diff --git a/README.md b/README.md
index fb7e1f84..b5192abd 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@
 
 OpenClaude is an open-source coding-agent CLI for cloud and local model providers.
 
-Use OpenAI-compatible APIs, Gemini, GitHub Models, Codex, Ollama, Atomic Chat, and other supported backends while keeping one terminal-first workflow: prompts, tools, agents, MCP, slash commands, and streaming output.
+Use OpenAI-compatible APIs, Gemini, GitHub Models, Codex OAuth, Codex, Ollama, Atomic Chat, and other supported backends while keeping one terminal-first workflow: prompts, tools, agents, MCP, slash commands, and streaming output.
 
 [![PR Checks](https://github.com/Gitlawb/openclaude/actions/workflows/pr-checks.yml/badge.svg?branch=main)](https://github.com/Gitlawb/openclaude/actions/workflows/pr-checks.yml)
 [![Release](https://img.shields.io/github/v/tag/Gitlawb/openclaude?label=release&color=0ea5e9)](https://github.com/Gitlawb/openclaude/tags)
@@ -16,7 +16,7 @@ Use OpenAI-compatible APIs, Gemini, GitHub Models, Codex, Ollama, Atomic Chat, a
 
 - Use one CLI across cloud APIs and local model backends
 - Save provider profiles inside the app with `/provider`
-- Run with OpenAI-compatible services, Gemini, GitHub Models, Codex, Ollama, Atomic Chat, and other supported providers
+- Run with OpenAI-compatible services, Gemini, GitHub Models, Codex OAuth, Codex, Ollama, Atomic Chat, and other supported providers
 - Keep coding-agent workflows in one place: bash, file tools, grep, glob, agents, tasks, MCP, and web tools
 - Use the bundled VS Code extension for launch integration and theme support
 
@@ -105,7 +105,8 @@ Advanced and source-build guides:
 | OpenAI-compatible | `/provider` or env vars | Works with OpenAI, OpenRouter, DeepSeek, Groq, Mistral, LM Studio, and other compatible `/v1` servers |
 | Gemini | `/provider` or env vars | Supports API key, access token, or local ADC workflow on current `main` |
 | GitHub Models | `/onboard-github` | Interactive onboarding with saved credentials |
-| Codex | `/provider` | Uses existing Codex credentials when available |
+| Codex OAuth | `/provider` | Opens ChatGPT sign-in in your browser and stores Codex credentials securely |
+| Codex | `/provider` | Uses existing Codex CLI auth, OpenClaude secure storage, or env credentials |
 | Ollama | `/provider` or env vars | Local inference with no API key |
 | Atomic Chat | advanced setup | Local Apple Silicon backend |
 | Bedrock / Vertex / Foundry | env vars | Additional provider integrations for supported environments |
diff --git a/docs/advanced-setup.md b/docs/advanced-setup.md
index 92fac618..75c401ee 100644
--- a/docs/advanced-setup.md
+++ b/docs/advanced-setup.md
@@ -48,6 +48,8 @@ export OPENAI_MODEL=gpt-4o
 `codexplan` maps to GPT-5.4 on the Codex backend with high reasoning.
 `codexspark` maps to GPT-5.3 Codex Spark for faster loops.
 
+If you use the in-app provider wizard, choose `Codex OAuth` to open ChatGPT sign-in in your browser and let OpenClaude store Codex credentials securely.
+
 If you already use the Codex CLI, OpenClaude reads `~/.codex/auth.json` automatically. You can also point it elsewhere with `CODEX_AUTH_JSON_PATH` or override the token directly with `CODEX_API_KEY`.
 
 ```bash
diff --git a/src/commands/provider/provider.test.tsx b/src/commands/provider/provider.test.tsx
index 6597fada..9c9461d7 100644
--- a/src/commands/provider/provider.test.tsx
+++ b/src/commands/provider/provider.test.tsx
@@ -1,20 +1,28 @@
 import { PassThrough } from 'node:stream'
 
-import { expect, test } from 'bun:test'
+import { afterEach, expect, mock, test } from 'bun:test'
 import React from 'react'
 import stripAnsi from 'strip-ansi'
 
 import { createRoot, render, useApp } from '../../ink.js'
 import { AppStateProvider } from '../../state/AppState.js'
 import {
+  applySavedProfileToCurrentSession,
+  buildCodexOAuthProfileEnv,
   buildCurrentProviderSummary,
   buildProfileSaveMessage,
   getProviderWizardDefaults,
+  ProviderWizard,
   TextEntryDialog,
 } from './provider.js'
+import { createProfileFile } from '../../utils/providerProfile.js'
 
 const SYNC_START = '\x1B[?2026h'
 const SYNC_END = '\x1B[?2026l'
+const ORIGINAL_SIMPLE_ENV = process.env.CLAUDE_CODE_SIMPLE
+const ORIGINAL_CODEX_API_KEY = process.env.CODEX_API_KEY
+const ORIGINAL_CHATGPT_ACCOUNT_ID = process.env.CHATGPT_ACCOUNT_ID
+const ORIGINAL_CODEX_ACCOUNT_ID = process.env.CODEX_ACCOUNT_ID
 
 function extractLastFrame(output: string): string {
   let lastFrame: string | null = null
@@ -60,6 +68,51 @@ async function renderFinalFrame(node: React.ReactNode): Promise<string> {
   return stripAnsi(extractLastFrame(getOutput()))
 }
 
+async function waitForOutput(
+  getOutput: () => string,
+  predicate: (output: string) => boolean,
+  timeoutMs = 2500,
+): Promise<string> {
+  const startedAt = Date.now()
+
+  while (Date.now() - startedAt < timeoutMs) {
+    const output = stripAnsi(extractLastFrame(getOutput()))
+    if (predicate(output)) {
+      return output
+    }
+    await Bun.sleep(10)
+  }
+
+  throw new Error('Timed out waiting for ProviderWizard test output')
+}
+
+async function renderProviderWizardFrame(): Promise<string> {
+  const { stdout, stdin, getOutput } = createTestStreams()
+  const root = await createRoot({
+    stdout: stdout as unknown as NodeJS.WriteStream,
+    stdin: stdin as unknown as NodeJS.ReadStream,
+    patchConsole: false,
+  })
+
+  root.render(
+    <AppStateProvider>
+      <ProviderWizard onDone={() => {}} />
+    </AppStateProvider>,
+  )
+
+  try {
+    return await waitForOutput(
+      getOutput,
+      output => output.includes('Set up a provider profile'),
+    )
+  } finally {
+    root.unmount()
+    stdin.end()
+    stdout.end()
+    await Bun.sleep(0)
+  }
+}
+
 function createTestStreams(): {
   stdout: PassThrough
   stdin: PassThrough & {
@@ -94,6 +147,34 @@ function createTestStreams(): {
   }
 }
 
+afterEach(() => {
+  mock.restore()
+
+  if (ORIGINAL_SIMPLE_ENV === undefined) {
+    delete process.env.CLAUDE_CODE_SIMPLE
+  } else {
+    process.env.CLAUDE_CODE_SIMPLE = ORIGINAL_SIMPLE_ENV
+  }
+
+  if (ORIGINAL_CODEX_API_KEY === undefined) {
+    delete process.env.CODEX_API_KEY
+  } else {
+    process.env.CODEX_API_KEY = ORIGINAL_CODEX_API_KEY
+  }
+
+  if (ORIGINAL_CHATGPT_ACCOUNT_ID === undefined) {
+    delete process.env.CHATGPT_ACCOUNT_ID
+  } else {
+    process.env.CHATGPT_ACCOUNT_ID = ORIGINAL_CHATGPT_ACCOUNT_ID
+  }
+
+  if (ORIGINAL_CODEX_ACCOUNT_ID === undefined) {
+    delete process.env.CODEX_ACCOUNT_ID
+  } else {
+    process.env.CODEX_ACCOUNT_ID = ORIGINAL_CODEX_ACCOUNT_ID
+  }
+})
+
 function StepChangeHarness(): React.ReactNode {
   const { exit } = useApp()
   const [step, setStep] = React.useState<'api' | 'model'>('api')
@@ -233,6 +314,167 @@ test('buildProfileSaveMessage describes Gemini access token / ADC mode clearly',
   expect(message).not.toContain('AIza')
 })
 
+test('buildProfileSaveMessage reflects immediate Codex activation for existing credentials', () => {
+  const message = buildProfileSaveMessage(
+    'codex',
+    {
+      OPENAI_MODEL: 'codexplan',
+      OPENAI_BASE_URL: 'https://chatgpt.com/backend-api/codex',
+      CHATGPT_ACCOUNT_ID: 'acct_codex',
+    },
+    'D:/codings/Opensource/openclaude/.openclaude-profile.json',
+    {
+      activatedInSession: true,
+    },
+  )
+
+  expect(message).toContain('Saved Codex profile.')
+  expect(message).toContain('OpenClaude switched to it for this session.')
+  expect(message).not.toContain('Restart OpenClaude to use it.')
+})
+
+test('buildProfileSaveMessage reflects immediate Codex OAuth activation when the session switched successfully', () => {
+  const message = buildProfileSaveMessage(
+    'codex',
+    {
+      OPENAI_MODEL: 'codexplan',
+      OPENAI_BASE_URL: 'https://chatgpt.com/backend-api/codex',
+      CHATGPT_ACCOUNT_ID: 'acct_codex',
+      CODEX_CREDENTIAL_SOURCE: 'oauth',
+    },
+    'D:/codings/Opensource/openclaude/.openclaude-profile.json',
+    {
+      activatedInSession: true,
+    },
+  )
+
+  expect(message).toContain('Saved Codex profile.')
+  expect(message).toContain('OpenClaude switched to it for this session.')
+  expect(message).not.toContain('Restart OpenClaude to use it.')
+})
+
+test('buildCodexOAuthProfileEnv uses the fresh OAuth account id without persisting an API key', () => {
+  process.env.CODEX_API_KEY = 'stale-codex-key'
+  process.env.CHATGPT_ACCOUNT_ID = 'acct_stale'
+
+  const env = buildCodexOAuthProfileEnv({
+    accessToken: 'oauth-access-token',
+    accountId: 'acct_oauth',
+  })
+
+  expect(env).toEqual({
+    OPENAI_BASE_URL: 'https://chatgpt.com/backend-api/codex',
+    OPENAI_MODEL: 'codexplan',
+    CHATGPT_ACCOUNT_ID: 'acct_oauth',
+    CODEX_CREDENTIAL_SOURCE: 'oauth',
+  })
+  expect(env).not.toHaveProperty('CODEX_API_KEY')
+})
+
+test('buildCodexProfileEnv derives oauth source from secure storage when no explicit source is provided', async () => {
+  const actualProviderConfig = await import('../../services/api/providerConfig.js')
+
+  mock.module('../../services/api/providerConfig.js', () => ({
+    ...actualProviderConfig,
+    resolveCodexApiCredentials: () => ({
+      apiKey: 'stored-access-token',
+      accountId: 'acct_secure_storage',
+      source: 'secure-storage' as const,
+    }),
+  }))
+
+  // @ts-expect-error cache-busting query string for Bun module mocks
+  const { buildCodexProfileEnv } = await import(
+    '../../utils/providerProfile.js?secure-storage-codex-source'
+  )
+
+  const env = buildCodexProfileEnv({
+    model: 'codexplan',
+    processEnv: {},
+  })
+
+  expect(env).toEqual({
+    OPENAI_BASE_URL: 'https://chatgpt.com/backend-api/codex',
+    OPENAI_MODEL: 'codexplan',
+    CHATGPT_ACCOUNT_ID: 'acct_secure_storage',
+    CODEX_CREDENTIAL_SOURCE: 'oauth',
+  })
+})
+
+test('applySavedProfileToCurrentSession switches the current env to the saved Codex profile', async () => {
+  // @ts-expect-error cache-busting query string for Bun module mocks
+  const { applySavedProfileToCurrentSession } = await import(
+    '../../utils/providerProfile.js?apply-saved-profile-codex'
+  )
+  const processEnv: NodeJS.ProcessEnv = {
+    CLAUDE_CODE_USE_OPENAI: '1',
+    OPENAI_MODEL: 'gpt-4o',
+    OPENAI_BASE_URL: 'https://api.openai.com/v1',
+    OPENAI_API_KEY: 'sk-openai',
+    CODEX_API_KEY: 'codex-live',
+    CHATGPT_ACCOUNT_ID: 'acct_codex',
+    CLAUDE_CODE_PROVIDER_PROFILE_ENV_APPLIED: '1',
+    CLAUDE_CODE_PROVIDER_PROFILE_ENV_APPLIED_ID: 'provider_old',
+  }
+  const profileFile = createProfileFile('codex', {
+    OPENAI_MODEL: 'codexplan',
+    OPENAI_BASE_URL: 'https://chatgpt.com/backend-api/codex',
+    CODEX_API_KEY: 'codex-live',
+    CHATGPT_ACCOUNT_ID: 'acct_codex',
+  })
+
+  const warning = await applySavedProfileToCurrentSession({
+    profileFile,
+    processEnv,
+  })
+
+  expect(warning).toBeNull()
+  expect(processEnv.CLAUDE_CODE_USE_OPENAI).toBe('1')
+  expect(processEnv.OPENAI_MODEL).toBe('codexplan')
+  expect(processEnv.OPENAI_BASE_URL).toBe(
+    'https://chatgpt.com/backend-api/codex',
+  )
+  expect(processEnv.CODEX_API_KEY).toBe('codex-live')
+  expect(processEnv.CHATGPT_ACCOUNT_ID).toBe('acct_codex')
+  expect(processEnv.OPENAI_API_KEY).toBeUndefined()
+  expect(processEnv.CLAUDE_CODE_PROVIDER_PROFILE_ENV_APPLIED).toBeUndefined()
+  expect(processEnv.CLAUDE_CODE_PROVIDER_PROFILE_ENV_APPLIED_ID).toBeUndefined()
+})
+
+test('applySavedProfileToCurrentSession ignores stale Codex env overrides for OAuth-backed profiles', async () => {
+  // @ts-expect-error cache-busting query string for Bun module mocks
+  const { applySavedProfileToCurrentSession } = await import(
+    '../../utils/providerProfile.js?apply-saved-profile-codex-oauth'
+  )
+  const processEnv: NodeJS.ProcessEnv = {
+    CLAUDE_CODE_USE_OPENAI: '1',
+    OPENAI_MODEL: 'gpt-4o',
+    OPENAI_BASE_URL: 'https://api.openai.com/v1',
+    CODEX_API_KEY: 'stale-codex-key',
+    CHATGPT_ACCOUNT_ID: 'acct_stale',
+  }
+  const profileFile = createProfileFile('codex', {
+    OPENAI_MODEL: 'codexplan',
+    OPENAI_BASE_URL: 'https://chatgpt.com/backend-api/codex',
+    CHATGPT_ACCOUNT_ID: 'acct_oauth',
+    CODEX_CREDENTIAL_SOURCE: 'oauth',
+  })
+
+  const warning = await applySavedProfileToCurrentSession({
+    profileFile,
+    processEnv,
+  })
+
+  expect(warning).toBeNull()
+  expect(processEnv.OPENAI_MODEL).toBe('codexplan')
+  expect(processEnv.OPENAI_BASE_URL).toBe(
+    'https://chatgpt.com/backend-api/codex',
+  )
+  expect(processEnv.CODEX_API_KEY).toBeUndefined()
+  expect(processEnv.CHATGPT_ACCOUNT_ID).not.toBe('acct_stale')
+  expect(processEnv.CHATGPT_ACCOUNT_ID).toBeTruthy()
+})
+
 test('buildCurrentProviderSummary redacts poisoned model and endpoint values', () => {
   const summary = buildCurrentProviderSummary({
     processEnv: {
@@ -307,3 +549,12 @@ test('getProviderWizardDefaults ignores poisoned current provider values', () =>
   expect(defaults.openAIBaseUrl).toBe('https://api.openai.com/v1')
   expect(defaults.geminiModel).toBe('gemini-2.0-flash')
 })
+
+test('ProviderWizard hides Codex OAuth while running in bare mode', async () => {
+  process.env.CLAUDE_CODE_SIMPLE = '1'
+
+  const output = await renderProviderWizardFrame()
+
+  expect(output).toContain('Set up a provider profile')
+  expect(output).not.toContain('Codex OAuth')
+})
diff --git a/src/commands/provider/provider.tsx b/src/commands/provider/provider.tsx
index 1a7491e9..0b026f7e 100644
--- a/src/commands/provider/provider.tsx
+++ b/src/commands/provider/provider.tsx
@@ -10,8 +10,12 @@ import {
 } from '../../components/CustomSelect/index.js'
 import { Dialog } from '../../components/design-system/Dialog.js'
 import { LoadingState } from '../../components/design-system/LoadingState.js'
+import { useCodexOAuthFlow } from '../../components/useCodexOAuthFlow.js'
 import { useTerminalSize } from '../../hooks/useTerminalSize.js'
 import { Box, Text } from '../../ink.js'
+import {
+  type CodexOAuthTokens,
+} from '../../services/api/codexOAuth.js'
 import {
   DEFAULT_CODEX_BASE_URL,
   DEFAULT_OPENAI_BASE_URL,
@@ -20,6 +24,8 @@ import {
   resolveProviderRequest,
 } from '../../services/api/providerConfig.js'
 import {
+  applySavedProfileToCurrentSession as applySharedProfileToCurrentSession,
+  buildCodexOAuthProfileEnv as buildSharedCodexOAuthProfileEnv,
   buildCodexProfileEnv,
   buildGeminiProfileEnv,
   buildMistralProfileEnv,
@@ -49,6 +55,7 @@ import {
   readGeminiAccessToken,
   saveGeminiAccessToken,
 } from '../../utils/geminiCredentials.js'
+import { isBareMode } from '../../utils/envUtils.js'
 import {
   getGoalDefaultOpenAIModel,
   normalizeRecommendationGoal,
@@ -57,12 +64,13 @@ import {
   type RecommendationGoal,
 } from '../../utils/providerRecommendation.js'
 import {
+  getOllamaChatBaseUrl,
   getLocalOpenAICompatibleProviderLabel,
   hasLocalOllama,
   listOllamaModels,
 } from '../../utils/providerDiscovery.js'
 
-type ProviderChoice = 'auto' | ProviderProfile | 'clear'
+type ProviderChoice = 'auto' | ProviderProfile | 'codex-oauth' | 'clear'
 
 type Step =
   | { name: 'choose' }
@@ -93,6 +101,7 @@ type Step =
       apiKey?: string
       authMode: 'api-key' | 'access-token' | 'adc'
     }
+  | { name: 'codex-oauth' }
   | { name: 'codex-check' }
 
 type CurrentProviderSummary = {
@@ -131,6 +140,8 @@ type ProviderWizardDefaults = {
   mistralBaseUrl: string
 }
 
+type SecretSourceEnv = NodeJS.ProcessEnv & Partial<ProfileEnv>
+
 function isEnvTruthy(value: string | undefined): boolean {
   if (!value) return false
   const normalized = value.trim().toLowerCase()
@@ -139,7 +150,7 @@ function isEnvTruthy(value: string | undefined): boolean {
 
 function getSafeDisplayValue(
   value: string | undefined,
-  processEnv: NodeJS.ProcessEnv,
+  processEnv: SecretSourceEnv,
   profileEnv?: ProfileEnv,
   fallback = '(not set)',
 ): string {
@@ -151,14 +162,15 @@ function getSafeDisplayValue(
 export function getProviderWizardDefaults(
   processEnv: NodeJS.ProcessEnv = process.env,
 ): ProviderWizardDefaults {
+  const secretSource = processEnv as SecretSourceEnv
   const safeOpenAIModel =
-    sanitizeProviderConfigValue(processEnv.OPENAI_MODEL, processEnv) ||
+    sanitizeProviderConfigValue(processEnv.OPENAI_MODEL, secretSource) ||
     'gpt-4o'
   const safeOpenAIBaseUrl =
-    sanitizeProviderConfigValue(processEnv.OPENAI_BASE_URL, processEnv) ||
+    sanitizeProviderConfigValue(processEnv.OPENAI_BASE_URL, secretSource) ||
     DEFAULT_OPENAI_BASE_URL
   const safeGeminiModel =
-    sanitizeProviderConfigValue(processEnv.GEMINI_MODEL, processEnv) ||
+    sanitizeProviderConfigValue(processEnv.GEMINI_MODEL, secretSource) ||
     DEFAULT_GEMINI_MODEL
   const safeMistralModel =
     sanitizeProviderConfigValue(processEnv.MISTRAL_MODEL, processEnv) ||
@@ -181,6 +193,7 @@ export function buildCurrentProviderSummary(options?: {
   persisted?: ProfileFile | null
 }): CurrentProviderSummary {
   const processEnv = options?.processEnv ?? process.env
+  const secretSource = processEnv as SecretSourceEnv
   const persisted = options?.persisted ?? loadProfileFile()
   const savedProfileLabel = persisted?.profile ?? 'none'
 
@@ -189,11 +202,11 @@ export function buildCurrentProviderSummary(options?: {
       providerLabel: 'Google Gemini',
       modelLabel: getSafeDisplayValue(
         processEnv.GEMINI_MODEL ?? DEFAULT_GEMINI_MODEL,
-        processEnv,
+        secretSource,
       ),
       endpointLabel: getSafeDisplayValue(
         processEnv.GEMINI_BASE_URL ?? DEFAULT_GEMINI_BASE_URL,
-        processEnv,
+        secretSource,
       ),
       savedProfileLabel,
     }
@@ -219,13 +232,13 @@ export function buildCurrentProviderSummary(options?: {
       providerLabel: 'GitHub Models',
       modelLabel: getSafeDisplayValue(
         processEnv.OPENAI_MODEL ?? 'github:copilot',
-        processEnv,
+        secretSource,
       ),
       endpointLabel: getSafeDisplayValue(
         processEnv.OPENAI_BASE_URL ??
           processEnv.OPENAI_API_BASE ??
           'https://models.github.ai/inference',
-        processEnv,
+        secretSource,
       ),
       savedProfileLabel,
     }
@@ -246,8 +259,8 @@ export function buildCurrentProviderSummary(options?: {
 
     return {
       providerLabel,
-      modelLabel: getSafeDisplayValue(request.requestedModel, processEnv),
-      endpointLabel: getSafeDisplayValue(request.baseUrl, processEnv),
+      modelLabel: getSafeDisplayValue(request.requestedModel, secretSource),
+      endpointLabel: getSafeDisplayValue(request.baseUrl, secretSource),
       savedProfileLabel,
     }
   }
@@ -258,11 +271,11 @@ export function buildCurrentProviderSummary(options?: {
       processEnv.ANTHROPIC_MODEL ??
         processEnv.CLAUDE_MODEL ??
         'claude-sonnet-4-6',
-      processEnv,
+      secretSource,
     ),
     endpointLabel: getSafeDisplayValue(
       processEnv.ANTHROPIC_BASE_URL ?? 'https://api.anthropic.com',
-      processEnv,
+      secretSource,
     ),
     savedProfileLabel,
   }
@@ -376,6 +389,10 @@ export function buildProfileSaveMessage(
   profile: ProviderProfile,
   env: ProfileEnv,
   filePath: string,
+  options?: {
+    activatedInSession?: boolean
+    activationWarning?: string | null
+  },
 ): string {
   const summary = buildSavedProfileSummary(profile, env)
   const lines = [
@@ -389,13 +406,24 @@ export function buildProfileSaveMessage(
   }
 
   lines.push(`Profile: ${filePath}`)
-  lines.push('Restart OpenClaude to use it.')
+  if (options?.activatedInSession) {
+    lines.push('OpenClaude switched to it for this session.')
+  } else if (options?.activationWarning) {
+    lines.push(
+      `Saved for next startup. Warning: could not activate it in this session (${options.activationWarning}).`,
+    )
+  } else {
+    lines.push('Restart OpenClaude to use it.')
+  }
 
   return lines.join('\n')
 }
 
 function buildUsageText(): string {
   const summary = buildCurrentProviderSummary()
+  const availableProviders = isBareMode()
+    ? 'Choose Auto, Ollama, OpenAI-compatible, Gemini, or Codex, then save a provider profile.'
+    : 'Choose Auto, Ollama, OpenAI-compatible, Gemini, Codex, or Codex OAuth, then save a provider profile.'
   return [
     'Usage: /provider',
     '',
@@ -406,7 +434,7 @@ function buildUsageText(): string {
     `Current endpoint: ${summary.endpointLabel}`,
     `Saved profile: ${summary.savedProfileLabel}`,
     '',
-    'Choose Auto, Ollama, OpenAI-compatible, Gemini, or Codex, then save a profile for the next OpenClaude restart.',
+    availableProviders,
   ].join('\n')
 }
 
@@ -415,12 +443,45 @@ function finishProfileSave(
   profile: ProviderProfile,
   env: ProfileEnv,
 ): void {
+  void saveProfileAndNotify(onDone, profile, env)
+}
+
+export function buildCodexOAuthProfileEnv(
+  tokens: Pick<CodexOAuthTokens, 'accessToken' | 'idToken' | 'accountId'>,
+): ProfileEnv | null {
+  return buildSharedCodexOAuthProfileEnv(tokens)
+}
+
+export async function applySavedProfileToCurrentSession(options: {
+  profileFile: ProfileFile
+  processEnv?: NodeJS.ProcessEnv
+}): Promise<string | null> {
+  return applySharedProfileToCurrentSession(options)
+}
+
+async function saveProfileAndNotify(
+  onDone: LocalJSXCommandOnDone,
+  profile: ProviderProfile,
+  env: ProfileEnv,
+): Promise<void> {
   try {
     const profileFile = createProfileFile(profile, env)
     const filePath = saveProfileFile(profileFile)
-    onDone(buildProfileSaveMessage(profile, env, filePath), {
-      display: 'system',
-    })
+    const shouldActivateInSession = profile === 'codex'
+    const activationWarning = shouldActivateInSession
+      ? await applySharedProfileToCurrentSession({ profileFile })
+      : null
+
+    onDone(
+      buildProfileSaveMessage(profile, env, filePath, {
+        activatedInSession:
+          shouldActivateInSession && activationWarning === null,
+        activationWarning,
+      }),
+      {
+        display: 'system',
+      },
+    )
   } catch (error) {
     const message = error instanceof Error ? error.message : String(error)
     onDone(`Failed to save provider profile: ${message}`, {
@@ -504,6 +565,10 @@ function ProviderChooser({
   onCancel: () => void
 }): React.ReactNode {
   const summary = buildCurrentProviderSummary()
+  const canUseCodexOAuth = !isBareMode()
+  const helperText = canUseCodexOAuth
+    ? 'Save a provider profile without editing environment variables first. Codex profiles backed by env, auth.json, or OpenClaude secure storage can switch this session immediately when validation succeeds.'
+    : 'Save a provider profile without editing environment variables first. Codex profiles backed by env or auth.json can switch this session immediately.'
   const options: OptionWithDescription<ProviderChoice>[] = [
     {
       label: 'Auto',
@@ -537,6 +602,16 @@ function ProviderChooser({
       value: 'codex',
       description: 'Use existing ChatGPT Codex CLI auth or env credentials',
     },
+    ...(canUseCodexOAuth
+      ? [
+          {
+            label: 'Codex OAuth',
+            value: 'codex-oauth' as const,
+            description:
+              'Sign in with ChatGPT in your browser and store Codex tokens securely',
+          },
+        ]
+      : []),
   ]
 
   if (summary.savedProfileLabel !== 'none') {
@@ -554,10 +629,7 @@ function ProviderChooser({
       onCancel={onCancel}
     >
       <Box flexDirection="column" gap={1}>
-        <Text>
-          Save a provider profile for the next OpenClaude restart without
-          editing environment variables first.
-        </Text>
+        <Text>{helperText}</Text>
         <Box flexDirection="column">
           <Text dimColor>Current model: {summary.modelLabel}</Text>
           <Text dimColor>Current endpoint: {summary.endpointLabel}</Text>
@@ -709,7 +781,9 @@ function AutoRecommendationStep({
               { label: 'Back', value: 'back' },
               { label: 'Cancel', value: 'cancel' },
             ]}
-            onChange={value => (value === 'back' ? onBack() : onCancel())}
+            onChange={(value: string) =>
+              value === 'back' ? onBack() : onCancel()
+            }
             onCancel={onCancel}
           />
         </Box>
@@ -732,7 +806,7 @@ function AutoRecommendationStep({
               { label: 'Back', value: 'back' },
               { label: 'Cancel', value: 'cancel' },
             ]}
-            onChange={value => {
+            onChange={(value: string) => {
               if (value === 'continue') {
                 onNeedOpenAI(status.defaultModel)
               } else if (value === 'back') {
@@ -765,7 +839,7 @@ function AutoRecommendationStep({
             { label: 'Back', value: 'back' },
             { label: 'Cancel', value: 'cancel' },
           ]}
-          onChange={value => {
+          onChange={(value: string) => {
             if (value === 'save') {
               onSave(
                 'ollama',
@@ -867,7 +941,9 @@ function OllamaModelStep({
               { label: 'Back', value: 'back' },
               { label: 'Cancel', value: 'cancel' },
             ]}
-            onChange={value => (value === 'back' ? onBack() : onCancel())}
+            onChange={(value: string) =>
+              value === 'back' ? onBack() : onCancel()
+            }
             onCancel={onCancel}
           />
         </Box>
@@ -888,7 +964,7 @@ function OllamaModelStep({
           defaultFocusValue={status.defaultValue}
           inlineDescriptions
           visibleOptionCount={Math.min(8, status.options.length)}
-          onChange={value => {
+          onChange={(value: string) => {
             onSave(
               'ollama',
               buildOllamaProfileEnv(value, {
@@ -903,6 +979,84 @@ function OllamaModelStep({
   )
 }
 
+function CodexOAuthStep({
+  onSave,
+  onBack,
+  onCancel,
+}: {
+  onSave: (profile: ProviderProfile, env: ProfileEnv) => void
+  onBack: () => void
+  onCancel: () => void
+}): React.ReactNode {
+  const handleAuthenticated = React.useCallback(async (
+    tokens: CodexOAuthTokens,
+    persistCredentials: (options?: { profileId?: string }) => void,
+  ) => {
+    const env = buildCodexOAuthProfileEnv(tokens)
+    if (!env) {
+      throw new Error(
+        'Codex OAuth succeeded, but OpenClaude could not build a Codex profile from the stored credentials.',
+      )
+    }
+
+    persistCredentials()
+    onSave('codex', env)
+  }, [onSave])
+
+  const status = useCodexOAuthFlow({
+    onAuthenticated: handleAuthenticated,
+  })
+
+  if (status.state === 'error') {
+    return (
+      <Dialog title="Codex OAuth failed" onCancel={onCancel} color="warning">
+        <Box flexDirection="column" gap={1}>
+          <Text>{status.message}</Text>
+          <Select
+            options={[
+              { label: 'Back', value: 'back' },
+              { label: 'Cancel', value: 'cancel' },
+            ]}
+            onChange={(value: string) =>
+              value === 'back' ? onBack() : onCancel()
+            }
+            onCancel={onCancel}
+          />
+        </Box>
+      </Dialog>
+    )
+  }
+
+  if (status.state === 'starting') {
+    return <LoadingState message="Starting Codex OAuth..." />
+  }
+
+  return (
+    <Dialog title="Codex OAuth" onCancel={onBack}>
+      <Box flexDirection="column" gap={1}>
+        <Text>
+          Finish signing in with ChatGPT in your browser. OpenClaude will store
+          the resulting Codex credentials securely for future sessions.
+        </Text>
+        {status.browserOpened === false ? (
+          <Text color="warning">
+            Browser did not open automatically. Visit this URL to continue:
+          </Text>
+        ) : status.browserOpened === true ? (
+          <Text dimColor>
+            Browser opened. Complete the sign-in there, then OpenClaude will
+            finish setup automatically.
+          </Text>
+        ) : (
+          <Text dimColor>Opening your browser...</Text>
+        )}
+        <Text>{status.authUrl}</Text>
+        <Text dimColor>Press Esc to cancel and go back.</Text>
+      </Box>
+    </Dialog>
+  )
+}
+
 function CodexCredentialStep({
   onSave,
   onBack,
@@ -924,7 +1078,9 @@ function CodexCredentialStep({
               { label: 'Back', value: 'back' },
               { label: 'Cancel', value: 'cancel' },
             ]}
-            onChange={value => (value === 'back' ? onBack() : onCancel())}
+            onChange={(value: string) =>
+              value === 'back' ? onBack() : onCancel()
+            }
             onCancel={onCancel}
           />
         </Box>
@@ -958,9 +1114,10 @@ function CodexCredentialStep({
           defaultFocusValue="codexplan"
           inlineDescriptions
           visibleOptionCount={options.length}
-          onChange={value => {
+          onChange={(value: string) => {
             const env = buildCodexProfileEnv({
               model: value,
+              credentialSource: credentials.credentialSource,
               processEnv: process.env,
             })
             if (env) {
@@ -975,9 +1132,16 @@ function CodexCredentialStep({
 }
 
 function resolveCodexCredentials(processEnv: NodeJS.ProcessEnv):
-  | { ok: true; sourceDescription: string }
+  | {
+      ok: true
+      sourceDescription: string
+      credentialSource: 'oauth' | 'existing'
+    }
   | { ok: false; message: string } {
   const credentials = resolveCodexApiCredentials(processEnv)
+  const oauthHint = isBareMode()
+    ? 'Re-login with the Codex CLI'
+    : 'Choose Codex OAuth in /provider, or re-login with the Codex CLI'
 
   if (!credentials.apiKey) {
     const authHint = credentials.authPath
@@ -985,7 +1149,7 @@ function resolveCodexCredentials(processEnv: NodeJS.ProcessEnv):
       : 'Set CODEX_API_KEY or re-login with the Codex CLI.'
     return {
       ok: false,
-      message: `Codex setup needs existing credentials. Re-login with the Codex CLI or set CODEX_API_KEY. ${authHint}`,
+      message: `Codex setup needs existing credentials. ${oauthHint}, or set CODEX_API_KEY. ${authHint}`,
     }
   }
 
@@ -993,15 +1157,19 @@ function resolveCodexCredentials(processEnv: NodeJS.ProcessEnv):
     return {
       ok: false,
       message:
-        'Codex auth is missing chatgpt_account_id. Re-login with the Codex CLI or set CHATGPT_ACCOUNT_ID/CODEX_ACCOUNT_ID first.',
+        `Codex auth is missing chatgpt_account_id. ${oauthHint}, or set CHATGPT_ACCOUNT_ID/CODEX_ACCOUNT_ID first.`,
     }
   }
 
   return {
     ok: true,
+    credentialSource:
+      credentials.source === 'secure-storage' ? 'oauth' : 'existing',
     sourceDescription:
       credentials.source === 'env'
         ? 'the current shell environment'
+        : credentials.source === 'secure-storage'
+          ? 'OpenClaude secure storage'
         : credentials.authPath ?? DEFAULT_CODEX_BASE_URL,
   }
 }
@@ -1035,6 +1203,8 @@ export function ProviderWizard({
                 name: 'mistral-key',
                 defaultModel: defaults.mistralModel,
               })
+            } else if (value === 'codex-oauth') {
+              setStep({ name: 'codex-oauth' })
             } else if (value === 'clear') {
               const filePath = deleteProfileFile()
               onDone(`Removed saved provider profile at ${filePath}. Restart OpenClaude to go back to normal startup.`, {
@@ -1314,7 +1484,7 @@ export function ProviderWizard({
               options={options}
               inlineDescriptions
               visibleOptionCount={options.length}
-              onChange={value => {
+              onChange={(value: string) => {
                 if (value === 'api-key') {
                   setStep({ name: 'gemini-key' })
                 } else if (value === 'access-token') {
@@ -1470,6 +1640,15 @@ export function ProviderWizard({
           onCancel={() => onDone()}
         />
       )
+
+    case 'codex-oauth':
+      return (
+        <CodexOAuthStep
+          onSave={(profile, env) => finishProfileSave(onDone, profile, env)}
+          onBack={() => setStep({ name: 'choose' })}
+          onCancel={() => onDone()}
+        />
+      )
   }
 }
 
diff --git a/src/components/EffortPicker.tsx b/src/components/EffortPicker.tsx
index ac8ee416..7a6377ea 100644
--- a/src/components/EffortPicker.tsx
+++ b/src/components/EffortPicker.tsx
@@ -101,9 +101,9 @@ export function EffortPicker({ onSelect, onCancel }: Props) {
       <Box marginBottom={1} flexDirection="column">
         <Text color="remember" bold={true}>Set effort level</Text>
         <Text dimColor={true}>
-          {usesOpenAIEffort
-            ? `OpenAI/Codex provider (${provider})`
-            : supportsEffort
+            {supportsEffort && usesOpenAIEffort
+              ? `OpenAI/Codex provider (${provider})`
+              : supportsEffort
               ? `Claude model · ${provider} provider`
               : `Effort not supported for this model`
           }
diff --git a/src/components/ProviderManager.test.tsx b/src/components/ProviderManager.test.tsx
index c257f819..79dc5110 100644
--- a/src/components/ProviderManager.test.tsx
+++ b/src/components/ProviderManager.test.tsx
@@ -5,13 +5,14 @@ import React from 'react'
 import stripAnsi from 'strip-ansi'
 
 import { createRoot } from '../ink.js'
-import { AppStateProvider } from '../state/AppState.js'
 import { KeybindingSetup } from '../keybindings/KeybindingProviderSetup.js'
+import { AppStateProvider } from '../state/AppState.js'
 
 const SYNC_START = '\x1B[?2026h'
 const SYNC_END = '\x1B[?2026l'
 
 const ORIGINAL_ENV = {
+  CLAUDE_CODE_SIMPLE: process.env.CLAUDE_CODE_SIMPLE,
   CLAUDE_CODE_USE_GITHUB: process.env.CLAUDE_CODE_USE_GITHUB,
   GITHUB_TOKEN: process.env.GITHUB_TOKEN,
   GH_TOKEN: process.env.GH_TOKEN,
@@ -109,6 +110,9 @@ function createDeferred<T>(): {
 
 function mockProviderProfilesModule(options?: {
   addProviderProfile?: (...args: unknown[]) => unknown
+  getProviderProfiles?: () => unknown[]
+  updateProviderProfile?: (...args: unknown[]) => unknown
+  setActiveProviderProfile?: (...args: unknown[]) => unknown
 }): void {
   mock.module('../utils/providerProfiles.js', () => ({
     addProviderProfile: options?.addProviderProfile ?? (() => null),
@@ -131,17 +135,20 @@ function mockProviderProfilesModule(options?: {
             model: 'mock-model',
             apiKey: '',
           },
-    getProviderProfiles: () => [],
-    setActiveProviderProfile: () => null,
-    updateProviderProfile: () => null,
+    getProviderProfiles: options?.getProviderProfiles ?? (() => []),
+    setActiveProviderProfile: options?.setActiveProviderProfile ?? (() => null),
+    updateProviderProfile: options?.updateProviderProfile ?? (() => null),
   }))
 }
 
 function mockProviderManagerDependencies(
-  syncRead: () => string | undefined,
-  asyncRead: () => Promise<string | undefined>,
+  githubSyncRead: () => string | undefined,
+  githubAsyncRead: () => Promise<string | undefined>,
   options?: {
     addProviderProfile?: (...args: unknown[]) => unknown
+    applySavedProfileToCurrentSession?: (...args: unknown[]) => Promise<string | null>
+    clearCodexCredentials?: () => { success: boolean; warning?: string }
+    getProviderProfiles?: () => unknown[]
     hasLocalOllama?: () => Promise<boolean>
     listOllamaModels?: () => Promise<
       Array<{
@@ -153,9 +160,33 @@ function mockProviderManagerDependencies(
         quantizationLevel?: string | null
       }>
     >
+    codexSyncRead?: () => unknown
+    codexAsyncRead?: () => Promise<unknown>
+    updateProviderProfile?: (...args: unknown[]) => unknown
+    setActiveProviderProfile?: (...args: unknown[]) => unknown
+    useCodexOAuthFlow?: (options: {
+      onAuthenticated: (tokens: {
+        accessToken: string
+        refreshToken: string
+        accountId?: string
+        idToken?: string
+        apiKey?: string
+      }, persistCredentials: (options?: { profileId?: string }) => void) =>
+        void | Promise<void>
+    }) => {
+      state: 'starting' | 'waiting' | 'error'
+      authUrl?: string
+      browserOpened?: boolean | null
+      message?: string
+    }
   },
 ): void {
-  mockProviderProfilesModule({ addProviderProfile: options?.addProviderProfile })
+  mockProviderProfilesModule({
+    addProviderProfile: options?.addProviderProfile,
+    getProviderProfiles: options?.getProviderProfiles,
+    updateProviderProfile: options?.updateProviderProfile,
+    setActiveProviderProfile: options?.setActiveProviderProfile,
+  })
 
   mock.module('../utils/providerDiscovery.js', () => ({
     hasLocalOllama: options?.hasLocalOllama ?? (async () => false),
@@ -166,13 +197,65 @@ function mockProviderManagerDependencies(
     clearGithubModelsToken: () => ({ success: true }),
     GITHUB_MODELS_HYDRATED_ENV_MARKER: 'CLAUDE_CODE_GITHUB_TOKEN_HYDRATED',
     hydrateGithubModelsTokenFromSecureStorage: () => {},
-    readGithubModelsToken: syncRead,
-    readGithubModelsTokenAsync: asyncRead,
+    readGithubModelsToken: githubSyncRead,
+    readGithubModelsTokenAsync: githubAsyncRead,
+  }))
+
+  mock.module('../utils/codexCredentials.js', () => ({
+    attachCodexProfileIdToStoredCredentials: () => ({ success: true }),
+    clearCodexCredentials:
+      options?.clearCodexCredentials ?? (() => ({ success: true })),
+    readCodexCredentials:
+      options?.codexSyncRead ?? (() => undefined),
+    readCodexCredentialsAsync:
+      options?.codexAsyncRead ?? (async () => undefined),
+  }))
+
+  mock.module('../utils/providerProfile.js', () => ({
+    applySavedProfileToCurrentSession:
+      options?.applySavedProfileToCurrentSession ?? (async () => null),
+    buildCodexOAuthProfileEnv: (tokens: {
+      accessToken: string
+      accountId?: string
+      idToken?: string
+    }) => {
+      const accountId =
+        tokens.accountId ??
+        (tokens.idToken ? 'acct_from_id_token' : undefined) ??
+        (tokens.accessToken ? 'acct_from_access_token' : undefined)
+
+      if (!accountId) {
+        return null
+      }
+
+      return {
+        OPENAI_BASE_URL: 'https://chatgpt.com/backend-api/codex',
+        OPENAI_MODEL: 'codexplan',
+        CHATGPT_ACCOUNT_ID: accountId,
+        CODEX_CREDENTIAL_SOURCE: 'oauth' as const,
+      }
+    },
+    clearPersistedCodexOAuthProfile: () => null,
+    createProfileFile: (profile: string, env: Record<string, unknown>) => ({
+      profile,
+      env,
+      createdAt: '2026-04-10T00:00:00.000Z',
+    }),
   }))
 
   mock.module('../utils/settings/settings.js', () => ({
     updateSettingsForSource: () => ({ error: null }),
   }))
+
+  mock.module('./useCodexOAuthFlow.js', () => ({
+    useCodexOAuthFlow:
+      options?.useCodexOAuthFlow ??
+      (() => ({
+        state: 'waiting' as const,
+        authUrl: 'https://chatgpt.com/codex',
+        browserOpened: true,
+      })),
+  }))
 }
 
 async function waitForFrameOutput(
@@ -240,9 +323,9 @@ async function renderProviderManagerFrame(
     onDone: (result?: unknown) => void
   }>,
   options?: {
+    mode?: 'first-run' | 'manage'
     waitForOutput?: (output: string) => boolean
     timeoutMs?: number
-    mode?: 'first-run' | 'manage'
   },
 ): Promise<string> {
   const mounted = await mountProviderManager(ProviderManager, {
@@ -305,6 +388,47 @@ test('ProviderManager resolves GitHub virtual provider from async storage withou
   expect(asyncRead).toHaveBeenCalled()
 })
 
+test('ProviderManager avoids first-frame false negative while stored-token lookup is pending', async () => {
+  delete process.env.CLAUDE_CODE_USE_GITHUB
+  delete process.env.GITHUB_TOKEN
+  delete process.env.GH_TOKEN
+
+  const syncRead = mock(() => {
+    throw new Error('sync credential read should not run in ProviderManager render flow')
+  })
+  const deferredStoredToken = createDeferred<string | undefined>()
+  const asyncRead = mock(async () => deferredStoredToken.promise)
+
+  mockProviderManagerDependencies(syncRead, asyncRead)
+
+  const nonce = `${Date.now()}-${Math.random()}`
+  const { ProviderManager } = await import(`./ProviderManager.js?ts=${nonce}`)
+  const mounted = await mountProviderManager(ProviderManager)
+
+  const firstFrame = await waitForFrameOutput(
+    mounted.getOutput,
+    frame => frame.includes('Provider manager'),
+  )
+
+  expect(firstFrame).toContain('Checking GitHub Models credentials...')
+  expect(firstFrame).not.toContain('No provider profiles configured yet.')
+
+  deferredStoredToken.resolve('stored-token')
+
+  const resolvedFrame = await waitForFrameOutput(
+    mounted.getOutput,
+    frame => frame.includes('GitHub Models') && frame.includes('token stored'),
+  )
+
+  expect(resolvedFrame).toContain('GitHub Models')
+  expect(resolvedFrame).toContain('token stored')
+
+  await mounted.dispose()
+
+  expect(syncRead).not.toHaveBeenCalled()
+  expect(asyncRead).toHaveBeenCalled()
+})
+
 test('ProviderManager first-run Ollama preset auto-detects installed models', async () => {
   delete process.env.CLAUDE_CODE_USE_GITHUB
   delete process.env.GITHUB_TOKEN
@@ -395,43 +519,411 @@ test('ProviderManager first-run Ollama preset auto-detects installed models', as
   await mounted.dispose()
 })
 
-test('ProviderManager avoids first-frame false negative while stored-token lookup is pending', async () => {
+test('ProviderManager first-run Codex OAuth switches the current session after login completes', async () => {
+  delete process.env.CLAUDE_CODE_SIMPLE
   delete process.env.CLAUDE_CODE_USE_GITHUB
   delete process.env.GITHUB_TOKEN
   delete process.env.GH_TOKEN
 
-  const syncRead = mock(() => {
-    throw new Error('sync credential read should not run in ProviderManager render flow')
-  })
-  const deferredStoredToken = createDeferred<string | undefined>()
-  const asyncRead = mock(async () => deferredStoredToken.promise)
+  const onDone = mock(() => {})
+  const applySavedProfileToCurrentSession = mock(async () => null)
+  const persistCredentials = mock(() => {})
+  const addProviderProfile = mock((payload: {
+    provider: string
+    name: string
+    baseUrl: string
+    model: string
+    apiKey?: string
+  }) => ({
+    id: 'provider_codex_oauth',
+    provider: payload.provider,
+    name: payload.name,
+    baseUrl: payload.baseUrl,
+    model: payload.model,
+    apiKey: payload.apiKey,
+  }))
 
-  mockProviderManagerDependencies(syncRead, asyncRead)
+  mockProviderManagerDependencies(
+    () => undefined,
+    async () => undefined,
+    {
+      addProviderProfile,
+      applySavedProfileToCurrentSession,
+      useCodexOAuthFlow: ({ onAuthenticated }) => {
+        React.useEffect(() => {
+          void onAuthenticated({
+            accessToken: 'oauth-access-token',
+            refreshToken: 'oauth-refresh-token',
+            accountId: 'acct_oauth',
+          }, persistCredentials)
+        }, [onAuthenticated])
+
+        return {
+          state: 'waiting',
+          authUrl: 'https://chatgpt.com/codex',
+          browserOpened: true,
+        }
+      },
+    },
+  )
+
+  const nonce = `${Date.now()}-${Math.random()}`
+  const { ProviderManager } = await import(`./ProviderManager.js?ts=${nonce}`)
+  const mounted = await mountProviderManager(ProviderManager, {
+    mode: 'first-run',
+    onDone,
+  })
+
+  await waitForFrameOutput(
+    mounted.getOutput,
+    frame => frame.includes('Set up provider') && frame.includes('Codex OAuth'),
+  )
+
+  mounted.stdin.write('j')
+  await Bun.sleep(25)
+  mounted.stdin.write('j')
+  await Bun.sleep(25)
+  mounted.stdin.write('j')
+  await Bun.sleep(25)
+  mounted.stdin.write('\r')
+
+  await waitForCondition(() => onDone.mock.calls.length > 0)
+
+  expect(addProviderProfile).toHaveBeenCalledWith(
+    expect.objectContaining({
+      provider: 'openai',
+      name: 'Codex OAuth',
+      baseUrl: 'https://chatgpt.com/backend-api/codex',
+      model: 'codexplan',
+      apiKey: '',
+    }),
+    expect.objectContaining({ makeActive: true }),
+  )
+  expect(applySavedProfileToCurrentSession).toHaveBeenCalled()
+  expect(persistCredentials).toHaveBeenCalledWith({
+    profileId: 'provider_codex_oauth',
+  })
+  expect(onDone).toHaveBeenCalledWith(
+    expect.objectContaining({
+      action: 'saved',
+      message:
+        'Codex OAuth configured. OpenClaude switched to it for this session.',
+    }),
+  )
+
+  await mounted.dispose()
+})
+
+test('ProviderManager first-run Codex OAuth reports next-startup fallback when session activation fails', async () => {
+  delete process.env.CLAUDE_CODE_SIMPLE
+  delete process.env.CLAUDE_CODE_USE_GITHUB
+  delete process.env.GITHUB_TOKEN
+  delete process.env.GH_TOKEN
+
+  const onDone = mock(() => {})
+  const applySavedProfileToCurrentSession = mock(
+    async () => 'validation failed',
+  )
+  const persistCredentials = mock(() => {})
+  const addProviderProfile = mock((payload: {
+    provider: string
+    name: string
+    baseUrl: string
+    model: string
+    apiKey?: string
+  }) => ({
+    id: 'provider_codex_oauth',
+    provider: payload.provider,
+    name: payload.name,
+    baseUrl: payload.baseUrl,
+    model: payload.model,
+    apiKey: payload.apiKey,
+  }))
+
+  mockProviderManagerDependencies(
+    () => undefined,
+    async () => undefined,
+    {
+      addProviderProfile,
+      applySavedProfileToCurrentSession,
+      useCodexOAuthFlow: ({ onAuthenticated }) => {
+        React.useEffect(() => {
+          void onAuthenticated({
+            accessToken: 'oauth-access-token',
+            refreshToken: 'oauth-refresh-token',
+            accountId: 'acct_oauth',
+          }, persistCredentials)
+        }, [onAuthenticated])
+
+        return {
+          state: 'waiting',
+          authUrl: 'https://chatgpt.com/codex',
+          browserOpened: true,
+        }
+      },
+    },
+  )
+
+  const nonce = `${Date.now()}-${Math.random()}`
+  const { ProviderManager } = await import(`./ProviderManager.js?ts=${nonce}`)
+  const mounted = await mountProviderManager(ProviderManager, {
+    mode: 'first-run',
+    onDone,
+  })
+
+  await waitForFrameOutput(
+    mounted.getOutput,
+    frame => frame.includes('Set up provider') && frame.includes('Codex OAuth'),
+  )
+
+  mounted.stdin.write('j')
+  await Bun.sleep(25)
+  mounted.stdin.write('j')
+  await Bun.sleep(25)
+  mounted.stdin.write('j')
+  await Bun.sleep(25)
+  mounted.stdin.write('\r')
+
+  await waitForCondition(() => onDone.mock.calls.length > 0)
+
+  expect(persistCredentials).toHaveBeenCalledWith({
+    profileId: 'provider_codex_oauth',
+  })
+  expect(onDone).toHaveBeenCalledWith(
+    expect.objectContaining({
+      action: 'saved',
+      message:
+        'Codex OAuth configured. Saved for next startup. Warning: validation failed.',
+    }),
+  )
+
+  await mounted.dispose()
+})
+
+test('ProviderManager does not hijack a manual Codex profile when OAuth credentials are not yet linked', async () => {
+  delete process.env.CLAUDE_CODE_SIMPLE
+  delete process.env.CLAUDE_CODE_USE_GITHUB
+  delete process.env.GITHUB_TOKEN
+  delete process.env.GH_TOKEN
+
+  const onDone = mock(() => {})
+  const manualProfile = {
+    id: 'provider_manual_codex',
+    provider: 'openai',
+    name: 'Codex OAuth',
+    baseUrl: 'https://chatgpt.com/backend-api/codex',
+    model: 'gpt-5.4',
+    apiKey: 'manual-key',
+  }
+  const addProviderProfile = mock((payload: {
+    provider: string
+    name: string
+    baseUrl: string
+    model: string
+    apiKey?: string
+  }) => ({
+    id: 'provider_codex_oauth',
+    provider: payload.provider,
+    name: payload.name,
+    baseUrl: payload.baseUrl,
+    model: payload.model,
+    apiKey: payload.apiKey,
+  }))
+  const updateProviderProfile = mock(() => manualProfile)
+  const persistCredentials = mock(() => {})
+
+  mockProviderManagerDependencies(
+    () => undefined,
+    async () => undefined,
+    {
+      addProviderProfile,
+      getProviderProfiles: () => [manualProfile],
+      updateProviderProfile,
+      useCodexOAuthFlow: ({ onAuthenticated }) => {
+        const hasAuthenticated = React.useRef(false)
+
+        React.useEffect(() => {
+          if (hasAuthenticated.current) {
+            return
+          }
+          hasAuthenticated.current = true
+          void onAuthenticated({
+            accessToken: 'oauth-access-token',
+            refreshToken: 'oauth-refresh-token',
+            accountId: 'acct_oauth',
+          }, persistCredentials)
+        }, [onAuthenticated])
+
+        return {
+          state: 'waiting',
+          authUrl: 'https://chatgpt.com/codex',
+          browserOpened: true,
+        }
+      },
+    },
+  )
+
+  const nonce = `${Date.now()}-${Math.random()}`
+  const { ProviderManager } = await import(`./ProviderManager.js?ts=${nonce}`)
+  const mounted = await mountProviderManager(ProviderManager, {
+    mode: 'first-run',
+    onDone,
+  })
+
+  await waitForFrameOutput(
+    mounted.getOutput,
+    frame => frame.includes('Set up provider') && frame.includes('Codex OAuth'),
+  )
+
+  mounted.stdin.write('j')
+  await Bun.sleep(25)
+  mounted.stdin.write('j')
+  await Bun.sleep(25)
+  mounted.stdin.write('j')
+  await Bun.sleep(25)
+  mounted.stdin.write('\r')
+
+  await waitForCondition(() => onDone.mock.calls.length > 0)
+
+  expect(addProviderProfile).toHaveBeenCalledTimes(1)
+  expect(updateProviderProfile).not.toHaveBeenCalled()
+  expect(persistCredentials).toHaveBeenCalledWith({
+    profileId: 'provider_codex_oauth',
+  })
+
+  await mounted.dispose()
+})
+
+test('ProviderManager keeps Codex OAuth as next-startup only when activating the session fails from the menu', async () => {
+  delete process.env.CLAUDE_CODE_SIMPLE
+  delete process.env.CLAUDE_CODE_USE_GITHUB
+  delete process.env.GITHUB_TOKEN
+  delete process.env.GH_TOKEN
+
+  const codexProfile = {
+    id: 'provider_codex_oauth',
+    provider: 'openai',
+    name: 'Codex OAuth',
+    baseUrl: 'https://chatgpt.com/backend-api/codex',
+    model: 'codexplan',
+    apiKey: '',
+  }
+
+  const applySavedProfileToCurrentSession = mock(
+    async () => 'validation failed',
+  )
+  const setActiveProviderProfile = mock(() => codexProfile)
+
+  mockProviderManagerDependencies(
+    () => undefined,
+    async () => undefined,
+    {
+      applySavedProfileToCurrentSession,
+      getProviderProfiles: () => [codexProfile],
+      setActiveProviderProfile,
+      codexAsyncRead: async () => ({
+        accessToken: 'oauth-access-token',
+        refreshToken: 'oauth-refresh-token',
+        accountId: 'acct_oauth',
+        profileId: 'provider_codex_oauth',
+      }),
+    },
+  )
 
   const nonce = `${Date.now()}-${Math.random()}`
   const { ProviderManager } = await import(`./ProviderManager.js?ts=${nonce}`)
   const mounted = await mountProviderManager(ProviderManager)
 
-  const firstFrame = await waitForFrameOutput(
+  await waitForFrameOutput(
     mounted.getOutput,
-    frame => frame.includes('Provider manager'),
+    frame =>
+      frame.includes('Provider manager') &&
+      frame.includes('Set active provider') &&
+      frame.includes('Log out Codex OAuth'),
   )
 
-  expect(firstFrame).toContain('Checking GitHub Models credentials...')
-  expect(firstFrame).not.toContain('No provider profiles configured yet.')
+  mounted.stdin.write('j')
+  await Bun.sleep(25)
+  mounted.stdin.write('\r')
 
-  deferredStoredToken.resolve('stored-token')
-
-  const resolvedFrame = await waitForFrameOutput(
+  await waitForFrameOutput(
     mounted.getOutput,
-    frame => frame.includes('GitHub Models') && frame.includes('token stored'),
+    frame => frame.includes('Set active provider') && frame.includes('Codex OAuth'),
   )
 
-  expect(resolvedFrame).toContain('GitHub Models')
-  expect(resolvedFrame).toContain('token stored')
+  await Bun.sleep(25)
+  mounted.stdin.write('\r')
+
+  await waitForCondition(() => setActiveProviderProfile.mock.calls.length > 0)
+  await waitForCondition(
+    () => applySavedProfileToCurrentSession.mock.calls.length > 0,
+  )
+  await Bun.sleep(50)
+  const output = stripAnsi(extractLastFrame(mounted.getOutput()))
+
+  expect(output).toContain(
+    'Active provider: Codex OAuth. Saved for next startup. Warning: validation failed.',
+  )
+  expect(applySavedProfileToCurrentSession).toHaveBeenCalled()
+  expect(setActiveProviderProfile).toHaveBeenCalledWith('provider_codex_oauth')
 
   await mounted.dispose()
-
-  expect(syncRead).not.toHaveBeenCalled()
-  expect(asyncRead).toHaveBeenCalled()
+})
+
+test('ProviderManager resolves Codex OAuth state from async storage without sync reads in render flow', async () => {
+  delete process.env.CLAUDE_CODE_SIMPLE
+  delete process.env.CLAUDE_CODE_USE_GITHUB
+  delete process.env.GITHUB_TOKEN
+  delete process.env.GH_TOKEN
+
+  const githubSyncRead = mock(() => undefined)
+  const githubAsyncRead = mock(async () => undefined)
+  const codexSyncRead = mock(() => {
+    throw new Error('sync codex credential read should not run in ProviderManager render flow')
+  })
+  const codexAsyncRead = mock(async () => ({
+    accessToken: 'codex-access-token',
+    refreshToken: 'codex-refresh-token',
+  }))
+
+  mockProviderManagerDependencies(githubSyncRead, githubAsyncRead, {
+    codexSyncRead,
+    codexAsyncRead,
+  })
+
+  const nonce = `${Date.now()}-${Math.random()}`
+  const { ProviderManager } = await import(`./ProviderManager.js?ts=${nonce}`)
+  const output = await renderProviderManagerFrame(ProviderManager, {
+    waitForOutput: frame =>
+      frame.includes('Provider manager') &&
+      frame.includes('Log out Codex OAuth'),
+  })
+
+  expect(output).toContain('Provider manager')
+  expect(output).toContain('Log out Codex OAuth')
+  expect(codexSyncRead).not.toHaveBeenCalled()
+  expect(codexAsyncRead).toHaveBeenCalled()
+})
+
+test('ProviderManager hides Codex OAuth setup in bare mode', async () => {
+  process.env.CLAUDE_CODE_SIMPLE = '1'
+  delete process.env.CLAUDE_CODE_USE_GITHUB
+  delete process.env.GITHUB_TOKEN
+  delete process.env.GH_TOKEN
+
+  const githubSyncRead = mock(() => undefined)
+  const githubAsyncRead = mock(async () => undefined)
+
+  mockProviderManagerDependencies(githubSyncRead, githubAsyncRead)
+
+  const nonce = `${Date.now()}-${Math.random()}`
+  const { ProviderManager } = await import(`./ProviderManager.js?ts=${nonce}`)
+  const output = await renderProviderManagerFrame(ProviderManager, {
+    mode: 'first-run',
+    waitForOutput: frame =>
+      frame.includes('Set up provider') && frame.includes('OpenAI'),
+  })
+
+  expect(output).toContain('Set up provider')
+  expect(output).not.toContain('Codex OAuth')
 })
diff --git a/src/components/ProviderManager.tsx b/src/components/ProviderManager.tsx
index 1d2d0925..271cc7d6 100644
--- a/src/components/ProviderManager.tsx
+++ b/src/components/ProviderManager.tsx
@@ -1,9 +1,20 @@
 import figures from 'figures'
 import * as React from 'react'
+import { DEFAULT_CODEX_BASE_URL } from '../services/api/providerConfig.js'
 import { Box, Text } from '../ink.js'
 import { useKeybinding } from '../keybindings/useKeybinding.js'
 import type { ProviderProfile } from '../utils/config.js'
-import { hasLocalOllama, listOllamaModels } from '../utils/providerDiscovery.js'
+import {
+  clearCodexCredentials,
+  readCodexCredentialsAsync,
+} from '../utils/codexCredentials.js'
+import { isBareMode, isEnvTruthy } from '../utils/envUtils.js'
+import {
+  applySavedProfileToCurrentSession,
+  buildCodexOAuthProfileEnv,
+  clearPersistedCodexOAuthProfile,
+  createProfileFile,
+} from '../utils/providerProfile.js'
 import {
   addProviderProfile,
   applyActiveProviderProfileFromConfig,
@@ -16,10 +27,6 @@ import {
   type ProviderProfileInput,
   updateProviderProfile,
 } from '../utils/providerProfiles.js'
-import {
-  rankOllamaModels,
-  recommendOllamaModel,
-} from '../utils/providerRecommendation.js'
 import {
   clearGithubModelsToken,
   GITHUB_MODELS_HYDRATED_ENV_MARKER,
@@ -27,11 +34,22 @@ import {
   readGithubModelsToken,
   readGithubModelsTokenAsync,
 } from '../utils/githubModelsCredentials.js'
-import { isEnvTruthy } from '../utils/envUtils.js'
+import {
+  hasLocalOllama,
+  listOllamaModels,
+} from '../utils/providerDiscovery.js'
+import {
+  rankOllamaModels,
+  recommendOllamaModel,
+} from '../utils/providerRecommendation.js'
 import { updateSettingsForSource } from '../utils/settings/settings.js'
-import { type OptionWithDescription, Select } from './CustomSelect/index.js'
+import {
+  type OptionWithDescription,
+  Select,
+} from './CustomSelect/index.js'
 import { Pane } from './design-system/Pane.js'
 import TextInput from './TextInput.js'
+import { useCodexOAuthFlow } from './useCodexOAuthFlow.js'
 
 export type ProviderManagerResult = {
   action: 'saved' | 'cancelled'
@@ -48,6 +66,7 @@ type Screen =
   | 'menu'
   | 'select-preset'
   | 'select-ollama-model'
+  | 'codex-oauth'
   | 'form'
   | 'select-active'
   | 'select-edit'
@@ -105,6 +124,8 @@ const GITHUB_PROVIDER_ID = '__github_models__'
 const GITHUB_PROVIDER_LABEL = 'GitHub Models'
 const GITHUB_PROVIDER_DEFAULT_MODEL = 'github:copilot'
 const GITHUB_PROVIDER_DEFAULT_BASE_URL = 'https://models.github.ai/inference'
+const CODEX_OAUTH_PROVIDER_NAME = 'Codex OAuth'
+const CODEX_OAUTH_PROVIDER_MODEL = 'codexplan'
 
 type GithubCredentialSource = 'stored' | 'env' | 'none'
 
@@ -193,6 +214,111 @@ function getGithubProviderSummary(
   return `github-models · ${GITHUB_PROVIDER_DEFAULT_BASE_URL} · ${getGithubProviderModel(processEnv)} · ${credentialSummary}${activeSuffix}`
 }
 
+function findCodexOAuthProfile(
+  profiles: ProviderProfile[],
+  profileId?: string,
+): ProviderProfile | undefined {
+  if (!profileId) {
+    return undefined
+  }
+
+  return profiles.find(profile => profile.id === profileId)
+}
+
+function isCodexOAuthProfile(
+  profile: ProviderProfile | null | undefined,
+  profileId?: string,
+): boolean {
+  return Boolean(profile && profileId && profile.id === profileId)
+}
+
+function CodexOAuthSetup({
+  onBack,
+  onConfigured,
+}: {
+  onBack: () => void
+  onConfigured: (tokens: {
+    accessToken: string
+    refreshToken: string
+    accountId?: string
+    idToken?: string
+    apiKey?: string
+  }, persistCredentials: (options?: { profileId?: string }) => void) => void | Promise<void>
+}): React.ReactNode {
+  const handleAuthenticated = React.useCallback(async (tokens: {
+    accessToken: string
+    refreshToken: string
+    accountId?: string
+    idToken?: string
+    apiKey?: string
+  }, persistCredentials: (options?: { profileId?: string }) => void) => {
+    await onConfigured(tokens, persistCredentials)
+  }, [onConfigured])
+  useKeybinding('confirm:no', onBack, [onBack])
+
+  const status = useCodexOAuthFlow({
+    onAuthenticated: handleAuthenticated,
+  })
+
+  if (status.state === 'error') {
+    return (
+      <Box flexDirection="column" gap={1}>
+        <Text color="error" bold>
+          Codex OAuth failed
+        </Text>
+        <Text>{status.message}</Text>
+        <Text dimColor>Press Enter or Esc to go back.</Text>
+        <Select
+          options={[
+            {
+              value: 'back',
+              label: 'Back',
+              description: 'Return to provider presets',
+            },
+          ]}
+          onChange={onBack}
+          onCancel={onBack}
+          visibleOptionCount={1}
+        />
+      </Box>
+    )
+  }
+
+  return (
+    <Box flexDirection="column" gap={1}>
+      <Text color="remember" bold>
+        Codex OAuth
+      </Text>
+      <Text>
+        Sign in with your ChatGPT account in the browser. OpenClaude will store
+        the resulting Codex credentials securely and switch this session to the
+        new Codex login when setup completes.
+      </Text>
+      {status.state === 'starting' ? (
+        <Text dimColor>Starting local callback and preparing your browser...</Text>
+      ) : status.browserOpened === false ? (
+        <>
+          <Text color="warning">
+            Browser did not open automatically. Visit this URL to continue:
+          </Text>
+          <Text>{status.authUrl}</Text>
+        </>
+      ) : status.browserOpened === true ? (
+        <>
+          <Text dimColor>
+            Browser opened. Finish the ChatGPT sign-in there and this setup will
+            complete automatically.
+          </Text>
+          <Text>{status.authUrl}</Text>
+        </>
+      ) : (
+        <Text dimColor>Opening your browser...</Text>
+      )}
+      <Text dimColor>Press Esc to cancel and go back.</Text>
+    </Box>
+  )
+}
+
 export function ProviderManager({ mode, onDone }: Props): React.ReactNode {
   const initialGithubCredentialSource = getGithubCredentialSourceFromEnv()
   const initialIsGithubActive = isEnvTruthy(process.env.CLAUDE_CODE_USE_GITHUB)
@@ -212,6 +338,7 @@ export function ProviderManager({ mode, onDone }: Props): React.ReactNode {
   const [isGithubCredentialSourceResolved, setIsGithubCredentialSourceResolved] =
     React.useState(() => initialHasGithubCredential || initialIsGithubActive)
   const githubRefreshEpochRef = React.useRef(0)
+  const codexRefreshEpochRef = React.useRef(0)
   const [screen, setScreen] = React.useState<Screen>(
     mode === 'first-run' ? 'select-preset' : 'menu',
   )
@@ -226,6 +353,10 @@ export function ProviderManager({ mode, onDone }: Props): React.ReactNode {
   const [cursorOffset, setCursorOffset] = React.useState(0)
   const [statusMessage, setStatusMessage] = React.useState<string | undefined>()
   const [errorMessage, setErrorMessage] = React.useState<string | undefined>()
+  const [hasStoredCodexOAuthCredentials, setHasStoredCodexOAuthCredentials] =
+    React.useState(false)
+  const [storedCodexOAuthProfileId, setStoredCodexOAuthProfileId] =
+    React.useState<string | undefined>()
   const [ollamaSelection, setOllamaSelection] = React.useState<OllamaSelectionState>({
     state: 'idle',
   })
@@ -263,19 +394,102 @@ export function ProviderManager({ mode, onDone }: Props): React.ReactNode {
     })()
   }, [])
 
+  const refreshCodexOAuthCredentialState = React.useCallback((): void => {
+    if (isBareMode()) {
+      codexRefreshEpochRef.current += 1
+      setHasStoredCodexOAuthCredentials(false)
+      setStoredCodexOAuthProfileId(undefined)
+      return
+    }
+
+    const refreshEpoch = ++codexRefreshEpochRef.current
+    void (async () => {
+      const credentials = await readCodexCredentialsAsync()
+      if (refreshEpoch !== codexRefreshEpochRef.current) {
+        return
+      }
+
+      setHasStoredCodexOAuthCredentials(
+        Boolean(
+          credentials?.apiKey ||
+            credentials?.accessToken ||
+            credentials?.refreshToken ||
+            credentials?.idToken,
+        ),
+      )
+      setStoredCodexOAuthProfileId(credentials?.profileId)
+    })()
+  }, [])
+
   React.useEffect(() => {
     refreshGithubProviderState()
+    refreshCodexOAuthCredentialState()
 
     return () => {
       githubRefreshEpochRef.current += 1
+      codexRefreshEpochRef.current += 1
     }
-  }, [refreshGithubProviderState])
+  }, [refreshCodexOAuthCredentialState, refreshGithubProviderState])
+
+  React.useEffect(() => {
+    if (screen !== 'select-ollama-model') {
+      return
+    }
+
+    let cancelled = false
+    setOllamaSelection({ state: 'loading' })
+
+    void (async () => {
+      const available = await hasLocalOllama(draft.baseUrl)
+      if (!available) {
+        if (!cancelled) {
+          setOllamaSelection({
+            state: 'unavailable',
+            message:
+              'Could not reach Ollama. Start Ollama first, or enter the endpoint manually.',
+          })
+        }
+        return
+      }
+
+      const models = await listOllamaModels(draft.baseUrl)
+      if (models.length === 0) {
+        if (!cancelled) {
+          setOllamaSelection({
+            state: 'unavailable',
+            message:
+              'Ollama is running, but no installed models were found. Pull a chat model such as qwen2.5-coder:7b or llama3.1:8b first, or enter details manually.',
+          })
+        }
+        return
+      }
+
+      const ranked = rankOllamaModels(models, 'balanced')
+      const recommended = recommendOllamaModel(models, 'balanced')
+      if (!cancelled) {
+        setOllamaSelection({
+          state: 'ready',
+          defaultValue: recommended?.name ?? ranked[0]?.name,
+          options: ranked.map(model => ({
+            label: model.name,
+            value: model.name,
+            description: model.summary,
+          })),
+        })
+      }
+    })()
+
+    return () => {
+      cancelled = true
+    }
+  }, [draft.baseUrl, screen])
 
   function refreshProfiles(): void {
     const nextProfiles = getProviderProfiles()
     setProfiles(nextProfiles)
     setActiveProfileId(getActiveProviderProfile()?.id)
     refreshGithubProviderState()
+    refreshCodexOAuthCredentialState()
   }
 
   function clearStartupProviderOverrideFromUserSettings(): string | null {
@@ -292,6 +506,123 @@ export function ProviderManager({ mode, onDone }: Props): React.ReactNode {
     return error ? error.message : null
   }
 
+  function buildCodexOAuthActivationMessage(options: {
+    prefix: string
+    activationWarning: string | null
+    warnings: string[]
+  }): string {
+    if (options.activationWarning) {
+      return `${options.prefix}. Saved for next startup. Warning: ${options.warnings.join('; ')}.`
+    }
+
+    if (options.warnings.length > 0) {
+      return `${options.prefix}. OpenClaude switched to it for this session with warnings: ${options.warnings.join('; ')}.`
+    }
+
+    return `${options.prefix}. OpenClaude switched to it for this session.`
+  }
+
+  async function activateCodexOAuthSession(tokens?: {
+    accessToken: string
+    refreshToken?: string
+    accountId?: string
+    idToken?: string
+  }): Promise<string | null> {
+    const oauthEnv = buildCodexOAuthProfileEnv({
+      accessToken: tokens?.accessToken ?? '',
+      accountId: tokens?.accountId,
+      idToken: tokens?.idToken,
+    })
+
+    if (oauthEnv) {
+      return applySavedProfileToCurrentSession({
+        profileFile: createProfileFile('codex', oauthEnv),
+      })
+    }
+
+    const storedCredentials = await readCodexCredentialsAsync()
+    if (!storedCredentials) {
+      return 'stored Codex OAuth credentials could not be loaded'
+    }
+
+    const storedEnv = buildCodexOAuthProfileEnv({
+      accessToken: storedCredentials.accessToken,
+      accountId: storedCredentials.accountId,
+      idToken: storedCredentials.idToken,
+    })
+    if (!storedEnv) {
+      return 'stored Codex OAuth credentials are missing a ChatGPT account id'
+    }
+
+    return applySavedProfileToCurrentSession({
+      profileFile: createProfileFile('codex', storedEnv),
+    })
+  }
+
+  async function activateSelectedProvider(profileId: string): Promise<void> {
+    let providerLabel = 'provider'
+
+    try {
+      if (profileId === GITHUB_PROVIDER_ID) {
+        providerLabel = GITHUB_PROVIDER_LABEL
+        const githubError = activateGithubProvider()
+        if (githubError) {
+          setErrorMessage(`Could not activate GitHub provider: ${githubError}`)
+          setScreen('menu')
+          return
+        }
+
+        refreshProfiles()
+        setStatusMessage(`Active provider: ${GITHUB_PROVIDER_LABEL}`)
+        setScreen('menu')
+        return
+      }
+
+      const active = setActiveProviderProfile(profileId)
+      if (!active) {
+        setErrorMessage('Could not change active provider.')
+        setScreen('menu')
+        return
+      }
+
+      providerLabel = active.name
+      const settingsOverrideError =
+        clearStartupProviderOverrideFromUserSettings()
+      const isActiveCodexOAuth = isCodexOAuthProfile(
+        active,
+        storedCodexOAuthProfileId,
+      )
+      const activationWarning = isActiveCodexOAuth
+        ? await activateCodexOAuthSession()
+        : null
+
+      refreshProfiles()
+      setStatusMessage(
+        isActiveCodexOAuth
+          ? buildCodexOAuthActivationMessage({
+              prefix: `Active provider: ${active.name}`,
+              activationWarning,
+              warnings: [
+                activationWarning,
+                settingsOverrideError
+                  ? `could not clear startup provider override (${settingsOverrideError})`
+                  : null,
+              ].filter((warning): warning is string => Boolean(warning)),
+            })
+          : settingsOverrideError
+            ? `Active provider: ${active.name}. Warning: could not clear startup provider override (${settingsOverrideError}).`
+            : `Active provider: ${active.name}`,
+      )
+      setScreen('menu')
+    } catch (error) {
+      refreshProfiles()
+      setStatusMessage(undefined)
+      const detail = error instanceof Error ? error.message : String(error)
+      setErrorMessage(`Could not finish activating ${providerLabel}: ${detail}`)
+      setScreen('menu')
+    }
+  }
+
   function closeWithCancelled(message: string): void {
     onDone({ action: 'cancelled', message })
   }
@@ -383,59 +714,6 @@ export function ProviderManager({ mode, onDone }: Props): React.ReactNode {
     return null
   }
 
-  React.useEffect(() => {
-    if (screen !== 'select-ollama-model') {
-      return
-    }
-
-    let cancelled = false
-    setOllamaSelection({ state: 'loading' })
-
-    void (async () => {
-      const available = await hasLocalOllama(draft.baseUrl)
-      if (!available) {
-        if (!cancelled) {
-          setOllamaSelection({
-            state: 'unavailable',
-            message:
-              'Could not reach Ollama. Start Ollama first, or enter the endpoint manually.',
-          })
-        }
-        return
-      }
-
-      const models = await listOllamaModels(draft.baseUrl)
-      if (models.length === 0) {
-        if (!cancelled) {
-          setOllamaSelection({
-            state: 'unavailable',
-            message:
-              'Ollama is running, but no installed models were found. Pull a chat model such as qwen2.5-coder:7b or llama3.1:8b first, or enter details manually.',
-          })
-        }
-        return
-      }
-
-      const ranked = rankOllamaModels(models, 'balanced')
-      const recommended = recommendOllamaModel(models, 'balanced')
-      if (!cancelled) {
-        setOllamaSelection({
-          state: 'ready',
-          defaultValue: recommended?.name ?? ranked[0]?.name,
-          options: ranked.map(model => ({
-            label: model.name,
-            value: model.name,
-            description: model.summary,
-          })),
-        })
-      }
-    })()
-
-    return () => {
-      cancelled = true
-    }
-  }, [draft.baseUrl, screen])
-
   function startCreateFromPreset(preset: ProviderPreset): void {
     const defaults = getProviderPresetDefaults(preset)
     const nextDraft = {
@@ -557,7 +835,7 @@ export function ProviderManager({ mode, onDone }: Props): React.ReactNode {
                 description: 'Choose another provider preset',
               },
             ]}
-            onChange={value => {
+            onChange={(value: string) => {
               if (value === 'manual') {
                 setFormStepIndex(0)
                 setCursorOffset(draft.name.length)
@@ -588,7 +866,7 @@ export function ProviderManager({ mode, onDone }: Props): React.ReactNode {
           defaultFocusValue={ollamaSelection.defaultValue}
           inlineDescriptions
           visibleOptionCount={Math.min(8, ollamaSelection.options.length)}
-          onChange={value => {
+          onChange={(value: string) => {
             const nextDraft = {
               ...draft,
               model: value,
@@ -654,6 +932,7 @@ export function ProviderManager({ mode, onDone }: Props): React.ReactNode {
   })
 
   function renderPresetSelection(): React.ReactNode {
+    const canUseCodexOAuth = !isBareMode()
     const options = [
       {
         value: 'anthropic',
@@ -670,6 +949,16 @@ export function ProviderManager({ mode, onDone }: Props): React.ReactNode {
         label: 'OpenAI',
         description: 'OpenAI API with API key',
       },
+      ...(canUseCodexOAuth
+        ? [
+            {
+              value: 'codex-oauth',
+              label: 'Codex OAuth',
+              description:
+                'Sign in with ChatGPT in your browser and store Codex credentials securely',
+            },
+          ]
+        : []),
       {
         value: 'moonshotai',
         label: 'Moonshot AI',
@@ -741,11 +1030,15 @@ export function ProviderManager({ mode, onDone }: Props): React.ReactNode {
         </Text>
         <Select
           options={options}
-          onChange={value => {
+          onChange={(value: string) => {
             if (value === 'skip') {
               closeWithCancelled('Provider setup skipped')
               return
             }
+            if (value === 'codex-oauth') {
+              setScreen('codex-oauth')
+              return
+            }
             startCreateFromPreset(value as ProviderPreset)
           }}
           onCancel={() => {
@@ -755,7 +1048,7 @@ export function ProviderManager({ mode, onDone }: Props): React.ReactNode {
             }
             setScreen('menu')
           }}
-          visibleOptionCount={Math.min(12, options.length)}
+          visibleOptionCount={Math.min(13, options.length)}
         />
       </Box>
     )
@@ -832,6 +1125,15 @@ export function ProviderManager({ mode, onDone }: Props): React.ReactNode {
         description: 'Remove a provider profile',
         disabled: !hasSelectableProviders,
       },
+      ...(hasStoredCodexOAuthCredentials
+        ? [
+            {
+              value: 'logout-codex-oauth',
+              label: 'Log out Codex OAuth',
+              description: 'Clear securely stored Codex OAuth credentials',
+            },
+          ]
+        : []),
       {
         value: 'done',
         label: 'Done',
@@ -876,7 +1178,7 @@ export function ProviderManager({ mode, onDone }: Props): React.ReactNode {
         </Box>
         <Select
           options={options}
-          onChange={value => {
+          onChange={(value: string) => {
             setErrorMessage(undefined)
             switch (value) {
               case 'add':
@@ -897,6 +1199,47 @@ export function ProviderManager({ mode, onDone }: Props): React.ReactNode {
                   setScreen('select-delete')
                 }
                 break
+              case 'logout-codex-oauth': {
+                const cleared = clearCodexCredentials()
+                if (!cleared.success) {
+                  setErrorMessage(
+                    cleared.warning ??
+                      'Could not clear Codex OAuth credentials.',
+                  )
+                  break
+                }
+
+                setHasStoredCodexOAuthCredentials(false)
+                setStoredCodexOAuthProfileId(undefined)
+                const codexProfile = findCodexOAuthProfile(
+                  getProviderProfiles(),
+                  storedCodexOAuthProfileId,
+                )
+                let settingsOverrideError: string | null = null
+                if (codexProfile) {
+                  const result = deleteProviderProfile(codexProfile.id)
+                  if (!result.removed) {
+                    setErrorMessage(
+                      'Codex OAuth credentials were cleared, but the Codex profile could not be removed.',
+                    )
+                    refreshProfiles()
+                    break
+                  }
+
+                  clearPersistedCodexOAuthProfile()
+                  settingsOverrideError = result.activeProfileId
+                    ? clearStartupProviderOverrideFromUserSettings()
+                    : null
+                }
+
+                refreshProfiles()
+                setStatusMessage(
+                  settingsOverrideError
+                    ? `Codex OAuth logged out. Warning: could not clear startup provider override (${settingsOverrideError}).`
+                    : 'Codex OAuth logged out.',
+                )
+                break
+              }
               default:
                 closeWithCancelled('Provider manager closed')
                 break
@@ -975,51 +1318,100 @@ export function ProviderManager({ mode, onDone }: Props): React.ReactNode {
 
   let content: React.ReactNode
 
-    switch (screen) {
-      case 'select-preset':
-        content = renderPresetSelection()
-        break
-      case 'select-ollama-model':
-        content = renderOllamaSelection()
-        break
-      case 'form':
-        content = renderForm()
-        break
+  switch (screen) {
+    case 'select-preset':
+      content = renderPresetSelection()
+      break
+    case 'select-ollama-model':
+      content = renderOllamaSelection()
+      break
+    case 'codex-oauth':
+      content = (
+        <CodexOAuthSetup
+          onBack={() => setScreen('select-preset')}
+          onConfigured={async (tokens, persistCredentials) => {
+            const payload: ProviderProfileInput = {
+              provider: 'openai',
+              name: CODEX_OAUTH_PROVIDER_NAME,
+              baseUrl: DEFAULT_CODEX_BASE_URL,
+              model: CODEX_OAUTH_PROVIDER_MODEL,
+              apiKey: '',
+            }
+
+            const existing = findCodexOAuthProfile(
+              getProviderProfiles(),
+              storedCodexOAuthProfileId,
+            )
+            const saved = existing
+              ? updateProviderProfile(existing.id, payload)
+              : addProviderProfile(payload, { makeActive: true })
+
+            if (!saved) {
+              setErrorMessage(
+                'Codex OAuth login finished, but the provider profile could not be saved.',
+              )
+              setScreen('menu')
+              return
+            }
+
+            const active =
+              existing && activeProfileId !== saved.id
+                ? setActiveProviderProfile(saved.id)
+                : saved
+            if (!active) {
+              setErrorMessage(
+                'Codex OAuth login finished, but the provider could not be set as the startup provider.',
+              )
+              setScreen('menu')
+              return
+            }
+
+            persistCredentials({ profileId: saved.id })
+            const settingsOverrideError =
+              clearStartupProviderOverrideFromUserSettings()
+            const activationWarning = await activateCodexOAuthSession(tokens)
+            setHasStoredCodexOAuthCredentials(true)
+            setStoredCodexOAuthProfileId(saved.id)
+            refreshProfiles()
+            const warnings = [
+              activationWarning,
+              settingsOverrideError
+                ? `could not clear startup provider override (${settingsOverrideError})`
+                : null,
+            ].filter((warning): warning is string => Boolean(warning))
+            const message = buildCodexOAuthActivationMessage({
+              prefix: 'Codex OAuth configured',
+              activationWarning,
+              warnings,
+            })
+
+            if (mode === 'first-run') {
+              onDone({
+                action: 'saved',
+                activeProfileId: active.id,
+                message,
+              })
+              return
+            }
+
+            setStatusMessage(message)
+            setErrorMessage(undefined)
+            setScreen('menu')
+          }}
+        />
+      )
+      break
+    case 'form':
+      content = renderForm()
+      break
     case 'select-active':
       content = renderProfileSelection(
         'Set active provider',
         'No providers available. Add one first.',
         profileId => {
-          if (profileId === GITHUB_PROVIDER_ID) {
-            const githubError = activateGithubProvider()
-            if (githubError) {
-              setErrorMessage(`Could not activate GitHub provider: ${githubError}`)
-              setScreen('menu')
-              return
-            }
-            refreshProfiles()
-            setStatusMessage(`Active provider: ${GITHUB_PROVIDER_LABEL}`)
-            setScreen('menu')
-            return
-          }
-
-          const active = setActiveProviderProfile(profileId)
-          if (!active) {
-            setErrorMessage('Could not change active provider.')
-            setScreen('menu')
-            return
-          }
-          const settingsOverrideError =
-            clearStartupProviderOverrideFromUserSettings()
-          refreshProfiles()
-          setStatusMessage(
-            settingsOverrideError
-              ? `Active provider: ${active.name}. Warning: could not clear startup provider override (${settingsOverrideError}).`
-              : `Active provider: ${active.name}`,
-          )
-          setScreen('menu')
+          void activateSelectedProvider(profileId)
         },
-          { includeGithub: true },
+        { includeGithub: true },
       )
       break
     case 'select-edit':
@@ -1048,10 +1440,27 @@ export function ProviderManager({ mode, onDone }: Props): React.ReactNode {
             return
           }
 
+          const deletedCodexOAuthProfile =
+            findCodexOAuthProfile(
+              profiles,
+              storedCodexOAuthProfileId,
+            )?.id === profileId
           const result = deleteProviderProfile(profileId)
           if (!result.removed) {
             setErrorMessage('Could not delete provider.')
           } else {
+            if (deletedCodexOAuthProfile) {
+              const cleared = clearCodexCredentials()
+              if (!cleared.success) {
+                setErrorMessage(
+                  cleared.warning ??
+                    'Provider deleted, but Codex OAuth credentials could not be cleared.',
+                )
+              } else {
+                setStoredCodexOAuthProfileId(undefined)
+              }
+              clearPersistedCodexOAuthProfile()
+            }
             const settingsOverrideError = result.activeProfileId
               ? clearStartupProviderOverrideFromUserSettings()
               : null
diff --git a/src/components/useCodexOAuthFlow.test.tsx b/src/components/useCodexOAuthFlow.test.tsx
new file mode 100644
index 00000000..5d39ce0f
--- /dev/null
+++ b/src/components/useCodexOAuthFlow.test.tsx
@@ -0,0 +1,220 @@
+import { PassThrough } from 'node:stream'
+
+import { afterEach, expect, mock, test } from 'bun:test'
+import React from 'react'
+
+import { createRoot, Text } from '../ink.js'
+
+const SYNC_START = '\x1B[?2026h'
+const SYNC_END = '\x1B[?2026l'
+
+function createTestStreams(): {
+  stdout: PassThrough
+  stdin: PassThrough & {
+    isTTY: boolean
+    setRawMode: (mode: boolean) => void
+    ref: () => void
+    unref: () => void
+  }
+  getOutput: () => string
+} {
+  let output = ''
+  const stdout = new PassThrough()
+  const stdin = new PassThrough() as PassThrough & {
+    isTTY: boolean
+    setRawMode: (mode: boolean) => void
+    ref: () => void
+    unref: () => void
+  }
+
+  stdin.isTTY = true
+  stdin.setRawMode = () => {}
+  stdin.ref = () => {}
+  stdin.unref = () => {}
+  ;(stdout as unknown as { columns: number }).columns = 120
+  stdout.on('data', chunk => {
+    output += chunk.toString()
+  })
+
+  return {
+    stdout,
+    stdin,
+    getOutput: () => output,
+  }
+}
+
+async function waitForCondition(
+  predicate: () => boolean,
+  options?: { timeoutMs?: number; intervalMs?: number },
+): Promise<void> {
+  const timeoutMs = options?.timeoutMs ?? 5000
+  const intervalMs = options?.intervalMs ?? 10
+  const startedAt = Date.now()
+
+  while (Date.now() - startedAt < timeoutMs) {
+    if (predicate()) {
+      return
+    }
+    await Bun.sleep(intervalMs)
+  }
+
+  throw new Error('Timed out waiting for useCodexOAuthFlow test condition')
+}
+
+function extractLastFrame(output: string): string {
+  let lastFrame: string | null = null
+  let cursor = 0
+
+  while (cursor < output.length) {
+    const start = output.indexOf(SYNC_START, cursor)
+    if (start === -1) break
+
+    const contentStart = start + SYNC_START.length
+    const end = output.indexOf(SYNC_END, contentStart)
+    if (end === -1) break
+
+    const frame = output.slice(contentStart, end)
+    if (frame.trim().length > 0) {
+      lastFrame = frame
+    }
+    cursor = end + SYNC_END.length
+  }
+
+  return lastFrame ?? output
+}
+
+const TOKENS = {
+  accessToken: 'oauth-access-token',
+  refreshToken: 'oauth-refresh-token',
+  accountId: 'acct_oauth',
+  idToken: 'oauth-id-token',
+  apiKey: 'oauth-api-key',
+}
+
+afterEach(() => {
+  mock.restore()
+})
+
+test('does not persist credentials when downstream setup rejects', async () => {
+  const saveCodexCredentials = mock(() => ({ success: true }))
+  const cleanup = mock(() => {})
+  const onAuthenticated = mock(async () => {
+    throw new Error('profile save failed')
+  })
+  const deps = {
+    createOAuthService: () => ({
+      async startOAuthFlow(
+        onAuthorizationUrl: (authUrl: string) => void | Promise<void>,
+      ) {
+        await onAuthorizationUrl('https://chatgpt.com/codex')
+        return TOKENS
+      },
+      cleanup,
+    }),
+    openBrowser: async () => true,
+    saveCodexCredentials,
+    isBareMode: () => false,
+  }
+
+  const { useCodexOAuthFlow } = await import(
+    `./useCodexOAuthFlow.js?real-reject-${Date.now()}-${Math.random()}`
+  )
+
+  function Harness(): React.ReactNode {
+    const handleAuthenticated = React.useCallback(onAuthenticated, [onAuthenticated])
+    const status = useCodexOAuthFlow({
+      onAuthenticated: handleAuthenticated,
+      deps,
+    })
+
+    return <Text>{status.state === 'error' ? status.message : status.state}</Text>
+  }
+
+  const streams = createTestStreams()
+  const root = await createRoot({
+    stdout: streams.stdout as unknown as NodeJS.WriteStream,
+    stdin: streams.stdin as unknown as NodeJS.ReadStream,
+    patchConsole: false,
+  })
+  root.render(<Harness />)
+
+  try {
+    await waitForCondition(() => onAuthenticated.mock.calls.length === 1)
+    await Bun.sleep(0)
+    await Bun.sleep(0)
+    expect(onAuthenticated).toHaveBeenCalled()
+    expect(saveCodexCredentials).not.toHaveBeenCalled()
+  } finally {
+    root.unmount()
+    streams.stdin.end()
+    streams.stdout.end()
+    await Bun.sleep(0)
+  }
+})
+
+test('persists credentials with profile linkage after downstream setup succeeds', async () => {
+  const saveCodexCredentials = mock(() => ({ success: true }))
+  const onAuthenticated = mock(
+    async (
+      _tokens: typeof TOKENS,
+      persistCredentials: (options?: { profileId?: string }) => void,
+    ) => {
+      persistCredentials({ profileId: 'profile_codex_oauth' })
+    },
+  )
+  const cleanup = mock(() => {})
+  const deps = {
+    createOAuthService: () => ({
+      async startOAuthFlow(
+        onAuthorizationUrl: (authUrl: string) => void | Promise<void>,
+      ) {
+        await onAuthorizationUrl('https://chatgpt.com/codex')
+        return TOKENS
+      },
+      cleanup,
+    }),
+    openBrowser: async () => true,
+    saveCodexCredentials,
+    isBareMode: () => false,
+  }
+
+  const { useCodexOAuthFlow } = await import(
+    `./useCodexOAuthFlow.js?real-persist-${Date.now()}-${Math.random()}`
+  )
+
+  function Harness(): React.ReactNode {
+    const handleAuthenticated = React.useCallback(onAuthenticated, [onAuthenticated])
+    useCodexOAuthFlow({
+      onAuthenticated: handleAuthenticated,
+      deps,
+    })
+    return <Text>waiting</Text>
+  }
+
+  const streams = createTestStreams()
+  const root = await createRoot({
+    stdout: streams.stdout as unknown as NodeJS.WriteStream,
+    stdin: streams.stdin as unknown as NodeJS.ReadStream,
+    patchConsole: false,
+  })
+  root.render(<Harness />)
+
+  try {
+    await waitForCondition(() => onAuthenticated.mock.calls.length === 1)
+    await waitForCondition(() => saveCodexCredentials.mock.calls.length === 1)
+    expect(onAuthenticated).toHaveBeenCalled()
+    expect(saveCodexCredentials).toHaveBeenCalledWith({
+      apiKey: TOKENS.apiKey,
+      accessToken: TOKENS.accessToken,
+      refreshToken: TOKENS.refreshToken,
+      idToken: TOKENS.idToken,
+      accountId: TOKENS.accountId,
+      profileId: 'profile_codex_oauth',
+    })
+  } finally {
+    root.unmount()
+    streams.stdin.end()
+    streams.stdout.end()
+    await Bun.sleep(0)
+  }
+})
diff --git a/src/components/useCodexOAuthFlow.ts b/src/components/useCodexOAuthFlow.ts
new file mode 100644
index 00000000..f0de299a
--- /dev/null
+++ b/src/components/useCodexOAuthFlow.ts
@@ -0,0 +1,134 @@
+import * as React from 'react'
+
+import {
+  CodexOAuthService,
+  type CodexOAuthTokens,
+} from '../services/api/codexOAuth.js'
+import { openBrowser } from '../utils/browser.js'
+import { saveCodexCredentials } from '../utils/codexCredentials.js'
+import { isBareMode } from '../utils/envUtils.js'
+
+export type CodexOAuthFlowStatus =
+  | { state: 'starting' }
+  | {
+      state: 'waiting'
+      authUrl: string
+      browserOpened: boolean | null
+    }
+  | {
+      state: 'error'
+      message: string
+    }
+
+type PersistCodexOAuthCredentials = (options?: {
+  profileId?: string
+}) => void
+
+type CodexOAuthFlowDependencies = {
+  createOAuthService?: () => Pick<
+    CodexOAuthService,
+    'startOAuthFlow' | 'cleanup'
+  >
+  openBrowser?: typeof openBrowser
+  saveCodexCredentials?: typeof saveCodexCredentials
+  isBareMode?: typeof isBareMode
+}
+
+function createDefaultOAuthService(): Pick<
+  CodexOAuthService,
+  'startOAuthFlow' | 'cleanup'
+> {
+  return new CodexOAuthService()
+}
+
+export function useCodexOAuthFlow(options: {
+  onAuthenticated: (
+    tokens: CodexOAuthTokens,
+    persistCredentials: PersistCodexOAuthCredentials,
+  ) => void | Promise<void>
+  deps?: CodexOAuthFlowDependencies
+}): CodexOAuthFlowStatus {
+  const { onAuthenticated } = options
+  const createOAuthService =
+    options.deps?.createOAuthService ?? createDefaultOAuthService
+  const openBrowserFn = options.deps?.openBrowser ?? openBrowser
+  const saveCredentials =
+    options.deps?.saveCodexCredentials ?? saveCodexCredentials
+  const isBareModeFn = options.deps?.isBareMode ?? isBareMode
+  const [status, setStatus] = React.useState<CodexOAuthFlowStatus>({
+    state: 'starting',
+  })
+
+  React.useEffect(() => {
+    if (isBareModeFn()) {
+      setStatus({
+        state: 'error',
+        message:
+          'Codex OAuth is unavailable in --bare because secure storage is disabled.',
+      })
+      return
+    }
+
+    let cancelled = false
+    const oauthService = createOAuthService()
+
+    void oauthService
+      .startOAuthFlow(async authUrl => {
+        if (cancelled) return
+        setStatus({
+          state: 'waiting',
+          authUrl,
+          browserOpened: null,
+        })
+        const browserOpened = await openBrowserFn(authUrl)
+        if (cancelled) return
+        setStatus({
+          state: 'waiting',
+          authUrl,
+          browserOpened,
+        })
+      })
+      .then(async tokens => {
+        if (cancelled) return
+
+        const persistCredentials: PersistCodexOAuthCredentials = options => {
+          const saved = saveCredentials({
+            apiKey: tokens.apiKey,
+            accessToken: tokens.accessToken,
+            refreshToken: tokens.refreshToken,
+            idToken: tokens.idToken,
+            accountId: tokens.accountId,
+            profileId: options?.profileId,
+          })
+          if (!saved.success) {
+            throw new Error(
+              saved.warning ??
+                'Codex OAuth succeeded, but credentials could not be saved securely.',
+            )
+          }
+        }
+
+        await onAuthenticated(tokens, persistCredentials)
+      })
+      .catch(error => {
+        if (cancelled) return
+        setStatus({
+          state: 'error',
+          message: error instanceof Error ? error.message : String(error),
+        })
+      })
+
+    return () => {
+      cancelled = true
+      oauthService.cleanup()
+    }
+  }, [
+    createOAuthService,
+    isBareModeFn,
+    onAuthenticated,
+    openBrowserFn,
+    saveCredentials,
+  ])
+
+  return status
+}
diff --git a/src/hooks/useApiKeyVerification.test.tsx b/src/hooks/useApiKeyVerification.test.tsx
new file mode 100644
index 00000000..438cfd17
--- /dev/null
+++ b/src/hooks/useApiKeyVerification.test.tsx
@@ -0,0 +1,123 @@
+import { PassThrough } from 'node:stream'
+
+import { afterEach, expect, mock, test } from 'bun:test'
+import React from 'react'
+import { createRoot, Text } from '../ink.js'
+
+type AuthState = {
+  anthropicAuthEnabled: boolean
+  claudeSubscriber: boolean
+  key?: string
+  source?: string
+}
+
+function createTestStreams(): {
+  stdout: PassThrough
+  stdin: PassThrough & {
+    isTTY: boolean
+    setRawMode: (mode: boolean) => void
+    ref: () => void
+    unref: () => void
+  }
+} {
+  const stdout = new PassThrough()
+  const stdin = new PassThrough() as PassThrough & {
+    isTTY: boolean
+    setRawMode: (mode: boolean) => void
+    ref: () => void
+    unref: () => void
+  }
+
+  stdin.isTTY = true
+  stdin.setRawMode = () => {}
+  stdin.ref = () => {}
+  stdin.unref = () => {}
+  ;(stdout as unknown as { columns: number }).columns = 120
+
+  return { stdout, stdin }
+}
+
+async function waitForCondition(
+  predicate: () => boolean,
+  timeoutMs = 2000,
+): Promise<void> {
+  const startedAt = Date.now()
+
+  while (Date.now() - startedAt < timeoutMs) {
+    if (predicate()) {
+      return
+    }
+    await Bun.sleep(10)
+  }
+
+  throw new Error('Timed out waiting for useApiKeyVerification test state')
+}
+
+afterEach(() => {
+  mock.restore()
+})
+
+test('useApiKeyVerification resets stale missing status when the session switches to a third-party provider', async () => {
+  const authState: AuthState = {
+    anthropicAuthEnabled: true,
+    claudeSubscriber: false,
+  }
+  const seenStatuses: string[] = []
+
+  mock.module('../utils/auth.js', () => ({
+    getAnthropicApiKeyWithSource: () => ({
+      key: authState.key,
+      source: authState.source,
+    }),
+    getApiKeyFromApiKeyHelper: async () => undefined,
+    isAnthropicAuthEnabled: () => authState.anthropicAuthEnabled,
+    isClaudeAISubscriber: () => authState.claudeSubscriber,
+  }))
+
+  mock.module('../bootstrap/state.js', () => ({
+    getIsNonInteractiveSession: () => false,
+  }))
+
+  mock.module('../services/api/claude.js', () => ({
+    verifyApiKey: async () => true,
+  }))
+
+  // @ts-expect-error cache-busting query string for Bun module mocks
+  const { useApiKeyVerification } = await import(
+    './useApiKeyVerification.ts?switch-to-third-party'
+  )
+
+  function Harness(): React.ReactNode {
+    const { status } = useApiKeyVerification()
+
+    React.useEffect(() => {
+      seenStatuses.push(status)
+    }, [status])
+
+    return <Text>{status}</Text>
+  }
+
+  const { stdout, stdin } = createTestStreams()
+  const root = await createRoot({
+    stdout: stdout as unknown as NodeJS.WriteStream,
+    stdin: stdin as unknown as NodeJS.ReadStream,
+    patchConsole: false,
+  })
+
+  root.render(<Harness />)
+
+  await waitForCondition(() => seenStatuses.includes('missing'))
+
+  authState.anthropicAuthEnabled = false
+  root.render(<Harness />)
+
+  await waitForCondition(() => seenStatuses.includes('valid'))
+
+  root.unmount()
+  stdin.end()
+  stdout.end()
+  await Bun.sleep(0)
+
+  expect(seenStatuses[0]).toBe('missing')
+  expect(seenStatuses).toContain('valid')
+})
diff --git a/src/hooks/useApiKeyVerification.ts b/src/hooks/useApiKeyVerification.ts
index d6433c57..87a5863d 100644
--- a/src/hooks/useApiKeyVerification.ts
+++ b/src/hooks/useApiKeyVerification.ts
@@ -1,4 +1,4 @@
-import { useCallback, useState } from 'react'
+import { useCallback, useEffect, useState } from 'react'
 import { getIsNonInteractiveSession } from '../bootstrap/state.js'
 import { verifyApiKey } from '../services/api/claude.js'
 import {
@@ -21,24 +21,43 @@ export type ApiKeyVerificationResult = {
   error: Error | null
 }
 
-export function useApiKeyVerification(): ApiKeyVerificationResult {
-  const [status, setStatus] = useState<VerificationStatus>(() => {
-    if (!isAnthropicAuthEnabled() || isClaudeAISubscriber()) {
-      return 'valid'
-    }
-    // Use skipRetrievingKeyFromApiKeyHelper to avoid executing apiKeyHelper
-    // before trust dialog is shown (security: prevents RCE via settings.json)
-    const { key, source } = getAnthropicApiKeyWithSource({
-      skipRetrievingKeyFromApiKeyHelper: true,
-    })
-    // If apiKeyHelper is configured, we have a key source even though we
-    // haven't executed it yet - return 'loading' to indicate we'll verify later
-    if (key || source === 'apiKeyHelper') {
-      return 'loading'
-    }
-    return 'missing'
+function getInitialVerificationStatus(): VerificationStatus {
+  if (!isAnthropicAuthEnabled() || isClaudeAISubscriber()) {
+    return 'valid'
+  }
+  // Use skipRetrievingKeyFromApiKeyHelper to avoid executing apiKeyHelper
+  // before trust dialog is shown (security: prevents RCE via settings.json)
+  const { key, source } = getAnthropicApiKeyWithSource({
+    skipRetrievingKeyFromApiKeyHelper: true,
   })
+  // If apiKeyHelper is configured, we have a key source even though we
+  // haven't executed it yet - return 'loading' to indicate we'll verify later
+  if (key || source === 'apiKeyHelper') {
+    return 'loading'
+  }
+  return 'missing'
+}
+
+export function useApiKeyVerification(): ApiKeyVerificationResult {
+  const [status, setStatus] = useState<VerificationStatus>(
+    getInitialVerificationStatus,
+  )
   const [error, setError] = useState<Error | null>(null)
+  const anthropicVerificationEnabled =
+    isAnthropicAuthEnabled() && !isClaudeAISubscriber()
+
+  useEffect(() => {
+    const nextStatus = anthropicVerificationEnabled
+      ? getInitialVerificationStatus()
+      : 'valid'
+
+    setStatus(currentStatus =>
+      currentStatus === nextStatus ? currentStatus : nextStatus,
+    )
+    if (nextStatus !== 'error') {
+      setError(null)
+    }
+  }, [anthropicVerificationEnabled])
 
   const verify = useCallback(async (): Promise<void> => {
     if (!isAnthropicAuthEnabled() || isClaudeAISubscriber()) {
diff --git a/src/services/api/codexOAuth.test.ts b/src/services/api/codexOAuth.test.ts
new file mode 100644
index 00000000..e98b5792
--- /dev/null
+++ b/src/services/api/codexOAuth.test.ts
@@ -0,0 +1,166 @@
+import { createServer } from 'node:http'
+
+import { afterEach, expect, mock, test } from 'bun:test'
+
+import { CodexOAuthService } from './codexOAuth.js'
+
+const originalFetch = globalThis.fetch
+const originalCallbackPort = process.env.CODEX_OAUTH_CALLBACK_PORT
+const originalClientId = process.env.CODEX_OAUTH_CLIENT_ID
+
+afterEach(() => {
+  mock.restore()
+  globalThis.fetch = originalFetch
+
+  if (originalCallbackPort === undefined) {
+    delete process.env.CODEX_OAUTH_CALLBACK_PORT
+  } else {
+    process.env.CODEX_OAUTH_CALLBACK_PORT = originalCallbackPort
+  }
+
+  if (originalClientId === undefined) {
+    delete process.env.CODEX_OAUTH_CLIENT_ID
+  } else {
+    process.env.CODEX_OAUTH_CLIENT_ID = originalClientId
+  }
+})
+
+async function getFreePort(): Promise<number> {
+  return await new Promise((resolve, reject) => {
+    const server = createServer()
+
+    server.once('error', reject)
+    server.listen(0, '127.0.0.1', () => {
+      const address = server.address()
+      if (!address || typeof address === 'string') {
+        server.close(() => reject(new Error('Failed to allocate test port.')))
+        return
+      }
+
+      const { port } = address
+      server.close(error => {
+        if (error) {
+          reject(error)
+          return
+        }
+        resolve(port)
+      })
+    })
+  })
+}
+
+function buildCallbackRequest(authUrl: string): string {
+  const authorizeUrl = new URL(authUrl)
+  const redirectUri = authorizeUrl.searchParams.get('redirect_uri')
+  const state = authorizeUrl.searchParams.get('state')
+
+  if (!redirectUri || !state) {
+    throw new Error('Codex OAuth test did not receive a valid authorization URL.')
+  }
+
+  const callbackUrl = new URL(redirectUri)
+  callbackUrl.searchParams.set('code', 'auth-code')
+  callbackUrl.searchParams.set('state', state)
+  return callbackUrl.toString()
+}
+
+test('serves updated success copy after a successful Codex OAuth flow', async () => {
+  const callbackPort = await getFreePort()
+  process.env.CODEX_OAUTH_CALLBACK_PORT = String(callbackPort)
+  process.env.CODEX_OAUTH_CLIENT_ID = 'test-client-id'
+
+  globalThis.fetch = mock(async (input, init) => {
+    const url = String(input)
+    if (url.startsWith('http://localhost:')) {
+      return originalFetch(input, init)
+    }
+
+    return new Response(
+      JSON.stringify({
+        access_token: 'access-token',
+        refresh_token: 'refresh-token',
+      }),
+      {
+        status: 200,
+        headers: { 'Content-Type': 'application/json' },
+      },
+    )
+  }) as typeof fetch
+
+  const service = new CodexOAuthService()
+  let callbackResponsePromise!: Promise<Response>
+
+  const flowPromise = service.startOAuthFlow(async authUrl => {
+    callbackResponsePromise = originalFetch(buildCallbackRequest(authUrl))
+  })
+
+  const tokens = await flowPromise
+  const callbackResponse = await callbackResponsePromise
+  const html = await callbackResponse.text()
+
+  expect(tokens.accessToken).toBe('access-token')
+  expect(tokens.refreshToken).toBe('refresh-token')
+  expect(html).toContain('You can return to OpenClaude now.')
+  expect(html).toContain(
+    'OpenClaude will finish activating your new Codex OAuth login.',
+  )
+  expect(html).not.toContain('continue automatically')
+})
+
+test('cancellation during token exchange returns a cancelled page and rejects the flow', async () => {
+  const callbackPort = await getFreePort()
+  process.env.CODEX_OAUTH_CALLBACK_PORT = String(callbackPort)
+  process.env.CODEX_OAUTH_CLIENT_ID = 'test-client-id'
+
+  let resolveFetchStart!: () => void
+  const fetchStarted = new Promise<void>(resolve => {
+    resolveFetchStart = resolve
+  })
+
+  globalThis.fetch = mock((input, init) => {
+    const url = String(input)
+    if (url.startsWith('http://localhost:')) {
+      return originalFetch(input, init)
+    }
+
+    return new Promise<Response>((_resolve, reject) => {
+      resolveFetchStart()
+
+      const signal = init?.signal
+      if (!signal) {
+        return
+      }
+
+      if (signal.aborted) {
+        reject(signal.reason)
+        return
+      }
+
+      signal.addEventListener(
+        'abort',
+        () => {
+          reject(signal.reason)
+        },
+        { once: true },
+      )
+    })
+  }) as typeof fetch
+
+  const service = new CodexOAuthService()
+  let callbackResponsePromise!: Promise<Response>
+
+  const flowPromise = service.startOAuthFlow(async authUrl => {
+    callbackResponsePromise = originalFetch(buildCallbackRequest(authUrl))
+  })
+
+  await fetchStarted
+  service.cleanup()
+
+  await expect(flowPromise).rejects.toThrow('Codex OAuth flow was cancelled.')
+
+  const callbackResponse = await callbackResponsePromise
+  const html = await callbackResponse.text()
+
+  expect(html).toContain('Codex login cancelled')
+  expect(html).toContain('retry in OpenClaude')
+})
diff --git a/src/services/api/codexOAuth.ts b/src/services/api/codexOAuth.ts
new file mode 100644
index 00000000..5604972d
--- /dev/null
+++ b/src/services/api/codexOAuth.ts
@@ -0,0 +1,307 @@
+import { AuthCodeListener } from '../oauth/auth-code-listener.js'
+import {
+  generateCodeChallenge,
+  generateCodeVerifier,
+  generateState,
+} from '../oauth/crypto.js'
+import {
+  asTrimmedString,
+  CODEX_OAUTH_ISSUER,
+  CODEX_OAUTH_ORIGINATOR,
+  CODEX_OAUTH_SCOPE,
+  escapeHtml,
+  exchangeCodexIdTokenForApiKey,
+  getCodexOAuthCallbackPort,
+  getCodexOAuthClientId,
+  parseChatgptAccountId,
+} from './codexOAuthShared.js'
+
+type CodexOAuthTokenResponse = {
+  id_token?: string
+  access_token?: string
+  refresh_token?: string
+}
+
+export type CodexOAuthTokens = {
+  apiKey?: string
+  accessToken: string
+  refreshToken: string
+  idToken?: string
+  accountId?: string
+}
+
+function buildCodexAuthorizeUrl(options: {
+  port: number
+  codeChallenge: string
+  state: string
+}): string {
+  const redirectUri = `http://localhost:${options.port}/auth/callback`
+  const authUrl = new URL(`${CODEX_OAUTH_ISSUER}/oauth/authorize`)
+
+  authUrl.searchParams.append('response_type', 'code')
+  authUrl.searchParams.append('client_id', getCodexOAuthClientId())
+  authUrl.searchParams.append('redirect_uri', redirectUri)
+  authUrl.searchParams.append('scope', CODEX_OAUTH_SCOPE)
+  authUrl.searchParams.append('code_challenge', options.codeChallenge)
+  authUrl.searchParams.append('code_challenge_method', 'S256')
+  authUrl.searchParams.append('id_token_add_organizations', 'true')
+  authUrl.searchParams.append('codex_cli_simplified_flow', 'true')
+  authUrl.searchParams.append('state', options.state)
+  authUrl.searchParams.append('originator', CODEX_OAUTH_ORIGINATOR)
+
+  return authUrl.toString()
+}
+
+function renderSuccessPage(): string {
+  return `<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8" />
+    <title>Codex Login Complete</title>
+    <style>
+      body { font-family: sans-serif; padding: 32px; line-height: 1.5; color: #111827; }
+      h1 { margin: 0 0 12px; font-size: 22px; }
+      p { margin: 0 0 10px; }
+    </style>
+  </head>
+  <body>
+    <h1>Codex login complete</h1>
+    <p>You can return to OpenClaude now.</p>
+    <p>OpenClaude will finish activating your new Codex OAuth login.</p>
+  </body>
+</html>`
+}
+
+function renderErrorPage(message: string): string {
+  const safeMessage = escapeHtml(message)
+  return `<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8" />
+    <title>Codex Login Failed</title>
+    <style>
+      body { font-family: sans-serif; padding: 32px; line-height: 1.5; color: #111827; }
+      h1 { margin: 0 0 12px; font-size: 22px; color: #991b1b; }
+      p { margin: 0 0 10px; }
+    </style>
+  </head>
+  <body>
+    <h1>Codex login failed</h1>
+    <p>${safeMessage}</p>
+    <p>You can close this window and try again in OpenClaude.</p>
+  </body>
+</html>`
+}
+
+function renderCancelledPage(): string {
+  return `<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8" />
+    <title>Codex Login Cancelled</title>
+    <style>
+      body { font-family: sans-serif; padding: 32px; line-height: 1.5; color: #111827; }
+      h1 { margin: 0 0 12px; font-size: 22px; }
+      p { margin: 0 0 10px; }
+    </style>
+  </head>
+  <body>
+    <h1>Codex login cancelled</h1>
+    <p>You can close this window and retry in OpenClaude.</p>
+  </body>
+</html>`
+}
+
+async function exchangeAuthorizationCode(options: {
+  authorizationCode: string
+  codeVerifier: string
+  port: number
+  signal?: AbortSignal
+}): Promise<CodexOAuthTokens> {
+  const redirectUri = `http://localhost:${options.port}/auth/callback`
+  const body = new URLSearchParams({
+    grant_type: 'authorization_code',
+    code: options.authorizationCode,
+    redirect_uri: redirectUri,
+    client_id: getCodexOAuthClientId(),
+    code_verifier: options.codeVerifier,
+  })
+
+  const response = await fetch(`${CODEX_OAUTH_ISSUER}/oauth/token`, {
+    method: 'POST',
+    headers: {
+      'Content-Type': 'application/x-www-form-urlencoded',
+    },
+    body,
+    signal: options.signal
+      ? AbortSignal.any([options.signal, AbortSignal.timeout(15_000)])
+      : AbortSignal.timeout(15_000),
+  })
+
+  if (!response.ok) {
+    const errorText = await response.text().catch(() => '')
+    throw new Error(
+      errorText.trim()
+        ? `Codex OAuth token exchange failed (${response.status}): ${errorText.trim()}`
+        : `Codex OAuth token exchange failed with status ${response.status}.`,
+    )
+  }
+
+  const payload = (await response.json()) as CodexOAuthTokenResponse
+  const accessToken = asTrimmedString(payload.access_token)
+  const refreshToken = asTrimmedString(payload.refresh_token)
+  if (!accessToken || !refreshToken) {
+    throw new Error(
+      'Codex OAuth completed, but the token response was missing credentials.',
+    )
+  }
+
+  const idToken = asTrimmedString(payload.id_token)
+  const apiKey = idToken
+    ? await exchangeCodexIdTokenForApiKey(idToken).catch(() => undefined)
+    : undefined
+
+  return {
+    apiKey,
+    accessToken,
+    refreshToken,
+    idToken,
+    accountId:
+      parseChatgptAccountId(idToken) ?? parseChatgptAccountId(accessToken),
+  }
+}
+
+export class CodexOAuthService {
+  private authCodeListener: AuthCodeListener | null = null
+  private port: number | null = null
+  private tokenExchangeAbortController: AbortController | null = null
+
+  private buildCancellationError(): Error {
+    return new Error('Codex OAuth flow was cancelled.')
+  }
+
+  async startOAuthFlow(
+    authURLHandler: (authUrl: string) => Promise<void>,
+  ): Promise<CodexOAuthTokens> {
+    const codeVerifier = generateCodeVerifier()
+    const callbackPort = getCodexOAuthCallbackPort()
+    const authCodeListener = new AuthCodeListener('/auth/callback')
+
+    this.authCodeListener = authCodeListener
+    this.port = null
+
+    try {
+      const port = await authCodeListener.start(callbackPort)
+      this.port = port
+
+      const state = generateState()
+      const codeChallenge = await generateCodeChallenge(codeVerifier)
+      const authUrl = buildCodexAuthorizeUrl({
+        port,
+        codeChallenge,
+        state,
+      })
+
+      try {
+        const authorizationCode = await authCodeListener.waitForAuthorization(
+          state,
+          async () => {
+            await authURLHandler(authUrl)
+          },
+        )
+
+        const tokenExchangeAbortController = new AbortController()
+        this.tokenExchangeAbortController = tokenExchangeAbortController
+
+        let tokens: CodexOAuthTokens
+        try {
+          tokens = await exchangeAuthorizationCode({
+            authorizationCode,
+            codeVerifier,
+            port,
+            signal: tokenExchangeAbortController.signal,
+          })
+        } finally {
+          if (
+            this.tokenExchangeAbortController === tokenExchangeAbortController
+          ) {
+            this.tokenExchangeAbortController = null
+          }
+        }
+
+        if (this.authCodeListener !== authCodeListener) {
+          throw this.buildCancellationError()
+        }
+
+        authCodeListener.handleSuccessRedirect([], res => {
+          res.writeHead(200, {
+            'Content-Type': 'text/html; charset=utf-8',
+          })
+          res.end(renderSuccessPage())
+        })
+
+        return tokens
+      } catch (error) {
+        const resolvedError =
+          this.authCodeListener === authCodeListener
+            ? error
+            : this.buildCancellationError()
+
+        if (authCodeListener.hasPendingResponse()) {
+          const isCancellation =
+            resolvedError instanceof Error &&
+            resolvedError.message === 'Codex OAuth flow was cancelled.'
+
+          authCodeListener.handleErrorRedirect(res => {
+            res.writeHead(isCancellation ? 200 : 400, {
+              'Content-Type': 'text/html; charset=utf-8',
+            })
+            res.end(
+              isCancellation
+                ? renderCancelledPage()
+                : renderErrorPage(
+                    resolvedError instanceof Error
+                      ? resolvedError.message
+                      : String(resolvedError),
+                  ),
+            )
+          })
+        }
+        throw resolvedError
+      } finally {
+        this.cleanup()
+      }
+    } catch (error) {
+      const message = error instanceof Error ? error.message : String(error)
+      if (
+        message.includes('EADDRINUSE') ||
+        message.includes(String(callbackPort))
+      ) {
+        throw new Error(
+          `Codex OAuth needs localhost:${callbackPort} for its callback. Close any app already using that port and try again.`,
+        )
+      }
+      throw error
+    }
+  }
+
+  cleanup(): void {
+    const cancellationError = this.buildCancellationError()
+
+    this.tokenExchangeAbortController?.abort(cancellationError)
+    this.tokenExchangeAbortController = null
+
+    if (this.authCodeListener?.hasPendingResponse()) {
+      this.authCodeListener.handleErrorRedirect(res => {
+        res.writeHead(200, {
+          'Content-Type': 'text/html; charset=utf-8',
+        })
+        res.end(renderCancelledPage())
+      })
+    }
+
+    this.authCodeListener?.cancelPendingAuthorization(cancellationError)
+    this.authCodeListener = null
+    this.port = null
+  }
+}
diff --git a/src/services/api/codexOAuthShared.ts b/src/services/api/codexOAuthShared.ts
new file mode 100644
index 00000000..f686c540
--- /dev/null
+++ b/src/services/api/codexOAuthShared.ts
@@ -0,0 +1,139 @@
+export const CODEX_OAUTH_ISSUER = 'https://auth.openai.com'
+export const CODEX_REFRESH_URL = `${CODEX_OAUTH_ISSUER}/oauth/token`
+export const DEFAULT_CODEX_OAUTH_CLIENT_ID = 'app_EMoamEEZ73f0CkXaXp7hrann'
+export const DEFAULT_CODEX_OAUTH_CALLBACK_PORT = 1455
+export const CODEX_OAUTH_SCOPE =
+  'openid profile email offline_access api.connectors.read api.connectors.invoke'
+export const CODEX_OAUTH_ORIGINATOR = 'codex_cli_rs'
+export const CODEX_API_KEY_TOKEN_NAME = 'openai-api-key'
+export const CODEX_ID_TOKEN_SUBJECT_TYPE =
+  'urn:ietf:params:oauth:token-type:id_token'
+export const CODEX_TOKEN_EXCHANGE_GRANT =
+  'urn:ietf:params:oauth:grant-type:token-exchange'
+
+export function asTrimmedString(value: unknown): string | undefined {
+  if (typeof value !== 'string') return undefined
+  const trimmed = value.trim()
+  return trimmed ? trimmed : undefined
+}
+
+export function getCodexOAuthClientId(
+  env: NodeJS.ProcessEnv = process.env,
+): string {
+  return asTrimmedString(env.CODEX_OAUTH_CLIENT_ID) ?? DEFAULT_CODEX_OAUTH_CLIENT_ID
+}
+
+export function getCodexOAuthCallbackPort(
+  env: NodeJS.ProcessEnv = process.env,
+): number {
+  const rawPort = asTrimmedString(env.CODEX_OAUTH_CALLBACK_PORT)
+  if (!rawPort) {
+    return DEFAULT_CODEX_OAUTH_CALLBACK_PORT
+  }
+
+  const parsed = Number.parseInt(rawPort, 10)
+  if (Number.isInteger(parsed) && parsed > 0 && parsed <= 65535) {
+    return parsed
+  }
+
+  return DEFAULT_CODEX_OAUTH_CALLBACK_PORT
+}
+
+export function decodeJwtPayload(
+  token: string,
+): Record<string, unknown> | undefined {
+  const parts = token.split('.')
+  if (parts.length < 2) return undefined
+
+  try {
+    const normalized = parts[1].replace(/-/g, '+').replace(/_/g, '/')
+    const padded = normalized + '='.repeat((4 - (normalized.length % 4)) % 4)
+    const json = Buffer.from(padded, 'base64').toString('utf8')
+    const parsed = JSON.parse(json)
+    return parsed && typeof parsed === 'object'
+      ? (parsed as Record<string, unknown>)
+      : undefined
+  } catch {
+    return undefined
+  }
+}
+
+export function parseChatgptAccountId(
+  token: string | undefined,
+): string | undefined {
+  if (!token) return undefined
+
+  const payload = decodeJwtPayload(token)
+  const nestedAuth =
+    payload?.['https://api.openai.com/auth'] &&
+    typeof payload['https://api.openai.com/auth'] === 'object'
+      ? (payload['https://api.openai.com/auth'] as Record<string, unknown>)
+      : undefined
+
+  return (
+    asTrimmedString(
+      nestedAuth?.chatgpt_account_id ??
+        payload?.['https://api.openai.com/auth.chatgpt_account_id'] ??
+        payload?.chatgpt_account_id,
+    ) ?? undefined
+  )
+}
+
+export function escapeHtml(value: string): string {
+  return value.replace(/[&<>"']/g, char => {
+    switch (char) {
+      case '&':
+        return '&amp;'
+      case '<':
+        return '&lt;'
+      case '>':
+        return '&gt;'
+      case '"':
+        return '&quot;'
+      case '\'':
+        return '&#39;'
+      default:
+        return char
+    }
+  })
+}
+
+export async function exchangeCodexIdTokenForApiKey(
+  idToken: string,
+): Promise<string> {
+  const body = new URLSearchParams({
+    grant_type: CODEX_TOKEN_EXCHANGE_GRANT,
+    client_id: getCodexOAuthClientId(),
+    requested_token: CODEX_API_KEY_TOKEN_NAME,
+    subject_token: idToken,
+    subject_token_type: CODEX_ID_TOKEN_SUBJECT_TYPE,
+  })
+
+  const response = await fetch(CODEX_REFRESH_URL, {
+    method: 'POST',
+    headers: {
+      'Content-Type': 'application/x-www-form-urlencoded',
+    },
+    body,
+    signal: AbortSignal.timeout(15_000),
+  })
+
+  if (!response.ok) {
+    const bodyText = await response.text().catch(() => '')
+    throw new Error(
+      bodyText.trim()
+        ? `Codex API key exchange failed (${response.status}): ${bodyText.trim()}`
+        : `Codex API key exchange failed with status ${response.status}.`,
+    )
+  }
+
+  const payload = (await response.json()) as { access_token?: string }
+  const apiKey = asTrimmedString(payload.access_token)
+  if (!apiKey) {
+    throw new Error(
+      'Codex API key exchange completed, but no API key token was returned.',
+    )
+  }
+
+  return apiKey
+}
diff --git a/src/services/api/codexShim.test.ts b/src/services/api/codexShim.test.ts
index a135425b..d2e39aae 100644
--- a/src/services/api/codexShim.test.ts
+++ b/src/services/api/codexShim.test.ts
@@ -8,10 +8,6 @@ import {
   convertCodexResponseToAnthropicMessage,
   convertToolsToResponsesTools,
 } from './codexShim.js'
-import {
-  resolveCodexApiCredentials,
-  resolveProviderRequest,
-} from './providerConfig.js'
 
 const tempDirs: string[] = []
 const originalEnv = {
@@ -63,6 +59,10 @@ async function collectStreamEventTypes(responseText: string): Promise<string[]>
   return events
 }
 
+async function importFreshProviderConfigModule() {
+  return import(`./providerConfig.js?ts=${Date.now()}-${Math.random()}`)
+}
+
 describe('Codex provider config', () => {
   const originalOpenaiBaseUrl = process.env.OPENAI_BASE_URL
   const originalOpenaiApiBase = process.env.OPENAI_API_BASE
@@ -79,7 +79,8 @@ describe('Codex provider config', () => {
     else process.env.OPENAI_API_BASE = originalOpenaiApiBase
   })
 
-  test('resolves codexplan alias to Codex transport with reasoning', () => {
+  test('resolves codexplan alias to Codex transport with reasoning', async () => {
+    const { resolveProviderRequest } = await importFreshProviderConfigModule()
     delete process.env.OPENAI_BASE_URL
     delete process.env.OPENAI_API_BASE
     delete process.env.CLAUDE_CODE_USE_GITHUB
@@ -91,7 +92,8 @@ describe('Codex provider config', () => {
     expect(resolved.baseUrl).toBe('https://chatgpt.com/backend-api/codex')
   })
 
-  test('resolves codexspark alias to Codex transport with Codex base URL', () => {
+  test('resolves codexspark alias to Codex transport with Codex base URL', async () => {
+    const { resolveProviderRequest } = await importFreshProviderConfigModule()
     delete process.env.OPENAI_BASE_URL
     delete process.env.OPENAI_API_BASE
     delete process.env.CLAUDE_CODE_USE_GITHUB
@@ -102,7 +104,8 @@ describe('Codex provider config', () => {
     expect(resolved.baseUrl).toBe('https://chatgpt.com/backend-api/codex')
   })
 
-  test('does not force Codex transport when a local non-Codex base URL is explicit', () => {
+  test('does not force Codex transport when a local non-Codex base URL is explicit', async () => {
+    const { resolveProviderRequest } = await importFreshProviderConfigModule()
     const resolved = resolveProviderRequest({
       model: 'codexplan',
       baseUrl: 'http://127.0.0.1:8080/v1',
@@ -113,7 +116,8 @@ describe('Codex provider config', () => {
     expect(resolved.resolvedModel).toBe('gpt-5.4')
   })
 
-  test('resolves codexplan to Codex transport even when OPENAI_BASE_URL is the string "undefined"', () => {
+  test('resolves codexplan to Codex transport even when OPENAI_BASE_URL is the string "undefined"', async () => {
+    const { resolveProviderRequest } = await importFreshProviderConfigModule()
     // On Windows, env vars can leak as the literal string "undefined" instead of
     // the JS value undefined when not properly unset (issue #336).
     process.env.OPENAI_BASE_URL = 'undefined'
@@ -121,20 +125,23 @@ describe('Codex provider config', () => {
     expect(resolved.transport).toBe('codex_responses')
   })
 
-  test('resolves codexplan to Codex transport even when OPENAI_BASE_URL is an empty string', () => {
+  test('resolves codexplan to Codex transport even when OPENAI_BASE_URL is an empty string', async () => {
+    const { resolveProviderRequest } = await importFreshProviderConfigModule()
     process.env.OPENAI_BASE_URL = ''
     const resolved = resolveProviderRequest({ model: 'codexplan' })
     expect(resolved.transport).toBe('codex_responses')
   })
 
-  test('prefers explicit baseUrl option over env var', () => {
+  test('prefers explicit baseUrl option over env var', async () => {
+    const { resolveProviderRequest } = await importFreshProviderConfigModule()
     process.env.OPENAI_BASE_URL = 'https://example.com/v1'
     const resolved = resolveProviderRequest({ model: 'codexplan', baseUrl: 'https://chatgpt.com/backend-api/codex' })
     expect(resolved.transport).toBe('codex_responses')
     expect(resolved.baseUrl).toBe('https://chatgpt.com/backend-api/codex')
   })
 
-  test('default gpt-4o uses OpenAI base URL (no regression)', () => {
+  test('default gpt-4o uses OpenAI base URL (no regression)', async () => {
+    const { resolveProviderRequest } = await importFreshProviderConfigModule()
     delete process.env.OPENAI_BASE_URL
     delete process.env.CLAUDE_CODE_USE_GITHUB
 
@@ -144,7 +151,8 @@ describe('Codex provider config', () => {
     expect(resolved.resolvedModel).toBe('gpt-4o')
   })
 
-  test('resolves codexplan from env var OPENAI_MODEL to Codex endpoint', () => {
+  test('resolves codexplan from env var OPENAI_MODEL to Codex endpoint', async () => {
+    const { resolveProviderRequest } = await importFreshProviderConfigModule()
     process.env.OPENAI_MODEL = 'codexplan'
     delete process.env.OPENAI_BASE_URL
     delete process.env.CLAUDE_CODE_USE_GITHUB
@@ -155,7 +163,8 @@ describe('Codex provider config', () => {
     expect(resolved.resolvedModel).toBe('gpt-5.4')
   })
 
-  test('does not override custom base URL for codexplan (e.g., local provider)', () => {
+  test('does not override custom base URL for codexplan (e.g., local provider)', async () => {
+    const { resolveProviderRequest } = await importFreshProviderConfigModule()
     process.env.OPENAI_MODEL = 'codexplan'
     process.env.OPENAI_BASE_URL = 'http://localhost:11434/v1'
     delete process.env.CLAUDE_CODE_USE_GITHUB
@@ -165,7 +174,8 @@ describe('Codex provider config', () => {
     expect(resolved.baseUrl).toBe('http://localhost:11434/v1')
   })
 
-  test('loads Codex credentials from auth.json fallback', () => {
+  test('loads Codex credentials from auth.json fallback', async () => {
+    const { resolveCodexApiCredentials } = await importFreshProviderConfigModule()
     const authPath = createTempAuthJson({
       tokens: {
         access_token: 'header.payload.signature',
@@ -181,6 +191,31 @@ describe('Codex provider config', () => {
     expect(credentials.accountId).toBe('acct_test')
     expect(credentials.source).toBe('auth.json')
   })
+
+  test('does not treat auth.json id_token as a Codex bearer credential', async () => {
+    const { resolveCodexApiCredentials } = await importFreshProviderConfigModule()
+    const idTokenPayload = Buffer.from(
+      JSON.stringify({
+        'https://api.openai.com/auth': {
+          chatgpt_account_id: 'acct_from_id_token',
+        },
+      }),
+      'utf8',
+    ).toString('base64url')
+    const authPath = createTempAuthJson({
+      tokens: {
+        id_token: `header.${idTokenPayload}.signature`,
+      },
+    })
+
+    const credentials = resolveCodexApiCredentials({
+      CODEX_AUTH_JSON_PATH: authPath,
+    } as NodeJS.ProcessEnv)
+
+    expect(credentials.apiKey).toBe('')
+    expect(credentials.accountId).toBe('acct_from_id_token')
+    expect(credentials.source).toBe('none')
+  })
 })
 
 describe('Codex request translation', () => {
diff --git a/src/services/api/codexUsage.ts b/src/services/api/codexUsage.ts
index 06a43290..76490dd3 100644
--- a/src/services/api/codexUsage.ts
+++ b/src/services/api/codexUsage.ts
@@ -1,7 +1,13 @@
+import {
+  readCodexCredentialsAsync,
+  refreshCodexAccessTokenIfNeeded,
+} from '../../utils/codexCredentials.js'
+import { logForDebugging } from '../../utils/debug.js'
+import { isBareMode } from '../../utils/envUtils.js'
 import {
   DEFAULT_CODEX_BASE_URL,
   isCodexBaseUrl,
-  resolveCodexApiCredentials,
+  resolveRuntimeCodexCredentials,
   resolveProviderRequest,
 } from './providerConfig.js'
 
@@ -391,6 +397,18 @@ export function getCodexUsageUrl(baseUrl = DEFAULT_CODEX_BASE_URL): string {
 }
 
 export async function fetchCodexUsage(): Promise<CodexUsageData> {
+  const refreshResult = await refreshCodexAccessTokenIfNeeded().catch(
+    async error => {
+      logForDebugging(
+        `[codex] access token refresh failed before usage fetch: ${error instanceof Error ? error.message : String(error)}`,
+        { level: 'warn' },
+      )
+      return {
+        refreshed: false,
+        credentials: await readCodexCredentialsAsync(),
+      }
+    },
+  )
   const request = resolveProviderRequest({
     model: process.env.OPENAI_MODEL,
     baseUrl: process.env.OPENAI_BASE_URL,
@@ -401,16 +419,19 @@ export async function fetchCodexUsage(): Promise<CodexUsageData> {
     )
   }
 
-  const credentials = resolveCodexApiCredentials()
+  const credentials = resolveRuntimeCodexCredentials({
+    storedCredentials: refreshResult.credentials,
+  })
   if (!credentials.apiKey) {
+    const oauthHint = isBareMode() ? '' : ', choose Codex OAuth in /provider'
     const authHint = credentials.authPath
-      ? ` or place a Codex auth.json at ${credentials.authPath}`
-      : ''
+      ? `${oauthHint} or place a Codex auth.json at ${credentials.authPath}`
+      : oauthHint
     throw new Error(`Codex auth is required. Set CODEX_API_KEY${authHint}.`)
   }
   if (!credentials.accountId) {
     throw new Error(
-      'Codex auth is missing chatgpt_account_id. Re-login with the Codex CLI or set CHATGPT_ACCOUNT_ID/CODEX_ACCOUNT_ID.',
+      'Codex auth is missing chatgpt_account_id. Re-login with Codex OAuth, the Codex CLI, or set CHATGPT_ACCOUNT_ID/CODEX_ACCOUNT_ID.',
     )
   }
 
diff --git a/src/services/api/openaiShim.ts b/src/services/api/openaiShim.ts
index 5e50ffe0..d78f6f6e 100644
--- a/src/services/api/openaiShim.ts
+++ b/src/services/api/openaiShim.ts
@@ -22,7 +22,12 @@
  */
 
 import { APIError } from '@anthropic-ai/sdk'
-import { isEnvTruthy } from '../../utils/envUtils.js'
+import {
+  readCodexCredentialsAsync,
+  refreshCodexAccessTokenIfNeeded,
+} from '../../utils/codexCredentials.js'
+import { logForDebugging } from '../../utils/debug.js'
+import { isBareMode, isEnvTruthy } from '../../utils/envUtils.js'
 import { resolveGeminiCredential } from '../../utils/geminiAuth.js'
 import { hydrateGeminiAccessTokenFromSecureStorage } from '../../utils/geminiCredentials.js'
 import { hydrateGithubModelsTokenFromSecureStorage } from '../../utils/githubModelsCredentials.js'
@@ -44,7 +49,7 @@ import {
 } from './codexShim.js'
 import {
   isLocalProviderUrl,
-  resolveCodexApiCredentials,
+  resolveRuntimeCodexCredentials,
   resolveProviderRequest,
   getGithubEndpointType,
 } from './providerConfig.js'
@@ -1139,7 +1144,6 @@ class OpenAIShimMessages {
     const githubEndpointType = getGithubEndpointType(request.baseUrl)
     const isGithubMode = isGithubModelsMode()
     const isGithubWithCodexTransport = isGithubMode && request.transport === 'codex_responses'
-    const isGithubCopilotEndpoint = isGithubMode && githubEndpointType === 'copilot'
 
     if (isGithubWithCodexTransport) {
       const apiKey = this.providerOverride?.apiKey ?? process.env.OPENAI_API_KEY ?? ''
@@ -1166,11 +1170,26 @@ class OpenAIShimMessages {
     }
 
     if (request.transport === 'codex_responses' && !isGithubMode) {
-      const credentials = resolveCodexApiCredentials()
+      const refreshResult = await refreshCodexAccessTokenIfNeeded().catch(
+        async error => {
+          logForDebugging(
+            `[codex] access token refresh failed before request: ${error instanceof Error ? error.message : String(error)}`,
+            { level: 'warn' },
+          )
+          return {
+            refreshed: false,
+            credentials: await readCodexCredentialsAsync(),
+          }
+        },
+      )
+      const credentials = resolveRuntimeCodexCredentials({
+        storedCredentials: refreshResult.credentials,
+      })
       if (!credentials.apiKey) {
+        const oauthHint = isBareMode() ? '' : ', choose Codex OAuth in /provider'
         const authHint = credentials.authPath
-          ? ` or place a Codex auth.json at ${credentials.authPath}`
-          : ''
+          ? `${oauthHint} or place a Codex auth.json at ${credentials.authPath}`
+          : oauthHint
         const safeModel =
           redactSecretValueForDisplay(request.requestedModel, process.env as SecretValueSource) ??
           'the requested model'
@@ -1180,7 +1199,7 @@ class OpenAIShimMessages {
       }
       if (!credentials.accountId) {
         throw new Error(
-          'Codex auth is missing chatgpt_account_id. Re-login with the Codex CLI or set CHATGPT_ACCOUNT_ID/CODEX_ACCOUNT_ID.',
+          'Codex auth is missing chatgpt_account_id. Re-login with Codex OAuth, the Codex CLI, or set CHATGPT_ACCOUNT_ID/CODEX_ACCOUNT_ID.',
         )
       }
 
diff --git a/src/services/api/providerConfig.codexSecureStorage.test.ts b/src/services/api/providerConfig.codexSecureStorage.test.ts
new file mode 100644
index 00000000..78cb9997
--- /dev/null
+++ b/src/services/api/providerConfig.codexSecureStorage.test.ts
@@ -0,0 +1,225 @@
+import { afterEach, describe, expect, mock, test } from 'bun:test'
+import { mkdirSync, mkdtempSync, rmSync, writeFileSync } from 'node:fs'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import * as realOs from 'node:os'
+
+function makeJwt(payload: Record<string, unknown>): string {
+  const header = Buffer.from(JSON.stringify({ alg: 'none', typ: 'JWT' }))
+    .toString('base64url')
+  const body = Buffer.from(JSON.stringify(payload)).toString('base64url')
+  return `${header}.${body}.signature`
+}
+
+describe('resolveCodexApiCredentials with secure storage', () => {
+  afterEach(() => {
+    mock.restore()
+  })
+
+  test('loads Codex credentials from OpenClaude secure storage', async () => {
+    mock.module('../../utils/codexCredentials.js', () => ({
+      isCodexRefreshFailureCoolingDown: () => false,
+      readCodexCredentials: () => ({
+        apiKey: 'codex-api-key-token',
+        accessToken: 'header.payload.signature',
+        accountId: 'acct_secure',
+      }),
+    }))
+
+    // @ts-expect-error cache-busting query string for Bun module mocks
+    const { resolveCodexApiCredentials } = await import(
+      './providerConfig.js?codex-secure-storage'
+    )
+
+    const credentials = resolveCodexApiCredentials({} as NodeJS.ProcessEnv)
+    expect(credentials.apiKey).toBe('codex-api-key-token')
+    expect(credentials.accountId).toBe('acct_secure')
+    expect(credentials.source).toBe('secure-storage')
+  })
+
+  test('prefers explicit env credentials over secure storage', async () => {
+    mock.module('../../utils/codexCredentials.js', () => ({
+      isCodexRefreshFailureCoolingDown: () => false,
+      readCodexCredentials: () => ({
+        accessToken: 'stored-token',
+        accountId: 'acct_stored',
+      }),
+    }))
+
+    // @ts-expect-error cache-busting query string for Bun module mocks
+    const { resolveCodexApiCredentials } = await import(
+      './providerConfig.js?codex-env-precedence'
+    )
+
+    const credentials = resolveCodexApiCredentials({
+      CODEX_API_KEY: 'env-token',
+      CHATGPT_ACCOUNT_ID: 'acct_env',
+    } as NodeJS.ProcessEnv)
+
+    expect(credentials.apiKey).toBe('env-token')
+    expect(credentials.accountId).toBe('acct_env')
+    expect(credentials.source).toBe('env')
+  })
+
+  test('parses nested chatgpt_account_id from a CODEX_API_KEY JWT', async () => {
+    mock.module('../../utils/codexCredentials.js', () => ({
+      isCodexRefreshFailureCoolingDown: () => false,
+      readCodexCredentials: () => undefined,
+    }))
+
+    // @ts-expect-error cache-busting query string for Bun module mocks
+    const { resolveCodexApiCredentials } = await import(
+      './providerConfig.js?codex-env-nested-account'
+    )
+
+    const credentials = resolveCodexApiCredentials({
+      CODEX_API_KEY: makeJwt({
+        'https://api.openai.com/auth': {
+          chatgpt_account_id: 'acct_nested_env',
+        },
+      }),
+    } as NodeJS.ProcessEnv)
+
+    expect(credentials.accountId).toBe('acct_nested_env')
+    expect(credentials.source).toBe('env')
+  })
+
+  test('parses nested chatgpt_account_id from auth.json tokens', async () => {
+    mock.module('../../utils/codexCredentials.js', () => ({
+      isCodexRefreshFailureCoolingDown: () => false,
+      readCodexCredentials: () => undefined,
+    }))
+
+    const tempDir = mkdtempSync(join(tmpdir(), 'openclaude-codex-auth-'))
+    const authPath = join(tempDir, 'auth.json')
+
+    writeFileSync(
+      authPath,
+      JSON.stringify({
+        openai_api_key: makeJwt({
+          'https://api.openai.com/auth': {
+            chatgpt_account_id: 'acct_nested_auth_json',
+          },
+        }),
+      }),
+      'utf8',
+    )
+
+    try {
+      // @ts-expect-error cache-busting query string for Bun module mocks
+      const { resolveCodexApiCredentials } = await import(
+        './providerConfig.js?codex-auth-json-nested-account'
+      )
+
+      const credentials = resolveCodexApiCredentials({
+        CODEX_AUTH_JSON_PATH: authPath,
+      } as NodeJS.ProcessEnv)
+
+      expect(credentials.accountId).toBe('acct_nested_auth_json')
+      expect(credentials.source).toBe('auth.json')
+    } finally {
+      rmSync(tempDir, { force: true, recursive: true })
+    }
+  })
+
+  test('does not read default auth.json when secure storage already has Codex credentials', async () => {
+    mock.module('../../utils/codexCredentials.js', () => ({
+      isCodexRefreshFailureCoolingDown: () => false,
+      readCodexCredentials: () => ({
+        apiKey: 'codex-api-key-token',
+        accessToken: 'header.payload.signature',
+        accountId: 'acct_secure',
+      }),
+    }))
+
+    // @ts-expect-error cache-busting query string for Bun module mocks
+    const { resolveCodexApiCredentials } = await import(
+      './providerConfig.js?codex-secure-storage-no-auth-io'
+    )
+
+    const credentials = resolveCodexApiCredentials({} as NodeJS.ProcessEnv)
+    expect(credentials.apiKey).toBe('codex-api-key-token')
+    expect(credentials.accountId).toBe('acct_secure')
+    expect(credentials.source).toBe('secure-storage')
+  })
+
+  test('falls back to the default auth.json when stored Codex refresh is cooling down', async () => {
+    const tempHomeDir = mkdtempSync(join(tmpdir(), 'openclaude-codex-home-'))
+    const authJson = JSON.stringify({
+      openai_api_key: makeJwt({
+        'https://api.openai.com/auth': {
+          chatgpt_account_id: 'acct_auth_json',
+        },
+      }),
+    })
+    mkdirSync(join(tempHomeDir, '.codex'), { recursive: true })
+    writeFileSync(join(tempHomeDir, '.codex', 'auth.json'), authJson, 'utf8')
+
+    mock.module('node:os', () => ({
+      ...realOs,
+      homedir: () => tempHomeDir,
+    }))
+
+    mock.module('../../utils/codexCredentials.js', () => ({
+      isCodexRefreshFailureCoolingDown: () => true,
+      readCodexCredentials: () => ({
+        accessToken: 'stored-token',
+        refreshToken: 'refresh-stored',
+        accountId: 'acct_stored',
+        lastRefreshFailureAt: Date.now(),
+      }),
+    }))
+
+    // @ts-expect-error cache-busting query string for Bun module mocks
+    const { resolveCodexApiCredentials } = await import(
+      './providerConfig.js?codex-refresh-cooldown-fallback'
+    )
+
+    try {
+      const credentials = resolveCodexApiCredentials({} as NodeJS.ProcessEnv)
+      expect(credentials.source).toBe('auth.json')
+      expect(credentials.accountId).toBe('acct_auth_json')
+      expect(credentials.apiKey).not.toBe('stored-token')
+    } finally {
+      rmSync(tempHomeDir, { force: true, recursive: true })
+    }
+  })
+
+  test('preserves the stored account id when auth.json fallback lacks one', async () => {
+    const tempHomeDir = mkdtempSync(join(tmpdir(), 'openclaude-codex-home-'))
+    const authJson = JSON.stringify({
+      openai_api_key: 'auth-json-access-token',
+    })
+    mkdirSync(join(tempHomeDir, '.codex'), { recursive: true })
+    writeFileSync(join(tempHomeDir, '.codex', 'auth.json'), authJson, 'utf8')
+
+    mock.module('node:os', () => ({
+      ...realOs,
+      homedir: () => tempHomeDir,
+    }))
+
+    mock.module('../../utils/codexCredentials.js', () => ({
+      isCodexRefreshFailureCoolingDown: () => true,
+      readCodexCredentials: () => ({
+        accessToken: 'stored-token',
+        refreshToken: 'refresh-stored',
+        accountId: 'acct_stored',
+        lastRefreshFailureAt: Date.now(),
+      }),
+    }))
+
+    // @ts-expect-error cache-busting query string for Bun module mocks
+    const { resolveCodexApiCredentials } = await import(
+      './providerConfig.js?codex-refresh-cooldown-account-id-fallback'
+    )
+
+    try {
+      const credentials = resolveCodexApiCredentials({} as NodeJS.ProcessEnv)
+      expect(credentials.source).toBe('auth.json')
+      expect(credentials.apiKey).toBe('auth-json-access-token')
+      expect(credentials.accountId).toBe('acct_stored')
+    } finally {
+      rmSync(tempHomeDir, { force: true, recursive: true })
+    }
+  })
+})
diff --git a/src/services/api/providerConfig.runtimeCodexCredentials.test.ts b/src/services/api/providerConfig.runtimeCodexCredentials.test.ts
new file mode 100644
index 00000000..2c9a3d52
--- /dev/null
+++ b/src/services/api/providerConfig.runtimeCodexCredentials.test.ts
@@ -0,0 +1,107 @@
+import { afterEach, expect, mock, test } from 'bun:test'
+import { mkdtempSync, rmSync, writeFileSync } from 'node:fs'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+
+import { resolveRuntimeCodexCredentials } from './providerConfig.js'
+
+afterEach(() => {
+  mock.restore()
+})
+
+function makeJwt(payload: Record<string, unknown>): string {
+  const header = Buffer.from(JSON.stringify({ alg: 'none', typ: 'JWT' }))
+    .toString('base64url')
+  const body = Buffer.from(JSON.stringify(payload)).toString('base64url')
+  return `${header}.${body}.signature`
+}
+
+test('runtime credential resolution honors explicit auth.json over stored secure-storage tokens', () => {
+  const tempDir = mkdtempSync(join(tmpdir(), 'openclaude-codex-explicit-auth-'))
+  const authPath = join(tempDir, 'auth.json')
+
+  writeFileSync(
+    authPath,
+    JSON.stringify({
+      openai_api_key: makeJwt({
+        'https://api.openai.com/auth': {
+          chatgpt_account_id: 'acct_explicit_auth_json',
+        },
+      }),
+    }),
+    'utf8',
+  )
+
+  try {
+    const credentials = resolveRuntimeCodexCredentials({
+      env: {
+        CODEX_AUTH_JSON_PATH: authPath,
+      } as NodeJS.ProcessEnv,
+      storedCredentials: {
+        apiKey: 'stored-api-key',
+        accessToken: 'stored-access-token',
+        accountId: 'acct_stored',
+      },
+    })
+
+    expect(credentials.source).toBe('auth.json')
+    expect(credentials.accountId).toBe('acct_explicit_auth_json')
+    expect(credentials.apiKey).not.toBe('stored-api-key')
+  } finally {
+    rmSync(tempDir, { force: true, recursive: true })
+  }
+})
+
+test('runtime credential resolution preserves an explicit auth.json path even when it is missing', () => {
+  const tempDir = mkdtempSync(join(tmpdir(), 'openclaude-codex-missing-auth-'))
+  const authPath = join(tempDir, 'missing-auth.json')
+
+  try {
+    const credentials = resolveRuntimeCodexCredentials({
+      env: {
+        CODEX_AUTH_JSON_PATH: authPath,
+      } as NodeJS.ProcessEnv,
+      storedCredentials: {
+        apiKey: 'stored-api-key',
+        accessToken: 'stored-access-token',
+        accountId: 'acct_stored',
+      },
+    })
+
+    expect(credentials.source).toBe('none')
+    expect(credentials.authPath).toBe(authPath)
+    expect(credentials.apiKey).toBe('')
+  } finally {
+    rmSync(tempDir, { force: true, recursive: true })
+  }
+})
+
+test('runtime credential resolution avoids sync secure-storage reads when async credentials are provided', async () => {
+  let syncReadCalled = false
+
+  mock.module('../../utils/codexCredentials.js', () => ({
+    isCodexRefreshFailureCoolingDown: () => false,
+    readCodexCredentials: () => {
+      syncReadCalled = true
+      throw new Error('sync secure-storage read should not run in runtime resolution')
+    },
+  }))
+
+  // @ts-expect-error cache-busting query string for Bun module mocks
+  const { resolveRuntimeCodexCredentials } = await import(
+    './providerConfig.js?runtime-no-sync-secure-storage'
+  )
+
+  const credentials = resolveRuntimeCodexCredentials({
+    env: {} as NodeJS.ProcessEnv,
+    storedCredentials: {
+      accessToken: 'stored-access-token',
+      accountId: 'acct_stored',
+    },
+  })
+
+  expect(syncReadCalled).toBe(false)
+  expect(credentials.source).toBe('secure-storage')
+  expect(credentials.apiKey).toBe('stored-access-token')
+  expect(credentials.accountId).toBe('acct_stored')
+})
diff --git a/src/services/api/providerConfig.ts b/src/services/api/providerConfig.ts
index d17b71a5..68c7e8fe 100644
--- a/src/services/api/providerConfig.ts
+++ b/src/services/api/providerConfig.ts
@@ -3,7 +3,16 @@ import { isIP } from 'node:net'
 import { homedir } from 'node:os'
 import { join } from 'node:path'
 
+import {
+  isCodexRefreshFailureCoolingDown,
+  readCodexCredentials,
+  type CodexCredentialBlob,
+} from '../../utils/codexCredentials.js'
 import { isEnvTruthy } from '../../utils/envUtils.js'
+import {
+  asTrimmedString,
+  parseChatgptAccountId,
+} from './codexOAuthShared.js'
 
 export const DEFAULT_OPENAI_BASE_URL = 'https://api.openai.com/v1'
 export const DEFAULT_CODEX_BASE_URL = 'https://chatgpt.com/backend-api/codex'
@@ -78,7 +87,7 @@ export type ResolvedCodexCredentials = {
   apiKey: string
   accountId?: string
   authPath?: string
-  source: 'env' | 'auth.json' | 'none'
+  source: 'env' | 'secure-storage' | 'auth.json' | 'none'
 }
 
 type ModelDescriptor = {
@@ -114,12 +123,6 @@ function isPrivateIpv6Address(hostname: string): boolean {
   return (prefix & 0xfe00) === 0xfc00 || (prefix & 0xffc0) === 0xfe80
 }
 
-function asTrimmedString(value: unknown): string | undefined {
-  if (typeof value !== 'string') return undefined
-  const trimmed = value.trim()
-  return trimmed ? trimmed : undefined
-}
-
 // Reads an env-var-style string intended as a URL or path, rejecting both
 // empty strings and the literal string "undefined" that Windows shells can
 // write when a variable is unset-then-referenced without quotes (issue #336).
@@ -151,23 +154,6 @@ function readNestedString(
   return undefined
 }
 
-function decodeJwtPayload(token: string): Record<string, unknown> | undefined {
-  const parts = token.split('.')
-  if (parts.length < 2) return undefined
-
-  try {
-    const normalized = parts[1].replace(/-/g, '+').replace(/_/g, '/')
-    const padded = normalized + '='.repeat((4 - (normalized.length % 4)) % 4)
-    const json = Buffer.from(padded, 'base64').toString('utf8')
-    const parsed = JSON.parse(json)
-    return parsed && typeof parsed === 'object'
-      ? (parsed as Record<string, unknown>)
-      : undefined
-  } catch {
-    return undefined
-  }
-}
-
 function parseReasoningEffort(value: string | undefined): ReasoningEffort | undefined {
   if (!value) return undefined
   const normalized = value.trim().toLowerCase()
@@ -494,18 +480,6 @@ export function resolveCodexAuthPath(
   return join(homedir(), '.codex', 'auth.json')
 }
 
-export function parseChatgptAccountId(
-  token: string | undefined,
-): string | undefined {
-  if (!token) return undefined
-  const payload = decodeJwtPayload(token)
-  const fromClaim = asTrimmedString(
-    payload?.['https://api.openai.com/auth.chatgpt_account_id'],
-  )
-  if (fromClaim) return fromClaim
-  return asTrimmedString(payload?.chatgpt_account_id)
-}
-
 function loadCodexAuthJson(
   authPath: string,
 ): Record<string, unknown> | undefined {
@@ -521,8 +495,97 @@ function loadCodexAuthJson(
   }
 }
 
-export function resolveCodexApiCredentials(
-  env: NodeJS.ProcessEnv = process.env,
+function resolveCodexAuthJsonCredentials(options: {
+  authJson: Record<string, unknown> | undefined
+  authPath: string
+  envAccountId?: string
+  missingSource?: ResolvedCodexCredentials['source']
+}): ResolvedCodexCredentials {
+  const { authJson, authPath, envAccountId } = options
+
+  if (!authJson) {
+    return {
+      apiKey: '',
+      authPath,
+      source: options.missingSource ?? 'none',
+    }
+  }
+
+  const apiKey = readNestedString(authJson, [
+    ['openai_api_key'],
+    ['openaiApiKey'],
+    ['access_token'],
+    ['accessToken'],
+    ['tokens', 'access_token'],
+    ['tokens', 'accessToken'],
+    ['auth', 'access_token'],
+    ['auth', 'accessToken'],
+    ['token', 'access_token'],
+    ['token', 'accessToken'],
+  ])
+  // OIDC identity tokens can carry the ChatGPT account id, but they are not
+  // valid bearer credentials for Codex API requests.
+  const idToken = readNestedString(authJson, [
+    ['id_token'],
+    ['idToken'],
+    ['tokens', 'id_token'],
+    ['tokens', 'idToken'],
+  ])
+  const accountId =
+    envAccountId ??
+    readNestedString(authJson, [
+      ['account_id'],
+      ['accountId'],
+      ['tokens', 'account_id'],
+      ['tokens', 'accountId'],
+      ['auth', 'account_id'],
+      ['auth', 'accountId'],
+    ]) ??
+    parseChatgptAccountId(apiKey) ??
+    parseChatgptAccountId(idToken)
+
+  if (!apiKey) {
+    return {
+      apiKey: '',
+      accountId,
+      authPath,
+      source: options.missingSource ?? 'none',
+    }
+  }
+
+  return {
+    apiKey,
+    accountId,
+    authPath,
+    source: 'auth.json',
+  }
+}
+
+export function resolveStoredCodexCredentials(options: {
+  storedCredentials: Pick<
+    CodexCredentialBlob,
+    'apiKey' | 'accessToken' | 'idToken' | 'accountId'
+  >
+  envAccountId?: string
+}): ResolvedCodexCredentials {
+  const { storedCredentials, envAccountId } = options
+
+  return {
+    apiKey: storedCredentials.apiKey ?? storedCredentials.accessToken,
+    accountId:
+      envAccountId ??
+      storedCredentials.accountId ??
+      parseChatgptAccountId(storedCredentials.idToken) ??
+      parseChatgptAccountId(storedCredentials.accessToken),
+    source: 'secure-storage',
+  }
+}
+
+function resolveEnvOrAuthJsonCodexCredentials(
+  env: NodeJS.ProcessEnv,
+  options?: {
+    explicitAuthPathOnly?: boolean
+  },
 ): ResolvedCodexCredentials {
   const envApiKey = asTrimmedString(env.CODEX_API_KEY)
   const envAccountId =
@@ -537,55 +600,127 @@ export function resolveCodexApiCredentials(
     }
   }
 
+  const explicitAuthPathConfigured = Boolean(
+    asTrimmedString(env.CODEX_AUTH_JSON_PATH) ?? asTrimmedString(env.CODEX_HOME),
+  )
+
+  if (!explicitAuthPathConfigured && options?.explicitAuthPathOnly) {
+    return {
+      apiKey: '',
+      accountId: envAccountId,
+      source: 'none',
+    }
+  }
+
   const authPath = resolveCodexAuthPath(env)
   const authJson = loadCodexAuthJson(authPath)
-  if (!authJson) {
-    return {
-      apiKey: '',
-      authPath,
-      source: 'none',
-    }
-  }
-
-  const apiKey = readNestedString(authJson, [
-    ['access_token'],
-    ['accessToken'],
-    ['tokens', 'access_token'],
-    ['tokens', 'accessToken'],
-    ['auth', 'access_token'],
-    ['auth', 'accessToken'],
-    ['token', 'access_token'],
-    ['token', 'accessToken'],
-    ['tokens', 'id_token'],
-    ['tokens', 'idToken'],
-  ])
-  const accountId =
-    envAccountId ??
-    readNestedString(authJson, [
-      ['account_id'],
-      ['accountId'],
-      ['tokens', 'account_id'],
-      ['tokens', 'accountId'],
-      ['auth', 'account_id'],
-      ['auth', 'accountId'],
-    ]) ??
-    parseChatgptAccountId(apiKey)
-
-  if (!apiKey) {
-    return {
-      apiKey: '',
-      accountId,
-      authPath,
-      source: 'none',
-    }
-  }
-
-  return {
-    apiKey,
-    accountId,
+  return resolveCodexAuthJsonCredentials({
+    authJson,
     authPath,
-    source: 'auth.json',
+    envAccountId,
+  })
+}
+
+export function resolveRuntimeCodexCredentials(options?: {
+  env?: NodeJS.ProcessEnv
+  storedCredentials?: Pick<
+    CodexCredentialBlob,
+    'apiKey' | 'accessToken' | 'idToken' | 'accountId'
+  >
+}): ResolvedCodexCredentials {
+  const env = options?.env ?? process.env
+  const explicitCredentials = resolveEnvOrAuthJsonCodexCredentials(env, {
+    explicitAuthPathOnly: true,
+  })
+  const explicitAuthPathConfigured = Boolean(
+    asTrimmedString(env.CODEX_AUTH_JSON_PATH) ?? asTrimmedString(env.CODEX_HOME),
+  )
+  const hasStoredCredentialsOption = Boolean(
+    options &&
+      Object.prototype.hasOwnProperty.call(options, 'storedCredentials'),
+  )
+
+  if (
+    explicitAuthPathConfigured ||
+    explicitCredentials.source === 'env' ||
+    explicitCredentials.source === 'auth.json'
+  ) {
+    return explicitCredentials
   }
+
+  if (options?.storedCredentials?.accessToken) {
+    return resolveStoredCodexCredentials({
+      storedCredentials: options.storedCredentials,
+      envAccountId:
+        asTrimmedString(env.CODEX_ACCOUNT_ID) ??
+        asTrimmedString(env.CHATGPT_ACCOUNT_ID),
+    })
+  }
+
+  if (hasStoredCredentialsOption) {
+    return resolveEnvOrAuthJsonCodexCredentials(env)
+  }
+
+  return resolveCodexApiCredentials(env)
+}
+
+export function resolveCodexApiCredentials(
+  env: NodeJS.ProcessEnv = process.env,
+): ResolvedCodexCredentials {
+  const envAccountId =
+    asTrimmedString(env.CODEX_ACCOUNT_ID) ??
+    asTrimmedString(env.CHATGPT_ACCOUNT_ID)
+  const envOrExplicitAuthJsonCredentials = resolveEnvOrAuthJsonCodexCredentials(
+    env,
+    {
+      explicitAuthPathOnly: true,
+    },
+  )
+
+  if (
+    envOrExplicitAuthJsonCredentials.source === 'env' ||
+    envOrExplicitAuthJsonCredentials.source === 'auth.json' ||
+    envOrExplicitAuthJsonCredentials.authPath
+  ) {
+    return envOrExplicitAuthJsonCredentials
+  }
+
+  const storedCredentials = readCodexCredentials()
+  if (storedCredentials?.accessToken) {
+    const resolvedStoredCredentials = resolveStoredCodexCredentials({
+      storedCredentials,
+      envAccountId,
+    })
+
+    const shouldCheckDefaultAuthJson =
+      !resolvedStoredCredentials.accountId ||
+      isCodexRefreshFailureCoolingDown(storedCredentials)
+
+    if (!shouldCheckDefaultAuthJson) {
+      return resolvedStoredCredentials
+    }
+
+    const authPath = resolveCodexAuthPath(env)
+    const authJson = loadCodexAuthJson(authPath)
+    const resolvedAuthJsonCredentials = resolveCodexAuthJsonCredentials({
+      authJson,
+      authPath,
+      envAccountId,
+    })
+
+    if (resolvedAuthJsonCredentials.apiKey) {
+      return {
+        ...resolvedAuthJsonCredentials,
+        accountId:
+          resolvedAuthJsonCredentials.accountId ??
+          resolvedStoredCredentials.accountId,
+      }
+    }
+
+    return resolvedStoredCredentials
+  }
+
+  return resolveEnvOrAuthJsonCodexCredentials(env)
 }
 
 export function getReasoningEffortForModel(model: string): ReasoningEffort | undefined {
@@ -595,3 +730,18 @@ export function getReasoningEffortForModel(model: string): ReasoningEffort | und
   const aliasConfig = CODEX_ALIAS_MODELS[alias]
   return aliasConfig?.reasoningEffort
 }
+
+export function supportsCodexReasoningEffort(model: string): boolean {
+  const normalized = model.trim().toLowerCase()
+  const base = normalized.split('?', 1)[0] ?? normalized
+
+  if (base === 'gpt-5.3-codex-spark' || base === 'codexspark') {
+    return false
+  }
+
+  if (getReasoningEffortForModel(base) !== undefined) {
+    return true
+  }
+
+  return /^gpt-5(?:[.-]|$)/.test(base)
+}
diff --git a/src/services/oauth/auth-code-listener.analytics.test.ts b/src/services/oauth/auth-code-listener.analytics.test.ts
new file mode 100644
index 00000000..27800596
--- /dev/null
+++ b/src/services/oauth/auth-code-listener.analytics.test.ts
@@ -0,0 +1,155 @@
+import { afterEach, expect, mock, test } from 'bun:test'
+
+afterEach(() => {
+  mock.restore()
+})
+
+test('custom error responses log the error redirect analytics event', async () => {
+  const events: Array<{
+    name: string
+    metadata: Record<string, boolean | number | undefined>
+  }> = []
+
+  mock.module('src/services/analytics/index.js', () => ({
+    logEvent: (
+      name: string,
+      metadata: Record<string, boolean | number | undefined>,
+    ) => {
+      events.push({ name, metadata })
+    },
+  }))
+
+  const { AuthCodeListener } = await import(
+    `./auth-code-listener.js?ts=${Date.now()}-${Math.random()}`
+  )
+  const listener = new AuthCodeListener('/callback')
+  const response = {
+    writeHead: () => {},
+    end: () => {},
+  }
+
+  ;(listener as any).pendingResponse = response
+
+  listener.handleErrorRedirect(res => {
+    res.writeHead(400, {
+      'Content-Type': 'text/plain; charset=utf-8',
+    })
+    res.end('cancelled')
+  })
+
+  expect(events).toEqual([
+    {
+      name: 'tengu_oauth_automatic_redirect_error',
+      metadata: { custom_handler: true },
+    },
+  ])
+})
+
+test('custom handlers that do not end the response are closed automatically and still log analytics', async () => {
+  const events: Array<{
+    name: string
+    metadata: Record<string, boolean | number | undefined>
+  }> = []
+  const response = {
+    destroyed: false,
+    headersSent: false,
+    writableEnded: false,
+    writeHead: () => {
+      response.headersSent = true
+    },
+    end: () => {
+      response.writableEnded = true
+    },
+  }
+
+  mock.module('src/services/analytics/index.js', () => ({
+    logEvent: (
+      name: string,
+      metadata: Record<string, boolean | number | undefined>,
+    ) => {
+      events.push({ name, metadata })
+    },
+  }))
+
+  mock.module('../../utils/log.js', () => ({
+    logError: () => {},
+  }))
+
+  const { AuthCodeListener } = await import(
+    `./auth-code-listener.js?ts=${Date.now()}-${Math.random()}`
+  )
+  const listener = new AuthCodeListener('/callback')
+
+  ;(listener as any).pendingResponse = response
+
+  listener.handleErrorRedirect(res => {
+    res.writeHead(400, {
+      'Content-Type': 'text/plain; charset=utf-8',
+    })
+  })
+
+  expect(response.writableEnded).toBe(true)
+  expect((listener as any).pendingResponse).toBeNull()
+  expect(events).toEqual([
+    {
+      name: 'tengu_oauth_automatic_redirect_error',
+      metadata: { custom_handler: true },
+    },
+  ])
+})
+
+test('custom handlers that throw are logged, converted to a fallback response, and do not log analytics', async () => {
+  const events: Array<{
+    name: string
+    metadata: Record<string, boolean | number | undefined>
+  }> = []
+  const loggedErrors: unknown[] = []
+  const response = {
+    destroyed: false,
+    headersSent: false,
+    writableEnded: false,
+    statusCode: 0,
+    body: '',
+    writeHead: (statusCode: number) => {
+      response.headersSent = true
+      response.statusCode = statusCode
+    },
+    end: (body = '') => {
+      response.writableEnded = true
+      response.body = body
+    },
+  }
+
+  mock.module('src/services/analytics/index.js', () => ({
+    logEvent: (
+      name: string,
+      metadata: Record<string, boolean | number | undefined>,
+    ) => {
+      events.push({ name, metadata })
+    },
+  }))
+
+  mock.module('../../utils/log.js', () => ({
+    logError: (error: unknown) => {
+      loggedErrors.push(error)
+    },
+  }))
+
+  const { AuthCodeListener } = await import(
+    `./auth-code-listener.js?ts=${Date.now()}-${Math.random()}`
+  )
+  const listener = new AuthCodeListener('/callback')
+
+  ;(listener as any).pendingResponse = response
+
+  listener.handleErrorRedirect(() => {
+    throw new Error('handler exploded')
+  })
+
+  expect(response.statusCode).toBe(500)
+  expect(response.body).toBe('Authentication redirect failed')
+  expect(response.writableEnded).toBe(true)
+  expect((listener as any).pendingResponse).toBeNull()
+  expect(loggedErrors).toHaveLength(1)
+  expect(events).toEqual([])
+})
diff --git a/src/services/oauth/auth-code-listener.test.ts b/src/services/oauth/auth-code-listener.test.ts
new file mode 100644
index 00000000..4e947755
--- /dev/null
+++ b/src/services/oauth/auth-code-listener.test.ts
@@ -0,0 +1,31 @@
+import { afterEach, expect, test } from 'bun:test'
+
+import { AuthCodeListener } from './auth-code-listener.js'
+
+const listeners: AuthCodeListener[] = []
+
+afterEach(() => {
+  while (listeners.length > 0) {
+    listeners.pop()?.close()
+  }
+})
+
+test('cancelPendingAuthorization rejects a pending OAuth wait', async () => {
+  const listener = new AuthCodeListener('/callback')
+  listeners.push(listener)
+
+  await listener.start()
+
+  const pendingAuthorization = listener.waitForAuthorization(
+    'state-test',
+    async () => {},
+  )
+
+  listener.cancelPendingAuthorization(
+    new Error('Codex OAuth flow was cancelled.'),
+  )
+
+  await expect(pendingAuthorization).rejects.toThrow(
+    'Codex OAuth flow was cancelled.',
+  )
+})
diff --git a/src/services/oauth/auth-code-listener.ts b/src/services/oauth/auth-code-listener.ts
index a46c33ec..431679b7 100644
--- a/src/services/oauth/auth-code-listener.ts
+++ b/src/services/oauth/auth-code-listener.ts
@@ -71,6 +71,42 @@ export class AuthCodeListener {
     })
   }
 
+  private respondToPendingRequest(options: {
+    handler: (res: ServerResponse) => void
+    analyticsEvent:
+      | 'tengu_oauth_automatic_redirect'
+      | 'tengu_oauth_automatic_redirect_error'
+    analyticsMetadata?: Record<string, boolean>
+  }): void {
+    if (!this.pendingResponse) return
+
+    const response = this.pendingResponse
+    try {
+      options.handler(response)
+
+      if (!response.writableEnded && !response.destroyed) {
+        response.end()
+      }
+
+      logEvent(options.analyticsEvent, options.analyticsMetadata ?? {})
+    } catch (error) {
+      logError(error)
+
+      if (!response.headersSent && !response.destroyed) {
+        response.writeHead(500, {
+          'Content-Type': 'text/plain; charset=utf-8',
+        })
+      }
+      if (!response.writableEnded && !response.destroyed) {
+        response.end('Authentication redirect failed')
+      }
+    } finally {
+      if (this.pendingResponse === response) {
+        this.pendingResponse = null
+      }
+    }
+  }
+
   /**
    * Completes the OAuth flow by redirecting the user's browser to a success page.
    * Different success pages are shown based on the granted scopes.
@@ -85,9 +121,13 @@ export class AuthCodeListener {
 
     // If custom handler provided, use it instead of default redirect
     if (customHandler) {
-      customHandler(this.pendingResponse, scopes)
-      this.pendingResponse = null
-      logEvent('tengu_oauth_automatic_redirect', { custom_handler: true })
+      this.respondToPendingRequest({
+        handler: res => {
+          customHandler(res, scopes)
+        },
+        analyticsEvent: 'tengu_oauth_automatic_redirect',
+        analyticsMetadata: { custom_handler: true },
+      })
       return
     }
 
@@ -97,29 +137,48 @@ export class AuthCodeListener {
       : getOauthConfig().CONSOLE_SUCCESS_URL
 
     // Send browser to success page
-    this.pendingResponse.writeHead(302, { Location: successUrl })
-    this.pendingResponse.end()
-    this.pendingResponse = null
-
-    logEvent('tengu_oauth_automatic_redirect', {})
+    this.respondToPendingRequest({
+      handler: res => {
+        res.writeHead(302, { Location: successUrl })
+        res.end()
+      },
+      analyticsEvent: 'tengu_oauth_automatic_redirect',
+    })
   }
 
   /**
    * Handles error case by sending a redirect to the appropriate success page with an error indicator,
    * ensuring the browser flow is completed properly.
    */
-  handleErrorRedirect(): void {
+  handleErrorRedirect(customHandler?: (res: ServerResponse) => void): void {
     if (!this.pendingResponse) return
 
+    if (customHandler) {
+      this.respondToPendingRequest({
+        handler: customHandler,
+        analyticsEvent: 'tengu_oauth_automatic_redirect_error',
+        analyticsMetadata: { custom_handler: true },
+      })
+      return
+    }
+
     // TODO: swap to a different url once we have an error page
     const errorUrl = getOauthConfig().CLAUDEAI_SUCCESS_URL
 
-    // Send browser to error page
-    this.pendingResponse.writeHead(302, { Location: errorUrl })
-    this.pendingResponse.end()
-    this.pendingResponse = null
+    this.respondToPendingRequest({
+      handler: res => {
+        res.writeHead(302, { Location: errorUrl })
+        res.end()
+      },
+      analyticsEvent: 'tengu_oauth_automatic_redirect_error',
+    })
+  }
 
-    logEvent('tengu_oauth_automatic_redirect_error', {})
+  cancelPendingAuthorization(
+    error: Error = new Error('OAuth authorization was cancelled.'),
+  ): void {
+    this.reject(error)
+    this.close()
   }
 
   private startLocalListener(onReady: () => Promise<void>): void {
@@ -176,8 +235,7 @@ export class AuthCodeListener {
 
   private handleError(err: Error): void {
     logError(err)
-    this.close()
-    this.reject(err)
+    this.cancelPendingAuthorization(err)
   }
 
   private resolve(authorizationCode: string): void {
@@ -185,6 +243,7 @@ export class AuthCodeListener {
       this.promiseResolver(authorizationCode)
       this.promiseResolver = null
       this.promiseRejecter = null
+      this.expectedState = null
     }
   }
 
@@ -193,6 +252,7 @@ export class AuthCodeListener {
       this.promiseRejecter(error)
       this.promiseResolver = null
       this.promiseRejecter = null
+      this.expectedState = null
     }
   }
 
@@ -207,5 +267,8 @@ export class AuthCodeListener {
       this.localServer.removeAllListeners()
       this.localServer.close()
     }
+
+    this.expectedState = null
+    this.port = 0
   }
 }
diff --git a/src/utils/codexCredentials.test.ts b/src/utils/codexCredentials.test.ts
new file mode 100644
index 00000000..dd5be38b
--- /dev/null
+++ b/src/utils/codexCredentials.test.ts
@@ -0,0 +1,607 @@
+/**
+ * These tests avoid static imports so Bun can mock secureStorage before
+ * codexCredentials is first loaded.
+ */
+import { afterEach, describe, expect, mock, test } from 'bun:test'
+
+function makeJwt(payload: Record<string, unknown>): string {
+  const header = Buffer.from(JSON.stringify({ alg: 'none', typ: 'JWT' }))
+    .toString('base64url')
+  const body = Buffer.from(JSON.stringify(payload)).toString('base64url')
+  return `${header}.${body}.signature`
+}
+
+describe('codexCredentials', () => {
+  const originalSimple = process.env.CLAUDE_CODE_SIMPLE
+  const originalCodeKey = process.env.CODEX_API_KEY
+  const originalFetch = globalThis.fetch
+
+  afterEach(() => {
+    mock.restore()
+    globalThis.fetch = originalFetch
+
+    if (originalSimple === undefined) {
+      delete process.env.CLAUDE_CODE_SIMPLE
+    } else {
+      process.env.CLAUDE_CODE_SIMPLE = originalSimple
+    }
+
+    if (originalCodeKey === undefined) {
+      delete process.env.CODEX_API_KEY
+    } else {
+      process.env.CODEX_API_KEY = originalCodeKey
+    }
+  })
+
+  test('save returns failure in bare mode', async () => {
+    process.env.CLAUDE_CODE_SIMPLE = '1'
+
+    // @ts-expect-error cache-busting query string for Bun module mocks
+    const { saveCodexCredentials } = await import(
+      './codexCredentials.js?save-bare-mode'
+    )
+
+    const result = saveCodexCredentials({
+      accessToken: 'token',
+      accountId: 'acct_123',
+    })
+
+    expect(result.success).toBe(false)
+    expect(result.warning).toContain('Bare mode')
+  })
+
+  test('saveCodexCredentials refuses plaintext fallback when native secure storage is unavailable', async () => {
+    delete process.env.CLAUDE_CODE_SIMPLE
+
+    mock.module('./secureStorage/index.js', () => ({
+      getSecureStorage: (options?: { allowPlainTextFallback?: boolean }) => {
+        expect(options?.allowPlainTextFallback).toBe(false)
+        return {
+          read: () => null,
+          readAsync: async () => null,
+          update: () => ({
+            success: false,
+            warning:
+              'Secure storage is unavailable on this platform without plaintext fallback.',
+          }),
+          delete: () => true,
+        }
+      },
+    }))
+
+    // @ts-expect-error cache-busting query string for Bun module mocks
+    const { saveCodexCredentials } = await import(
+      './codexCredentials.js?save-no-plaintext-fallback'
+    )
+
+    const result = saveCodexCredentials({
+      accessToken: 'token',
+      accountId: 'acct_123',
+    })
+
+    expect(result.success).toBe(false)
+    expect(result.warning).toContain('without plaintext fallback')
+  })
+
+  test('refreshCodexAccessTokenIfNeeded refreshes expired stored credentials', async () => {
+    delete process.env.CLAUDE_CODE_SIMPLE
+    delete process.env.CODEX_API_KEY
+
+    const expiredToken = makeJwt({
+      exp: Math.floor((Date.now() - 60_000) / 1000),
+      chatgpt_account_id: 'acct_old',
+    })
+    const freshAccessToken = makeJwt({
+      exp: Math.floor((Date.now() + 3_600_000) / 1000),
+      chatgpt_account_id: 'acct_new',
+    })
+    const freshIdToken = makeJwt({
+      exp: Math.floor((Date.now() + 3_600_000) / 1000),
+      'https://api.openai.com/auth': {
+        chatgpt_account_id: 'acct_new',
+      },
+    })
+
+    let storageState: Record<string, unknown> = {
+      codex: {
+        accessToken: expiredToken,
+        refreshToken: 'refresh-old',
+        accountId: 'acct_old',
+      },
+    }
+
+    mock.module('./secureStorage/index.js', () => ({
+      getSecureStorage: () => ({
+        read: () => storageState,
+        readAsync: async () => storageState,
+        update: (next: Record<string, unknown>) => {
+          storageState = next
+          return { success: true }
+        },
+      }),
+    }))
+
+    globalThis.fetch = mock(
+      async (_input, init) => {
+        const bodyText =
+          typeof init?.body === 'string'
+            ? init.body
+            : init?.body instanceof URLSearchParams
+              ? init.body.toString()
+              : ''
+
+        if (
+          bodyText.includes('grant_type=refresh_token') ||
+          bodyText.includes('"grant_type":"refresh_token"')
+        ) {
+          return new Response(
+            JSON.stringify({
+              access_token: freshAccessToken,
+              refresh_token: 'refresh-new',
+              id_token: freshIdToken,
+            }),
+            {
+              status: 200,
+              headers: {
+                'Content-Type': 'application/json',
+              },
+            },
+          )
+        }
+
+        return new Response(
+          JSON.stringify({
+            access_token: 'codex-api-key-token',
+          }),
+          {
+            status: 200,
+            headers: {
+              'Content-Type': 'application/json',
+            },
+          },
+        )
+      },
+    ) as unknown as typeof fetch
+
+    // @ts-expect-error cache-busting query string for Bun module mocks
+    const { refreshCodexAccessTokenIfNeeded, readCodexCredentials } =
+      await import('./codexCredentials.js?refresh-success')
+
+    const result = await refreshCodexAccessTokenIfNeeded()
+    expect(result.refreshed).toBe(true)
+
+    const stored = readCodexCredentials()
+    expect(stored?.accessToken).toBe(freshAccessToken)
+    expect(stored?.apiKey).toBe('codex-api-key-token')
+    expect(stored?.refreshToken).toBe('refresh-new')
+    expect(stored?.accountId).toBe('acct_new')
+  })
+
+  test('refreshCodexAccessTokenIfNeeded backs off after a failed refresh attempt', async () => {
+    delete process.env.CLAUDE_CODE_SIMPLE
+    delete process.env.CODEX_API_KEY
+
+    const expiredToken = makeJwt({
+      exp: Math.floor((Date.now() - 60_000) / 1000),
+      chatgpt_account_id: 'acct_old',
+    })
+
+    let storageState: Record<string, unknown> = {
+      codex: {
+        accessToken: expiredToken,
+        refreshToken: 'refresh-old',
+        accountId: 'acct_old',
+      },
+    }
+
+    mock.module('./secureStorage/index.js', () => ({
+      getSecureStorage: () => ({
+        read: () => storageState,
+        readAsync: async () => storageState,
+        update: (next: Record<string, unknown>) => {
+          storageState = next
+          return { success: true }
+        },
+      }),
+    }))
+
+    let refreshAttempts = 0
+    globalThis.fetch = mock(async () => {
+      refreshAttempts += 1
+      return new Response(
+        JSON.stringify({
+          error: {
+            code: 'invalid_grant',
+            message: 'refresh token expired',
+          },
+        }),
+        {
+          status: 400,
+          headers: {
+            'Content-Type': 'application/json',
+          },
+        },
+      )
+    }) as unknown as typeof fetch
+
+    // @ts-expect-error cache-busting query string for Bun module mocks
+    const { refreshCodexAccessTokenIfNeeded, readCodexCredentials } =
+      await import('./codexCredentials.js?refresh-cooldown')
+
+    await expect(refreshCodexAccessTokenIfNeeded()).rejects.toThrow(
+      'Codex token refresh failed (invalid_grant): refresh token expired',
+    )
+
+    const afterFailure = readCodexCredentials()
+    expect(typeof afterFailure?.lastRefreshFailureAt).toBe('number')
+
+    const secondAttempt = await refreshCodexAccessTokenIfNeeded()
+    expect(secondAttempt.refreshed).toBe(false)
+    expect(secondAttempt.credentials?.accessToken).toBe(expiredToken)
+    expect(refreshAttempts).toBe(1)
+  })
+
+  test('refreshCodexAccessTokenIfNeeded drops a stale api key when id-token exchange fails', async () => {
+    delete process.env.CLAUDE_CODE_SIMPLE
+    delete process.env.CODEX_API_KEY
+
+    const expiredToken = makeJwt({
+      exp: Math.floor((Date.now() - 60_000) / 1000),
+      chatgpt_account_id: 'acct_old',
+    })
+    const freshAccessToken = makeJwt({
+      exp: Math.floor((Date.now() + 3_600_000) / 1000),
+      chatgpt_account_id: 'acct_new',
+    })
+    const freshIdToken = makeJwt({
+      exp: Math.floor((Date.now() + 3_600_000) / 1000),
+      'https://api.openai.com/auth': {
+        chatgpt_account_id: 'acct_new',
+      },
+    })
+
+    let storageState: Record<string, unknown> = {
+      codex: {
+        apiKey: 'stale-api-key',
+        accessToken: expiredToken,
+        refreshToken: 'refresh-old',
+        accountId: 'acct_old',
+      },
+    }
+
+    mock.module('./secureStorage/index.js', () => ({
+      getSecureStorage: () => ({
+        read: () => storageState,
+        readAsync: async () => storageState,
+        update: (next: Record<string, unknown>) => {
+          storageState = next
+          return { success: true }
+        },
+      }),
+    }))
+
+    globalThis.fetch = mock(
+      async (_input, init) => {
+        const bodyText =
+          typeof init?.body === 'string'
+            ? init.body
+            : init?.body instanceof URLSearchParams
+              ? init.body.toString()
+              : ''
+
+        if (bodyText.includes('grant_type=refresh_token')) {
+          return new Response(
+            JSON.stringify({
+              access_token: freshAccessToken,
+              refresh_token: 'refresh-new',
+              id_token: freshIdToken,
+            }),
+            {
+              status: 200,
+              headers: {
+                'Content-Type': 'application/json',
+              },
+            },
+          )
+        }
+
+        return new Response('exchange failed', {
+          status: 500,
+        })
+      },
+    ) as unknown as typeof fetch
+
+    // @ts-expect-error cache-busting query string for Bun module mocks
+    const { refreshCodexAccessTokenIfNeeded, readCodexCredentials } =
+      await import('./codexCredentials.js?refresh-drop-stale-api-key')
+
+    const result = await refreshCodexAccessTokenIfNeeded()
+    expect(result.refreshed).toBe(true)
+
+    const stored = readCodexCredentials()
+    expect(stored?.accessToken).toBe(freshAccessToken)
+    expect(stored?.apiKey).toBeUndefined()
+    expect(stored?.refreshToken).toBe('refresh-new')
+    expect(stored?.accountId).toBe('acct_new')
+  })
+
+  test('refreshCodexAccessTokenIfNeeded deduplicates concurrent refresh attempts', async () => {
+    delete process.env.CLAUDE_CODE_SIMPLE
+    delete process.env.CODEX_API_KEY
+
+    const expiredToken = makeJwt({
+      exp: Math.floor((Date.now() - 60_000) / 1000),
+      chatgpt_account_id: 'acct_old',
+    })
+    const freshAccessToken = makeJwt({
+      exp: Math.floor((Date.now() + 3_600_000) / 1000),
+      chatgpt_account_id: 'acct_new',
+    })
+    const freshIdToken = makeJwt({
+      exp: Math.floor((Date.now() + 3_600_000) / 1000),
+      'https://api.openai.com/auth': {
+        chatgpt_account_id: 'acct_new',
+      },
+    })
+
+    let storageState: Record<string, unknown> = {
+      codex: {
+        accessToken: expiredToken,
+        refreshToken: 'refresh-old',
+        accountId: 'acct_old',
+      },
+    }
+
+    mock.module('./secureStorage/index.js', () => ({
+      getSecureStorage: () => ({
+        read: () => storageState,
+        readAsync: async () => storageState,
+        update: (next: Record<string, unknown>) => {
+          storageState = next
+          return { success: true }
+        },
+      }),
+    }))
+
+    let refreshAttempts = 0
+    let releaseRefresh: (() => void) | undefined
+    const refreshGate = new Promise<void>(resolve => {
+      releaseRefresh = resolve
+    })
+
+    globalThis.fetch = mock(async (_input, init) => {
+      const bodyText =
+        typeof init?.body === 'string'
+          ? init.body
+          : init?.body instanceof URLSearchParams
+            ? init.body.toString()
+            : ''
+
+      if (bodyText.includes('grant_type=refresh_token')) {
+        refreshAttempts += 1
+        await refreshGate
+        return new Response(
+          JSON.stringify({
+            access_token: freshAccessToken,
+            refresh_token: 'refresh-new',
+            id_token: freshIdToken,
+          }),
+          {
+            status: 200,
+            headers: {
+              'Content-Type': 'application/json',
+            },
+          },
+        )
+      }
+
+      return new Response(
+        JSON.stringify({
+          access_token: 'codex-api-key-token',
+        }),
+        {
+          status: 200,
+          headers: {
+            'Content-Type': 'application/json',
+          },
+        },
+      )
+    }) as unknown as typeof fetch
+
+    // @ts-expect-error cache-busting query string for Bun module mocks
+    const { refreshCodexAccessTokenIfNeeded } = await import(
+      './codexCredentials.js?refresh-dedupe'
+    )
+
+    const firstRefresh = refreshCodexAccessTokenIfNeeded()
+    const secondRefresh = refreshCodexAccessTokenIfNeeded()
+    releaseRefresh?.()
+
+    const [firstResult, secondResult] = await Promise.all([
+      firstRefresh,
+      secondRefresh,
+    ])
+
+    expect(refreshAttempts).toBe(1)
+    expect(firstResult).toEqual(secondResult)
+    expect(firstResult.refreshed).toBe(true)
+    expect(firstResult.credentials?.accessToken).toBe(freshAccessToken)
+  })
+
+  test('saveCodexCredentials preserves an existing linked profile id', async () => {
+    delete process.env.CLAUDE_CODE_SIMPLE
+
+    let storageState: Record<string, unknown> = {
+      codex: {
+        accessToken: 'access-old',
+        refreshToken: 'refresh-old',
+        accountId: 'acct_old',
+        profileId: 'profile_codex_oauth',
+      },
+    }
+
+    mock.module('./secureStorage/index.js', () => ({
+      getSecureStorage: () => ({
+        read: () => storageState,
+        readAsync: async () => storageState,
+        update: (next: Record<string, unknown>) => {
+          storageState = next
+          return { success: true }
+        },
+      }),
+    }))
+
+    // @ts-expect-error cache-busting query string for Bun module mocks
+    const { readCodexCredentials, saveCodexCredentials } = await import(
+      './codexCredentials.js?preserve-profile-id'
+    )
+
+    const saved = saveCodexCredentials({
+      accessToken: 'access-new',
+      refreshToken: 'refresh-new',
+      accountId: 'acct_new',
+    })
+
+    expect(saved.success).toBe(true)
+    expect(readCodexCredentials()?.profileId).toBe('profile_codex_oauth')
+  })
+
+  test('attachCodexProfileIdToStoredCredentials links the saved profile id', async () => {
+    delete process.env.CLAUDE_CODE_SIMPLE
+
+    let storageState: Record<string, unknown> = {
+      codex: {
+        accessToken: 'access-old',
+        refreshToken: 'refresh-old',
+        accountId: 'acct_old',
+      },
+    }
+
+    mock.module('./secureStorage/index.js', () => ({
+      getSecureStorage: () => ({
+        read: () => storageState,
+        readAsync: async () => storageState,
+        update: (next: Record<string, unknown>) => {
+          storageState = next
+          return { success: true }
+        },
+      }),
+    }))
+
+    // @ts-expect-error cache-busting query string for Bun module mocks
+    const {
+      attachCodexProfileIdToStoredCredentials,
+      readCodexCredentials,
+    } = await import('./codexCredentials.js?attach-profile-id')
+
+    const result =
+      attachCodexProfileIdToStoredCredentials('profile_codex_oauth')
+
+    expect(result.success).toBe(true)
+    expect(readCodexCredentials()?.profileId).toBe('profile_codex_oauth')
+  })
+
+  test('refreshCodexAccessTokenIfNeeded uses async secure-storage reads in its request path', async () => {
+    delete process.env.CLAUDE_CODE_SIMPLE
+    delete process.env.CODEX_API_KEY
+
+    const freshToken = makeJwt({
+      exp: Math.floor((Date.now() + 3_600_000) / 1000),
+      chatgpt_account_id: 'acct_async',
+    })
+
+    let storageState: Record<string, unknown> = {
+      codex: {
+        accessToken: freshToken,
+        refreshToken: 'refresh-async',
+        accountId: 'acct_async',
+      },
+    }
+
+    mock.module('./secureStorage/index.js', () => ({
+      getSecureStorage: () => ({
+        read: () => {
+          throw new Error(
+            'sync storage read should not run during refresh checks',
+          )
+        },
+        readAsync: async () => storageState,
+        update: (next: Record<string, unknown>) => {
+          storageState = next
+          return { success: true }
+        },
+      }),
+    }))
+
+    // @ts-expect-error cache-busting query string for Bun module mocks
+    const { refreshCodexAccessTokenIfNeeded } = await import(
+      './codexCredentials.js?refresh-async-read'
+    )
+
+    const result = await refreshCodexAccessTokenIfNeeded()
+    expect(result.refreshed).toBe(false)
+    expect(result.credentials?.accessToken).toBe(freshToken)
+  })
+
+  test('refreshCodexAccessTokenIfNeeded keeps a cooldown in memory when secure storage cannot persist it', async () => {
+    delete process.env.CLAUDE_CODE_SIMPLE
+    delete process.env.CODEX_API_KEY
+
+    const expiredToken = makeJwt({
+      exp: Math.floor((Date.now() - 60_000) / 1000),
+      chatgpt_account_id: 'acct_old',
+    })
+
+    const storageState: Record<string, unknown> = {
+      codex: {
+        accessToken: expiredToken,
+        refreshToken: 'refresh-old',
+        accountId: 'acct_old',
+      },
+    }
+
+    mock.module('./secureStorage/index.js', () => ({
+      getSecureStorage: () => ({
+        read: () => storageState,
+        readAsync: async () => storageState,
+        update: () => ({
+          success: false,
+          warning: 'secure storage unavailable',
+        }),
+      }),
+    }))
+
+    let refreshAttempts = 0
+    globalThis.fetch = mock(async () => {
+      refreshAttempts += 1
+      return new Response(
+        JSON.stringify({
+          error: {
+            code: 'invalid_grant',
+            message: 'refresh token expired',
+          },
+        }),
+        {
+          status: 400,
+          headers: {
+            'Content-Type': 'application/json',
+          },
+        },
+      )
+    }) as unknown as typeof fetch
+
+    // @ts-expect-error cache-busting query string for Bun module mocks
+    const { refreshCodexAccessTokenIfNeeded } = await import(
+      './codexCredentials.js?refresh-memory-cooldown'
+    )
+
+    await expect(refreshCodexAccessTokenIfNeeded()).rejects.toThrow(
+      'Codex token refresh failed (invalid_grant): refresh token expired',
+    )
+
+    const secondAttempt = await refreshCodexAccessTokenIfNeeded()
+    expect(secondAttempt.refreshed).toBe(false)
+    expect(secondAttempt.credentials?.accessToken).toBe(expiredToken)
+    expect(refreshAttempts).toBe(1)
+  })
+})
diff --git a/src/utils/codexCredentials.ts b/src/utils/codexCredentials.ts
new file mode 100644
index 00000000..81c3393f
--- /dev/null
+++ b/src/utils/codexCredentials.ts
@@ -0,0 +1,375 @@
+import { isBareMode } from './envUtils.js'
+import { getSecureStorage } from './secureStorage/index.js'
+import {
+  asTrimmedString,
+  CODEX_REFRESH_URL,
+  exchangeCodexIdTokenForApiKey,
+  getCodexOAuthClientId,
+  parseChatgptAccountId,
+  decodeJwtPayload,
+} from '../services/api/codexOAuthShared.js'
+
+export const CODEX_STORAGE_KEY = 'codex' as const
+const CODEX_TOKEN_REFRESH_SKEW_MS = 60_000
+const CODEX_TOKEN_REFRESH_RETRY_COOLDOWN_MS = 60_000
+
+export type CodexCredentialBlob = {
+  apiKey?: string
+  accessToken: string
+  refreshToken?: string
+  idToken?: string
+  accountId?: string
+  profileId?: string
+  lastRefreshAt?: number
+  lastRefreshFailureAt?: number
+}
+
+type CodexTokenRefreshResponse = {
+  access_token?: string
+  refresh_token?: string
+  id_token?: string
+}
+
+let inFlightCodexRefresh:
+  | Promise<{
+      refreshed: boolean
+      credentials?: CodexCredentialBlob
+    }>
+  | null = null
+let inMemoryLastRefreshFailureAt: number | null = null
+
+function getCodexSecureStorage() {
+  return getSecureStorage({ allowPlainTextFallback: false })
+}
+
+function parseJwtExpiryMs(token: string | undefined): number | undefined {
+  if (!token) return undefined
+  const payload = decodeJwtPayload(token)
+  const exp = payload?.exp
+  if (typeof exp === 'number' && Number.isFinite(exp)) {
+    return exp * 1000
+  }
+  return undefined
+}
+
+function normalizeCodexCredentialBlob(
+  value: unknown,
+): CodexCredentialBlob | undefined {
+  if (!value || typeof value !== 'object') return undefined
+
+  const record = value as Record<string, unknown>
+  const apiKey = asTrimmedString(record.apiKey)
+  const accessToken = asTrimmedString(record.accessToken)
+  if (!accessToken) return undefined
+
+  const refreshToken = asTrimmedString(record.refreshToken)
+  const idToken = asTrimmedString(record.idToken)
+  const accountId =
+    asTrimmedString(record.accountId) ??
+    parseChatgptAccountId(idToken) ??
+    parseChatgptAccountId(accessToken)
+  const profileId = asTrimmedString(record.profileId)
+
+  const lastRefreshAt =
+    typeof record.lastRefreshAt === 'number' &&
+    Number.isFinite(record.lastRefreshAt)
+      ? record.lastRefreshAt
+      : undefined
+  const lastRefreshFailureAt =
+    typeof record.lastRefreshFailureAt === 'number' &&
+    Number.isFinite(record.lastRefreshFailureAt)
+      ? record.lastRefreshFailureAt
+      : undefined
+
+  return {
+    apiKey,
+    accessToken,
+    refreshToken,
+    idToken,
+    accountId,
+    profileId,
+    lastRefreshAt,
+    lastRefreshFailureAt,
+  }
+}
+
+function shouldRefreshCodexToken(blob: CodexCredentialBlob): boolean {
+  const expiresAt =
+    parseJwtExpiryMs(blob.accessToken) ?? parseJwtExpiryMs(blob.idToken)
+  if (expiresAt === undefined) {
+    return false
+  }
+  return expiresAt <= Date.now() + CODEX_TOKEN_REFRESH_SKEW_MS
+}
+
+function isWithinRefreshFailureCooldown(
+  blob: CodexCredentialBlob,
+  now = Date.now(),
+): boolean {
+  const lastRefreshFailureAt = Math.max(
+    blob.lastRefreshFailureAt ?? 0,
+    inMemoryLastRefreshFailureAt ?? 0,
+  )
+
+  if (!lastRefreshFailureAt) {
+    return false
+  }
+
+  return (
+    now - lastRefreshFailureAt < CODEX_TOKEN_REFRESH_RETRY_COOLDOWN_MS
+  )
+}
+
+function getRefreshErrorMessage(
+  status: number,
+  bodyText: string,
+): string {
+  if (!bodyText.trim()) {
+    return `Codex token refresh failed with status ${status}.`
+  }
+
+  try {
+    const parsed = JSON.parse(bodyText) as Record<string, unknown>
+    const nestedError =
+      parsed.error && typeof parsed.error === 'object'
+        ? (parsed.error as Record<string, unknown>)
+        : undefined
+    const code = asTrimmedString(nestedError?.code ?? parsed.code)
+    const message =
+      asTrimmedString(nestedError?.message ?? parsed.error_description) ??
+      bodyText.trim()
+    return code
+      ? `Codex token refresh failed (${code}): ${message}`
+      : `Codex token refresh failed with status ${status}: ${message}`
+  } catch {
+    return `Codex token refresh failed with status ${status}: ${bodyText.trim()}`
+  }
+}
+
+export function readCodexCredentials(): CodexCredentialBlob | undefined {
+  if (isBareMode()) return undefined
+
+  try {
+    const data = getCodexSecureStorage().read()
+    return normalizeCodexCredentialBlob(data?.codex)
+  } catch {
+    return undefined
+  }
+}
+
+export async function readCodexCredentialsAsync(): Promise<
+  CodexCredentialBlob | undefined
+> {
+  if (isBareMode()) return undefined
+
+  try {
+    const data = await getCodexSecureStorage().readAsync()
+    return normalizeCodexCredentialBlob(data?.codex)
+  } catch {
+    return undefined
+  }
+}
+
+export function isCodexRefreshFailureCoolingDown(
+  blob: Pick<CodexCredentialBlob, 'lastRefreshFailureAt'>,
+  now = Date.now(),
+): boolean {
+  return isWithinRefreshFailureCooldown(
+    blob as CodexCredentialBlob,
+    now,
+  )
+}
+
+export function saveCodexCredentials(
+  credentials: CodexCredentialBlob,
+): { success: boolean; warning?: string } {
+  if (isBareMode()) {
+    return { success: false, warning: 'Bare mode: secure storage is disabled.' }
+  }
+
+  const normalized = normalizeCodexCredentialBlob(credentials)
+  if (!normalized) {
+    return { success: false, warning: 'Codex credentials are incomplete.' }
+  }
+
+  const secureStorage = getCodexSecureStorage()
+  const previous = secureStorage.read() || {}
+  const previousCodex = normalizeCodexCredentialBlob(previous[CODEX_STORAGE_KEY])
+  const next = {
+    ...(previous as Record<string, unknown>),
+    [CODEX_STORAGE_KEY]: {
+      ...normalized,
+      profileId: normalized.profileId ?? previousCodex?.profileId,
+      lastRefreshAt: normalized.lastRefreshAt ?? Date.now(),
+    },
+  }
+  const result = secureStorage.update(next as typeof previous)
+  if (result.success) {
+    const storedCodex = normalizeCodexCredentialBlob(next[CODEX_STORAGE_KEY])
+    inMemoryLastRefreshFailureAt = storedCodex?.lastRefreshFailureAt ?? null
+  }
+  return result
+}
+
+export function attachCodexProfileIdToStoredCredentials(profileId: string): {
+  success: boolean
+  warning?: string
+} {
+  if (isBareMode()) {
+    return { success: false, warning: 'Bare mode: secure storage is disabled.' }
+  }
+
+  const current = readCodexCredentials()
+  if (!current) {
+    return {
+      success: false,
+      warning: 'Codex credentials are not stored securely yet.',
+    }
+  }
+
+  return saveCodexCredentials({
+    ...current,
+    profileId,
+  })
+}
+
+function persistCodexRefreshFailure(
+  credentials: CodexCredentialBlob,
+  occurredAt: number,
+): void {
+  const result = saveCodexCredentials({
+    ...credentials,
+    lastRefreshFailureAt: occurredAt,
+  })
+  if (!result.success) {
+    inMemoryLastRefreshFailureAt = occurredAt
+  }
+}
+
+export function clearCodexCredentials(): {
+  success: boolean
+  warning?: string
+} {
+  if (isBareMode()) {
+    return { success: true }
+  }
+
+  const secureStorage = getCodexSecureStorage()
+  const previous = secureStorage.read() || {}
+  const next = { ...(previous as Record<string, unknown>) }
+  delete next[CODEX_STORAGE_KEY]
+  const result = secureStorage.update(next as typeof previous)
+  if (result.success) {
+    inMemoryLastRefreshFailureAt = null
+  }
+  return result
+}
+
+export async function refreshCodexAccessTokenIfNeeded(options?: {
+  force?: boolean
+}): Promise<{
+  refreshed: boolean
+  credentials?: CodexCredentialBlob
+}> {
+  if (isBareMode()) {
+    return { refreshed: false }
+  }
+
+  if (process.env.CODEX_API_KEY?.trim()) {
+    return { refreshed: false }
+  }
+
+  const current = await readCodexCredentialsAsync()
+  if (!current) {
+    return { refreshed: false }
+  }
+
+  if (!current.refreshToken) {
+    return { refreshed: false, credentials: current }
+  }
+
+  if (!options?.force && !shouldRefreshCodexToken(current)) {
+    return { refreshed: false, credentials: current }
+  }
+
+  if (!options?.force && isWithinRefreshFailureCooldown(current)) {
+    return { refreshed: false, credentials: current }
+  }
+
+  if (inFlightCodexRefresh) {
+    return inFlightCodexRefresh
+  }
+
+  inFlightCodexRefresh = (async () => {
+    const refreshAttemptedAt = Date.now()
+
+    try {
+      const body = new URLSearchParams({
+        client_id: getCodexOAuthClientId(),
+        grant_type: 'refresh_token',
+        refresh_token: current.refreshToken,
+      })
+
+      const response = await fetch(CODEX_REFRESH_URL, {
+        method: 'POST',
+        headers: {
+          'Content-Type': 'application/x-www-form-urlencoded',
+        },
+        body,
+        signal: AbortSignal.timeout(15_000),
+      })
+
+      if (!response.ok) {
+        const bodyText = await response.text().catch(() => '')
+        throw new Error(getRefreshErrorMessage(response.status, bodyText))
+      }
+
+      const payload = (await response.json()) as CodexTokenRefreshResponse
+      const accessToken = asTrimmedString(payload.access_token)
+      if (!accessToken) {
+        throw new Error(
+          'Codex token refresh succeeded without a new access token.',
+        )
+      }
+
+      const next: CodexCredentialBlob = {
+        accessToken,
+        refreshToken:
+          asTrimmedString(payload.refresh_token) ?? current.refreshToken,
+        idToken: asTrimmedString(payload.id_token) ?? current.idToken,
+        accountId:
+          parseChatgptAccountId(payload.id_token) ??
+          parseChatgptAccountId(payload.access_token) ??
+          current.accountId,
+        lastRefreshAt: Date.now(),
+      }
+
+      const idTokenForExchange = next.idToken ?? current.idToken
+      if (idTokenForExchange) {
+        next.apiKey = await exchangeCodexIdTokenForApiKey(
+          idTokenForExchange,
+        ).catch(() => undefined)
+      }
+
+      const saveResult = saveCodexCredentials(next)
+      if (!saveResult.success) {
+        throw new Error(
+          saveResult.warning ??
+            'Codex token refresh succeeded but credentials could not be saved.',
+        )
+      }
+
+      return {
+        refreshed: true,
+        credentials: next,
+      }
+    } catch (error) {
+      persistCodexRefreshFailure(current, refreshAttemptedAt)
+      throw error
+    } finally {
+      inFlightCodexRefresh = null
+    }
+  })()
+
+  return inFlightCodexRefresh
+}
diff --git a/src/utils/effort.codex.test.ts b/src/utils/effort.codex.test.ts
new file mode 100644
index 00000000..2d3a3468
--- /dev/null
+++ b/src/utils/effort.codex.test.ts
@@ -0,0 +1,65 @@
+import { afterEach, expect, mock, test } from 'bun:test'
+
+afterEach(() => {
+  mock.restore()
+})
+
+async function importFreshEffortModule(options: {
+  provider: 'codex' | 'openai'
+  supportsCodexReasoningEffort: boolean
+}) {
+  mock.module('./model/providers.js', () => ({
+    getAPIProvider: () => options.provider,
+  }))
+  mock.module('./model/modelSupportOverrides.js', () => ({
+    get3PModelCapabilityOverride: () => undefined,
+  }))
+  mock.module('../services/api/providerConfig.js', () => ({
+    supportsCodexReasoningEffort: () => options.supportsCodexReasoningEffort,
+  }))
+
+  return import(`./effort.js?ts=${Date.now()}-${Math.random()}`)
+}
+
+test('gpt-5.4 on the ChatGPT Codex backend supports effort selection', async () => {
+  const { getAvailableEffortLevels, modelSupportsEffort } =
+    await importFreshEffortModule({
+      provider: 'codex',
+      supportsCodexReasoningEffort: true,
+    })
+
+  expect(modelSupportsEffort('gpt-5.4')).toBe(true)
+  expect(getAvailableEffortLevels('gpt-5.4')).toEqual([
+    'low',
+    'medium',
+    'high',
+    'xhigh',
+  ])
+})
+
+test('gpt-5.4 on the OpenAI provider still supports effort selection', async () => {
+  const { getAvailableEffortLevels, modelSupportsEffort } =
+    await importFreshEffortModule({
+      provider: 'openai',
+      supportsCodexReasoningEffort: true,
+    })
+
+  expect(modelSupportsEffort('gpt-5.4')).toBe(true)
+  expect(getAvailableEffortLevels('gpt-5.4')).toEqual([
+    'low',
+    'medium',
+    'high',
+    'xhigh',
+  ])
+})
+
+test('gpt-5.3-codex-spark stays without effort controls', async () => {
+  const { getAvailableEffortLevels, modelSupportsEffort } =
+    await importFreshEffortModule({
+      provider: 'codex',
+      supportsCodexReasoningEffort: false,
+    })
+
+  expect(modelSupportsEffort('gpt-5.3-codex-spark')).toBe(false)
+  expect(getAvailableEffortLevels('gpt-5.3-codex-spark')).toEqual([])
+})
diff --git a/src/utils/effort.ts b/src/utils/effort.ts
index 13fd6699..af1a525b 100644
--- a/src/utils/effort.ts
+++ b/src/utils/effort.ts
@@ -5,6 +5,7 @@ import { isProSubscriber, isMaxSubscriber, isTeamSubscriber } from './auth.js'
 import { getFeatureValue_CACHED_MAY_BE_STALE } from 'src/services/analytics/growthbook.js'
 import { getAPIProvider } from './model/providers.js'
 import { get3PModelCapabilityOverride } from './model/modelSupportOverrides.js'
+import { supportsCodexReasoningEffort } from '../services/api/providerConfig.js'
 import { isEnvTruthy } from './envUtils.js'
 import type { EffortLevel } from 'src/entrypoints/sdk/runtimeTypes.js'
 
@@ -37,6 +38,9 @@ export function modelSupportsEffort(model: string): boolean {
   if (supported3P !== undefined) {
     return supported3P
   }
+  if (modelUsesOpenAIEffort(model) && supportsCodexReasoningEffort(model)) {
+    return true
+  }
   // Supported by a subset of Claude 4 models
   if (m.includes('opus-4-6') || m.includes('sonnet-4-6')) {
     return true
@@ -86,6 +90,9 @@ export function modelUsesOpenAIEffort(model: string): boolean {
 }
 
 export function getAvailableEffortLevels(model: string): EffortLevel[] | OpenAIEffortLevel[] {
+  if (!modelSupportsEffort(model)) {
+    return []
+  }
   if (modelUsesOpenAIEffort(model)) {
     return [...OPENAI_EFFORT_LEVELS] as OpenAIEffortLevel[]
   }
diff --git a/src/utils/providerProfile.test.ts b/src/utils/providerProfile.test.ts
index b5014931..af6cc0be 100644
--- a/src/utils/providerProfile.test.ts
+++ b/src/utils/providerProfile.test.ts
@@ -4,6 +4,7 @@ import { tmpdir } from 'node:os'
 import { join } from 'node:path'
 import test from 'node:test'
 
+import { DEFAULT_CODEX_BASE_URL } from '../services/api/providerConfig.ts'
 import {
   buildStartupEnvFromProfile,
   buildAtomicChatProfileEnv,
@@ -12,7 +13,9 @@ import {
   buildLaunchEnv,
   buildOllamaProfileEnv,
   buildOpenAIProfileEnv,
+  clearPersistedCodexOAuthProfile,
   createProfileFile,
+  isPersistedCodexOAuthProfile,
   maskSecretForDisplay,
   loadProfileFile,
   PROFILE_FILE_NAME,
@@ -23,6 +26,13 @@ import {
   type ProfileFile,
 } from './providerProfile.ts'
 
+function makeJwt(payload: Record<string, unknown>): string {
+  const header = Buffer.from(JSON.stringify({ alg: 'none', typ: 'JWT' }))
+    .toString('base64url')
+  const body = Buffer.from(JSON.stringify(payload)).toString('base64url')
+  return `${header}.${body}.signature`
+}
+
 function profile(profile: ProfileFile['profile'], env: ProfileFile['env']): ProfileFile {
   return {
     profile,
@@ -330,6 +340,7 @@ test('codex profiles accept explicit codex credentials', () => {
   assert.deepEqual(env, {
     OPENAI_BASE_URL: 'https://chatgpt.com/backend-api/codex',
     OPENAI_MODEL: 'codexspark',
+    CODEX_CREDENTIAL_SOURCE: 'existing',
     CODEX_API_KEY: 'codex-live',
     CHATGPT_ACCOUNT_ID: 'acct_123',
   })
@@ -417,6 +428,77 @@ test('saveProfileFile writes a profile that loadProfileFile can read back', () =
   }
 })
 
+test('buildCodexProfileEnv tags OAuth-saved profiles so logout can remove them safely', () => {
+  const env = buildCodexProfileEnv({
+    model: 'codexplan',
+    apiKey: makeJwt({
+      'https://api.openai.com/auth': {
+        chatgpt_account_id: 'acct_oauth',
+      },
+    }),
+    credentialSource: 'oauth',
+    processEnv: {},
+  })
+
+  assert.deepEqual(env, {
+    OPENAI_BASE_URL: DEFAULT_CODEX_BASE_URL,
+    OPENAI_MODEL: 'codexplan',
+    CODEX_CREDENTIAL_SOURCE: 'oauth',
+    CODEX_API_KEY: makeJwt({
+      'https://api.openai.com/auth': {
+        chatgpt_account_id: 'acct_oauth',
+      },
+    }),
+    CHATGPT_ACCOUNT_ID: 'acct_oauth',
+  })
+})
+
+test('clearPersistedCodexOAuthProfile removes only persisted Codex OAuth profiles', async () => {
+  const cwd = mkdtempSync(join(tmpdir(), 'openclaude-codex-oauth-profile-'))
+
+  try {
+    const providerProfileModule = await import(
+      `./providerProfile.ts?ts=${Date.now()}-${Math.random()}`
+    )
+    const {
+      PROFILE_FILE_NAME,
+      clearPersistedCodexOAuthProfile,
+      createProfileFile,
+      isPersistedCodexOAuthProfile,
+      loadProfileFile,
+      saveProfileFile,
+    } = providerProfileModule
+    const oauthProfile = createProfileFile('codex', {
+      OPENAI_MODEL: 'codexplan',
+      OPENAI_BASE_URL: DEFAULT_CODEX_BASE_URL,
+      CHATGPT_ACCOUNT_ID: 'acct_oauth',
+      CODEX_CREDENTIAL_SOURCE: 'oauth',
+    })
+    saveProfileFile(oauthProfile, { cwd })
+
+    assert.equal(isPersistedCodexOAuthProfile(loadProfileFile({ cwd })), true)
+    assert.equal(
+      clearPersistedCodexOAuthProfile({ cwd }),
+      join(cwd, PROFILE_FILE_NAME),
+    )
+    assert.equal(loadProfileFile({ cwd }), null)
+
+    const existingCredentialProfile = createProfileFile('codex', {
+      OPENAI_MODEL: 'codexplan',
+      OPENAI_BASE_URL: DEFAULT_CODEX_BASE_URL,
+      CHATGPT_ACCOUNT_ID: 'acct_existing',
+      CODEX_CREDENTIAL_SOURCE: 'existing',
+    })
+    saveProfileFile(existingCredentialProfile, { cwd })
+
+    assert.equal(isPersistedCodexOAuthProfile(loadProfileFile({ cwd })), false)
+    assert.equal(clearPersistedCodexOAuthProfile({ cwd }), null)
+    assert.deepEqual(loadProfileFile({ cwd }), existingCredentialProfile)
+  } finally {
+    rmSync(cwd, { recursive: true, force: true })
+  }
+})
+
 test('buildStartupEnvFromProfile applies persisted gemini settings when no provider is explicitly selected', async () => {
   const env = await buildStartupEnvFromProfile({
     persisted: profile('gemini', {
diff --git a/src/utils/providerProfile.ts b/src/utils/providerProfile.ts
index a5609015..ce39e1f1 100644
--- a/src/utils/providerProfile.ts
+++ b/src/utils/providerProfile.ts
@@ -7,6 +7,7 @@ import {
   resolveCodexApiCredentials,
   resolveProviderRequest,
 } from '../services/api/providerConfig.ts'
+import { parseChatgptAccountId } from '../services/api/codexOAuthShared.js'
 import {
   getGoalDefaultOpenAIModel,
   normalizeRecommendationGoal,
@@ -14,6 +15,20 @@ import {
 } from './providerRecommendation.ts'
 import { readGeminiAccessToken } from './geminiCredentials.ts'
 import { getOllamaChatBaseUrl } from './providerDiscovery.ts'
+import { getProviderValidationError } from './providerValidation.ts'
+import {
+  maskSecretForDisplay,
+  redactSecretValueForDisplay,
+  sanitizeApiKey,
+  sanitizeProviderConfigValue,
+} from './providerSecrets.ts'
+
+export {
+  maskSecretForDisplay,
+  redactSecretValueForDisplay,
+  sanitizeApiKey,
+  sanitizeProviderConfigValue,
+} from './providerSecrets.ts'
 
 export const PROFILE_FILE_NAME = '.openclaude-profile.json'
 export const DEFAULT_GEMINI_BASE_URL =
@@ -33,6 +48,7 @@ const PROFILE_ENV_KEYS = [
   'OPENAI_MODEL',
   'OPENAI_API_KEY',
   'CODEX_API_KEY',
+  'CODEX_CREDENTIAL_SOURCE',
   'CHATGPT_ACCOUNT_ID',
   'CODEX_ACCOUNT_ID',
   'GEMINI_API_KEY',
@@ -46,21 +62,20 @@ const PROFILE_ENV_KEYS = [
   'MISTRAL_MODEL',
 ] as const
 
-const SECRET_ENV_KEYS = [
-  'OPENAI_API_KEY',
-  'CODEX_API_KEY',
-  'GEMINI_API_KEY',
-  'GOOGLE_API_KEY',
-  'MISTRAL_API_KEY',
-] as const
-
-export type ProviderProfile = 'openai' | 'ollama' | 'codex' | 'gemini' | 'atomic-chat' | 'mistral'
+export type ProviderProfile =
+  | 'openai'
+  | 'ollama'
+  | 'codex'
+  | 'gemini'
+  | 'atomic-chat'
+  | 'mistral'
 
 export type ProfileEnv = {
   OPENAI_BASE_URL?: string
   OPENAI_MODEL?: string
   OPENAI_API_KEY?: string
   CODEX_API_KEY?: string
+  CODEX_CREDENTIAL_SOURCE?: 'oauth' | 'existing'
   CHATGPT_ACCOUNT_ID?: string
   CODEX_ACCOUNT_ID?: string
   GEMINI_API_KEY?: string
@@ -78,13 +93,6 @@ export type ProfileFile = {
   createdAt: string
 }
 
-type SecretValueSource = Partial<
-  Pick<
-    NodeJS.ProcessEnv & ProfileEnv,
-    (typeof SECRET_ENV_KEYS)[number]
-  >
->
-
 type ProfileFileLocation = {
   cwd?: string
   filePath?: string
@@ -109,102 +117,6 @@ export function isProviderProfile(value: unknown): value is ProviderProfile {
   )
 }
 
-export function sanitizeApiKey(
-  key: string | null | undefined,
-): string | undefined {
-  if (!key || key === 'SUA_CHAVE') return undefined
-  return key
-}
-
-function looksLikeSecretValue(value: string): boolean {
-  const trimmed = value.trim()
-  if (!trimmed) return false
-
-  if (trimmed.startsWith('sk-') || trimmed.startsWith('sk-ant-')) {
-    return true
-  }
-
-  if (trimmed.startsWith('AIza')) {
-    return true
-  }
-
-  return false
-}
-
-function collectSecretValues(
-  sources: Array<SecretValueSource | null | undefined>,
-): string[] {
-  const values = new Set<string>()
-
-  for (const source of sources) {
-    if (!source) continue
-
-    for (const key of SECRET_ENV_KEYS) {
-      const value = sanitizeApiKey(source[key])
-      if (value) {
-        values.add(value)
-      }
-    }
-  }
-
-  return [...values]
-}
-
-export function maskSecretForDisplay(
-  value: string | null | undefined,
-): string | undefined {
-  const sanitized = sanitizeApiKey(value)
-  if (!sanitized) return undefined
-
-  if (sanitized.length <= 8) {
-    return 'configured'
-  }
-
-  if (sanitized.startsWith('sk-')) {
-    return `${sanitized.slice(0, 3)}...${sanitized.slice(-4)}`
-  }
-
-  if (sanitized.startsWith('AIza')) {
-    return `${sanitized.slice(0, 4)}...${sanitized.slice(-4)}`
-  }
-
-  return `${sanitized.slice(0, 2)}...${sanitized.slice(-4)}`
-}
-
-export function redactSecretValueForDisplay(
-  value: string | null | undefined,
-  ...sources: Array<SecretValueSource | null | undefined>
-): string | undefined {
-  if (!value) return undefined
-
-  const trimmed = value.trim()
-  if (!trimmed) return trimmed
-
-  const secretValues = collectSecretValues(sources)
-  if (secretValues.includes(trimmed) || looksLikeSecretValue(trimmed)) {
-    return maskSecretForDisplay(trimmed) ?? 'configured'
-  }
-
-  return trimmed
-}
-
-export function sanitizeProviderConfigValue(
-  value: string | null | undefined,
-  ...sources: Array<SecretValueSource | null | undefined>
-): string | undefined {
-  if (!value) return undefined
-
-  const trimmed = value.trim()
-  if (!trimmed) return undefined
-
-  const secretValues = collectSecretValues(sources)
-  if (secretValues.includes(trimmed) || looksLikeSecretValue(trimmed)) {
-    return undefined
-  }
-
-  return trimmed
-}
-
 export function buildOllamaProfileEnv(
   model: string,
   options: {
@@ -335,6 +247,7 @@ export function buildCodexProfileEnv(options: {
   model?: string | null
   baseUrl?: string | null
   apiKey?: string | null
+  credentialSource?: 'oauth' | 'existing'
   processEnv?: NodeJS.ProcessEnv
 }): ProfileEnv | null {
   const processEnv = options.processEnv ?? process.env
@@ -346,10 +259,14 @@ export function buildCodexProfileEnv(options: {
   if (!credentials.apiKey || !credentials.accountId) {
     return null
   }
+  const credentialSource =
+    options.credentialSource ??
+    (credentials.source === 'secure-storage' ? 'oauth' : 'existing')
 
   const env: ProfileEnv = {
     OPENAI_BASE_URL: options.baseUrl || DEFAULT_CODEX_BASE_URL,
     OPENAI_MODEL: options.model || 'codexplan',
+    CODEX_CREDENTIAL_SOURCE: credentialSource,
   }
 
   if (key) {
@@ -399,6 +316,30 @@ export function buildMistralProfileEnv(options: {
   return env
 }
 
+export function buildCodexOAuthProfileEnv(
+  tokens: {
+    accessToken: string
+    idToken?: string
+    accountId?: string
+  },
+): ProfileEnv | null {
+  const accountId =
+    tokens.accountId ??
+    parseChatgptAccountId(tokens.idToken) ??
+    parseChatgptAccountId(tokens.accessToken)
+
+  if (!accountId) {
+    return null
+  }
+
+  return {
+    OPENAI_BASE_URL: DEFAULT_CODEX_BASE_URL,
+    OPENAI_MODEL: 'codexplan',
+    CHATGPT_ACCOUNT_ID: accountId,
+    CODEX_CREDENTIAL_SOURCE: 'oauth',
+  }
+}
+
 export function createProfileFile(
   profile: ProviderProfile,
   env: ProfileEnv,
@@ -410,6 +351,26 @@ export function createProfileFile(
   }
 }
 
+export function isPersistedCodexOAuthProfile(
+  persisted: ProfileFile | null,
+): boolean {
+  return (
+    persisted?.profile === 'codex' &&
+    persisted.env.CODEX_CREDENTIAL_SOURCE === 'oauth'
+  )
+}
+
+export function clearPersistedCodexOAuthProfile(
+  options?: ProfileFileLocation,
+): string | null {
+  const persisted = loadProfileFile(options)
+  if (!isPersistedCodexOAuthProfile(persisted)) {
+    return null
+  }
+
+  return deleteProfileFile(options)
+}
+
 export function loadProfileFile(options?: ProfileFileLocation): ProfileFile | null {
   const filePath = resolveProfileFilePath(options)
   if (!existsSync(filePath)) {
@@ -545,6 +506,7 @@ export async function buildLaunchEnv(options: {
 
     delete env.CLAUDE_CODE_USE_OPENAI
     delete env.CLAUDE_CODE_USE_GITHUB
+    delete env.CODEX_CREDENTIAL_SOURCE
 
     env.GEMINI_MODEL =
       shellGeminiModel ||
@@ -668,6 +630,7 @@ export async function buildLaunchEnv(options: {
   delete env.CLAUDE_CODE_USE_FOUNDRY
   delete env.CLAUDE_CODE_USE_GEMINI
   delete env.CLAUDE_CODE_USE_GITHUB
+  delete env.CODEX_CREDENTIAL_SOURCE
   delete env.GEMINI_API_KEY
   delete env.GEMINI_AUTH_MODE
   delete env.GEMINI_ACCESS_TOKEN
@@ -838,3 +801,40 @@ export function applyProfileEnvToProcessEnv(
 
   Object.assign(targetEnv, nextEnv)
 }
+
+export async function applySavedProfileToCurrentSession(options: {
+  profileFile: ProfileFile
+  processEnv?: NodeJS.ProcessEnv
+}): Promise<string | null> {
+  const processEnv = options.processEnv ?? process.env
+  const baseEnv = { ...processEnv }
+  const isCodexOAuthProfile =
+    options.profileFile.profile === 'codex' &&
+    options.profileFile.env.CODEX_CREDENTIAL_SOURCE === 'oauth'
+
+  delete baseEnv.CLAUDE_CODE_PROVIDER_PROFILE_ENV_APPLIED
+  delete baseEnv.CLAUDE_CODE_PROVIDER_PROFILE_ENV_APPLIED_ID
+  if (isCodexOAuthProfile) {
+    delete baseEnv.CODEX_API_KEY
+    delete baseEnv.CODEX_ACCOUNT_ID
+    delete baseEnv.CHATGPT_ACCOUNT_ID
+  }
+
+  const nextEnv = await buildLaunchEnv({
+    profile: options.profileFile.profile,
+    persisted: options.profileFile,
+    goal: normalizeRecommendationGoal(processEnv.OPENCLAUDE_PROFILE_GOAL),
+    processEnv: baseEnv,
+    getOllamaChatBaseUrl,
+    readGeminiAccessToken,
+  })
+  const validationError = await getProviderValidationError(nextEnv)
+  if (validationError) {
+    return validationError
+  }
+
+  delete processEnv.CLAUDE_CODE_PROVIDER_PROFILE_ENV_APPLIED
+  delete processEnv.CLAUDE_CODE_PROVIDER_PROFILE_ENV_APPLIED_ID
+  applyProfileEnvToProcessEnv(processEnv, nextEnv)
+  return null
+}
diff --git a/src/utils/providerSecrets.ts b/src/utils/providerSecrets.ts
new file mode 100644
index 00000000..78c2c9bf
--- /dev/null
+++ b/src/utils/providerSecrets.ts
@@ -0,0 +1,107 @@
+const SECRET_ENV_KEYS = [
+  'OPENAI_API_KEY',
+  'CODEX_API_KEY',
+  'GEMINI_API_KEY',
+  'GOOGLE_API_KEY',
+  'MISTRAL_API_KEY',
+] as const
+
+export type SecretValueSource = Partial<
+  Record<(typeof SECRET_ENV_KEYS)[number], string | undefined>
+>
+
+export function sanitizeApiKey(
+  key: string | null | undefined,
+): string | undefined {
+  if (!key || key === 'SUA_CHAVE') return undefined
+  return key
+}
+
+function looksLikeSecretValue(value: string): boolean {
+  const trimmed = value.trim()
+  if (!trimmed) return false
+
+  if (trimmed.startsWith('sk-') || trimmed.startsWith('sk-ant-')) {
+    return true
+  }
+
+  if (trimmed.startsWith('AIza')) {
+    return true
+  }
+
+  return false
+}
+
+function collectSecretValues(
+  sources: Array<SecretValueSource | null | undefined>,
+): string[] {
+  const values = new Set<string>()
+
+  for (const source of sources) {
+    if (!source) continue
+
+    for (const key of SECRET_ENV_KEYS) {
+      const value = sanitizeApiKey(source[key])
+      if (value) {
+        values.add(value)
+      }
+    }
+  }
+
+  return [...values]
+}
+
+export function maskSecretForDisplay(
+  value: string | null | undefined,
+): string | undefined {
+  const sanitized = sanitizeApiKey(value)
+  if (!sanitized) return undefined
+
+  if (sanitized.length <= 8) {
+    return 'configured'
+  }
+
+  if (sanitized.startsWith('sk-')) {
+    return `${sanitized.slice(0, 3)}...${sanitized.slice(-4)}`
+  }
+
+  if (sanitized.startsWith('AIza')) {
+    return `${sanitized.slice(0, 4)}...${sanitized.slice(-4)}`
+  }
+
+  return `${sanitized.slice(0, 2)}...${sanitized.slice(-4)}`
+}
+
+export function redactSecretValueForDisplay(
+  value: string | null | undefined,
+  ...sources: Array<SecretValueSource | null | undefined>
+): string | undefined {
+  if (!value) return undefined
+
+  const trimmed = value.trim()
+  if (!trimmed) return trimmed
+
+  const secretValues = collectSecretValues(sources)
+  if (secretValues.includes(trimmed) || looksLikeSecretValue(trimmed)) {
+    return maskSecretForDisplay(trimmed) ?? 'configured'
+  }
+
+  return trimmed
+}
+
+export function sanitizeProviderConfigValue(
+  value: string | null | undefined,
+  ...sources: Array<SecretValueSource | null | undefined>
+): string | undefined {
+  if (!value) return undefined
+
+  const trimmed = value.trim()
+  if (!trimmed) return undefined
+
+  const secretValues = collectSecretValues(sources)
+  if (secretValues.includes(trimmed) || looksLikeSecretValue(trimmed)) {
+    return undefined
+  }
+
+  return trimmed
+}
diff --git a/src/utils/providerValidation.ts b/src/utils/providerValidation.ts
index 5f462c35..fa671388 100644
--- a/src/utils/providerValidation.ts
+++ b/src/utils/providerValidation.ts
@@ -6,11 +6,13 @@ import {
   resolveProviderRequest,
 } from '../services/api/providerConfig.js'
 import { getGlobalClaudeFile } from './env.js'
+import { isBareMode } from './envUtils.js'
 import {
   type GeminiResolvedCredential,
   resolveGeminiCredential,
 } from './geminiAuth.js'
-import { PROFILE_FILE_NAME, redactSecretValueForDisplay } from './providerProfile.js'
+import { PROFILE_FILE_NAME } from './providerProfile.js'
+import { redactSecretValueForDisplay } from './providerSecrets.js'
 
 function isEnvTruthy(value: string | undefined): boolean {
   if (!value) return false
@@ -82,6 +84,7 @@ export async function getProviderValidationError(
     ) => Promise<GeminiResolvedCredential>
   },
 ): Promise<string | null> {
+  const secretSource = env
   const useOpenAI = isEnvTruthy(env.CLAUDE_CODE_USE_OPENAI)
   const useGithub = isEnvTruthy(env.CLAUDE_CODE_USE_GITHUB)
 
@@ -131,16 +134,17 @@ export async function getProviderValidationError(
   if (request.transport === 'codex_responses') {
     const credentials = resolveCodexApiCredentials(env)
     if (!credentials.apiKey) {
+      const oauthHint = isBareMode() ? '' : ', choose Codex OAuth in /provider'
       const authHint = credentials.authPath
-        ? ` or put auth.json at ${credentials.authPath}`
-        : ''
+        ? `${oauthHint} or put auth.json at ${credentials.authPath}`
+        : oauthHint
       const safeModel =
-        redactSecretValueForDisplay(request.requestedModel, env) ??
+        redactSecretValueForDisplay(request.requestedModel, secretSource) ??
         'the requested model'
       return `Codex auth is required for ${safeModel}. Set CODEX_API_KEY${authHint}.`
     }
     if (!credentials.accountId) {
-      return 'Codex auth is missing chatgpt_account_id. Re-login with Codex or set CHATGPT_ACCOUNT_ID/CODEX_ACCOUNT_ID.'
+      return 'Codex auth is missing chatgpt_account_id. Re-login with Codex OAuth, Codex CLI, or set CHATGPT_ACCOUNT_ID/CODEX_ACCOUNT_ID.'
     }
     return null
   }
diff --git a/src/utils/secureStorage/index.ts b/src/utils/secureStorage/index.ts
index 817d2320..aea357e0 100644
--- a/src/utils/secureStorage/index.ts
+++ b/src/utils/secureStorage/index.ts
@@ -5,6 +5,16 @@ import { windowsCredentialStorage } from './windowsCredentialStorage.js'
 import { plainTextStorage } from './plainTextStorage.js'
 
 export interface SecureStorageData {
+  codex?: {
+    apiKey?: string
+    accessToken: string
+    refreshToken?: string
+    idToken?: string
+    accountId?: string
+    profileId?: string
+    lastRefreshAt?: number
+    lastRefreshFailureAt?: number
+  }
   mcpOAuth?: Record<
     string,
     {
@@ -36,22 +46,44 @@ export interface SecureStorage {
   delete(): boolean
 }
 
+const unavailableSecureStorage: SecureStorage = {
+  name: 'unavailable-secure-storage',
+  read: () => null,
+  readAsync: async () => null,
+  update: () => ({
+    success: false,
+    warning:
+      'Secure storage is unavailable on this platform without plaintext fallback.',
+  }),
+  delete: () => true,
+}
+
 /**
  * Get the appropriate secure storage implementation for the current platform.
  * Prefers native OS vaults (Keychain, libsecret, Credential Locker) with a plaintext fallback.
  */
-export function getSecureStorage(): SecureStorage {
+export function getSecureStorage(options?: {
+  allowPlainTextFallback?: boolean
+}): SecureStorage {
+  const allowPlainTextFallback = options?.allowPlainTextFallback ?? true
+
   if (process.platform === 'darwin') {
-    return createFallbackStorage(macOsKeychainStorage, plainTextStorage)
+    return allowPlainTextFallback
+      ? createFallbackStorage(macOsKeychainStorage, plainTextStorage)
+      : macOsKeychainStorage
   }
 
   if (process.platform === 'linux') {
-    return createFallbackStorage(linuxSecretStorage, plainTextStorage)
+    return allowPlainTextFallback
+      ? createFallbackStorage(linuxSecretStorage, plainTextStorage)
+      : linuxSecretStorage
   }
 
   if (process.platform === 'win32') {
-    return createFallbackStorage(windowsCredentialStorage, plainTextStorage)
+    return allowPlainTextFallback
+      ? createFallbackStorage(windowsCredentialStorage, plainTextStorage)
+      : windowsCredentialStorage
   }
 
-  return plainTextStorage
+  return allowPlainTextFallback ? plainTextStorage : unavailableSecureStorage
 }
diff --git a/src/utils/secureStorage/platformStorage.test.ts b/src/utils/secureStorage/platformStorage.test.ts
index 6b835243..76b14522 100644
--- a/src/utils/secureStorage/platformStorage.test.ts
+++ b/src/utils/secureStorage/platformStorage.test.ts
@@ -64,8 +64,10 @@ describe("Secure Storage Platform Implementations", () => {
       windowsCredentialStorage.update(testData);
 
       const script = mockExecaSync.mock.calls[0][1][1];
+      const options = mockExecaSync.mock.calls[0][2];
       expect(script).toContain(expectedName);
-      expect(script).toContain("Add-Type -AssemblyName System.Runtime.WindowsRuntime");
+      expect(script).toContain("ProtectedData");
+      expect(options.input).toContain("secret-token");
     });
   });
 
@@ -85,32 +87,54 @@ describe("Secure Storage Platform Implementations", () => {
       windowsCredentialStorage.update(dataWithDollar);
 
       const script = mockExecaSync.mock.calls[0][1][1];
-      // Should use single quotes for the payload
-      expect(script).toMatch(/'\{.*\}'/);
-      // Should escape ' by doubling it
-      expect(script).not.toContain("'token-with-$env:USERNAME'");
-      // But since it's JSON, the value will be "token-with-$env:USERNAME" inside the single-quoted string
-      // The JSON itself shouldn't have single quotes unless the data has them.
+      const options = mockExecaSync.mock.calls[0][2];
+      expect(script).toContain("[Console]::In.ReadToEnd()");
+      expect(options.input).toContain("token-with-$env:USERNAME");
 
       const dataWithQuote = { mcpOAuth: { "s": { accessToken: "token'quote", expiresAt: 1, serverName: "s", serverUrl: "u" } } };
       windowsCredentialStorage.update(dataWithQuote);
-      const script2 = mockExecaSync.mock.calls[1][1][1];
-      expect(script2).toContain("token''quote");
+      const options2 = mockExecaSync.mock.calls[1][2];
+      expect(options2.input).toContain("token'quote");
     });
 
     test("delete() includes assembly load", () => {
       windowsCredentialStorage.delete();
-      const script = mockExecaSync.mock.calls[0][1][1];
+      const script = mockExecaSync.mock.calls[1][1][1];
       expect(script).toContain("Add-Type -AssemblyName System.Runtime.WindowsRuntime");
     });
 
     test("escapes double quotes in username", () => {
       process.env.USER = 'user"name';
       windowsCredentialStorage.read();
-      const script = mockExecaSync.mock.calls[0][1][1];
+      const script = mockExecaSync.mock.calls[1][1][1];
       expect(script).toContain('user`"name');
       expect(script).not.toContain('user"name');
     });
+
+    test("read() falls back to legacy PasswordVault when the DPAPI payload is invalid JSON", () => {
+      mockExecaSync
+        .mockImplementationOnce(() => ({ exitCode: 0, stdout: "{not-json" }))
+        .mockImplementationOnce(() => ({
+          exitCode: 0,
+          stdout: JSON.stringify(testData),
+        }));
+
+      const result = windowsCredentialStorage.read();
+
+      expect(result).toEqual(testData);
+      expect(mockExecaSync).toHaveBeenCalledTimes(2);
+    });
+
+    test("read() fails closed when the legacy PasswordVault payload is invalid JSON", () => {
+      mockExecaSync
+        .mockImplementationOnce(() => ({ exitCode: 1, stdout: "" }))
+        .mockImplementationOnce(() => ({ exitCode: 0, stdout: "{not-json" }));
+
+      const result = windowsCredentialStorage.read();
+
+      expect(result).toBeNull();
+      expect(mockExecaSync).toHaveBeenCalledTimes(2);
+    });
   });
 
   describe("Linux secret-tool Interaction", () => {
diff --git a/src/utils/secureStorage/windowsCredentialStorage.ts b/src/utils/secureStorage/windowsCredentialStorage.ts
index 050fe781..938a79ad 100644
--- a/src/utils/secureStorage/windowsCredentialStorage.ts
+++ b/src/utils/secureStorage/windowsCredentialStorage.ts
@@ -1,4 +1,6 @@
 import { execaSync } from 'execa'
+import { join } from 'path'
+import { getClaudeConfigHomeDir } from '../envUtils.js'
 import { jsonParse, jsonStringify } from '../slowOperations.js'
 import {
   CREDENTIALS_SERVICE_SUFFIX,
@@ -8,90 +10,216 @@ import {
 import type { SecureStorage, SecureStorageData } from './index.js'
 
 /**
- * Windows-specific secure storage implementation using the Windows Credential Locker.
- * Accessed via PowerShell's [Windows.Security.Credentials.PasswordVault].
+ * Windows-specific secure storage implementation using DPAPI for new writes,
+ * with best-effort reads/deletes from the legacy PasswordVault path.
  */
-export const windowsCredentialStorage: SecureStorage = {
-  name: 'credential-locker',
-  read(): SecureStorageData | null {
-    const resourceName = getSecureStorageServiceName(
-      CREDENTIALS_SERVICE_SUFFIX,
-    ).replace(/"/g, '`"')
-    const username = getUsername().replace(/"/g, '`"')
-    // PowerShell script to retrieve password from vault
-    const script = `
-      Add-Type -AssemblyName System.Runtime.WindowsRuntime
+function escapePowerShellSingleQuoted(value: string): string {
+  return value.replace(/'/g, "''")
+}
+
+function getLegacyResourceName(): string {
+  return getSecureStorageServiceName(CREDENTIALS_SERVICE_SUFFIX)
+}
+
+function getWindowsSecureStorageEntropy(): string {
+  return `${getLegacyResourceName()}:${getUsername()}`
+}
+
+function getWindowsSecureStorageFilePath(): string {
+  const resourceName = getLegacyResourceName().replace(/[^a-zA-Z0-9._-]/g, '_')
+  return join(getClaudeConfigHomeDir(), `${resourceName}.secure.dpapi`)
+}
+
+function runPowerShell(
+  script: string,
+  options?: { input?: string },
+): ReturnType<typeof execaSync> | null {
+  try {
+    return execaSync('powershell.exe', ['-Command', script], {
+      input: options?.input,
+      reject: false,
+    })
+  } catch {
+    return null
+  }
+}
+
+function getFailureWarning(
+  result: ReturnType<typeof execaSync> | null,
+  fallback: string,
+): string {
+  const stderr = result?.stderr?.trim()
+  if (stderr) {
+    return stderr
+  }
+
+  if (typeof result?.exitCode === 'number' && result.exitCode !== 0) {
+    return `${fallback} (exit code ${result.exitCode}).`
+  }
+
+  return fallback
+}
+
+function readLegacyPasswordVault(): SecureStorageData | null {
+  const resourceName = getLegacyResourceName().replace(/"/g, '`"')
+  const username = getUsername().replace(/"/g, '`"')
+  const script = `
+    Add-Type -AssemblyName System.Runtime.WindowsRuntime
+    try {
       $vault = New-Object Windows.Security.Credentials.PasswordVault
+      $cred = $vault.Retrieve("${resourceName}", "${username}")
+      $cred.FillPassword()
+      [Console]::Out.Write($cred.Password)
+    } catch {
+      exit 1
+    }
+  `
+
+  const result = runPowerShell(script)
+  if (result?.exitCode === 0 && result.stdout) {
+    try {
+      return jsonParse(result.stdout)
+    } catch {
+      return null
+    }
+  }
+
+  return null
+}
+
+export const windowsCredentialStorage: SecureStorage = {
+  name: 'credential-locker-dpapi',
+  read(): SecureStorageData | null {
+    const filePath = escapePowerShellSingleQuoted(
+      getWindowsSecureStorageFilePath(),
+    )
+    const entropy = escapePowerShellSingleQuoted(
+      getWindowsSecureStorageEntropy(),
+    )
+    const script = `
       try {
-        $cred = $vault.Retrieve("${resourceName}", "${username}")
-        $cred.FillPassword()
-        $cred.Password
+        Add-Type -AssemblyName System.Security
+        $path = '${filePath}'
+        if (!(Test-Path -LiteralPath $path)) {
+          exit 1
+        }
+
+        $protectedBase64 = [System.IO.File]::ReadAllText(
+          $path,
+          [System.Text.Encoding]::UTF8
+        ).Trim()
+        if (-not $protectedBase64) {
+          exit 1
+        }
+
+        $protectedBytes = [Convert]::FromBase64String($protectedBase64)
+        $entropyBytes = [System.Text.Encoding]::UTF8.GetBytes('${entropy}')
+        $bytes = [System.Security.Cryptography.ProtectedData]::Unprotect(
+          $protectedBytes,
+          $entropyBytes,
+          [System.Security.Cryptography.DataProtectionScope]::CurrentUser
+        )
+        [Console]::Out.Write([System.Text.Encoding]::UTF8.GetString($bytes))
       } catch {
         exit 1
       }
     `
-    try {
-      const result = execaSync('powershell.exe', ['-Command', script], {
-        reject: false,
-      })
-      if (result.exitCode === 0 && result.stdout) {
+
+    const result = runPowerShell(script)
+    if (result?.exitCode === 0 && result.stdout) {
+      try {
         return jsonParse(result.stdout)
+      } catch {
+        return readLegacyPasswordVault()
       }
-    } catch {
-      // fall through
     }
-    return null
+
+    return readLegacyPasswordVault()
   },
   async readAsync(): Promise<SecureStorageData | null> {
     return this.read()
   },
   update(data: SecureStorageData): { success: boolean; warning?: string } {
-    const resourceName = getSecureStorageServiceName(
-      CREDENTIALS_SERVICE_SUFFIX,
-    ).replace(/"/g, '`"')
-    const username = getUsername().replace(/"/g, '`"')
-    // Use single quotes for the payload and escape ' by doubling it ('').
-    // This prevents PowerShell from expanding $... inside the string.
-    const payload = jsonStringify(data).replace(/'/g, "''")
-    // PowerShell script to add/update credential in vault
+    const filePath = escapePowerShellSingleQuoted(
+      getWindowsSecureStorageFilePath(),
+    )
+    const entropy = escapePowerShellSingleQuoted(
+      getWindowsSecureStorageEntropy(),
+    )
+    const payload = jsonStringify(data)
     const script = `
-      Add-Type -AssemblyName System.Runtime.WindowsRuntime
-      $vault = New-Object Windows.Security.Credentials.PasswordVault
-      $cred = New-Object Windows.Security.Credentials.PasswordCredential("${resourceName}", "${username}", '${payload}')
-      $vault.Add($cred)
+      try {
+        Add-Type -AssemblyName System.Security
+        $path = '${filePath}'
+        $directory = [System.IO.Path]::GetDirectoryName($path)
+        if ($directory) {
+          [System.IO.Directory]::CreateDirectory($directory) | Out-Null
+        }
+
+        $payload = [Console]::In.ReadToEnd()
+        $bytes = [System.Text.Encoding]::UTF8.GetBytes($payload)
+        $entropyBytes = [System.Text.Encoding]::UTF8.GetBytes('${entropy}')
+        $protectedBytes = [System.Security.Cryptography.ProtectedData]::Protect(
+          $bytes,
+          $entropyBytes,
+          [System.Security.Cryptography.DataProtectionScope]::CurrentUser
+        )
+        $protectedBase64 = [Convert]::ToBase64String($protectedBytes)
+        [System.IO.File]::WriteAllText(
+          $path,
+          $protectedBase64,
+          [System.Text.Encoding]::UTF8
+        )
+      } catch {
+        Write-Error $_.Exception.Message
+        exit 1
+      }
     `
-    try {
-      const result = execaSync('powershell.exe', ['-Command', script], {
-        reject: false,
-      })
-      return { success: result.exitCode === 0 }
-    } catch {
-      return { success: false }
+    const result = runPowerShell(script, { input: payload })
+    if (result?.exitCode === 0) {
+      return { success: true }
+    }
+
+    return {
+      success: false,
+      warning: getFailureWarning(
+        result,
+        'Windows secure storage could not encrypt credentials with DPAPI',
+      ),
     }
   },
   delete(): boolean {
-    const resourceName = getSecureStorageServiceName(
-      CREDENTIALS_SERVICE_SUFFIX,
-    ).replace(/"/g, '`"')
-    const username = getUsername().replace(/"/g, '`"')
-    // PowerShell script to remove credential from vault
-    const script = `
-      Add-Type -AssemblyName System.Runtime.WindowsRuntime
-      $vault = New-Object Windows.Security.Credentials.PasswordVault
+    const filePath = escapePowerShellSingleQuoted(
+      getWindowsSecureStorageFilePath(),
+    )
+    const removeDpapiScript = `
       try {
+        $path = '${filePath}'
+        if (Test-Path -LiteralPath $path) {
+          Remove-Item -LiteralPath $path -Force
+        }
+      } catch {
+        exit 1
+      }
+    `
+    const removeDpapiResult = runPowerShell(removeDpapiScript)
+
+    const resourceName = getLegacyResourceName().replace(/"/g, '`"')
+    const username = getUsername().replace(/"/g, '`"')
+    const removeLegacyScript = `
+      Add-Type -AssemblyName System.Runtime.WindowsRuntime
+      try {
+        $vault = New-Object Windows.Security.Credentials.PasswordVault
         $cred = $vault.Retrieve("${resourceName}", "${username}")
         $vault.Remove($cred)
       } catch {
         exit 0
       }
     `
-    try {
-      const result = execaSync('powershell.exe', ['-Command', script], {
-        reject: false,
-      })
-      return result.exitCode === 0
-    } catch {
-      return false
-    }
+    const removeLegacyResult = runPowerShell(removeLegacyScript)
+
+    void removeLegacyResult
+
+    return (removeDpapiResult?.exitCode ?? 1) === 0
   },
 }