diff --git a/src/setup.ts b/src/setup.ts
index cd9c116c..df31c82a 100644
--- a/src/setup.ts
+++ b/src/setup.ts
@@ -6,7 +6,6 @@ import {
   type AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
   logEvent,
 } from 'src/services/analytics/index.js'
-import { isAntEmployee } from 'src/utils/buildConfig.js'
 import { getCwd } from 'src/utils/cwd.js'
 import { checkForReleaseNotes } from 'src/utils/releaseNotes.js'
 import { setCwd } from 'src/utils/Shell.js'
@@ -335,19 +334,6 @@ export async function setup(
   // overhead. NOT an early-return: the --dangerously-skip-permissions safety
   // gate, tengu_started beacon, and apiKeyHelper prefetch below must still run.
   if (!isBareMode()) {
-    if (isAntEmployee()) {
-      // Prime repo classification cache for auto-undercover mode. Default is
-      // undercover ON until proven internal; if this resolves to internal, clear
-      // the prompt cache so the next turn picks up the OFF state.
-      void import('./utils/commitAttribution.js').then(async m => {
-        if (await m.isInternalModelRepo()) {
-          const { clearSystemPromptSections } = await import(
-            './constants/systemPromptSections.js'
-          )
-          clearSystemPromptSections()
-        }
-      })
-    }
     if (feature('COMMIT_ATTRIBUTION')) {
       // Dynamic import to enable dead code elimination (module contains excluded strings).
       // Defer to next tick so the git subprocess spawn runs after first render
@@ -414,32 +400,6 @@ export async function setup(
       process.exit(1)
     }
 
-    if (
-      isAntEmployee() &&
-      // Skip for Desktop's local agent mode — same trust model as CCR/BYOC
-      // (trusted Anthropic-managed launcher intentionally pre-approving everything).
-      // Precedent: permissionSetup.ts:861, applySettingsChange.ts:55 (PR #19116)
-      process.env.CLAUDE_CODE_ENTRYPOINT !== 'local-agent' &&
-      // Same for CCD (Claude Code in Desktop) — apps#29127 passes the flag
-      // unconditionally to unlock mid-session bypass switching
-      process.env.CLAUDE_CODE_ENTRYPOINT !== 'claude-desktop'
-    ) {
-      // Only await if permission mode is set to bypass
-      const [isDocker, hasInternet] = await Promise.all([
-        envDynamic.getIsDocker(),
-        env.hasInternetAccess(),
-      ])
-      const isBubblewrap = envDynamic.getIsBubblewrapSandbox()
-      const isSandbox = process.env.IS_SANDBOX === '1'
-      const isSandboxed = isDocker || isBubblewrap || isSandbox
-      if (!isSandboxed || hasInternet) {
-        // biome-ignore lint/suspicious/noConsole:: intentional console output
-        console.error(
-          `--dangerously-skip-permissions can only be used in Docker/sandbox containers with no internet access but got Docker: ${isDocker}, Bubblewrap: ${isBubblewrap}, IS_SANDBOX: ${isSandbox}, hasInternet: ${hasInternet}`,
-        )
-        process.exit(1)
-      }
-    }
   }
 
   if (process.env.NODE_ENV === 'test') {
diff --git a/src/utils/fastMode.test.ts b/src/utils/fastMode.test.ts
new file mode 100644
index 00000000..e7d3130a
--- /dev/null
+++ b/src/utils/fastMode.test.ts
@@ -0,0 +1,162 @@
+import { afterEach, describe, expect, mock, test } from 'bun:test'
+
+const originalEnv = { ...process.env }
+
+async function importFreshFastModeModule() {
+  return import(`./fastMode.ts?ts=${Date.now()}-${Math.random()}`)
+}
+
+function installCommonMocks(options?: {
+  cachedEnabled?: boolean
+  apiKey?: string | null
+  oauthToken?: string | null
+  hasProfileScope?: boolean
+  axiosReject?: boolean
+}) {
+  mock.module('axios', () => ({
+    default: {
+      get: options?.axiosReject
+        ? async () => {
+            throw new Error('network fail')
+          }
+        : async () => ({ data: { enabled: false, disabled_reason: 'preference' } }),
+      isAxiosError: () => false,
+    },
+  }))
+
+  mock.module('src/constants/oauth.js', () => ({
+    getOauthConfig: () => ({ BASE_API_URL: 'https://api.anthropic.com' }),
+    OAUTH_BETA_HEADER: 'test-beta',
+  }))
+
+  mock.module('src/services/analytics/growthbook.js', () => ({
+    getFeatureValue_CACHED_MAY_BE_STALE: (_name: string, defaultValue: unknown) =>
+      defaultValue,
+  }))
+
+  mock.module('../bootstrap/state.js', () => ({
+    getIsNonInteractiveSession: () => false,
+    getKairosActive: () => false,
+    preferThirdPartyAuthentication: () => false,
+  }))
+
+  mock.module('../services/analytics/index.js', () => ({
+    logEvent: () => {},
+  }))
+
+  mock.module('./auth.js', () => ({
+    getAnthropicApiKey: () => options?.apiKey ?? null,
+    getClaudeAIOAuthTokens: () =>
+      options?.oauthToken ? { accessToken: options.oauthToken } : null,
+    handleOAuth401Error: async () => {},
+    hasProfileScope: () => options?.hasProfileScope ?? false,
+  }))
+
+  mock.module('./bundledMode.js', () => ({
+    isInBundledMode: () => true,
+  }))
+
+  mock.module('./config.js', () => ({
+    getGlobalConfig: () => ({
+      penguinModeOrgEnabled: options?.cachedEnabled === true,
+    }),
+    saveGlobalConfig: (updater: (current: Record<string, unknown>) => Record<string, unknown>) =>
+      updater({ penguinModeOrgEnabled: options?.cachedEnabled === true }),
+  }))
+
+  mock.module('./debug.js', () => ({
+    logForDebugging: () => {},
+  }))
+
+  mock.module('./envUtils.js', () => ({
+    isEnvTruthy: (value: string | undefined) =>
+      !!value && value !== '0' && value.toLowerCase() !== 'false',
+  }))
+
+  mock.module('./model/model.js', () => ({
+    getDefaultMainLoopModelSetting: () => 'claude-sonnet-4-6',
+    isOpus1mMergeEnabled: () => false,
+    parseUserSpecifiedModel: (model: string) => model,
+  }))
+
+  mock.module('./model/providers.js', () => ({
+    getAPIProvider: () => 'firstParty',
+  }))
+
+  mock.module('./privacyLevel.js', () => ({
+    isEssentialTrafficOnly: () => false,
+  }))
+
+  mock.module('./settings/settings.js', () => ({
+    getInitialSettings: () => ({ fastMode: true }),
+    getSettingsForSource: () => ({}),
+    updateSettingsForSource: () => {},
+  }))
+
+  mock.module('./signal.js', () => ({
+    createSignal: () => {
+      const subscribe = () => () => {}
+      const emit = () => {}
+      return { subscribe, emit }
+    },
+  }))
+}
+
+afterEach(() => {
+  mock.restore()
+  process.env = { ...originalEnv }
+})
+
+describe('fastMode ant-only fallback cleanup', () => {
+  test('resolveFastModeStatusFromCache does not force-enable from USER_TYPE=ant', async () => {
+    process.env.USER_TYPE = 'ant'
+    installCommonMocks({ cachedEnabled: false })
+
+    const {
+      resolveFastModeStatusFromCache,
+      getFastModeUnavailableReason,
+    } = await importFreshFastModeModule()
+
+    resolveFastModeStatusFromCache()
+
+    expect(getFastModeUnavailableReason()).toBe(
+      'Fast mode is currently unavailable',
+    )
+  })
+
+  test('prefetchFastModeStatus without auth does not force-enable from USER_TYPE=ant', async () => {
+    process.env.USER_TYPE = 'ant'
+    installCommonMocks({ cachedEnabled: false, apiKey: null, oauthToken: null })
+
+    const {
+      prefetchFastModeStatus,
+      getFastModeUnavailableReason,
+    } = await importFreshFastModeModule()
+
+    await prefetchFastModeStatus()
+
+    expect(getFastModeUnavailableReason()).toBe(
+      'Fast mode has been disabled by your organization',
+    )
+  })
+
+  test('prefetchFastModeStatus network failure does not force-enable from USER_TYPE=ant', async () => {
+    process.env.USER_TYPE = 'ant'
+    installCommonMocks({
+      cachedEnabled: false,
+      apiKey: 'test-key',
+      axiosReject: true,
+    })
+
+    const {
+      prefetchFastModeStatus,
+      getFastModeUnavailableReason,
+    } = await importFreshFastModeModule()
+
+    await prefetchFastModeStatus()
+
+    expect(getFastModeUnavailableReason()).toBe(
+      'Fast mode unavailable due to network connectivity issues',
+    )
+  })
+})
diff --git a/src/utils/fastMode.ts b/src/utils/fastMode.ts
index a0b2d1a7..33bba143 100644
--- a/src/utils/fastMode.ts
+++ b/src/utils/fastMode.ts
@@ -396,10 +396,9 @@ export function resolveFastModeStatusFromCache(): void {
   if (orgStatus.status !== 'pending') {
     return
   }
-  const isAnt = process.env.USER_TYPE === 'ant'
   const cachedEnabled = getGlobalConfig().penguinModeOrgEnabled === true
   orgStatus =
-    isAnt || cachedEnabled
+    cachedEnabled
       ? { status: 'enabled' }
       : { status: 'disabled', reason: 'unknown' }
 }
@@ -428,10 +427,9 @@ export async function prefetchFastModeStatus(): Promise<void> {
   const hasUsableOAuth =
     getClaudeAIOAuthTokens()?.accessToken && hasProfileScope()
   if (!hasUsableOAuth && !apiKey) {
-    const isAnt = process.env.USER_TYPE === 'ant'
     const cachedEnabled = getGlobalConfig().penguinModeOrgEnabled === true
     orgStatus =
-      isAnt || cachedEnabled
+      cachedEnabled
         ? { status: 'enabled' }
         : { status: 'disabled', reason: 'preference' }
     return
@@ -511,10 +509,9 @@ export async function prefetchFastModeStatus(): Promise<void> {
       // On failure: ants default to enabled (don't block internal users).
       // External users: fall back to the cached penguinModeOrgEnabled value;
       // if no positive cache, disable with network_error reason.
-      const isAnt = process.env.USER_TYPE === 'ant'
       const cachedEnabled = getGlobalConfig().penguinModeOrgEnabled === true
       orgStatus =
-        isAnt || cachedEnabled
+        cachedEnabled
           ? { status: 'enabled' }
           : { status: 'disabled', reason: 'network_error' }
       logForDebugging(