_LABELS[value] }),
 );
 
+export const VALID_EFFORTS: ReadonlySet<string> = new Set(REASONING_EFFORT_VALUES);
+
 /** Normalize a raw `agent.reasoning_effort` config value to a selectable
  *  option. Empty/unknown → `medium` (Hermes' default when unset). */
 export function normalizeEffort(raw: unknown): string {
   const value = String(raw ?? "").trim().toLowerCase();
-  if (!value) return "medium";
-  return VALID_EFFORTS.has(value) ? value : "medium";
+  if (!value) return DEFAULT_REASONING_EFFORT;
+  return VALID_EFFORTS.has(value) ? value : DEFAULT_REASONING_EFFORT;
 }
diff --git a/web/src/pages/ModelsPage.tsx b/web/src/pages/ModelsPage.tsx
index a1fbe0d122..a4a6161e9e 100644
--- a/web/src/pages/ModelsPage.tsx
+++ b/web/src/pages/ModelsPage.tsx
@@ -28,7 +28,7 @@ import {
   DASHBOARD_MODAL_PANEL,
   shouldCloseOuterModalOnEscape,
 } from "@/lib/dashboard-modal-shell";
-import { formatTokenCount } from "@/lib/format";
+import { compactNumber } from "@hermes/shared";
 import { Button } from "@nous-research/ui/ui/components/button";
 import { Spinner } from "@nous-research/ui/ui/components/spinner";
 import { Stats } from "@nous-research/ui/ui/components/stats";
@@ -430,12 +430,12 @@ function ModelCard({
               )}
               {caps.context_window && caps.context_window > 0 && (
                 <span className="text-xs text-text-secondary">
-                  {formatTokenCount(caps.context_window)} ctx
+                  {compactNumber(caps.context_window)} ctx
                 </span>
               )}
               {caps.max_output_tokens && caps.max_output_tokens > 0 && (
                 <span className="text-xs text-text-secondary">
-                  {formatTokenCount(caps.max_output_tokens)} out
+                  {compactNumber(caps.max_output_tokens)} out
                 </span>
               )}
             </div>