fix(models): expose current Claude official lineup

adapters/telegram/__tests__/commands.test.ts

@@ -271,8 +271,8 @@ describe('Telegram command controller helpers', () => {
     await controller.handleProviderCommand(allowed.ctx)
 
     expect(deps.httpClient.activateOfficialProvider).toHaveBeenCalled()
-    expect(deps.httpClient.setCurrentModel).toHaveBeenCalledWith('claude-opus-4-7')
-    expect(runtimeModels).toEqual(['claude-opus-4-7'])
+    expect(deps.httpClient.setCurrentModel).toHaveBeenCalledWith('claude-opus-4-8')
+    expect(runtimeModels).toEqual(['claude-opus-4-8'])
     expect(allowed.replies[0]).toContain('Claude 官方')
 
     const denied = createCommandContext({ userId: 999 })

adapters/telegram/commands.ts

@@ -16,7 +16,7 @@ import {
 export const TELEGRAM_SELECTION_TTL_MS = 15 * 60 * 1000
 export const OFFICIAL_PROVIDER_VALUE = 'official'
 export const OPENAI_OFFICIAL_PROVIDER_ID = 'openai-official'
-export const OFFICIAL_DEFAULT_MODEL_ID = 'claude-opus-4-7'
+export const OFFICIAL_DEFAULT_MODEL_ID = 'claude-opus-4-8'
 export const OPENAI_OFFICIAL_DEFAULT_MODEL_ID = 'gpt-5.3-codex'
 
 type TelegramSendApi = {

desktop/src/__tests__/generalSettings.test.tsx

@@ -1906,6 +1906,20 @@ describe('Settings > Providers tab', () => {
     expect(providerStoreState.testConfig).not.toHaveBeenCalledWith(expect.objectContaining({
       modelId: 'deepseek-v4-pro',
     }))
+
+    fireEvent.click(within(dialog).getByRole('button', { name: /Save|Add|保存|添加/i }))
+
+    await waitFor(() => {
+      expect(providerStoreState.createProvider).toHaveBeenCalledWith(expect.objectContaining({
+        models: expect.objectContaining({
+          fable: 'Qwen3Coder',
+          main: 'claude-sonnet-4-6',
+          haiku: 'claude-haiku-4-5',
+          sonnet: 'claude-sonnet-4-6',
+          opus: 'claude-opus-4-8',
+        }),
+      }))
+    })
   })
 
   it('keeps the provider form locked while save is in flight', async () => {

desktop/src/components/controls/ModelSelector.test.tsx

@@ -43,6 +43,44 @@ beforeEach(() => {
 })
 
 describe('ModelSelector', () => {
+  it('keeps the current Claude Official catalog visible when the API returns legacy settings models', async () => {
+    const legacyModels: ModelInfo[] = [
+      { id: 'claude-opus-4-7', name: 'Opus 4.7', description: 'Legacy Opus', context: '1m' },
+      { id: 'claude-sonnet-4-6', name: 'Sonnet 4.6', description: 'Legacy Sonnet', context: '200k' },
+      { id: 'claude-haiku-4-5', name: 'Haiku 4.5', description: 'Legacy Haiku', context: '200k' },
+    ]
+    useHahaOAuthStore.setState({
+      status: {
+        loggedIn: true,
+        expiresAt: null,
+        scopes: [],
+        subscriptionType: 'pro',
+      },
+      fetchStatus: async () => {},
+    })
+    useSettingsStore.setState({
+      locale: 'en',
+      availableModels: legacyModels,
+      currentModel: legacyModels[0],
+      activeProviderName: 'Claude Official',
+    })
+    useProviderStore.setState({
+      providers: [],
+      activeId: null,
+      hasLoadedProviders: true,
+      isLoading: false,
+    })
+
+    render(<ModelSelector runtimeKey="session-claude-legacy" />)
+
+    await clickByRole(/Opus 4\.7/i)
+
+    expect(screen.getByRole('button', { name: /Fable 5/ })).toBeInTheDocument()
+    expect(screen.getByRole('button', { name: /Opus 4\.8/ })).toBeInTheDocument()
+    expect(screen.getByRole('button', { name: /Sonnet 5/ })).toBeInTheDocument()
+    expect(screen.getAllByRole('button', { name: /Opus 4\.7/ }).length).toBeGreaterThan(0)
+  })
+
   it('does not query official OAuth status when mounted', () => {
     const fetchClaudeStatus = vi.fn(async () => {})
     const fetchOpenAIStatus = vi.fn(async () => {})

desktop/src/components/controls/ModelSelector.tsx

@@ -76,6 +76,18 @@ function officialChoices(
   }
 }
 
+function mergeOfficialModels(availableModels: ModelInfo[]): ModelInfo[] {
+  const merged = [...OFFICIAL_MODELS]
+  const knownIds = new Set(merged.map(model => model.id))
+  for (const model of availableModels) {
+    if (!knownIds.has(model.id)) {
+      knownIds.add(model.id)
+      merged.push(model)
+    }
+  }
+  return merged
+}
+
 function buildProviderModels(
   provider: SavedProvider,
   labels: Record<'main' | 'haiku' | 'sonnet' | 'opus', string>,
@@ -121,7 +133,7 @@ function buildProviderChoices(
   grokOfficialLoggedIn: boolean,
 ): ProviderChoice[] {
   const claudeOfficialModels = activeId === null && availableModels.length > 0
-    ? availableModels
+    ? mergeOfficialModels(availableModels)
     : OFFICIAL_MODELS
   const openAIOfficialModels = activeId === OPENAI_OFFICIAL_PROVIDER_ID && availableModels.length > 0
     ? availableModels

desktop/src/constants/modelCatalog.ts

@@ -1,24 +1,34 @@
 import type { ModelInfo } from '../types/settings'
 
-export const OFFICIAL_DEFAULT_MODEL_ID = 'claude-opus-4-7'
+export const OFFICIAL_DEFAULT_MODEL_ID = 'claude-opus-4-8'
 
 export const OFFICIAL_MODELS: ModelInfo[] = [
   {
-    id: 'claude-opus-4-7',
-    name: 'Opus 4.7',
-    description: 'Most capable for ambitious work',
+    id: 'claude-fable-5',
+    name: 'Fable 5',
+    description: 'Highest capability for long-running tasks',
     context: '1m',
   },
   {
-    id: 'claude-sonnet-4-6',
-    name: 'Sonnet 4.6',
-    description: 'Most efficient for everyday tasks',
-    context: '200k',
+    id: 'claude-opus-4-8',
+    name: 'Opus 4.8',
+    description: 'Best for complex agentic coding and enterprise work',
+    context: '1m',
+    defaultReasoningEffort: 'high',
+    supportedReasoningEfforts: ['low', 'medium', 'high', 'xhigh', 'max'],
+  },
+  {
+    id: 'claude-sonnet-5',
+    name: 'Sonnet 5',
+    description: 'Best combination of speed and intelligence',
+    context: '1m',
+    defaultReasoningEffort: 'high',
+    supportedReasoningEfforts: ['low', 'medium', 'high', 'xhigh', 'max'],
   },
   {
     id: 'claude-haiku-4-5',
     name: 'Haiku 4.5',
-    description: 'Fastest for quick answers',
+    description: 'Fastest with near-frontier intelligence',
     context: '200k',
   },
 ]

desktop/src/lib/__tests__/providerSettingsJson.test.ts

@@ -67,6 +67,8 @@ describe('provider settings JSON helpers', () => {
         ANTHROPIC_AUTH_TOKEN: 'old-auth-token',
         ANTHROPIC_BASE_URL: 'https://old.example.com',
         ANTHROPIC_MODEL: 'old-model',
+        ANTHROPIC_DEFAULT_FABLE_MODEL: 'old-fable',
+        ANTHROPIC_DEFAULT_FABLE_MODEL_NAME: 'Old Fable',
         CLAUDE_CODE_MODEL_CONTEXT_WINDOWS: '{"old":100000}',
         CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS: '1',
         CC_HAHA_OPENAI_OAUTH_PROVIDER: '1',

desktop/src/lib/providerSettingsJson.ts

@@ -8,6 +8,10 @@ const PROVIDER_SETTINGS_JSON_ENV_KEYS = new Set([
   'ANTHROPIC_API_KEY',
   'ANTHROPIC_AUTH_TOKEN',
   'ANTHROPIC_MODEL',
+  'ANTHROPIC_DEFAULT_FABLE_MODEL',
+  'ANTHROPIC_DEFAULT_FABLE_MODEL_DESCRIPTION',
+  'ANTHROPIC_DEFAULT_FABLE_MODEL_NAME',
+  'ANTHROPIC_DEFAULT_FABLE_MODEL_SUPPORTED_CAPABILITIES',
   'ANTHROPIC_DEFAULT_HAIKU_MODEL',
   'ANTHROPIC_DEFAULT_HAIKU_MODEL_DESCRIPTION',
   'ANTHROPIC_DEFAULT_HAIKU_MODEL_NAME',

desktop/src/mocks/data.ts

@@ -146,8 +146,9 @@ export const mockPermissionModes = [
 ]
 
 export const mockModels = [
-  { id: 'opus', name: 'Opus 4.7', active: false },
-  { id: 'sonnet', name: 'Sonnet 4.6', active: true },
+  { id: 'fable', name: 'Fable 5', active: false },
+  { id: 'opus', name: 'Opus 4.8', active: true },
+  { id: 'sonnet', name: 'Sonnet 5', active: false },
   { id: 'haiku', name: 'Haiku 4.5', active: false },
 ]
 

desktop/src/pages/SessionControls.tsx

@@ -408,7 +408,7 @@ export default function SessionControls() {
                 <span className="material-symbols-outlined text-base">
                   {modelIcons[selectedModel] || 'smart_toy'}
                 </span>
-                {activeModel?.name || 'Sonnet 4.6'}
+                {activeModel?.name || 'Opus 4.8'}
               </button>
 
               {/* Attach file button */}

desktop/src/pages/Settings.tsx

@@ -900,6 +900,7 @@ function stripModel1mMarker(model: string): string {
 function stripModel1mMarkers(models: ModelMapping): ModelMapping {
   return {
     main: stripModel1mMarker(models.main),
+    ...(models.fable ? { fable: stripModel1mMarker(models.fable) } : {}),
     haiku: stripModel1mMarker(models.haiku),
     sonnet: stripModel1mMarker(models.sonnet),
     opus: stripModel1mMarker(models.opus),
@@ -929,6 +930,7 @@ function applyModel1mSupportMapping(
 ): ModelMapping {
   return {
     main: applyModel1mSupport(models.main, model1mSupport.main),
+    ...(models.fable ? { fable: stripModel1mMarker(models.fable) } : {}),
     haiku: applyModel1mSupport(models.haiku, model1mSupport.haiku),
     sonnet: applyModel1mSupport(models.sonnet, model1mSupport.sonnet),
     opus: applyModel1mSupport(models.opus, model1mSupport.opus),
@@ -968,6 +970,7 @@ function normalizeModelMapping(models: ModelMapping): ModelMapping {
   const main = models.main.trim()
   return {
     main,
+    ...(models.fable?.trim() ? { fable: models.fable.trim() } : {}),
     haiku: models.haiku.trim() || main,
     sonnet: models.sonnet.trim() || main,
     opus: models.opus.trim() || main,
@@ -982,6 +985,14 @@ function readSettingsEnvString(env: Record<string, unknown>, key: string): strin
 }
 
 function readModelMappingFromSettingsEnv(env: Record<string, unknown>): Partial<ModelMapping> {
+  const hasModelEnv = [
+    'ANTHROPIC_MODEL',
+    'ANTHROPIC_DEFAULT_FABLE_MODEL',
+    'ANTHROPIC_DEFAULT_HAIKU_MODEL',
+    'ANTHROPIC_DEFAULT_SONNET_MODEL',
+    'ANTHROPIC_DEFAULT_OPUS_MODEL',
+  ].some((key) => Object.prototype.hasOwnProperty.call(env, key))
+  const fable = readSettingsEnvString(env, 'ANTHROPIC_DEFAULT_FABLE_MODEL')
   const haiku = readSettingsEnvString(env, 'ANTHROPIC_DEFAULT_HAIKU_MODEL')
   const sonnet = readSettingsEnvString(env, 'ANTHROPIC_DEFAULT_SONNET_MODEL')
   const opus = readSettingsEnvString(env, 'ANTHROPIC_DEFAULT_OPUS_MODEL')
@@ -989,6 +1000,7 @@ function readModelMappingFromSettingsEnv(env: Record<string, unknown>): Partial<
 
   return {
     ...(main ? { main } : {}),
+    ...(hasModelEnv ? { fable } : {}),
     ...(haiku ? { haiku } : {}),
     ...(sonnet ? { sonnet } : {}),
     ...(opus ? { opus } : {}),
@@ -1133,9 +1145,15 @@ function updateSettingsJsonModels(
       ? parsed.env
       : {}
     const runtimeModels = applyModel1mSupportMapping(models, model1mSupport)
+    const env = { ...existingEnv }
+    delete env.ANTHROPIC_DEFAULT_FABLE_MODEL
+    delete env.ANTHROPIC_DEFAULT_FABLE_MODEL_DESCRIPTION
+    delete env.ANTHROPIC_DEFAULT_FABLE_MODEL_NAME
+    delete env.ANTHROPIC_DEFAULT_FABLE_MODEL_SUPPORTED_CAPABILITIES
     parsed.env = {
-      ...existingEnv,
+      ...env,
       ANTHROPIC_MODEL: runtimeModels.main,
+      ...(runtimeModels.fable ? { ANTHROPIC_DEFAULT_FABLE_MODEL: runtimeModels.fable } : {}),
       ANTHROPIC_DEFAULT_HAIKU_MODEL: runtimeModels.haiku,
       ANTHROPIC_DEFAULT_SONNET_MODEL: runtimeModels.sonnet,
       ANTHROPIC_DEFAULT_OPUS_MODEL: runtimeModels.opus,
@@ -1282,6 +1300,7 @@ function ProviderFormModal({ open, onClose, mode, provider, presets }: ProviderF
           ANTHROPIC_BASE_URL: needsProxy ? providerProxyBaseUrl : baseUrl,
           ...buildSettingsJsonAuthEnv(apiFormat, authStrategy, apiKey, selectedPreset),
           ANTHROPIC_MODEL: runtimeModels.main,
+          ...(runtimeModels.fable ? { ANTHROPIC_DEFAULT_FABLE_MODEL: runtimeModels.fable } : {}),
           ANTHROPIC_DEFAULT_HAIKU_MODEL: runtimeModels.haiku,
           ANTHROPIC_DEFAULT_SONNET_MODEL: runtimeModels.sonnet,
           ANTHROPIC_DEFAULT_OPUS_MODEL: runtimeModels.opus,

desktop/src/types/provider.ts

@@ -13,6 +13,7 @@ export type ProviderRuntimeKind = 'anthropic_compatible' | 'openai_oauth' | 'gro
 
 export type ModelMapping = {
   main: string
+  fable?: string
   haiku: string
   sonnet: string
   opus: string

desktop/src/types/providerPreset.ts

@@ -2,6 +2,7 @@ import type { ApiFormat, ProviderAuthStrategy } from './provider'
 
 export type ModelMapping = {
   main: string
+  fable?: string
   haiku: string
   sonnet: string
   opus: string

src/constants/prompts.ts

@@ -115,12 +115,13 @@ export const SYSTEM_PROMPT_DYNAMIC_BOUNDARY =
   '__SYSTEM_PROMPT_DYNAMIC_BOUNDARY__'
 
 // @[MODEL LAUNCH]: Update the latest frontier model.
-const FRONTIER_MODEL_NAME = 'Claude Opus 4.7'
+const FRONTIER_MODEL_NAME = 'Claude Opus 4.8'
 
 // @[MODEL LAUNCH]: Update the model family IDs below to the latest in each tier.
-const CLAUDE_4_5_OR_4_6_MODEL_IDS = {
-  opus: 'claude-opus-4-7',
-  sonnet: 'claude-sonnet-4-6',
+const LATEST_CLAUDE_MODEL_IDS = {
+  fable: 'claude-fable-5',
+  opus: 'claude-opus-4-8',
+  sonnet: 'claude-sonnet-5',
   haiku: 'claude-haiku-4-5',
 }
 
@@ -693,7 +694,7 @@ export async function computeSimpleEnvInfo(
     knowledgeCutoffMessage,
     process.env.USER_TYPE === 'ant' && isUndercover()
       ? null
-      : `The most recent Claude model family is Claude 4.5/4.6. Model IDs — Opus 4.7: '${CLAUDE_4_5_OR_4_6_MODEL_IDS.opus}', Sonnet 4.6: '${CLAUDE_4_5_OR_4_6_MODEL_IDS.sonnet}', Haiku 4.5: '${CLAUDE_4_5_OR_4_6_MODEL_IDS.haiku}'. When building AI applications, default to the latest and most capable Claude models.`,
+      : `The most recent Claude flagship models are Claude Fable 5, Claude Opus 4.8, Claude Sonnet 5, and Claude Haiku 4.5. Model IDs — Fable 5: '${LATEST_CLAUDE_MODEL_IDS.fable}', Opus 4.8: '${LATEST_CLAUDE_MODEL_IDS.opus}', Sonnet 5: '${LATEST_CLAUDE_MODEL_IDS.sonnet}', Haiku 4.5: '${LATEST_CLAUDE_MODEL_IDS.haiku}'. When building AI applications, default to the latest and most capable Claude models.`,
     process.env.USER_TYPE === 'ant' && isUndercover()
       ? null
       : `Claude Code is available as a CLI in the terminal, desktop app (Mac/Windows), web app (claude.ai/code), and IDE extensions (VS Code, JetBrains).`,
@@ -712,7 +713,13 @@ export async function computeSimpleEnvInfo(
 // @[MODEL LAUNCH]: Add a knowledge cutoff date for the new model.
 function getKnowledgeCutoff(modelId: string): string | null {
   const canonical = getCanonicalName(modelId)
-  if (canonical.includes('claude-sonnet-4-6')) {
+  if (
+    canonical.includes('claude-fable-5') ||
+    canonical.includes('claude-opus-4-8') ||
+    canonical.includes('claude-sonnet-5')
+  ) {
+    return 'January 2026'
+  } else if (canonical.includes('claude-sonnet-4-6')) {
     return 'August 2025'
   } else if (canonical.includes('claude-opus-4-7')) {
     return 'May 2025'

src/server/__tests__/e2e/business-flow.test.ts

@@ -374,27 +374,28 @@ describe('Business Flow: Models & Effort', () => {
 
   it('should return available fallback models', async () => {
     const { data } = await api('GET', '/api/models')
-    expect(data.models.length).toBe(3)
+    expect(data.models.length).toBe(4)
     const names = data.models.map((m: any) => m.name)
-    expect(names).toContain('Opus 4.7')
-    expect(names).toContain('Sonnet 4.6')
+    expect(names).toContain('Fable 5')
+    expect(names).toContain('Opus 4.8')
+    expect(names).toContain('Sonnet 5')
     expect(names).toContain('Haiku 4.5')
   })
 
   it('should default to Opus model', async () => {
     const { data } = await api('GET', '/api/models/current')
-    expect(data.model.id).toBe('claude-opus-4-7')
+    expect(data.model.id).toBe('claude-opus-4-8')
   })
 
-  it('should switch to Opus 4.7', async () => {
+  it('should switch to Opus 4.8', async () => {
     const { status } = await api('PUT', '/api/models/current', {
-      modelId: 'claude-opus-4-7',
+      modelId: 'claude-opus-4-8',
     })
     expect(status).toBe(200)
 
     const { data } = await api('GET', '/api/models/current')
-    expect(data.model.id).toBe('claude-opus-4-7')
-    expect(data.model.name).toBe('Opus 4.7')
+    expect(data.model.id).toBe('claude-opus-4-8')
+    expect(data.model.name).toBe('Opus 4.8')
   })
 
   it('should switch to Haiku 4.5', async () => {

src/server/__tests__/e2e/full-flow.test.ts

@@ -205,8 +205,8 @@ describe('E2E: Full Flow', () => {
 
   it('should list available models', async () => {
     const { data } = await api('GET', '/api/models')
-    expect(data.models.length).toBe(3)
-    expect(data.models[0].name).toBe('Opus 4.7')
+    expect(data.models.length).toBe(4)
+    expect(data.models[0].name).toBe('Fable 5')
   })
 
   it('should switch model', async () => {

src/server/__tests__/provider-runtime-env.test.ts

@@ -82,6 +82,7 @@ describe('providerRuntimeEnv', () => {
           apiFormat: 'anthropic',
           models: {
             main: 'active-main',
+            fable: 'active-fable',
             haiku: '',
             sonnet: 'active-sonnet',
             opus: '',
@@ -98,6 +99,9 @@ describe('providerRuntimeEnv', () => {
       ANTHROPIC_AUTH_TOKEN: 'sk-active',
       ENABLE_TOOL_SEARCH: 'true',
       ANTHROPIC_MODEL: 'active-main',
+      ANTHROPIC_DEFAULT_FABLE_MODEL: 'active-fable',
+      ANTHROPIC_DEFAULT_FABLE_MODEL_SUPPORTED_CAPABILITIES:
+        'thinking,effort,adaptive_thinking,xhigh_effort,max_effort',
       ANTHROPIC_DEFAULT_HAIKU_MODEL: 'active-main',
       ANTHROPIC_DEFAULT_HAIKU_MODEL_SUPPORTED_CAPABILITIES:
         'thinking,effort,adaptive_thinking,xhigh_effort,max_effort',

src/server/__tests__/settings.test.ts

@@ -24,7 +24,17 @@ import {
   primeKeychainCacheFromPrefetch,
 } from '../../utils/secureStorage/macOsKeychainHelpers.js'
 import type { OpenAIOAuthTokens } from '../../services/openaiAuth/types.js'
-import { getModelOptions } from '../../utils/model/modelOptions.js'
+import {
+  getMaxOpus46_1MOption,
+  getMaxSonnet46_1MOption,
+  getModelOptions,
+  getOpus46_1MOption,
+  getSonnet46_1MOption,
+} from '../../utils/model/modelOptions.js'
+import {
+  getDefaultMainLoopModelSetting,
+  parseUserSpecifiedModel,
+} from '../../utils/model/model.js'
 import {
   getSettingsForSource,
   updateSettingsForSource,
@@ -49,6 +59,8 @@ let originalAnthropicDefaultHaikuModel: string | undefined
 let originalAnthropicDefaultSonnetModel: string | undefined
 let originalAnthropicDefaultOpusModel: string | undefined
 let originalAnthropicDefaultFableModel: string | undefined
+let originalAnthropicDefaultFableModelName: string | undefined
+let originalDisable1mContext: string | undefined
 
 async function setup() {
   tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), 'claude-test-'))
@@ -68,6 +80,8 @@ async function setup() {
   originalAnthropicDefaultSonnetModel = process.env.ANTHROPIC_DEFAULT_SONNET_MODEL
   originalAnthropicDefaultOpusModel = process.env.ANTHROPIC_DEFAULT_OPUS_MODEL
   originalAnthropicDefaultFableModel = process.env.ANTHROPIC_DEFAULT_FABLE_MODEL
+  originalAnthropicDefaultFableModelName = process.env.ANTHROPIC_DEFAULT_FABLE_MODEL_NAME
+  originalDisable1mContext = process.env.CLAUDE_CODE_DISABLE_1M_CONTEXT
   process.env.CLAUDE_CONFIG_DIR = tmpDir
   process.env.HOME = tmpDir
   process.env.USERPROFILE = tmpDir
@@ -80,6 +94,8 @@ async function setup() {
   delete process.env.ANTHROPIC_DEFAULT_SONNET_MODEL
   delete process.env.ANTHROPIC_DEFAULT_OPUS_MODEL
   delete process.env.ANTHROPIC_DEFAULT_FABLE_MODEL
+  delete process.env.ANTHROPIC_DEFAULT_FABLE_MODEL_NAME
+  delete process.env.CLAUDE_CODE_DISABLE_1M_CONTEXT
   clearKeychainCache()
   primeKeychainCacheFromPrefetch(null)
   clearOpenAIOAuthTokenCache()
@@ -171,6 +187,18 @@ async function teardown() {
     delete process.env.ANTHROPIC_DEFAULT_FABLE_MODEL
   }
 
+  if (originalAnthropicDefaultFableModelName !== undefined) {
+    process.env.ANTHROPIC_DEFAULT_FABLE_MODEL_NAME = originalAnthropicDefaultFableModelName
+  } else {
+    delete process.env.ANTHROPIC_DEFAULT_FABLE_MODEL_NAME
+  }
+
+  if (originalDisable1mContext !== undefined) {
+    process.env.CLAUDE_CODE_DISABLE_1M_CONTEXT = originalDisable1mContext
+  } else {
+    delete process.env.CLAUDE_CODE_DISABLE_1M_CONTEXT
+  }
+
   await fs.rm(tmpDir, { recursive: true, force: true })
 }
 
@@ -645,9 +673,36 @@ describe('Models API', () => {
 
     expect(res.status).toBe(200)
     const body = await res.json()
-    expect(body.models).toBeArray()
-    expect(body.models.length).toBe(3)
-    expect(body.models[0].id).toContain('claude')
+    expect(body.models).toEqual([
+      {
+        id: 'claude-fable-5',
+        name: 'Fable 5',
+        description: 'Highest capability for long-running tasks',
+        context: '1m',
+      },
+      {
+        id: 'claude-opus-4-8',
+        name: 'Opus 4.8',
+        description: 'Best for complex agentic coding and enterprise work',
+        context: '1m',
+        defaultReasoningEffort: 'high',
+        supportedReasoningEfforts: ['low', 'medium', 'high', 'xhigh', 'max'],
+      },
+      {
+        id: 'claude-sonnet-5',
+        name: 'Sonnet 5',
+        description: 'Best combination of speed and intelligence',
+        context: '1m',
+        defaultReasoningEffort: 'high',
+        supportedReasoningEfforts: ['low', 'medium', 'high', 'xhigh', 'max'],
+      },
+      {
+        id: 'claude-haiku-4-5',
+        name: 'Haiku 4.5',
+        description: 'Fastest with near-frontier intelligence',
+        context: '200k',
+      },
+    ])
   })
 
   it('GET /api/models should merge env-configured provider models with saved OpenAI OAuth models', async () => {
@@ -731,7 +786,7 @@ describe('Models API', () => {
 
     expect(res.status).toBe(200)
     const body = await res.json()
-    expect(body.model.id).toBe('claude-opus-4-7')
+    expect(body.model.id).toBe('claude-opus-4-8')
   })
 
   it('GET /api/models/current should respect env-configured default model when no provider is active', async () => {
@@ -976,6 +1031,92 @@ describe('Model Options', () => {
   beforeEach(setup)
   afterEach(teardown)
 
+  it('defaults Anthropic API users to Opus 4.8 and exposes the current official options once', () => {
+    process.env.ANTHROPIC_API_KEY = 'test-api-key'
+
+    expect(getDefaultMainLoopModelSetting()).toBe('claude-opus-4-8')
+
+    const options = getModelOptions()
+    const values = options.map(option => option.value)
+
+    expect(options[0]?.description).toContain('Opus 4.8')
+    expect(options[0]?.description).toContain('$5')
+    expect(values).toContain('fable')
+    expect(values).toContain('sonnet')
+    expect(values).not.toContain('opus')
+    expect(values).not.toContain('opus[1m]')
+  })
+
+  it('keeps Anthropic-compatible third-party URLs on lag-safe defaults', () => {
+    process.env.ANTHROPIC_API_KEY = 'third-party-key'
+    process.env.ANTHROPIC_BASE_URL = 'https://api.deepseek.com/anthropic'
+
+    expect(getDefaultMainLoopModelSetting()).toBe('claude-sonnet-4-5-20250929')
+    expect(parseUserSpecifiedModel('best')).toBe('claude-opus-4-7')
+    expect(parseUserSpecifiedModel('fable')).toBe('claude-opus-4-7')
+
+    const options = getModelOptions()
+    const values = options.map(option => option.value)
+
+    expect(options[0]?.description).toContain('Sonnet 4.5')
+    expect(values).not.toContain('fable')
+    expect(values).not.toContain('claude-fable-5')
+  })
+
+  it('exposes a custom Fable alias only when a third-party provider configures it', () => {
+    process.env.ANTHROPIC_API_KEY = 'third-party-key'
+    process.env.ANTHROPIC_BASE_URL = 'https://api.deepseek.com/anthropic'
+    process.env.ANTHROPIC_DEFAULT_FABLE_MODEL = 'deepseek-v4-fable'
+    process.env.ANTHROPIC_DEFAULT_FABLE_MODEL_NAME = 'DeepSeek Fable'
+
+    expect(parseUserSpecifiedModel('fable')).toBe('deepseek-v4-fable')
+    expect(parseUserSpecifiedModel('best')).toBe('deepseek-v4-fable')
+    expect(getModelOptions()).toContainEqual(expect.objectContaining({
+      value: 'fable',
+      label: 'DeepSeek Fable',
+    }))
+  })
+
+  it('labels extended-context options with current first-party and conservative third-party names', () => {
+    process.env.ANTHROPIC_API_KEY = 'test-api-key'
+
+    expect(getSonnet46_1MOption().description).toContain('Sonnet 5')
+    expect(getOpus46_1MOption().description).toContain('Opus 4.8')
+    expect(getMaxSonnet46_1MOption().description).toContain('Sonnet 5')
+    expect(getMaxOpus46_1MOption().description).toContain('Opus 4.8')
+
+    process.env.ANTHROPIC_BASE_URL = 'https://api.deepseek.com/anthropic'
+
+    expect(getSonnet46_1MOption().description).toContain('Sonnet 4.6')
+    expect(getOpus46_1MOption().description).toContain('Opus 4.7')
+  })
+
+  it('does not offer redundant Sonnet 1M choices when extended context is disabled', () => {
+    process.env.ANTHROPIC_API_KEY = 'test-api-key'
+    process.env.CLAUDE_CODE_DISABLE_1M_CONTEXT = '1'
+
+    expect(getModelOptions().map(option => option.value)).not.toContain('sonnet[1m]')
+  })
+
+  it('renders explicit current aliases and Fable model IDs with current marketing names', () => {
+    process.env.ANTHROPIC_API_KEY = 'test-api-key'
+
+    process.env.ANTHROPIC_MODEL = 'opus'
+    expect(getModelOptions().find(option => option.value === 'opus')?.description)
+      .toContain('Opus 4.8')
+
+    process.env.ANTHROPIC_MODEL = 'opus[1m]'
+    expect(getModelOptions().find(option => option.value === 'opus[1m]')?.description)
+      .toContain('Opus 4.8')
+
+    process.env.ANTHROPIC_MODEL = 'claude-fable-5'
+    expect(getModelOptions()).toContainEqual(expect.objectContaining({
+      value: 'claude-fable-5',
+      label: 'Fable 5',
+      description: 'claude-fable-5',
+    }))
+  })
+
   it('should keep OpenAI OAuth models visible alongside env-configured provider models', () => {
     process.env.ANTHROPIC_API_KEY = 'deepseek-key'
     process.env.ANTHROPIC_BASE_URL = 'https://api.deepseek.com/anthropic'

src/server/api/models.ts

@@ -39,28 +39,38 @@ import { hahaGrokOAuthService } from '../services/hahaGrokOAuthService.js'
 
 const DEFAULT_MODELS = [
   {
-    id: 'claude-opus-4-7',
-    name: 'Opus 4.7',
-    description: 'Most capable for ambitious work',
+    id: 'claude-fable-5',
+    name: 'Fable 5',
+    description: 'Highest capability for long-running tasks',
     context: '1m',
   },
   {
-    id: 'claude-sonnet-4-6',
-    name: 'Sonnet 4.6',
-    description: 'Most efficient for everyday tasks',
-    context: '200k',
+    id: 'claude-opus-4-8',
+    name: 'Opus 4.8',
+    description: 'Best for complex agentic coding and enterprise work',
+    context: '1m',
+    defaultReasoningEffort: 'high',
+    supportedReasoningEfforts: ['low', 'medium', 'high', 'xhigh', 'max'],
+  },
+  {
+    id: 'claude-sonnet-5',
+    name: 'Sonnet 5',
+    description: 'Best combination of speed and intelligence',
+    context: '1m',
+    defaultReasoningEffort: 'high',
+    supportedReasoningEfforts: ['low', 'medium', 'high', 'xhigh', 'max'],
   },
   {
     id: 'claude-haiku-4-5',
     name: 'Haiku 4.5',
-    description: 'Fastest for quick answers',
+    description: 'Fastest with near-frontier intelligence',
     context: '200k',
   },
 ] as const
 
 const EFFORT_LEVELS = ['low', 'medium', 'high', 'max'] as const
 
-const DEFAULT_MODEL = 'claude-opus-4-7'
+const DEFAULT_MODEL = 'claude-opus-4-8'
 const DEFAULT_EFFORT = 'max'
 
 const settingsService = new SettingsService()

src/server/config/providerPresets.ts

@@ -8,6 +8,7 @@ import { ApiFormatSchema, ProviderAuthStrategySchema } from '../types/provider.j
 
 const ModelMappingSchema = z.object({
   main: z.string(),
+  fable: z.string().optional(),
   haiku: z.string(),
   sonnet: z.string(),
   opus: z.string(),

src/server/services/conversationService.ts

@@ -1336,6 +1336,10 @@ export class ConversationService {
       'ANTHROPIC_AUTH_TOKEN',
       'ENABLE_TOOL_SEARCH',
       'ANTHROPIC_MODEL',
+      'ANTHROPIC_DEFAULT_FABLE_MODEL',
+      'ANTHROPIC_DEFAULT_FABLE_MODEL_DESCRIPTION',
+      'ANTHROPIC_DEFAULT_FABLE_MODEL_NAME',
+      'ANTHROPIC_DEFAULT_FABLE_MODEL_SUPPORTED_CAPABILITIES',
       'ANTHROPIC_DEFAULT_HAIKU_MODEL',
       'ANTHROPIC_DEFAULT_HAIKU_MODEL_SUPPORTED_CAPABILITIES',
       'ANTHROPIC_DEFAULT_SONNET_MODEL',
@@ -1600,6 +1604,10 @@ export class ConversationService {
         'ANTHROPIC_AUTH_TOKEN',
         'ENABLE_TOOL_SEARCH',
         'ANTHROPIC_MODEL',
+        'ANTHROPIC_DEFAULT_FABLE_MODEL',
+        'ANTHROPIC_DEFAULT_FABLE_MODEL_DESCRIPTION',
+        'ANTHROPIC_DEFAULT_FABLE_MODEL_NAME',
+        'ANTHROPIC_DEFAULT_FABLE_MODEL_SUPPORTED_CAPABILITIES',
         'ANTHROPIC_DEFAULT_HAIKU_MODEL',
         'ANTHROPIC_DEFAULT_HAIKU_MODEL_SUPPORTED_CAPABILITIES',
         'ANTHROPIC_DEFAULT_SONNET_MODEL',

src/server/services/persistentStorageMigrations.ts

@@ -44,6 +44,7 @@ function isProviderModels(value: unknown): value is JsonObject {
   return (
     isRecord(value) &&
     typeof value.main === 'string' &&
+    (value.fable === undefined || typeof value.fable === 'string') &&
     typeof value.haiku === 'string' &&
     typeof value.sonnet === 'string' &&
     typeof value.opus === 'string'
@@ -311,6 +312,7 @@ function buildManagedSettingsForMigratedProvider(provider: JsonObject | undefine
       ANTHROPIC_BASE_URL: baseUrl,
       ANTHROPIC_AUTH_TOKEN: apiKey,
       ANTHROPIC_MODEL: provider.models.main,
+      ...(provider.models.fable ? { ANTHROPIC_DEFAULT_FABLE_MODEL: provider.models.fable } : {}),
       ANTHROPIC_DEFAULT_HAIKU_MODEL: provider.models.haiku,
       ANTHROPIC_DEFAULT_SONNET_MODEL: provider.models.sonnet,
       ANTHROPIC_DEFAULT_OPUS_MODEL: provider.models.opus,

src/server/services/providerRuntimeEnv.ts

@@ -36,6 +36,10 @@ export const MANAGED_PROVIDER_ENV_KEYS = [
   'ENABLE_TOOL_SEARCH',
   'CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS',
   'ANTHROPIC_MODEL',
+  'ANTHROPIC_DEFAULT_FABLE_MODEL',
+  'ANTHROPIC_DEFAULT_FABLE_MODEL_DESCRIPTION',
+  'ANTHROPIC_DEFAULT_FABLE_MODEL_NAME',
+  'ANTHROPIC_DEFAULT_FABLE_MODEL_SUPPORTED_CAPABILITIES',
   'ANTHROPIC_DEFAULT_HAIKU_MODEL',
   'ANTHROPIC_DEFAULT_HAIKU_MODEL_SUPPORTED_CAPABILITIES',
   'ANTHROPIC_DEFAULT_SONNET_MODEL',
@@ -67,6 +71,7 @@ function isProviderModels(value: unknown): value is SavedProvider['models'] {
   return (
     isRecord(value) &&
     typeof value.main === 'string' &&
+    (value.fable === undefined || typeof value.fable === 'string') &&
     typeof value.haiku === 'string' &&
     typeof value.sonnet === 'string' &&
     typeof value.opus === 'string'
@@ -128,6 +133,7 @@ export function normalizeModelMapping(models: SavedProvider['models']): SavedPro
   const main = models.main.trim()
   return {
     main,
+    ...(models.fable?.trim() ? { fable: models.fable.trim() } : {}),
     haiku: models.haiku.trim() || main,
     sonnet: models.sonnet.trim() || main,
     opus: models.opus.trim() || main,
@@ -159,6 +165,7 @@ function applyModel1mSupportMapping(
 ): SavedProvider['models'] {
   return {
     main: applyModel1mSupport(models.main, model1mSupport?.main),
+    ...(models.fable ? { fable: models.fable.trim() } : {}),
     haiku: applyModel1mSupport(models.haiku, model1mSupport?.haiku),
     sonnet: applyModel1mSupport(models.sonnet, model1mSupport?.sonnet),
     opus: applyModel1mSupport(models.opus, model1mSupport?.opus),
@@ -309,6 +316,9 @@ function getProviderCapabilityEnv(
   if (provider.presetId === 'custom') {
     const capabilities = getCustomProviderModelCapabilities(provider, models)
     return {
+      ...(models.fable
+        ? { ANTHROPIC_DEFAULT_FABLE_MODEL_SUPPORTED_CAPABILITIES: capabilities }
+        : {}),
       ANTHROPIC_DEFAULT_HAIKU_MODEL_SUPPORTED_CAPABILITIES: capabilities,
       ANTHROPIC_DEFAULT_SONNET_MODEL_SUPPORTED_CAPABILITIES: capabilities,
       ANTHROPIC_DEFAULT_OPUS_MODEL_SUPPORTED_CAPABILITIES: capabilities,
@@ -409,6 +419,9 @@ export function buildProviderManagedEnv(
     ANTHROPIC_BASE_URL: baseUrl,
     ...buildProviderAuthEnv(provider, presetDefaultEnv, needsProxy),
     ANTHROPIC_MODEL: runtimeModels.main,
+    ...(runtimeModels.fable && {
+      ANTHROPIC_DEFAULT_FABLE_MODEL: runtimeModels.fable,
+    }),
     ANTHROPIC_DEFAULT_HAIKU_MODEL: runtimeModels.haiku,
     ANTHROPIC_DEFAULT_SONNET_MODEL: runtimeModels.sonnet,
     ANTHROPIC_DEFAULT_OPUS_MODEL: runtimeModels.opus,

src/server/services/sessionService.ts

@@ -2208,6 +2208,7 @@ export class SessionService {
     // (e.g. "LongCat-2.0-Preview-LongCatAI" instead of "LongCat-2.0-Preview").
     const providerEnvModelKeys = [
       'ANTHROPIC_MODEL',
+      'ANTHROPIC_DEFAULT_FABLE_MODEL',
       'ANTHROPIC_DEFAULT_HAIKU_MODEL',
       'ANTHROPIC_DEFAULT_SONNET_MODEL',
       'ANTHROPIC_DEFAULT_OPUS_MODEL',
@@ -2280,6 +2281,7 @@ export class SessionService {
     const matches: number[] = []
     const providerEnvModelKeys = [
       'ANTHROPIC_MODEL',
+      'ANTHROPIC_DEFAULT_FABLE_MODEL',
       'ANTHROPIC_DEFAULT_HAIKU_MODEL',
       'ANTHROPIC_DEFAULT_SONNET_MODEL',
       'ANTHROPIC_DEFAULT_OPUS_MODEL',

src/server/types/provider.ts

@@ -45,6 +45,7 @@ export type ProviderRuntimeKind = z.infer<typeof ProviderRuntimeKindSchema>
 
 export const ModelMappingSchema = z.object({
   main: z.string(),
+  fable: z.string().optional(),
   haiku: z.string(),
   sonnet: z.string(),
   opus: z.string(),

src/skills/bundled/claudeApiContent.ts

@@ -34,10 +34,10 @@ import typescriptClaudeApiToolUse from './claude-api/typescript/claude-api/tool-
 //   - claude-api/SKILL.md (Current Models pricing table)
 //   - claude-api/shared/models.md (full model catalog with legacy versions and alias mappings)
 export const SKILL_MODEL_VARS = {
-  OPUS_ID: 'claude-opus-4-7',
-  OPUS_NAME: 'Claude Opus 4.7',
-  SONNET_ID: 'claude-sonnet-4-6',
-  SONNET_NAME: 'Claude Sonnet 4.6',
+  OPUS_ID: 'claude-opus-4-8',
+  OPUS_NAME: 'Claude Opus 4.8',
+  SONNET_ID: 'claude-sonnet-5',
+  SONNET_NAME: 'Claude Sonnet 5',
   HAIKU_ID: 'claude-haiku-4-5',
   HAIKU_NAME: 'Claude Haiku 4.5',
   // Previous Sonnet ID — used in "do not append date suffixes" example in SKILL.md.

src/utils/__tests__/providerManagedEnvCompat.test.ts

@@ -13,6 +13,9 @@ describe('provider managed env compatibility', () => {
 
     expect(changed).toBe(true)
     expect(env.CC_HAHA_SEND_DISABLED_THINKING).toBeUndefined()
+    expect(env.ANTHROPIC_DEFAULT_FABLE_MODEL_SUPPORTED_CAPABILITIES).toBe(
+      'thinking,effort,adaptive_thinking,max_effort',
+    )
     expect(env.ANTHROPIC_DEFAULT_HAIKU_MODEL_SUPPORTED_CAPABILITIES).toBe(
       'thinking,effort,adaptive_thinking,max_effort',
     )

src/utils/__tests__/thinking.test.ts

@@ -1,6 +1,15 @@
 import { afterEach, beforeEach, describe, expect, test } from 'bun:test'
 import { get3PModelCapabilityOverride } from '../model/modelSupportOverrides.js'
 import { resolveSideQueryThinkingConfig } from '../sideQuery.js'
+import {
+  getModelBetas,
+  modelSupportsAutoMode,
+  modelSupportsContextManagement,
+  modelSupportsISP,
+  modelSupportsStructuredOutputs,
+  shouldIncludeFirstPartyOnlyBetas,
+  shouldUseGlobalCacheScope,
+} from '../betas.js'
 import {
   modelSupportsEffort,
   modelSupportsMaxEffort,
@@ -15,6 +24,7 @@ import {
 } from '../thinking.js'
 
 describe('provider-aware thinking support', () => {
+  let originalApiKey: string | undefined
   let originalBaseUrl: string | undefined
   let originalFableModel: string | undefined
   let originalFableCapabilities: string | undefined
@@ -26,6 +36,7 @@ describe('provider-aware thinking support', () => {
   let originalExplicitDisabledThinking: string | undefined
 
   beforeEach(() => {
+    originalApiKey = process.env.ANTHROPIC_API_KEY
     originalBaseUrl = process.env.ANTHROPIC_BASE_URL
     originalFableModel = process.env.ANTHROPIC_DEFAULT_FABLE_MODEL
     originalFableCapabilities = process.env.ANTHROPIC_DEFAULT_FABLE_MODEL_SUPPORTED_CAPABILITIES
@@ -36,12 +47,14 @@ describe('provider-aware thinking support', () => {
     originalFoundry = process.env.CLAUDE_CODE_USE_FOUNDRY
     originalExplicitDisabledThinking = process.env.CC_HAHA_SEND_DISABLED_THINKING
 
+    delete process.env.ANTHROPIC_API_KEY
     delete process.env.CLAUDE_CODE_USE_BEDROCK
     delete process.env.CLAUDE_CODE_USE_VERTEX
     delete process.env.CLAUDE_CODE_USE_FOUNDRY
   })
 
   afterEach(() => {
+    restoreEnv('ANTHROPIC_API_KEY', originalApiKey)
     restoreEnv('ANTHROPIC_BASE_URL', originalBaseUrl)
     restoreEnv('ANTHROPIC_DEFAULT_FABLE_MODEL', originalFableModel)
     restoreEnv('ANTHROPIC_DEFAULT_FABLE_MODEL_SUPPORTED_CAPABILITIES', originalFableCapabilities)
@@ -52,9 +65,11 @@ describe('provider-aware thinking support', () => {
     restoreEnv('CLAUDE_CODE_USE_FOUNDRY', originalFoundry)
     restoreEnv('CC_HAHA_SEND_DISABLED_THINKING', originalExplicitDisabledThinking)
     clearCapabilityCache()
+    clearBetaCache()
   })
 
   test('does not assume adaptive thinking for Anthropic-compatible third-party base URLs', () => {
+    process.env.ANTHROPIC_API_KEY = 'third-party-key'
     process.env.ANTHROPIC_BASE_URL = 'https://api.jiekou.ai/anthropic'
     delete process.env.ANTHROPIC_DEFAULT_SONNET_MODEL_SUPPORTED_CAPABILITIES
     clearCapabilityCache()
@@ -63,6 +78,7 @@ describe('provider-aware thinking support', () => {
   })
 
   test('honors explicit provider capability overrides with no supported capabilities', () => {
+    process.env.ANTHROPIC_API_KEY = 'third-party-key'
     process.env.ANTHROPIC_BASE_URL = 'https://api.jiekou.ai/anthropic'
     process.env.ANTHROPIC_DEFAULT_SONNET_MODEL = 'claude-sonnet-4-6'
     process.env.ANTHROPIC_DEFAULT_SONNET_MODEL_SUPPORTED_CAPABILITIES = 'none'
@@ -82,6 +98,23 @@ describe('provider-aware thinking support', () => {
     expect(modelSupportsAdaptiveThinking('claude-sonnet-4-6')).toBe(true)
   })
 
+  test('recognizes current first-party flagship model capabilities', () => {
+    process.env.ANTHROPIC_BASE_URL = 'https://api.anthropic.com'
+    clearCapabilityCache()
+
+    for (const model of ['claude-fable-5', 'claude-opus-4-8', 'claude-sonnet-5']) {
+      expect(modelSupportsThinking(model)).toBe(true)
+      expect(modelSupportsAdaptiveThinking(model)).toBe(true)
+      expect(modelSupportsEffort(model)).toBe(true)
+      expect(modelSupportsMaxEffort(model)).toBe(true)
+      expect(modelSupportsISP(model)).toBe(true)
+      expect(modelSupportsContextManagement(model)).toBe(true)
+      expect(modelSupportsStructuredOutputs(model)).toBe(true)
+    }
+    expect(shouldIncludeFirstPartyOnlyBetas()).toBe(true)
+    expect(shouldUseGlobalCacheScope()).toBe(true)
+  })
+
   test('normalizes Fable to required adaptive thinking', () => {
     process.env.ANTHROPIC_BASE_URL = 'https://api.anthropic.com'
     delete process.env.ANTHROPIC_DEFAULT_FABLE_MODEL
@@ -95,6 +128,7 @@ describe('provider-aware thinking support', () => {
   })
 
   test('lets an explicit third-party capability declaration disable Fable thinking', () => {
+    process.env.ANTHROPIC_API_KEY = 'third-party-key'
     process.env.ANTHROPIC_BASE_URL = 'https://provider.example.test/anthropic'
     process.env.ANTHROPIC_DEFAULT_FABLE_MODEL = 'claude-fable-5'
     process.env.ANTHROPIC_DEFAULT_FABLE_MODEL_SUPPORTED_CAPABILITIES = 'effort'
@@ -115,6 +149,7 @@ describe('provider-aware thinking support', () => {
   })
 
   test('DeepSeek preset can follow the global thinking setting through capability overrides', () => {
+    process.env.ANTHROPIC_API_KEY = 'third-party-key'
     process.env.ANTHROPIC_BASE_URL = 'https://api.deepseek.com/anthropic'
     process.env.ANTHROPIC_DEFAULT_SONNET_MODEL = 'deepseek-v4-pro'
     process.env.ANTHROPIC_DEFAULT_SONNET_MODEL_SUPPORTED_CAPABILITIES =
@@ -131,6 +166,7 @@ describe('provider-aware thinking support', () => {
   })
 
   test('MiniMax preset models declare adaptive thinking without effort passthrough', () => {
+    process.env.ANTHROPIC_API_KEY = 'third-party-key'
     process.env.ANTHROPIC_BASE_URL = 'https://api.minimaxi.com/anthropic'
     process.env.ANTHROPIC_DEFAULT_SONNET_MODEL = 'MiniMax-M3[1m]'
     process.env.ANTHROPIC_DEFAULT_SONNET_MODEL_SUPPORTED_CAPABILITIES =
@@ -145,6 +181,7 @@ describe('provider-aware thinking support', () => {
   })
 
   test('Kimi K3 preset requires thinking and supports effort passthrough', () => {
+    process.env.ANTHROPIC_API_KEY = 'third-party-key'
     process.env.ANTHROPIC_BASE_URL = 'https://api.kimi.com/coding/'
     process.env.ANTHROPIC_DEFAULT_SONNET_MODEL = 'k3'
     process.env.ANTHROPIC_DEFAULT_SONNET_MODEL_SUPPORTED_CAPABILITIES =
@@ -163,6 +200,7 @@ describe('provider-aware thinking support', () => {
   })
 
   test('third-party base URLs do not default unknown model names to effort support', () => {
+    process.env.ANTHROPIC_API_KEY = 'third-party-key'
     process.env.ANTHROPIC_BASE_URL = 'https://api.kimi.com/coding/'
     delete process.env.ANTHROPIC_DEFAULT_SONNET_MODEL_SUPPORTED_CAPABILITIES
     clearCapabilityCache()
@@ -171,6 +209,27 @@ describe('provider-aware thinking support', () => {
     expect(modelSupportsMaxEffort('kimi-k2.6')).toBe(false)
   })
 
+  test('does not infer first-party effort or betas from current model names on third-party URLs', () => {
+    process.env.ANTHROPIC_API_KEY = 'third-party-key'
+    process.env.ANTHROPIC_BASE_URL = 'https://api.deepseek.com/anthropic'
+    delete process.env.ANTHROPIC_DEFAULT_FABLE_MODEL_SUPPORTED_CAPABILITIES
+    delete process.env.ANTHROPIC_DEFAULT_SONNET_MODEL_SUPPORTED_CAPABILITIES
+    clearCapabilityCache()
+    clearBetaCache()
+
+    for (const model of ['claude-fable-5', 'claude-opus-4-8', 'claude-sonnet-5']) {
+      expect(modelSupportsEffort(model)).toBe(false)
+      expect(modelSupportsMaxEffort(model)).toBe(false)
+      expect(modelSupportsISP(model)).toBe(false)
+      expect(modelSupportsContextManagement(model)).toBe(false)
+      expect(modelSupportsStructuredOutputs(model)).toBe(false)
+      expect(modelSupportsAutoMode(model)).toBe(false)
+      expect(getModelBetas(model)).not.toContain('interleaved-thinking-2025-05-14')
+    }
+    expect(shouldIncludeFirstPartyOnlyBetas()).toBe(false)
+    expect(shouldUseGlobalCacheScope()).toBe(false)
+  })
+
   test('side queries inherit explicit disabled thinking for opted-in providers', () => {
     delete process.env.CC_HAHA_SEND_DISABLED_THINKING
     expect(resolveSideQueryThinkingConfig(undefined, 1024)).toBeUndefined()
@@ -195,3 +254,9 @@ function clearCapabilityCache() {
     cache?: { clear?: () => void }
   }).cache?.clear?.()
 }
+
+function clearBetaCache() {
+  ;(getModelBetas as typeof getModelBetas & {
+    cache?: { clear?: () => void }
+  }).cache?.clear?.()
+}

src/utils/attribution.ts

@@ -69,13 +69,13 @@ export function getAttributionTexts(): AttributionTexts {
 
   // @[MODEL LAUNCH]: Update the hardcoded fallback model name below (guards against codename leaks).
   // For internal repos, use the real model name. For external repos,
-  // fall back to "Claude Opus 4.7" for unrecognized models to avoid leaking codenames.
+  // fall back to "Claude Opus 4.8" for unrecognized models to avoid leaking codenames.
   const model = getMainLoopModel()
   const isKnownPublicModel = getPublicModelDisplayName(model) !== null
   const modelName =
     isInternalModelRepoCached() || isKnownPublicModel
       ? getPublicModelName(model)
-      : 'Claude Opus 4.7'
+      : 'Claude Opus 4.8'
   const defaultAttribution = `🤖 Generated with [Claude Code](${PRODUCT_URL})`
   const defaultCommit = `Co-Authored-By: ${modelName} <noreply@anthropic.com>`
 

src/utils/auth.ts

@@ -10,7 +10,10 @@ import {
   logEvent,
 } from 'src/services/analytics/index.js'
 import { getModelStrings } from 'src/utils/model/modelStrings.js'
-import { getAPIProvider } from 'src/utils/model/providers.js'
+import {
+  getAPIProvider,
+  isFirstPartyAnthropicBaseUrl,
+} from 'src/utils/model/providers.js'
 import {
   getIsNonInteractiveSession,
   preferThirdPartyAuthentication,
@@ -129,9 +132,14 @@ export function isAnthropicAuthEnabled(): boolean {
     process.env.CLAUDE_CODE_API_KEY_FILE_DESCRIPTOR
 
   // Check if API key is from an external source (not managed by /login)
-  const { source: apiKeySource } = getAnthropicApiKeyWithSource({
-    skipRetrievingKeyFromApiKeyHelper: true,
-  })
+  let apiKeySource: ApiKeySource = 'none'
+  try {
+    ;({ source: apiKeySource } = getAnthropicApiKeyWithSource({
+      skipRetrievingKeyFromApiKeyHelper: true,
+    }))
+  } catch {
+    apiKeySource = 'none'
+  }
   const hasExternalApiKey =
     apiKeySource === 'ANTHROPIC_API_KEY' || apiKeySource === 'apiKeyHelper'
 
@@ -1585,7 +1593,14 @@ async function checkAndRefreshOAuthTokenIfNeededImpl(
 }
 
 export function isClaudeAISubscriber(): boolean {
-  if (!isAnthropicAuthEnabled()) {
+  let anthropicAuthEnabled = false
+  try {
+    anthropicAuthEnabled = isAnthropicAuthEnabled()
+  } catch {
+    anthropicAuthEnabled = false
+  }
+
+  if (!anthropicAuthEnabled) {
     return false
   }
 
@@ -1623,6 +1638,10 @@ export function is1PApiCustomer(): boolean {
     return false
   }
 
+  if (!isFirstPartyAnthropicBaseUrl()) {
+    return false
+  }
+
   // Exclude Claude.ai subscribers
   if (isClaudeAISubscriber()) {
     return false

src/utils/betas.ts

@@ -89,6 +89,14 @@ export function filterAllowedSdkBetas(
 // Generally, foundry supports all 1P features;
 // however out of an abundance of caution, we do not enable any which are behind an experiment
 
+function shouldTrustBuiltInClaudeCapabilities(): boolean {
+  return (
+    getAPIProvider() !== 'firstParty' ||
+    isFirstPartyAnthropicBaseUrl() ||
+    isClaudeAISubscriber()
+  )
+}
+
 export function modelSupportsISP(model: string): boolean {
   const supported3P = get3PModelCapabilityOverride(
     model,
@@ -104,6 +112,9 @@ export function modelSupportsISP(model: string): boolean {
     return true
   }
   if (provider === 'firstParty') {
+    if (!shouldTrustBuiltInClaudeCapabilities()) {
+      return false
+    }
     return !canonical.includes('claude-3-')
   }
   return (
@@ -129,9 +140,14 @@ export function modelSupportsContextManagement(model: string): boolean {
     return true
   }
   if (provider === 'firstParty') {
+    if (!shouldTrustBuiltInClaudeCapabilities()) {
+      return false
+    }
     return !canonical.includes('claude-3-')
   }
   return (
+    canonical.includes('claude-fable-5') ||
+    canonical.includes('claude-sonnet-5') ||
     canonical.includes('claude-opus-4') ||
     canonical.includes('claude-sonnet-4') ||
     canonical.includes('claude-haiku-4')
@@ -146,11 +162,17 @@ export function modelSupportsStructuredOutputs(model: string): boolean {
   if (provider !== 'firstParty' && provider !== 'foundry') {
     return false
   }
+  if (provider === 'firstParty' && !shouldTrustBuiltInClaudeCapabilities()) {
+    return false
+  }
   return (
+    canonical.includes('claude-fable-5') ||
+    canonical.includes('claude-sonnet-5') ||
     canonical.includes('claude-sonnet-4-6') ||
     canonical.includes('claude-sonnet-4-5') ||
     canonical.includes('claude-opus-4-1') ||
     canonical.includes('claude-opus-4-5') ||
+    canonical.includes('claude-opus-4-8') ||
     canonical.includes('claude-opus-4-7') ||
     canonical.includes('claude-haiku-4-5')
   )
@@ -163,7 +185,10 @@ export function modelSupportsAutoMode(model: string): boolean {
     // External: firstParty-only at launch (PI probes not wired for
     // Bedrock/Vertex/Foundry yet). Checked before allowModels so the GB
     // override can't enable auto mode on unsupported providers.
-    if (process.env.USER_TYPE !== 'ant' && getAPIProvider() !== 'firstParty') {
+    if (
+      process.env.USER_TYPE !== 'ant' &&
+      (getAPIProvider() !== 'firstParty' || !shouldTrustBuiltInClaudeCapabilities())
+    ) {
       return false
     }
     // GrowthBook override: tengu_auto_mode_config.allowModels force-enables
@@ -215,7 +240,11 @@ export function getToolSearchBetaHeader(): string {
 export function shouldIncludeFirstPartyOnlyBetas(): boolean {
   return (
     (getAPIProvider() === 'firstParty' || getAPIProvider() === 'foundry') &&
-    (getAPIProvider() !== 'firstParty' || isFirstPartyAnthropicBaseUrl()) &&
+    (
+      getAPIProvider() !== 'firstParty' ||
+      isFirstPartyAnthropicBaseUrl() ||
+      isClaudeAISubscriber()
+    ) &&
     !isEnvTruthy(process.env.CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS)
   )
 }
@@ -228,6 +257,7 @@ export function shouldIncludeFirstPartyOnlyBetas(): boolean {
 export function shouldUseGlobalCacheScope(): boolean {
   return (
     getAPIProvider() === 'firstParty' &&
+    (isFirstPartyAnthropicBaseUrl() || isClaudeAISubscriber()) &&
     !isEnvTruthy(process.env.CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS)
   )
 }

src/utils/commitAttribution.ts

@@ -153,10 +153,13 @@ export function sanitizeSurfaceKey(surfaceKey: string): string {
  */
 export function sanitizeModelName(shortName: string): string {
   // Map internal variants to public equivalents based on model family
+  if (shortName.includes('fable-5')) return 'claude-fable-5'
+  if (shortName.includes('opus-4-8')) return 'claude-opus-4-8'
   if (shortName.includes('opus-4-6')) return 'claude-opus-4-7'
   if (shortName.includes('opus-4-5')) return 'claude-opus-4-5'
   if (shortName.includes('opus-4-1')) return 'claude-opus-4-1'
   if (shortName.includes('opus-4')) return 'claude-opus-4'
+  if (shortName.includes('sonnet-5')) return 'claude-sonnet-5'
   if (shortName.includes('sonnet-4-6')) return 'claude-sonnet-4-6'
   if (shortName.includes('sonnet-4-5')) return 'claude-sonnet-4-5'
   if (shortName.includes('sonnet-4')) return 'claude-sonnet-4'

src/utils/context.ts

@@ -54,6 +54,9 @@ export function modelSupports1M(model: string): boolean {
   const canonical = getCanonicalName(model)
   return (
     canonical.includes('claude-fable-5') ||
+    canonical.includes('claude-sonnet-5') ||
+    canonical.includes('claude-opus-4-8') ||
+    canonical.includes('claude-opus-4-7') ||
     canonical.includes('claude-sonnet-4') ||
     canonical.includes('opus-4-6')
   )
@@ -232,7 +235,13 @@ export function getModelMaxOutputTokens(model: string): {
 
   const m = getCanonicalName(model)
 
-  if (m.includes('opus-4-6')) {
+  if (
+    m.includes('fable-5') ||
+    m.includes('opus-4-8') ||
+    m.includes('opus-4-7') ||
+    m.includes('opus-4-6') ||
+    m.includes('sonnet-5')
+  ) {
     defaultTokens = 64_000
     upperLimit = 128_000
   } else if (m.includes('sonnet-4-6')) {

src/utils/effort.ts

@@ -1,9 +1,13 @@
 // biome-ignore-all assist/source/organizeImports: ANT-ONLY import markers must not be reordered
 import { isUltrathinkEnabled } from './thinking.js'
 import { getInitialSettings } from './settings/settings.js'
-import { isProSubscriber, isMaxSubscriber, isTeamSubscriber } from './auth.js'
+import { isClaudeAISubscriber, isProSubscriber, isMaxSubscriber, isTeamSubscriber } from './auth.js'
 import { getFeatureValue_CACHED_MAY_BE_STALE } from 'src/services/analytics/growthbook.js'
-import { getAPIProvider, isFirstPartyAnthropicBaseUrl } from './model/providers.js'
+import {
+  getAPIProvider,
+  hasAnthropicCompatibleThirdPartyConfig,
+  isFirstPartyAnthropicBaseUrl,
+} from './model/providers.js'
 import { get3PModelCapabilityOverride } from './model/modelSupportOverrides.js'
 import { isEnvTruthy } from './envUtils.js'
 import type { EffortLevel as RuntimeEffortLevel } from 'src/entrypoints/sdk/runtimeTypes.js'
@@ -24,6 +28,17 @@ export const EFFORT_LEVELS = [
 
 export type EffortValue = EffortLevel | number
 
+function shouldTrustBuiltInClaudeCapabilityList(): boolean {
+  if (hasAnthropicCompatibleThirdPartyConfig()) {
+    return false
+  }
+  return (
+    getAPIProvider() !== 'firstParty' ||
+    isFirstPartyAnthropicBaseUrl() ||
+    isClaudeAISubscriber()
+  )
+}
+
 // @[MODEL LAUNCH]: Add the new model to the allowlist if it supports the effort parameter.
 export function modelSupportsEffort(model: string): boolean {
   const m = model.toLowerCase()
@@ -38,7 +53,7 @@ export function modelSupportsEffort(model: string): boolean {
     return true
   }
   // Supported by a subset of Claude 4 models
-  if (
+  if (shouldTrustBuiltInClaudeCapabilityList() && (
     m.includes('opus-4-6') ||
     m.includes('opus-4-7') ||
     m.includes('opus-4-8') ||
@@ -48,7 +63,7 @@ export function modelSupportsEffort(model: string): boolean {
     m.includes('fable-5') ||
     m.includes('mythos-5') ||
     m.includes('mythos-preview')
-  ) {
+  )) {
     return true
   }
   // Exclude any other known legacy models (haiku, older opus/sonnet variants)
@@ -63,7 +78,10 @@ export function modelSupportsEffort(model: string): boolean {
   // Default to true for unknown model strings on 1P.
   // Do not default to true for 3P as they have different formats for their
   // model strings (ex. anthropics/claude-code#30795)
-  return getAPIProvider() === 'firstParty' && isFirstPartyAnthropicBaseUrl()
+  return (
+    getAPIProvider() === 'firstParty' &&
+    (isFirstPartyAnthropicBaseUrl() || isClaudeAISubscriber())
+  )
 }
 
 // @[MODEL LAUNCH]: Add new models that expose the 'xhigh' effort level.
@@ -77,7 +95,7 @@ export function modelSupportsXHighEffort(model: string): boolean {
     return entry?.supportedReasoningEfforts.includes('xhigh') ?? true
   }
   const m = model.toLowerCase()
-  return (
+  return shouldTrustBuiltInClaudeCapabilityList() && (
     m.includes('opus-4-7') ||
     m.includes('opus-4-8') ||
     m.includes('sonnet-5') ||
@@ -97,7 +115,7 @@ export function modelSupportsMaxEffort(model: string): boolean {
     return entry?.supportedReasoningEfforts.includes('max') ?? true
   }
   const m = model.toLowerCase()
-  if (
+  if (shouldTrustBuiltInClaudeCapabilityList() && (
     m.includes('opus-4-6') ||
     m.includes('opus-4-7') ||
     m.includes('opus-4-8') ||
@@ -106,7 +124,7 @@ export function modelSupportsMaxEffort(model: string): boolean {
     m.includes('fable-5') ||
     m.includes('mythos-5') ||
     m.includes('mythos-preview')
-  ) {
+  )) {
     return true
   }
   if (process.env.USER_TYPE === 'ant' && resolveAntModel(model)) {

src/utils/fastMode.ts

@@ -140,7 +140,7 @@ export function getFastModeUnavailableReason(): string | null {
 }
 
 // @[MODEL LAUNCH]: Update supported Fast Mode models.
-export const FAST_MODE_MODEL_DISPLAY = 'Opus 4.7'
+export const FAST_MODE_MODEL_DISPLAY = 'Opus 4.8'
 
 export function getFastModeModel(): string {
   return 'opus' + (isOpus1mMergeEnabled() ? '[1m]' : '')

src/utils/managedEnvConstants.ts

@@ -47,6 +47,10 @@ const PROVIDER_MANAGED_ENV_VARS = new Set([
   'GROK_OAUTH_FILE',
   // Model defaults — often set to provider-specific ID formats
   'ANTHROPIC_MODEL',
+  'ANTHROPIC_DEFAULT_FABLE_MODEL',
+  'ANTHROPIC_DEFAULT_FABLE_MODEL_DESCRIPTION',
+  'ANTHROPIC_DEFAULT_FABLE_MODEL_NAME',
+  'ANTHROPIC_DEFAULT_FABLE_MODEL_SUPPORTED_CAPABILITIES',
   'ANTHROPIC_DEFAULT_HAIKU_MODEL',
   'ANTHROPIC_DEFAULT_HAIKU_MODEL_DESCRIPTION',
   'ANTHROPIC_DEFAULT_HAIKU_MODEL_NAME',
@@ -124,6 +128,10 @@ export const SAFE_ENV_VARS = new Set([
   'ANTHROPIC_CUSTOM_MODEL_OPTION',
   'ANTHROPIC_CUSTOM_MODEL_OPTION_DESCRIPTION',
   'ANTHROPIC_CUSTOM_MODEL_OPTION_NAME',
+  'ANTHROPIC_DEFAULT_FABLE_MODEL',
+  'ANTHROPIC_DEFAULT_FABLE_MODEL_DESCRIPTION',
+  'ANTHROPIC_DEFAULT_FABLE_MODEL_NAME',
+  'ANTHROPIC_DEFAULT_FABLE_MODEL_SUPPORTED_CAPABILITIES',
   'ANTHROPIC_DEFAULT_HAIKU_MODEL',
   'ANTHROPIC_DEFAULT_HAIKU_MODEL_DESCRIPTION',
   'ANTHROPIC_DEFAULT_HAIKU_MODEL_NAME',

src/utils/model/configs.ts

@@ -40,12 +40,20 @@ export const CLAUDE_HAIKU_4_5_CONFIG = {
 
 export const CLAUDE_FABLE_5_CONFIG = {
   firstParty: 'claude-fable-5',
-  bedrock: 'us.anthropic.claude-fable-5',
+  bedrock: 'anthropic.claude-fable-5',
   vertex: 'claude-fable-5',
   foundry: 'claude-fable-5',
   azureOpenAI: 'claude-fable-5',
 } as const satisfies ModelConfig
 
+export const CLAUDE_SONNET_5_CONFIG = {
+  firstParty: 'claude-sonnet-5',
+  bedrock: 'anthropic.claude-sonnet-5',
+  vertex: 'claude-sonnet-5',
+  foundry: 'claude-sonnet-5',
+  azureOpenAI: 'claude-sonnet-5',
+} as const satisfies ModelConfig
+
 export const CLAUDE_SONNET_4_CONFIG = {
   firstParty: 'claude-sonnet-4-20250514',
   bedrock: 'us.anthropic.claude-sonnet-4-20250514-v1:0',
@@ -94,6 +102,14 @@ export const CLAUDE_OPUS_4_6_CONFIG = {
   azureOpenAI: 'claude-opus-4-7',
 } as const satisfies ModelConfig
 
+export const CLAUDE_OPUS_4_8_CONFIG = {
+  firstParty: 'claude-opus-4-8',
+  bedrock: 'anthropic.claude-opus-4-8',
+  vertex: 'claude-opus-4-8',
+  foundry: 'claude-opus-4-8',
+  azureOpenAI: 'claude-opus-4-8',
+} as const satisfies ModelConfig
+
 export const CLAUDE_SONNET_4_6_CONFIG = {
   firstParty: 'claude-sonnet-4-6',
   bedrock: 'us.anthropic.claude-sonnet-4-6',
@@ -136,10 +152,12 @@ export const ALL_MODEL_CONFIGS = {
   sonnet40: CLAUDE_SONNET_4_CONFIG,
   sonnet45: CLAUDE_SONNET_4_5_CONFIG,
   sonnet46: CLAUDE_SONNET_4_6_CONFIG,
+  sonnet50: CLAUDE_SONNET_5_CONFIG,
   opus40: CLAUDE_OPUS_4_CONFIG,
   opus41: CLAUDE_OPUS_4_1_CONFIG,
   opus45: CLAUDE_OPUS_4_5_CONFIG,
   opus46: CLAUDE_OPUS_4_6_CONFIG,
+  opus48: CLAUDE_OPUS_4_8_CONFIG,
   gpt52codex: GPT_5_2_CODEX_CONFIG,
   gpt53codex: GPT_5_3_CODEX_CONFIG,
   gpt54codex: GPT_5_4_CODEX_CONFIG,

src/utils/model/fable.test.ts

@@ -1,23 +1,35 @@
 import { afterEach, beforeEach, describe, expect, test } from 'bun:test'
 import { getContextWindowForModel, modelSupports1M } from '../context.js'
+import { computeSimpleEnvInfo } from '../../constants/prompts.js'
+import { SKILL_MODEL_VARS } from '../../skills/bundled/claudeApiContent.js'
+import { sanitizeModelName } from '../commitAttribution.js'
+import { getHardcodedTeammateModelFallback } from '../swarm/teammateModel.js'
 import { getAgentModel, getAgentModelOptions } from './agent.js'
 import { isModelAlias, isModelFamilyAlias } from './aliases.js'
-import { CLAUDE_FABLE_5_CONFIG } from './configs.js'
+import {
+  CLAUDE_FABLE_5_CONFIG,
+  CLAUDE_OPUS_4_6_CONFIG,
+  CLAUDE_OPUS_4_8_CONFIG,
+  CLAUDE_SONNET_5_CONFIG,
+} from './configs.js'
 import {
   firstPartyNameToCanonical,
   getDefaultFableModel,
   getMarketingNameForModel,
   getPublicModelDisplayName,
   parseUserSpecifiedModel,
+  renderDefaultModelSetting,
 } from './model.js'
 import { getModelStrings } from './modelStrings.js'
 import { get3PModelCapabilityOverride } from './modelSupportOverrides.js'
 
 const ENV_KEYS = [
   'ANTHROPIC_BASE_URL',
+  'ANTHROPIC_API_KEY',
   'ANTHROPIC_DEFAULT_FABLE_MODEL',
   'ANTHROPIC_DEFAULT_FABLE_MODEL_SUPPORTED_CAPABILITIES',
   'CLAUDE_CODE_DISABLE_1M_CONTEXT',
+  'CLAUDE_CODE_USE_BEDROCK',
   'CLAUDE_CODE_SUBAGENT_MODEL',
 ] as const
 
@@ -40,11 +52,25 @@ describe('Fable model configuration', () => {
   test('uses the official provider IDs', () => {
     expect(CLAUDE_FABLE_5_CONFIG).toEqual({
       firstParty: 'claude-fable-5',
-      bedrock: 'us.anthropic.claude-fable-5',
+      bedrock: 'anthropic.claude-fable-5',
       vertex: 'claude-fable-5',
       foundry: 'claude-fable-5',
       azureOpenAI: 'claude-fable-5',
     })
+    expect(CLAUDE_OPUS_4_8_CONFIG).toEqual({
+      firstParty: 'claude-opus-4-8',
+      bedrock: 'anthropic.claude-opus-4-8',
+      vertex: 'claude-opus-4-8',
+      foundry: 'claude-opus-4-8',
+      azureOpenAI: 'claude-opus-4-8',
+    })
+    expect(CLAUDE_SONNET_5_CONFIG).toEqual({
+      firstParty: 'claude-sonnet-5',
+      bedrock: 'anthropic.claude-sonnet-5',
+      vertex: 'claude-sonnet-5',
+      foundry: 'claude-sonnet-5',
+      azureOpenAI: 'claude-sonnet-5',
+    })
   })
 
   test('recognizes fable as an alias and model family', () => {
@@ -74,12 +100,63 @@ describe('Fable model configuration', () => {
     expect(getMarketingNameForModel('claude-fable-5[1m]')).toBe(
       'Fable 5 (with 1M context)',
     )
+    expect(firstPartyNameToCanonical('anthropic.claude-opus-4-8')).toBe(
+      'claude-opus-4-8',
+    )
+    expect(firstPartyNameToCanonical('claude-sonnet-5')).toBe(
+      'claude-sonnet-5',
+    )
+    expect(getPublicModelDisplayName(getModelStrings().opus48)).toBe('Opus 4.8')
+    expect(getPublicModelDisplayName(`${getModelStrings().opus48}[1m]`)).toBe(
+      'Opus 4.8 (1M context)',
+    )
+    expect(getPublicModelDisplayName(getModelStrings().sonnet50)).toBe('Sonnet 5')
+    expect(getPublicModelDisplayName(`${getModelStrings().sonnet50}[1m]`)).toBe(
+      'Sonnet 5 (1M context)',
+    )
+    expect(getMarketingNameForModel('claude-opus-4-8')).toBe('Opus 4.8')
+    expect(getMarketingNameForModel('claude-sonnet-5')).toBe('Sonnet 5')
+    expect(renderDefaultModelSetting('opusplan')).toBe(
+      'Opus 4.8 in plan mode, else Sonnet 5',
+    )
+  })
+
+  test('publishes current model IDs and knowledge cutoffs in environment context', async () => {
+    expect(SKILL_MODEL_VARS).toMatchObject({
+      OPUS_ID: 'claude-opus-4-8',
+      OPUS_NAME: 'Claude Opus 4.8',
+      SONNET_ID: 'claude-sonnet-5',
+      SONNET_NAME: 'Claude Sonnet 5',
+    })
+
+    for (const model of ['claude-fable-5', 'claude-opus-4-8', 'claude-sonnet-5']) {
+      const info = await computeSimpleEnvInfo(model)
+      expect(info).toContain('Assistant knowledge cutoff is January 2026.')
+      expect(info).toContain("Fable 5: 'claude-fable-5'")
+      expect(info).toContain("Opus 4.8: 'claude-opus-4-8'")
+      expect(info).toContain("Sonnet 5: 'claude-sonnet-5'")
+      expect(info).toContain('same Claude Opus 4.8 model')
+    }
+  })
+
+  test('sanitizes new model trailers and keeps teammate fallbacks provider-safe', () => {
+    expect(sanitizeModelName('claude-fable-5-experimental')).toBe('claude-fable-5')
+    expect(sanitizeModelName('claude-opus-4-8-experimental')).toBe('claude-opus-4-8')
+    expect(sanitizeModelName('claude-sonnet-5-experimental')).toBe('claude-sonnet-5')
+    expect(getHardcodedTeammateModelFallback()).toBe('claude-opus-4-8')
+
+    process.env.CLAUDE_CODE_USE_BEDROCK = '1'
+    expect(getHardcodedTeammateModelFallback()).toBe(
+      CLAUDE_OPUS_4_6_CONFIG.bedrock,
+    )
   })
 
   test('exposes the native 1M context window', () => {
     expect(modelSupports1M('claude-fable-5')).toBe(true)
     expect(getContextWindowForModel('claude-fable-5')).toBe(1_000_000)
     expect(getContextWindowForModel('anthropic/claude-fable-5')).toBe(1_000_000)
+    expect(getContextWindowForModel('claude-opus-4-8')).toBe(1_000_000)
+    expect(getContextWindowForModel('claude-sonnet-5')).toBe(1_000_000)
   })
 })
 

src/utils/model/model.ts

@@ -8,6 +8,7 @@
 import { getMainLoopModelOverride } from '../../bootstrap/state.js'
 import {
   getSubscriptionType,
+  is1PApiCustomer,
   isClaudeAISubscriber,
   isMaxSubscriber,
   isOpenAIAuthActive,
@@ -24,7 +25,10 @@ import { getModelStrings, resolveOverriddenModel } from './modelStrings.js'
 import { formatModelPricing, getOpus46CostTier } from '../modelCost.js'
 import { getSettings_DEPRECATED } from '../settings/settings.js'
 import type { PermissionMode } from '../permissions/PermissionMode.js'
-import { getAPIProvider } from './providers.js'
+import {
+  getAPIProvider,
+  hasAnthropicCompatibleThirdPartyConfig,
+} from './providers.js'
 import { LIGHTNING_BOLT } from '../../constants/figures.js'
 import { isModelAllowed } from './modelAllowlist.js'
 import { type ModelAlias, isModelAlias } from './aliases.js'
@@ -47,7 +51,8 @@ export function isNonCustomOpusModel(model: ModelName): boolean {
     model === getModelStrings().opus40 ||
     model === getModelStrings().opus41 ||
     model === getModelStrings().opus45 ||
-    model === getModelStrings().opus46
+    model === getModelStrings().opus46 ||
+    model === getModelStrings().opus48
   )
 }
 
@@ -103,7 +108,11 @@ export function getMainLoopModel(): ModelName {
 }
 
 export function getBestModel(): ModelName {
-  return getDefaultOpusModel()
+  return getDefaultFableModel()
+}
+
+function shouldUseThirdPartyAnthropicModelDefaults(): boolean {
+  return !isClaudeAISubscriber() && hasAnthropicCompatibleThirdPartyConfig()
 }
 
 export function getDefaultFableModel(): ModelName {
@@ -113,6 +122,9 @@ export function getDefaultFableModel(): ModelName {
   if (process.env.ANTHROPIC_DEFAULT_FABLE_MODEL) {
     return process.env.ANTHROPIC_DEFAULT_FABLE_MODEL
   }
+  if (shouldUseThirdPartyAnthropicModelDefaults()) {
+    return getDefaultOpusModel()
+  }
   return getModelStrings().fable5
 }
 
@@ -127,10 +139,10 @@ export function getDefaultOpusModel(): ModelName {
   // 3P providers (Bedrock, Vertex, Foundry) — kept as a separate branch
   // even when values match, since 3P availability lags firstParty and
   // these will diverge again at the next model launch.
-  if (getAPIProvider() !== 'firstParty') {
+  if (shouldUseThirdPartyAnthropicModelDefaults()) {
     return getModelStrings().opus46
   }
-  return getModelStrings().opus46
+  return getModelStrings().opus48
 }
 
 // @[MODEL LAUNCH]: Update the default Sonnet model (3P providers may lag so keep defaults unchanged).
@@ -142,10 +154,10 @@ export function getDefaultSonnetModel(): ModelName {
     return process.env.ANTHROPIC_DEFAULT_SONNET_MODEL
   }
   // Default to Sonnet 4.5 for 3P since they may not have 4.6 yet
-  if (getAPIProvider() !== 'firstParty') {
+  if (shouldUseThirdPartyAnthropicModelDefaults()) {
     return getModelStrings().sonnet45
   }
-  return getModelStrings().sonnet46
+  return getModelStrings().sonnet50
 }
 
 // @[MODEL LAUNCH]: Update the default Haiku model (3P providers may lag so keep defaults unchanged).
@@ -194,8 +206,9 @@ export function getRuntimeMainLoopModel(params: {
  * Get the default main loop model setting.
  *
  * This handles the built-in default:
- * - Opus for Max and Team Premium users
- * - Sonnet 4.6 for all other users (including Team Standard, Pro, Enterprise)
+ * - Opus for Anthropic API/PAYG, Max, and Team Premium users
+ * - Sonnet for Pro, Team Standard, and Enterprise subscription users
+ * - Sonnet for third-party providers, where built-in aliases may lag
  *
  * @returns The default model setting to use
  */
@@ -216,6 +229,10 @@ export function getDefaultMainLoopModelSetting(): ModelName | ModelAlias {
     return resolveOpenAICodexModel('opus')
   }
 
+  if (is1PApiCustomer()) {
+    return getDefaultOpusModel()
+  }
+
   // Max users get Opus as default
   if (isMaxSubscriber()) {
     return getDefaultOpusModel() + (isOpus1mMergeEnabled() ? '[1m]' : '')
@@ -226,8 +243,8 @@ export function getDefaultMainLoopModelSetting(): ModelName | ModelAlias {
     return getDefaultOpusModel() + (isOpus1mMergeEnabled() ? '[1m]' : '')
   }
 
-  // PAYG (1P and 3P), Enterprise, Team Standard, and Pro get Sonnet as default
-  // Note that PAYG (3P) may default to an older Sonnet model
+  // Third-party provider defaults and subscription tiers that are not
+  // Opus-defaulted above use Sonnet. Third-party provider aliases may lag.
   return getDefaultSonnetModel()
 }
 
@@ -253,6 +270,9 @@ export function firstPartyNameToCanonical(name: ModelName): ModelShortName {
   if (name.includes('claude-fable-5')) {
     return 'claude-fable-5'
   }
+  if (name.includes('claude-opus-4-8')) {
+    return 'claude-opus-4-8'
+  }
   if (name.includes('claude-opus-4-7')) {
     return 'claude-opus-4-7'
   }
@@ -265,6 +285,9 @@ export function firstPartyNameToCanonical(name: ModelName): ModelShortName {
   if (name.includes('claude-opus-4')) {
     return 'claude-opus-4'
   }
+  if (name.includes('claude-sonnet-5')) {
+    return 'claude-sonnet-5'
+  }
   if (name.includes('claude-sonnet-4-6')) {
     return 'claude-sonnet-4-6'
   }
@@ -329,18 +352,18 @@ export function getClaudeAiUserDefaultModelDescription(
   }
   if (isMaxSubscriber() || isTeamPremiumSubscriber()) {
     if (isOpus1mMergeEnabled()) {
-      return `Opus 4.7 with 1M context · Most capable for complex work${fastMode ? getOpus46PricingSuffix(true) : ''}`
+      return `Opus 4.8 with 1M context · Most capable for complex work${fastMode ? getOpus46PricingSuffix(true) : ''}`
     }
-    return `Opus 4.7 · Most capable for complex work${fastMode ? getOpus46PricingSuffix(true) : ''}`
+    return `Opus 4.8 · Most capable for complex work${fastMode ? getOpus46PricingSuffix(true) : ''}`
   }
-  return 'Sonnet 4.6 · Best for everyday tasks'
+  return 'Sonnet 5 · Best for everyday tasks'
 }
 
 export function renderDefaultModelSetting(
   setting: ModelName | ModelAlias,
 ): string {
   if (setting === 'opusplan') {
-    return 'Opus 4.7 in plan mode, else Sonnet 4.6'
+    return `${renderModelName(getDefaultOpusModel())} in plan mode, else ${renderModelName(getDefaultSonnetModel())}`
   }
   return renderModelName(parseUserSpecifiedModel(setting))
 }
@@ -397,6 +420,10 @@ export function getPublicModelDisplayName(model: ModelName): string | null {
       return 'Fable 5'
     case getModelStrings().fable5 + '[1m]':
       return 'Fable 5 (1M context)'
+    case getModelStrings().opus48:
+      return 'Opus 4.8'
+    case getModelStrings().opus48 + '[1m]':
+      return 'Opus 4.8 (1M context)'
     case getModelStrings().opus46:
       return 'Opus 4.7'
     case getModelStrings().opus46 + '[1m]':
@@ -411,6 +438,10 @@ export function getPublicModelDisplayName(model: ModelName): string | null {
       return 'Sonnet 4.6 (1M context)'
     case getModelStrings().sonnet46:
       return 'Sonnet 4.6'
+    case getModelStrings().sonnet50 + '[1m]':
+      return 'Sonnet 5 (1M context)'
+    case getModelStrings().sonnet50:
+      return 'Sonnet 5'
     case getModelStrings().sonnet45 + '[1m]':
       return 'Sonnet 4.5 (1M context)'
     case getModelStrings().sonnet45:
@@ -634,6 +665,9 @@ export function getMarketingNameForModel(modelId: string): string | undefined {
   if (canonical.includes('claude-fable-5')) {
     return has1m ? 'Fable 5 (with 1M context)' : 'Fable 5'
   }
+  if (canonical.includes('claude-opus-4-8')) {
+    return has1m ? 'Opus 4.8 (with 1M context)' : 'Opus 4.8'
+  }
   if (canonical.includes('claude-opus-4-7')) {
     return has1m ? 'Opus 4.7 (with 1M context)' : 'Opus 4.7'
   }
@@ -646,6 +680,9 @@ export function getMarketingNameForModel(modelId: string): string | undefined {
   if (canonical.includes('claude-opus-4')) {
     return 'Opus 4'
   }
+  if (canonical.includes('claude-sonnet-5')) {
+    return has1m ? 'Sonnet 5 (with 1M context)' : 'Sonnet 5'
+  }
   if (canonical.includes('claude-sonnet-4-6')) {
     return has1m ? 'Sonnet 4.6 (with 1M context)' : 'Sonnet 4.6'
   }

src/utils/model/modelContextWindows.ts

@@ -4,7 +4,9 @@ export const MODEL_CONTEXT_WINDOW_MAX = 10_000_000
 
 const DIRECT_MODEL_CONTEXT_WINDOWS: Record<string, number> = {
   'claude-fable-5': 1_000_000,
+  'claude-opus-4-8': 1_000_000,
   'claude-opus-4-7': 1_000_000,
+  'claude-sonnet-5': 1_000_000,
   'claude-sonnet-4-6': 200_000,
   'claude-haiku-4-5': 200_000,
   'deepseek-v4-pro': 1_000_000,
@@ -39,6 +41,8 @@ const DIRECT_MODEL_CONTEXT_WINDOWS: Record<string, number> = {
 
 const PATTERN_MODEL_CONTEXT_WINDOWS: Array<[RegExp, number]> = [
   [/^anthropic\/claude-fable-5\b/i, 1_000_000],
+  [/^anthropic\/claude-opus-4\.8\b/i, 1_000_000],
+  [/^anthropic\/claude-sonnet-5\b/i, 1_000_000],
   [/^anthropic\/claude-opus-4\.7\b/i, 1_000_000],
   [/^anthropic\/claude-sonnet-4\.6\b/i, 200_000],
   [/^anthropic\/claude-haiku-4\.5\b/i, 200_000],

src/utils/model/modelOptions.ts

@@ -9,6 +9,7 @@ import {
 } from '../auth.js'
 import { getModelStrings } from './modelStrings.js'
 import {
+  COST_TIER_10_50,
   COST_TIER_3_15,
   COST_HAIKU_35,
   COST_HAIKU_45,
@@ -16,11 +17,15 @@ import {
 } from '../modelCost.js'
 import { getSettings_DEPRECATED } from '../settings/settings.js'
 import { checkOpus1mAccess, checkSonnet1mAccess } from './check1mAccess.js'
-import { getAPIProvider, isFirstPartyAnthropicBaseUrl } from './providers.js'
+import {
+  getAPIProvider,
+  hasAnthropicCompatibleThirdPartyConfig,
+} from './providers.js'
 import { isModelAllowed } from './modelAllowlist.js'
 import {
   getCanonicalName,
   getClaudeAiUserDefaultModelDescription,
+  getDefaultFableModel,
   getDefaultSonnetModel,
   getDefaultOpusModel,
   getDefaultHaikuModel,
@@ -45,10 +50,6 @@ export type ModelOption = {
   descriptionForModel?: string
 }
 
-function hasAnthropicCompatibleThirdPartyConfig(): boolean {
-  return getAPIProvider() !== 'firstParty' || !isFirstPartyAnthropicBaseUrl()
-}
-
 function pushUniqueOption(
   options: ModelOption[],
   option: ModelOption | undefined,
@@ -64,6 +65,21 @@ function pushUniqueOption(
   options.push(option)
 }
 
+function shouldOfferSonnet1mOption(): boolean {
+  if (!checkSonnet1mAccess()) {
+    return false
+  }
+
+  return (
+    shouldUseThirdPartyAnthropicOptions() ||
+    !getDefaultSonnetModel().toLowerCase().includes('sonnet-5')
+  )
+}
+
+function shouldUseThirdPartyAnthropicOptions(): boolean {
+  return !isClaudeAISubscriber() && hasAnthropicCompatibleThirdPartyConfig()
+}
+
 export function getDefaultOptionForUser(fastMode = false): ModelOption {
   if (process.env.USER_TYPE === 'ant') {
     const currentModel = renderDefaultModelSetting(
@@ -99,16 +115,23 @@ export function getDefaultOptionForUser(fastMode = false): ModelOption {
   }
 
   // PAYG
-  const is3P = hasAnthropicCompatibleThirdPartyConfig()
+  const is3P = shouldUseThirdPartyAnthropicOptions()
+  const currentModel = renderDefaultModelSetting(getDefaultMainLoopModelSetting())
+  const pricingSuffix =
+    is3P
+      ? ''
+      : currentModel.includes('Opus')
+        ? getOpus46PricingSuffix(fastMode)
+        : ` · ${formatModelPricing(COST_TIER_3_15)}`
   return {
     value: null,
     label: 'Default (recommended)',
-    description: `Use the default model (currently ${renderDefaultModelSetting(getDefaultMainLoopModelSetting())})${is3P ? '' : ` · ${formatModelPricing(COST_TIER_3_15)}`}`,
+    description: `Use the default model (currently ${currentModel})${pricingSuffix}`,
   }
 }
 
 function getCustomSonnetOption(): ModelOption | undefined {
-  const is3P = hasAnthropicCompatibleThirdPartyConfig()
+  const is3P = shouldUseThirdPartyAnthropicOptions()
   const customSonnetModel = process.env.ANTHROPIC_DEFAULT_SONNET_MODEL
   // When a 3P user has a custom sonnet model string, show it directly
   if (is3P && customSonnetModel) {
@@ -127,19 +150,50 @@ function getCustomSonnetOption(): ModelOption | undefined {
 
 // @[MODEL LAUNCH]: Update or add model option functions (getSonnetXXOption, getOpusXXOption, etc.)
 // with the new model's label and description. These appear in the /model picker.
+function getCustomFableOption(): ModelOption | undefined {
+  const is3P = shouldUseThirdPartyAnthropicOptions()
+  const customFableModel = process.env.ANTHROPIC_DEFAULT_FABLE_MODEL
+  if (is3P && customFableModel) {
+    const is1m = has1mContext(customFableModel)
+    return {
+      value: 'fable',
+      label:
+        process.env.ANTHROPIC_DEFAULT_FABLE_MODEL_NAME ?? customFableModel,
+      description:
+        process.env.ANTHROPIC_DEFAULT_FABLE_MODEL_DESCRIPTION ??
+        `Custom Fable model${is1m ? ' (1M context)' : ''}`,
+      descriptionForModel: `${process.env.ANTHROPIC_DEFAULT_FABLE_MODEL_DESCRIPTION ?? `Custom Fable model${is1m ? ' with 1M context' : ''}`} (${customFableModel})`,
+    }
+  }
+}
+
+function getFable5Option(): ModelOption | undefined {
+  if (shouldUseThirdPartyAnthropicOptions()) {
+    return undefined
+  }
+  return {
+    value: 'fable',
+    label: 'Fable',
+    description: `Fable 5 · Highest capability for long-running tasks · ${formatModelPricing(COST_TIER_10_50)}`,
+    descriptionForModel:
+      'Fable 5 - highest capability for hard, long-running tasks',
+  }
+}
+
 function getSonnet46Option(): ModelOption {
-  const is3P = hasAnthropicCompatibleThirdPartyConfig()
+  const is3P = shouldUseThirdPartyAnthropicOptions()
+  const modelName = is3P ? 'Sonnet 4.6' : 'Sonnet 5'
   return {
     value: is3P ? getModelStrings().sonnet46 : 'sonnet',
     label: 'Sonnet',
-    description: `Sonnet 4.6 · Best for everyday tasks${is3P ? '' : ` · ${formatModelPricing(COST_TIER_3_15)}`}`,
+    description: `${modelName} · Best for everyday tasks${is3P ? '' : ` · ${formatModelPricing(COST_TIER_3_15)}`}`,
     descriptionForModel:
-      'Sonnet 4.6 - best for everyday tasks. Generally recommended for most coding tasks',
+      `${modelName} - best for everyday tasks. Generally recommended for most coding tasks`,
   }
 }
 
 function getCustomOpusOption(): ModelOption | undefined {
-  const is3P = hasAnthropicCompatibleThirdPartyConfig()
+  const is3P = shouldUseThirdPartyAnthropicOptions()
   const customOpusModel = process.env.ANTHROPIC_DEFAULT_OPUS_MODEL
   // When a 3P user has a custom opus model string, show it directly
   if (is3P && customOpusModel) {
@@ -165,39 +219,41 @@ function getOpus41Option(): ModelOption {
 }
 
 function getOpus46Option(fastMode = false): ModelOption {
-  const is3P = getAPIProvider() !== 'firstParty'
+  const is3P = shouldUseThirdPartyAnthropicOptions()
   return {
     value: is3P ? getModelStrings().opus46 : 'opus',
     label: 'Opus',
-    description: `Opus 4.7 · Most capable for complex work${getOpus46PricingSuffix(fastMode)}`,
-    descriptionForModel: 'Opus 4.7 - most capable for complex work',
+    description: `${is3P ? 'Opus 4.7' : 'Opus 4.8'} · Most capable for complex work${getOpus46PricingSuffix(fastMode)}`,
+    descriptionForModel: `${is3P ? 'Opus 4.7' : 'Opus 4.8'} - most capable for complex work`,
   }
 }
 
 export function getSonnet46_1MOption(): ModelOption {
-  const is3P = hasAnthropicCompatibleThirdPartyConfig()
+  const is3P = shouldUseThirdPartyAnthropicOptions()
+  const modelName = is3P ? 'Sonnet 4.6' : 'Sonnet 5'
   return {
     value: is3P ? getModelStrings().sonnet46 + '[1m]' : 'sonnet[1m]',
     label: 'Sonnet (1M context)',
-    description: `Sonnet 4.6 for long sessions${is3P ? '' : ` · ${formatModelPricing(COST_TIER_3_15)}`}`,
+    description: `${modelName} for long sessions${is3P ? '' : ` · ${formatModelPricing(COST_TIER_3_15)}`}`,
     descriptionForModel:
-      'Sonnet 4.6 with 1M context window - for long sessions with large codebases',
+      `${modelName} with 1M context window - for long sessions with large codebases`,
   }
 }
 
 export function getOpus46_1MOption(fastMode = false): ModelOption {
-  const is3P = hasAnthropicCompatibleThirdPartyConfig()
+  const is3P = shouldUseThirdPartyAnthropicOptions()
+  const modelName = is3P ? 'Opus 4.7' : 'Opus 4.8'
   return {
     value: is3P ? getModelStrings().opus46 + '[1m]' : 'opus[1m]',
     label: 'Opus (1M context)',
-    description: `Opus 4.7 for long sessions${getOpus46PricingSuffix(fastMode)}`,
+    description: `${modelName} for long sessions${getOpus46PricingSuffix(fastMode)}`,
     descriptionForModel:
-      'Opus 4.7 with 1M context window - for long sessions with large codebases',
+      `${modelName} with 1M context window - for long sessions with large codebases`,
   }
 }
 
 function getCustomHaikuOption(): ModelOption | undefined {
-  const is3P = hasAnthropicCompatibleThirdPartyConfig()
+  const is3P = shouldUseThirdPartyAnthropicOptions()
   const customHaikuModel = process.env.ANTHROPIC_DEFAULT_HAIKU_MODEL
   // When a 3P user has a custom haiku model string, show it directly
   if (is3P && customHaikuModel) {
@@ -213,7 +269,7 @@ function getCustomHaikuOption(): ModelOption | undefined {
 }
 
 function getHaiku45Option(): ModelOption {
-  const is3P = hasAnthropicCompatibleThirdPartyConfig()
+  const is3P = shouldUseThirdPartyAnthropicOptions()
   return {
     value: 'haiku',
     label: 'Haiku',
@@ -224,7 +280,7 @@ function getHaiku45Option(): ModelOption {
 }
 
 function getHaiku35Option(): ModelOption {
-  const is3P = getAPIProvider() !== 'firstParty'
+  const is3P = shouldUseThirdPartyAnthropicOptions()
   return {
     value: 'haiku',
     label: 'Haiku',
@@ -246,17 +302,17 @@ function getMaxOpusOption(fastMode = false): ModelOption {
   return {
     value: 'opus',
     label: 'Opus',
-    description: `Opus 4.7 · Most capable for complex work${fastMode ? getOpus46PricingSuffix(true) : ''}`,
+    description: `Opus 4.8 · Most capable for complex work${fastMode ? getOpus46PricingSuffix(true) : ''}`,
   }
 }
 
 export function getMaxSonnet46_1MOption(): ModelOption {
-  const is3P = hasAnthropicCompatibleThirdPartyConfig()
+  const is3P = shouldUseThirdPartyAnthropicOptions()
   const billingInfo = isClaudeAISubscriber() ? ' · Billed as extra usage' : ''
   return {
     value: 'sonnet[1m]',
     label: 'Sonnet (1M context)',
-    description: `Sonnet 4.6 with 1M context${billingInfo}${is3P ? '' : ` · ${formatModelPricing(COST_TIER_3_15)}`}`,
+    description: `Sonnet 5 with 1M context${billingInfo}${is3P ? '' : ` · ${formatModelPricing(COST_TIER_3_15)}`}`,
   }
 }
 
@@ -265,25 +321,25 @@ export function getMaxOpus46_1MOption(fastMode = false): ModelOption {
   return {
     value: 'opus[1m]',
     label: 'Opus (1M context)',
-    description: `Opus 4.7 with 1M context${billingInfo}${getOpus46PricingSuffix(fastMode)}`,
+    description: `Opus 4.8 with 1M context${billingInfo}${getOpus46PricingSuffix(fastMode)}`,
   }
 }
 
 function getMergedOpus1MOption(fastMode = false): ModelOption {
-  const is3P = hasAnthropicCompatibleThirdPartyConfig()
+  const is3P = shouldUseThirdPartyAnthropicOptions()
   return {
     value: is3P ? getModelStrings().opus46 + '[1m]' : 'opus[1m]',
     label: 'Opus (1M context)',
-    description: `Opus 4.7 with 1M context · Most capable for complex work${!is3P && fastMode ? getOpus46PricingSuffix(fastMode) : ''}`,
+    description: `${is3P ? 'Opus 4.7' : 'Opus 4.8'} with 1M context · Most capable for complex work${!is3P && fastMode ? getOpus46PricingSuffix(fastMode) : ''}`,
     descriptionForModel:
-      'Opus 4.7 with 1M context - most capable for complex work',
+      `${is3P ? 'Opus 4.7' : 'Opus 4.8'} with 1M context - most capable for complex work`,
   }
 }
 
 const MaxSonnet46Option: ModelOption = {
   value: 'sonnet',
   label: 'Sonnet',
-  description: 'Sonnet 4.6 · Best for everyday tasks',
+  description: 'Sonnet 5 · Best for everyday tasks',
 }
 
 const MaxHaiku45Option: ModelOption = {
@@ -296,7 +352,7 @@ function getOpusPlanOption(): ModelOption {
   return {
     value: 'opusplan',
     label: 'Opus Plan Mode',
-    description: 'Use Opus 4.7 in plan mode, Sonnet 4.6 otherwise',
+    description: 'Use Opus in plan mode, Sonnet otherwise',
   }
 }
 
@@ -340,11 +396,12 @@ function getOpenAIModelOptions(): ModelOption[] {
     })),
   ]
 
-  if (!hasAnthropicCompatibleThirdPartyConfig()) {
+  if (!shouldUseThirdPartyAnthropicOptions()) {
     return options
   }
 
   pushUniqueOption(options, getCustomSonnetOption())
+  pushUniqueOption(options, getCustomFableOption())
   pushUniqueOption(options, getCustomOpusOption())
   pushUniqueOption(options, getCustomHaikuOption())
 
@@ -365,8 +422,10 @@ function getModelOptionsBase(fastMode = false): ModelOption[] {
       description: m.description ?? `[ANT-ONLY] ${m.label} (${m.model})`,
     }))
 
+    const fableOption = getFable5Option()
     return [
       getDefaultOptionForUser(),
+      ...(fableOption ? [fableOption] : []),
       ...antModelOptions,
       getMergedOpus1MOption(fastMode),
       getSonnet46Option(),
@@ -383,12 +442,13 @@ function getModelOptionsBase(fastMode = false): ModelOption[] {
     if (isMaxSubscriber() || isTeamPremiumSubscriber()) {
       // Max and Team Premium users: Opus is default, show Sonnet as alternative
       const premiumOptions = [getDefaultOptionForUser(fastMode)]
+      pushUniqueOption(premiumOptions, getFable5Option())
       if (!isOpus1mMergeEnabled() && checkOpus1mAccess()) {
         premiumOptions.push(getMaxOpus46_1MOption(fastMode))
       }
 
       premiumOptions.push(MaxSonnet46Option)
-      if (checkSonnet1mAccess()) {
+      if (shouldOfferSonnet1mOption()) {
         premiumOptions.push(getMaxSonnet46_1MOption())
       }
 
@@ -398,7 +458,8 @@ function getModelOptionsBase(fastMode = false): ModelOption[] {
 
     // Pro/Team Standard/Enterprise users: Sonnet is default, show Opus as alternative
     const standardOptions = [getDefaultOptionForUser(fastMode)]
-    if (checkSonnet1mAccess()) {
+    pushUniqueOption(standardOptions, getFable5Option())
+    if (shouldOfferSonnet1mOption()) {
       standardOptions.push(getMaxSonnet46_1MOption())
     }
 
@@ -415,34 +476,31 @@ function getModelOptionsBase(fastMode = false): ModelOption[] {
     return standardOptions
   }
 
-  // PAYG 1P API: Default (Sonnet) + Sonnet 1M + Opus 4.7 + Opus 1M + Haiku
-  if (!hasAnthropicCompatibleThirdPartyConfig()) {
+  // PAYG 1P API: Default (Opus 4.8) + Fable + Sonnet + Haiku.
+  // Opus 4.8 and Sonnet 5 already have native 1M context windows.
+  if (!shouldUseThirdPartyAnthropicOptions()) {
     const payg1POptions = [getDefaultOptionForUser(fastMode)]
-    if (checkSonnet1mAccess()) {
+    pushUniqueOption(payg1POptions, getFable5Option())
+    payg1POptions.push(getSonnet46Option())
+    if (shouldOfferSonnet1mOption()) {
       payg1POptions.push(getSonnet46_1MOption())
     }
-    if (isOpus1mMergeEnabled()) {
-      payg1POptions.push(getMergedOpus1MOption(fastMode))
-    } else {
-      payg1POptions.push(getOpus46Option(fastMode))
-      if (checkOpus1mAccess()) {
-        payg1POptions.push(getOpus46_1MOption(fastMode))
-      }
-    }
     payg1POptions.push(getHaiku45Option())
     return payg1POptions
   }
 
-  // PAYG 3P: Default (Sonnet 4.5) + Sonnet (3P custom) or Sonnet 4.6/1M + Opus (3P custom) or Opus 4.1/Opus 4.7/Opus1M + Haiku + Opus 4.1
+  // PAYG 3P: Default (Sonnet 4.5) + optional custom Fable + Sonnet + Opus + Haiku
   const payg3pOptions = [getDefaultOptionForUser(fastMode)]
 
+  pushUniqueOption(payg3pOptions, getCustomFableOption())
+
   const customSonnet = getCustomSonnetOption()
   if (customSonnet !== undefined) {
     pushUniqueOption(payg3pOptions, customSonnet)
   } else {
-    // Add Sonnet 4.6 since Sonnet 4.5 is the default
+    // Add Sonnet 4.6 since Sonnet 4.5 is the third-party default
     payg3pOptions.push(getSonnet46Option())
-    if (checkSonnet1mAccess()) {
+    if (shouldOfferSonnet1mOption()) {
       payg3pOptions.push(getSonnet46_1MOption())
     }
   }
@@ -479,8 +537,17 @@ function getModelFamilyInfo(
 ): { alias: string; currentVersionName: string } | null {
   const canonical = getCanonicalName(model)
 
+  // Fable family
+  if (canonical.includes('claude-fable-5')) {
+    const currentName = getMarketingNameForModel(getDefaultFableModel())
+    if (currentName) {
+      return { alias: 'Fable', currentVersionName: currentName }
+    }
+  }
+
   // Sonnet family
   if (
+    canonical.includes('claude-sonnet-5') ||
     canonical.includes('claude-sonnet-4-6') ||
     canonical.includes('claude-sonnet-4-5') ||
     canonical.includes('claude-sonnet-4-') ||

src/utils/model/providers.ts

@@ -45,3 +45,7 @@ export function isFirstPartyAnthropicBaseUrl(): boolean {
     return false
   }
 }
+
+export function hasAnthropicCompatibleThirdPartyConfig(): boolean {
+  return getAPIProvider() !== 'firstParty' || !isFirstPartyAnthropicBaseUrl()
+}

src/utils/modelCost.ts

@@ -7,14 +7,17 @@ import {
   CLAUDE_3_5_HAIKU_CONFIG,
   CLAUDE_3_5_V2_SONNET_CONFIG,
   CLAUDE_3_7_SONNET_CONFIG,
+  CLAUDE_FABLE_5_CONFIG,
   CLAUDE_HAIKU_4_5_CONFIG,
   CLAUDE_OPUS_4_1_CONFIG,
   CLAUDE_OPUS_4_5_CONFIG,
   CLAUDE_OPUS_4_6_CONFIG,
+  CLAUDE_OPUS_4_8_CONFIG,
   CLAUDE_OPUS_4_CONFIG,
   CLAUDE_SONNET_4_5_CONFIG,
   CLAUDE_SONNET_4_6_CONFIG,
   CLAUDE_SONNET_4_CONFIG,
+  CLAUDE_SONNET_5_CONFIG,
 } from './model/configs.js'
 import {
   firstPartyNameToCanonical,
@@ -59,6 +62,15 @@ export const COST_TIER_5_25 = {
   webSearchRequests: 0.01,
 } as const satisfies ModelCosts
 
+// Pricing tier for Fable 5: $10 input / $50 output per Mtok
+export const COST_TIER_10_50 = {
+  inputTokens: 10,
+  outputTokens: 50,
+  promptCacheWriteTokens: 12.5,
+  promptCacheReadTokens: 1,
+  webSearchRequests: 0.01,
+} as const satisfies ModelCosts
+
 // Fast mode pricing for Opus 4.7: $30 input / $150 output per Mtok
 export const COST_TIER_30_150 = {
   inputTokens: 30,
@@ -102,6 +114,8 @@ export function getOpus46CostTier(fastMode: boolean): ModelCosts {
 // Costs from https://platform.claude.com/docs/en/about-claude/pricing
 // Web search cost: $10 per 1000 requests = $0.01 per request
 export const MODEL_COSTS: Record<ModelShortName, ModelCosts> = {
+  [firstPartyNameToCanonical(CLAUDE_FABLE_5_CONFIG.firstParty)]:
+    COST_TIER_10_50,
   [firstPartyNameToCanonical(CLAUDE_3_5_HAIKU_CONFIG.firstParty)]:
     COST_HAIKU_35,
   [firstPartyNameToCanonical(CLAUDE_HAIKU_4_5_CONFIG.firstParty)]:
@@ -116,6 +130,8 @@ export const MODEL_COSTS: Record<ModelShortName, ModelCosts> = {
     COST_TIER_3_15,
   [firstPartyNameToCanonical(CLAUDE_SONNET_4_6_CONFIG.firstParty)]:
     COST_TIER_3_15,
+  [firstPartyNameToCanonical(CLAUDE_SONNET_5_CONFIG.firstParty)]:
+    COST_TIER_3_15,
   [firstPartyNameToCanonical(CLAUDE_OPUS_4_CONFIG.firstParty)]: COST_TIER_15_75,
   [firstPartyNameToCanonical(CLAUDE_OPUS_4_1_CONFIG.firstParty)]:
     COST_TIER_15_75,
@@ -123,6 +139,8 @@ export const MODEL_COSTS: Record<ModelShortName, ModelCosts> = {
     COST_TIER_5_25,
   [firstPartyNameToCanonical(CLAUDE_OPUS_4_6_CONFIG.firstParty)]:
     COST_TIER_5_25,
+  [firstPartyNameToCanonical(CLAUDE_OPUS_4_8_CONFIG.firstParty)]:
+    COST_TIER_5_25,
 }
 
 /**

src/utils/providerManagedEnvCompat.ts

@@ -1,6 +1,7 @@
 const DEEPSEEK_THINKING_CAPABILITIES = 'thinking,effort,adaptive_thinking,max_effort'
 
 const DEEPSEEK_CAPABILITY_ENV_KEYS = [
+  'ANTHROPIC_DEFAULT_FABLE_MODEL_SUPPORTED_CAPABILITIES',
   'ANTHROPIC_DEFAULT_HAIKU_MODEL_SUPPORTED_CAPABILITIES',
   'ANTHROPIC_DEFAULT_SONNET_MODEL_SUPPORTED_CAPABILITIES',
   'ANTHROPIC_DEFAULT_OPUS_MODEL_SUPPORTED_CAPABILITIES',
@@ -10,6 +11,7 @@ function looksLikeDeepSeekManagedEnv(env: Record<string, string>): boolean {
   const baseUrl = env.ANTHROPIC_BASE_URL ?? ''
   const modelIds = [
     env.ANTHROPIC_MODEL,
+    env.ANTHROPIC_DEFAULT_FABLE_MODEL,
     env.ANTHROPIC_DEFAULT_HAIKU_MODEL,
     env.ANTHROPIC_DEFAULT_SONNET_MODEL,
     env.ANTHROPIC_DEFAULT_OPUS_MODEL,

src/utils/swarm/teammateModel.ts

@@ -1,10 +1,13 @@
-import { CLAUDE_OPUS_4_6_CONFIG } from '../model/configs.js'
+import { CLAUDE_OPUS_4_6_CONFIG, CLAUDE_OPUS_4_8_CONFIG } from '../model/configs.js'
 import { getAPIProvider } from '../model/providers.js'
 
 // @[MODEL LAUNCH]: Update the fallback model below.
 // When the user has never set teammateDefaultModel in /config, new teammates
-// use Opus 4.7. Must be provider-aware so Bedrock/Vertex/Foundry customers get
-// the correct model ID.
+// use the current Opus default. Must be provider-aware so Bedrock/Vertex/Foundry
+// customers get a conservative provider ID.
 export function getHardcodedTeammateModelFallback(): string {
-  return CLAUDE_OPUS_4_6_CONFIG[getAPIProvider()]
+  const provider = getAPIProvider()
+  return provider === 'firstParty'
+    ? CLAUDE_OPUS_4_8_CONFIG.firstParty
+    : CLAUDE_OPUS_4_6_CONFIG[provider]
 }

src/utils/thinking.ts

@@ -161,8 +161,14 @@ export function modelSupportsAdaptiveThinking(model: string): boolean {
     return false
   }
 
-  // Supported by a subset of Claude 4 models
-  if (canonical.includes('opus-4-6') || canonical.includes('sonnet-4-6')) {
+  // Supported by current Claude Code flagship models.
+  if (
+    canonical.includes('sonnet-5') ||
+    canonical.includes('opus-4-8') ||
+    canonical.includes('opus-4-7') ||
+    canonical.includes('opus-4-6') ||
+    canonical.includes('sonnet-4-6')
+  ) {
     return true
   }
   // Exclude any other known legacy models (allowlist above catches 4-6 variants first)