feat: 修复 Codex 模型映射并添加登录后模型配置面板

- configs.ts: 将 codex 字段从 Anthropic 模型名改为实际 OpenAI 模型名
  (opus→gpt-5.4, sonnet→gpt-5.4-mini, haiku→gpt-5.4-mini, opus47→gpt-5.5)
- modelMapping.ts: 移除不存在的 gpt-5.4-nano，修复 haiku 映射，添加 opus47
- ConsoleOAuthFlow.tsx: OAuth 成功后显示模型配置面板，可编辑三种模型名称
- 已登录用户再次选择 Codex 时跳过 OAuth 直接进入模型配置
- Ctrl+R 快捷键清除登录状态并重新 OAuth
- modelOptions.ts: codex provider 支持 CODEX_DEFAULT_*_MODEL 环境变量

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

packages/@ant/model-provider/src/index.ts

@@ -61,3 +61,10 @@ export { anthropicMessagesToOpenAI } from './shared/openaiConvertMessages.js'
 export type { ConvertMessagesOptions } from './shared/openaiConvertMessages.js'
 export { anthropicToolsToOpenAI, anthropicToolChoiceToOpenAI } from './shared/openaiConvertTools.js'
 export { adaptOpenAIStreamToAnthropic } from './shared/openaiStreamAdapter.js'
+
+// Codex provider utilities
+export { normalizeCodexCallId, resolveCodexCallId, createCodexFallbackCallId } from './providers/codex/callIds.js'
+export { resolveCodexModel, resolveCodexMaxTokens } from './providers/codex/modelMapping.js'
+export { anthropicMessagesToCodexInput } from './providers/codex/convertMessages.js'
+export type { CodexImageConversionOptions } from './providers/codex/convertMessages.js'
+export { anthropicToolsToCodex } from './providers/codex/convertTools.js'

packages/@ant/model-provider/src/providers/codex/__tests__/modelMapping.test.ts

@@ -0,0 +1,94 @@
+import { describe, expect, test, beforeEach, afterEach } from 'bun:test'
+import { resolveCodexModel } from '../modelMapping.js'
+
+describe('resolveCodexModel', () => {
+  const originalEnv = {
+    CODEX_MODEL: process.env.CODEX_MODEL,
+    CODEX_DEFAULT_HAIKU_MODEL: process.env.CODEX_DEFAULT_HAIKU_MODEL,
+    CODEX_DEFAULT_SONNET_MODEL: process.env.CODEX_DEFAULT_SONNET_MODEL,
+    CODEX_DEFAULT_OPUS_MODEL: process.env.CODEX_DEFAULT_OPUS_MODEL,
+  }
+
+  beforeEach(() => {
+    delete process.env.CODEX_MODEL
+    delete process.env.CODEX_DEFAULT_HAIKU_MODEL
+    delete process.env.CODEX_DEFAULT_SONNET_MODEL
+    delete process.env.CODEX_DEFAULT_OPUS_MODEL
+  })
+
+  afterEach(() => {
+    Object.assign(process.env, originalEnv)
+  })
+
+  test('CODEX_MODEL env var overrides all', () => {
+    process.env.CODEX_MODEL = 'my-custom-model'
+    expect(resolveCodexModel('claude-sonnet-4-6')).toBe('my-custom-model')
+  })
+
+  test('CODEX_DEFAULT_SONNET_MODEL overrides default map', () => {
+    process.env.CODEX_DEFAULT_SONNET_MODEL = 'my-sonnet'
+    expect(resolveCodexModel('claude-sonnet-4-6')).toBe('my-sonnet')
+  })
+
+  test('CODEX_DEFAULT_HAIKU_MODEL overrides default map', () => {
+    process.env.CODEX_DEFAULT_HAIKU_MODEL = 'my-haiku'
+    expect(resolveCodexModel('claude-haiku-4-5-20251001')).toBe('my-haiku')
+  })
+
+  test('CODEX_DEFAULT_OPUS_MODEL overrides default map', () => {
+    process.env.CODEX_DEFAULT_OPUS_MODEL = 'my-opus'
+    expect(resolveCodexModel('claude-opus-4-6')).toBe('my-opus')
+  })
+
+  test('maps known sonnet model via DEFAULT_MODEL_MAP', () => {
+    expect(resolveCodexModel('claude-sonnet-4-6')).toBe('gpt-5.4-mini')
+  })
+
+  test('maps known haiku model via DEFAULT_MODEL_MAP', () => {
+    expect(resolveCodexModel('claude-haiku-4-5-20251001')).toBe('gpt-5.4-mini')
+  })
+
+  test('maps known opus model via DEFAULT_MODEL_MAP', () => {
+    expect(resolveCodexModel('claude-opus-4-6')).toBe('gpt-5.4')
+  })
+
+  test('maps legacy sonnet models', () => {
+    expect(resolveCodexModel('claude-sonnet-4-20250514')).toBe('gpt-5.4-mini')
+    expect(resolveCodexModel('claude-3-5-sonnet-20241022')).toBe('gpt-5.4-mini')
+  })
+
+  test('maps legacy haiku models', () => {
+    expect(resolveCodexModel('claude-3-5-haiku-20241022')).toBe('gpt-5.4-mini')
+  })
+
+  test('maps legacy opus models', () => {
+    expect(resolveCodexModel('claude-opus-4-20250514')).toBe('gpt-5.4')
+    expect(resolveCodexModel('claude-opus-4-5-20251101')).toBe('gpt-5.4')
+  })
+
+  test('uses family default for unrecognized haiku model', () => {
+    expect(resolveCodexModel('claude-haiku-99')).toBe('gpt-5.4-mini')
+  })
+
+  test('uses family default for unrecognized sonnet model', () => {
+    expect(resolveCodexModel('claude-sonnet-99')).toBe('gpt-5.4-mini')
+  })
+
+  test('uses family default for unrecognized opus model', () => {
+    expect(resolveCodexModel('claude-opus-99')).toBe('gpt-5.4')
+  })
+
+  test('passes through unknown model name without family', () => {
+    expect(resolveCodexModel('some-random-model')).toBe('some-random-model')
+  })
+
+  test('strips [1m] suffix', () => {
+    expect(resolveCodexModel('claude-sonnet-4-6[1m]')).toBe('gpt-5.4-mini')
+  })
+
+  test('CODEX_MODEL takes precedence over family-specific vars', () => {
+    process.env.CODEX_MODEL = 'global-override'
+    process.env.CODEX_DEFAULT_SONNET_MODEL = 'family-override'
+    expect(resolveCodexModel('claude-sonnet-4-6')).toBe('global-override')
+  })
+})

packages/@ant/model-provider/src/providers/codex/callIds.ts

@@ -0,0 +1,31 @@
+import { createHash } from 'crypto'
+
+const MAX_CODEX_CALL_ID_LENGTH = 96
+
+export function normalizeCodexCallId(value: unknown): string | null {
+  if (typeof value !== 'string') {
+    return null
+  }
+
+  const sanitized = value
+    .trim()
+    .replace(/\s+/g, '_')
+    .replace(/[^A-Za-z0-9._:-]/g, '_')
+    .replace(/_+/g, '_')
+    .slice(0, MAX_CODEX_CALL_ID_LENGTH)
+
+  return sanitized.length > 0 ? sanitized : null
+}
+
+export function createCodexFallbackCallId(seed: string): string {
+  const hash = createHash('sha1')
+    .update(seed.length > 0 ? seed : 'codex-call')
+    .digest('hex')
+    .slice(0, 24)
+
+  return `call_${hash}`
+}
+
+export function resolveCodexCallId(value: unknown, seed: string): string {
+  return normalizeCodexCallId(value) ?? createCodexFallbackCallId(seed)
+}

packages/@ant/model-provider/src/providers/codex/convertMessages.ts

@@ -0,0 +1,392 @@
+import type {
+  ResponseFunctionToolCallOutputItem,
+  ResponseInputImage,
+  ResponseInputItem,
+  ResponseInputText,
+} from 'openai/resources/responses/responses.mjs'
+import type { Message } from '../../types/index.js'
+import {
+  normalizeCodexCallId,
+  resolveCodexCallId,
+} from './callIds.js'
+
+type ContentBlock = {
+  type: string
+  text?: string
+  source?: {
+    type?: string
+    data?: string
+    media_type?: string
+    url?: string
+  }
+}
+
+type ToolUseLikeBlock = {
+  type: 'tool_use'
+  id: string
+  name: string
+  input: unknown
+}
+
+type ToolResultLikeBlock = {
+  type: 'tool_result'
+  tool_use_id: string
+  content?: string | ReadonlyArray<ContentBlock>
+}
+
+export type CodexImageConversionOptions = {
+  resolveBase64ImageUrl?: (
+    data: string,
+    mediaType?: string,
+  ) => Promise<string | null>
+}
+
+type CodexCallIdState = {
+  byOriginalId: Map<string, string>
+  sequence: number
+}
+
+function createInputText(text: string): ResponseInputText {
+  return {
+    type: 'input_text',
+    text,
+  }
+}
+
+function createInputImage(imageUrl: string): ResponseInputImage {
+  return {
+    type: 'input_image',
+    image_url: imageUrl,
+    detail: 'high',
+  }
+}
+
+function getUnsupportedBlockText(type: string): string | null {
+  switch (type) {
+    case 'image':
+      return '[Image omitted: codex gateway currently requires remote image URLs. Configure CODEX_IMGBB_API_KEY to auto-convert local images.]'
+    case 'document':
+      return '[Document omitted: codex gateway does not support document replay.]'
+    default:
+      return null
+  }
+}
+
+function getImageUrl(block: ContentBlock): string | null {
+  const source = block.source
+  if (!source) {
+    return null
+  }
+
+  if (source.type === 'url' && typeof source.url === 'string' && source.url.length > 0) {
+    return source.url
+  }
+
+  return null
+}
+
+async function resolveImageUrl(
+  block: ContentBlock,
+  options: CodexImageConversionOptions,
+): Promise<string | null> {
+  const directUrl = getImageUrl(block)
+  if (directUrl) {
+    return directUrl
+  }
+
+  if (block.source?.type !== 'base64') {
+    return null
+  }
+
+  if (options.resolveBase64ImageUrl && typeof block.source.data === 'string') {
+    const uploadedUrl = await options.resolveBase64ImageUrl(
+      block.source.data,
+      block.source.media_type,
+    )
+    if (uploadedUrl) {
+      return uploadedUrl
+    }
+  }
+  return null
+}
+
+async function convertBlocksToInputContent(
+  content: ReadonlyArray<ContentBlock>,
+  options: CodexImageConversionOptions,
+): Promise<Array<ResponseInputText | ResponseInputImage>> {
+  const output: Array<ResponseInputText | ResponseInputImage> = []
+
+  for (const block of content) {
+    if (block.type === 'text' && block.text) {
+      output.push(createInputText(block.text))
+      continue
+    }
+
+    if (block.type === 'image') {
+      const imageUrl = await resolveImageUrl(block, options)
+      if (imageUrl) {
+        output.push(createInputImage(imageUrl))
+        continue
+      }
+    }
+
+    const fallback = getUnsupportedBlockText(block.type)
+    if (fallback) {
+      output.push(createInputText(fallback))
+    }
+  }
+
+  return output
+}
+
+async function convertToolResultOutput(
+  content: string | ReadonlyArray<ContentBlock> | undefined,
+  options: CodexImageConversionOptions,
+): Promise<ResponseFunctionToolCallOutputItem['output']> {
+  if (!content) {
+    return ''
+  }
+
+  if (typeof content === 'string') {
+    return content
+  }
+
+  const output = await convertBlocksToInputContent(content, options)
+
+  if (output.length === 0) {
+    return ''
+  }
+
+  if (output.length === 1 && output[0].type === 'input_text') {
+    return output[0].text
+  }
+
+  return output
+}
+
+function pushUserMessage(
+  items: ResponseInputItem[],
+  textParts: string[],
+  imageUrls: string[] = [],
+): void {
+  const text = textParts.join('\n').trim()
+  if (text.length === 0 && imageUrls.length === 0) {
+    return
+  }
+
+  items.push({
+    type: 'message',
+    role: 'user',
+    content: [
+      ...(text.length > 0 ? [createInputText(text)] : []),
+      ...imageUrls.map(createInputImage),
+    ],
+  } as unknown as ResponseInputItem)
+}
+
+function pushAssistantMessage(
+  items: ResponseInputItem[],
+  textParts: string[],
+): void {
+  const text = textParts.join('\n').trim()
+  if (text.length === 0) {
+    return
+  }
+
+  items.push({
+    type: 'message',
+    role: 'assistant',
+    content: [
+      {
+        type: 'output_text',
+        text,
+        annotations: [],
+      },
+    ],
+  } as unknown as ResponseInputItem)
+}
+
+function stringifyToolInput(input: unknown): string {
+  if (typeof input === 'string') {
+    return input
+  }
+
+  try {
+    return JSON.stringify(input ?? {})
+  } catch {
+    return '{}'
+  }
+}
+
+function createCodexCallIdState(): CodexCallIdState {
+  return {
+    byOriginalId: new Map(),
+    sequence: 0,
+  }
+}
+
+function resolveAssistantCallId(
+  block: ToolUseLikeBlock,
+  state: CodexCallIdState,
+): string {
+  const originalId = typeof block.id === 'string' ? block.id : ''
+  const seed = `${block.name}:${stringifyToolInput(block.input)}:${state.sequence}`
+  const callId = resolveCodexCallId(originalId, seed)
+
+  if (originalId.length > 0) {
+    state.byOriginalId.set(originalId, callId)
+  }
+  state.sequence += 1
+
+  return callId
+}
+
+function resolveToolResultCallId(
+  toolUseId: unknown,
+  state: CodexCallIdState,
+): string | null {
+  if (typeof toolUseId !== 'string') {
+    return null
+  }
+
+  return state.byOriginalId.get(toolUseId) ?? normalizeCodexCallId(toolUseId)
+}
+
+async function convertUserContentToInputItems(
+  items: ResponseInputItem[],
+  content: ReadonlyArray<string | ContentBlock>,
+  options: CodexImageConversionOptions,
+  callIdState: CodexCallIdState,
+): Promise<void> {
+  const textParts: string[] = []
+  const imageUrls: string[] = []
+
+  for (const block of content) {
+    if (typeof block === 'string') {
+      textParts.push(block)
+      continue
+    }
+
+    if (block.type === 'tool_result') {
+      pushUserMessage(items, textParts, imageUrls)
+      textParts.length = 0
+      imageUrls.length = 0
+
+      const toolResultBlock = block as ToolResultLikeBlock
+      const callId = resolveToolResultCallId(
+        toolResultBlock.tool_use_id,
+        callIdState,
+      )
+      if (!callId) {
+        continue
+      }
+
+      items.push({
+        type: 'function_call_output',
+        call_id: callId,
+        output: await convertToolResultOutput(toolResultBlock.content, options),
+      })
+      continue
+    }
+
+    if (block.type === 'text' && block.text) {
+      textParts.push(block.text)
+      continue
+    }
+
+    if (block.type === 'image') {
+      const imageUrl = await resolveImageUrl(block, options)
+      if (imageUrl) {
+        imageUrls.push(imageUrl)
+        continue
+      }
+    }
+
+    const fallback = getUnsupportedBlockText(block.type)
+    if (fallback) {
+      textParts.push(fallback)
+    }
+  }
+
+  pushUserMessage(items, textParts, imageUrls)
+}
+
+function convertAssistantContentToInputItems(
+  items: ResponseInputItem[],
+  content: ReadonlyArray<string | ContentBlock>,
+  callIdState: CodexCallIdState,
+): void {
+  const textParts: string[] = []
+
+  for (const block of content) {
+    if (typeof block === 'string') {
+      textParts.push(block)
+      continue
+    }
+
+    if (block.type === 'tool_use') {
+      pushAssistantMessage(items, textParts)
+      textParts.length = 0
+
+      const toolUseBlock = block as unknown as ToolUseLikeBlock
+      items.push({
+        type: 'function_call',
+        call_id: resolveAssistantCallId(toolUseBlock, callIdState),
+        name: toolUseBlock.name,
+        arguments: stringifyToolInput(toolUseBlock.input),
+      })
+      continue
+    }
+
+    if (block.type === 'text' && block.text) {
+      textParts.push(block.text)
+    }
+  }
+
+  pushAssistantMessage(items, textParts)
+}
+
+export async function anthropicMessagesToCodexInput(
+  messages: Message[],
+  options: CodexImageConversionOptions = {},
+): Promise<ResponseInputItem[]> {
+  const items: ResponseInputItem[] = []
+  const callIdState = createCodexCallIdState()
+
+  for (const message of messages) {
+    if (message.type !== 'user' && message.type !== 'assistant') {
+      continue
+    }
+
+    const apiMessage = message.message
+    if (!apiMessage?.content) {
+      continue
+    }
+
+    if (typeof apiMessage.content === 'string') {
+      if (message.type === 'user') {
+        pushUserMessage(items, [apiMessage.content])
+      } else {
+        pushAssistantMessage(items, [apiMessage.content])
+      }
+      continue
+    }
+
+    if (message.type === 'user') {
+      await convertUserContentToInputItems(
+        items,
+        apiMessage.content as ReadonlyArray<string | ContentBlock>,
+        options,
+        callIdState,
+      )
+    } else {
+      convertAssistantContentToInputItems(
+        items,
+        apiMessage.content as ReadonlyArray<string | ContentBlock>,
+        callIdState,
+      )
+    }
+  }
+
+  return items
+}

packages/@ant/model-provider/src/providers/codex/convertTools.ts

@@ -0,0 +1,39 @@
+import type { BetaToolUnion } from '@anthropic-ai/sdk/resources/beta/messages/messages.mjs'
+import type { Tool as CodexTool } from 'openai/resources/responses/responses.mjs'
+
+function isClientFunctionTool(
+  tool: BetaToolUnion,
+): tool is BetaToolUnion & {
+  name: string
+  description?: string
+  input_schema?: { [key: string]: unknown }
+  strict?: boolean
+  defer_loading?: boolean
+} {
+  const value = tool as unknown as Record<string, unknown>
+  return typeof value.name === 'string'
+}
+
+export function anthropicToolsToCodex(
+  tools: BetaToolUnion[],
+): CodexTool[] {
+  return tools.flatMap(tool => {
+    const value = tool as unknown as Record<string, unknown>
+    if (
+      value.type === 'advisor_20260301' ||
+      value.type === 'computer_20250124' ||
+      !isClientFunctionTool(tool)
+    ) {
+      return []
+    }
+
+    return [{
+      type: 'function',
+      name: tool.name,
+      description: tool.description,
+      parameters: tool.input_schema ?? {},
+      strict: tool.strict ?? null,
+      ...(tool.defer_loading && { defer_loading: true }),
+    }]
+  })
+}

packages/@ant/model-provider/src/providers/codex/modelMapping.ts

@@ -0,0 +1,86 @@
+/**
+ * Default mapping from Anthropic model names to Codex (OpenAI Responses API) model names.
+ * Used only when CODEX_DEFAULT_{FAMILY}_MODEL env vars are not set.
+ */
+const DEFAULT_MODEL_MAP: Record<string, string> = {
+  'claude-sonnet-4-20250514': 'gpt-5.4-mini',
+  'claude-sonnet-4-5-20250929': 'gpt-5.4-mini',
+  'claude-sonnet-4-6': 'gpt-5.4-mini',
+  'claude-3-7-sonnet-20250219': 'gpt-5.4-mini',
+  'claude-3-5-sonnet-20241022': 'gpt-5.4-mini',
+  'claude-opus-4-20250514': 'gpt-5.4',
+  'claude-opus-4-1-20250805': 'gpt-5.4',
+  'claude-opus-4-5-20251101': 'gpt-5.4',
+  'claude-opus-4-6': 'gpt-5.4',
+  'claude-opus-4-7': 'gpt-5.5',
+  'claude-haiku-4-5-20251001': 'gpt-5.4-mini',
+  'claude-3-5-haiku-20241022': 'gpt-5.4-mini',
+}
+
+/**
+ * Default model for each family when an exact match is not in DEFAULT_MODEL_MAP.
+ */
+const DEFAULT_FAMILY_MAP: Record<string, string> = {
+  haiku: 'gpt-5.4-mini',
+  sonnet: 'gpt-5.4-mini',
+  opus: 'gpt-5.4',
+}
+
+function getModelFamily(model: string): 'haiku' | 'sonnet' | 'opus' | null {
+  if (/haiku/i.test(model)) return 'haiku'
+  if (/opus/i.test(model)) return 'opus'
+  if (/sonnet/i.test(model)) return 'sonnet'
+  return null
+}
+
+/**
+ * Resolve the Codex (OpenAI Responses API) model name for a given Anthropic model.
+ *
+ * Priority:
+ * 1. CODEX_MODEL env var (override all)
+ * 2. CODEX_DEFAULT_{FAMILY}_MODEL env var (e.g. CODEX_DEFAULT_SONNET_MODEL)
+ * 3. DEFAULT_MODEL_MAP lookup (exact Anthropic model name match)
+ * 4. DEFAULT_FAMILY_MAP lookup (family-based default)
+ * 5. Pass through original model name
+ */
+export function resolveCodexModel(model: string): string {
+  if (process.env.CODEX_MODEL) {
+    return process.env.CODEX_MODEL
+  }
+
+  const cleanModel = model.replace(/\[1m\]$/, '')
+  const family = getModelFamily(cleanModel)
+  if (family) {
+    const familyOverride = process.env[`CODEX_DEFAULT_${family.toUpperCase()}_MODEL`]
+    if (familyOverride) {
+      return familyOverride
+    }
+  }
+
+  const mapped = DEFAULT_MODEL_MAP[cleanModel]
+  if (mapped) {
+    return mapped
+  }
+
+  if (family) {
+    return DEFAULT_FAMILY_MAP[family]
+  }
+
+  return cleanModel
+}
+
+export function resolveCodexMaxTokens(
+  upperLimit: number,
+  maxOutputTokensOverride?: number,
+): number {
+  return (
+    maxOutputTokensOverride ??
+    (process.env.CODEX_MAX_TOKENS
+      ? parseInt(process.env.CODEX_MAX_TOKENS, 10) || undefined
+      : undefined) ??
+    (process.env.CLAUDE_CODE_MAX_OUTPUT_TOKENS
+      ? parseInt(process.env.CLAUDE_CODE_MAX_OUTPUT_TOKENS, 10) || undefined
+      : undefined) ??
+    upperLimit
+  )
+}

src/commands/provider.ts

@@ -63,6 +63,7 @@ const call: LocalCommandCall = async (args, context) => {
   const validProviders = [
     'anthropic',
     'openai',
+    'codex',
     'gemini',
     'grok',
     'bedrock',
@@ -120,10 +121,23 @@ const call: LocalCommandCall = async (args, context) => {
     }
   }
 
+  // Check env vars when switching to codex (including settings.env)
+  if (arg === 'codex') {
+    const mergedEnv = getMergedEnv()
+    const hasKey = !!(mergedEnv.CODEX_API_KEY || mergedEnv.CODEX_ACCESS_TOKEN)
+    if (!hasKey) {
+      updateSettingsForSource('userSettings', { modelType: 'codex' })
+      return {
+        type: 'text',
+        value: `Switched to Codex provider.\nWarning: No CODEX_API_KEY or CODEX_ACCESS_TOKEN found.\nUse /login (ChatGPT Subscription) or set manually.`,
+      }
+    }
+  }
+
   // Handle different provider types
   // - 'anthropic', 'openai', 'gemini' are stored in settings.json (persistent)
   // - 'bedrock', 'vertex', 'foundry' are env-only (do NOT touch settings.json)
-  if (arg === 'anthropic' || arg === 'openai' || arg === 'gemini' || arg === 'grok') {
+  if (arg === 'anthropic' || arg === 'openai' || arg === 'codex' || arg === 'gemini' || arg === 'grok') {
     // Clear any cloud provider env vars to avoid conflicts
     delete process.env.CLAUDE_CODE_USE_BEDROCK
     delete process.env.CLAUDE_CODE_USE_VERTEX
@@ -131,7 +145,7 @@ const call: LocalCommandCall = async (args, context) => {
     delete process.env.CLAUDE_CODE_USE_OPENAI
     delete process.env.CLAUDE_CODE_USE_GEMINI
     delete process.env.CLAUDE_CODE_USE_GROK
-    // Update settings.json
+    delete process.env.CLAUDE_CODE_USE_CODEX
     updateSettingsForSource('userSettings', { modelType: arg })
     // Ensure settings.env gets applied to process.env
     applyConfigEnvironmentVariables()
@@ -157,9 +171,9 @@ const provider = {
   type: 'local',
   name: 'provider',
   description:
-    'Switch API provider (anthropic/openai/gemini/grok/bedrock/vertex/foundry)',
+    'Switch API provider (anthropic/openai/codex/gemini/grok/bedrock/vertex/foundry)',
   aliases: ['api'],
-  argumentHint: '[anthropic|openai|gemini|grok|bedrock|vertex|foundry|unset]',
+  argumentHint: '[anthropic|openai|codex|gemini|grok|bedrock|vertex|foundry|unset]',
   supportsNonInteractive: true,
   load: () => Promise.resolve({ call }),
 } satisfies Command

src/components/ConsoleOAuthFlow.tsx

@@ -10,6 +10,7 @@ import { useKeybinding } from '../keybindings/useKeybinding.js'
 import { getSSLErrorHint } from '@ant/model-provider'
 import { sendNotification } from '../services/notifier.js'
 import { OAuthService } from '../services/oauth/index.js'
+import { performOpenAICodexLogin, parseManualCodeInput } from '../services/oauth/openai-codex.js'
 import { getOauthAccountInfo, validateForceLoginOrg } from '../utils/auth.js'
 import { logError } from '../utils/log.js'
 import { getSettings_DEPRECATED, updateSettingsForSource } from '../utils/settings/settings.js'
@@ -55,6 +56,20 @@ type OAuthStatus =
       opusModel: string
       activeField: 'base_url' | 'api_key' | 'haiku_model' | 'sonnet_model' | 'opus_model'
     } // Gemini Generate Content API platform
+  | { state: 'codex_oauth_waiting'; url: string } // ChatGPT OAuth browser login in progress
+  | { state: 'codex_oauth_start' } // Trigger ChatGPT OAuth flow
+  | {
+      state: 'codex_models'
+      haikuModel: string
+      sonnetModel: string
+      opusModel: string
+      activeField: 'haiku_model' | 'sonnet_model' | 'opus_model'
+      codexResult: {
+        apiKey: string | null
+        accessToken: string
+        refreshToken: string
+      }
+    } // Codex model name configuration after OAuth success
   | { state: 'ready_to_start' } // Flow started, waiting for browser to open
   | { state: 'waiting_for_login'; url: string } // Browser opened, waiting for user to login
   | { state: 'creating_api_key' } // Got access token, creating API key
@@ -108,6 +123,13 @@ export function ConsoleOAuthFlow({
   const [showPastePrompt, setShowPastePrompt] = useState(false)
   const [urlCopied, setUrlCopied] = useState(false)
 
+  // Codex ChatGPT OAuth states
+  const [showCodexPastePrompt, setShowCodexPastePrompt] = useState(false)
+  const [codexUrlCopied, setCodexUrlCopied] = useState(false)
+  const [codexPastedCode, setCodexPastedCode] = useState('')
+  const [codexPastedCursor, setCodexPastedCursor] = useState(0)
+  const codexManualCodeResolveRef = useRef<((code: string) => void) | null>(null)
+
   const textInputColumns = useTerminalSize().columns - PASTE_HERE_MSG.length - 1
 
   // Log forced login method on mount
@@ -186,6 +208,39 @@ export function ConsoleOAuthFlow({
     }
   }, [pastedCode, oauthStatus, showPastePrompt, urlCopied])
 
+  // Codex OAuth: copy URL on 'c'
+  useEffect(() => {
+    if (
+      codexPastedCode === 'c' &&
+      oauthStatus.state === 'codex_oauth_waiting' &&
+      showCodexPastePrompt &&
+      !codexUrlCopied
+    ) {
+      const url = (oauthStatus as { state: 'codex_oauth_waiting'; url: string }).url
+      void setClipboard(url).then(raw => {
+        if (raw) process.stdout.write(raw)
+        setCodexUrlCopied(true)
+        setTimeout(setCodexUrlCopied, 2000, false)
+      })
+      setCodexPastedCode('')
+    }
+  }, [codexPastedCode, oauthStatus, showCodexPastePrompt, codexUrlCopied])
+
+  // Codex OAuth: submit pasted code
+  const handleCodexPasteSubmit = useCallback((value: string) => {
+    const code = parseManualCodeInput(value)
+    if (!code) {
+      setOAuthStatus({
+        state: 'error',
+        message: 'Invalid code. Paste the full redirect URL or just the authorization code.',
+        toRetry: oauthStatus as any,
+      })
+      return
+    }
+    codexManualCodeResolveRef.current?.(code)
+    codexManualCodeResolveRef.current = null
+  }, [oauthStatus])
+
   async function handleSubmitCode(value: string, url: string) {
     try {
       // Expecting format "authorizationCode#state" from the authorization callback URL
@@ -301,6 +356,52 @@ export function ConsoleOAuthFlow({
     }
   }, [oauthService, setShowPastePrompt, loginWithClaudeAi, mode, orgUUID])
 
+  const startCodexOAuth = useCallback(async () => {
+    setShowCodexPastePrompt(false)
+    setCodexUrlCopied(false)
+    setCodexPastedCode('')
+    setCodexPastedCursor(0)
+
+    let manualCodeResolve: ((code: string) => void) | null = null
+    const manualCodePromise = new Promise<string>(resolve => {
+      manualCodeResolve = resolve
+    })
+    codexManualCodeResolveRef.current = manualCodeResolve
+
+    try {
+      const result = await performOpenAICodexLogin({
+        onUrl: url => {
+          setOAuthStatus({ state: 'codex_oauth_waiting', url })
+          setTimeout(setShowCodexPastePrompt, 3000, true)
+        },
+        manualCode: manualCodePromise,
+      })
+
+      // Transition to model configuration panel with defaults
+      setOAuthStatus({
+        state: 'codex_models',
+        haikuModel: process.env.CODEX_DEFAULT_HAIKU_MODEL || 'gpt-5.4-mini',
+        sonnetModel: process.env.CODEX_DEFAULT_SONNET_MODEL || 'gpt-5.4-mini',
+        opusModel: process.env.CODEX_DEFAULT_OPUS_MODEL || 'gpt-5.5',
+        activeField: 'haiku_model',
+        codexResult: {
+          apiKey: result.apiKey,
+          accessToken: result.accessToken,
+          refreshToken: result.refreshToken,
+        },
+      })
+    } catch (err) {
+      logError(err as Error)
+      setOAuthStatus({
+        state: 'error',
+        message: (err as Error).message,
+        toRetry: { state: 'idle' },
+      })
+    } finally {
+      codexManualCodeResolveRef.current = null
+    }
+  }, [onDone])
+
   const pendingOAuthStartRef = useRef(false)
 
   useEffect(() => {
@@ -316,6 +417,19 @@ export function ConsoleOAuthFlow({
     }
   }, [oauthStatus.state, startOAuth])
 
+  const pendingCodexOAuthRef = useRef(false)
+  useEffect(() => {
+    if (
+      oauthStatus.state === 'codex_oauth_start' &&
+      !pendingCodexOAuthRef.current
+    ) {
+      pendingCodexOAuthRef.current = true
+      void startCodexOAuth().finally(() => {
+        pendingCodexOAuthRef.current = false
+      })
+    }
+  }, [oauthStatus.state, startCodexOAuth])
+
   // Auto-exit for setup-token mode
   useEffect(() => {
     if (mode === 'setup-token' && oauthStatus.state === 'success') {
@@ -334,6 +448,20 @@ export function ConsoleOAuthFlow({
     }
   }, [mode, oauthStatus, loginWithClaudeAi, onDone])
 
+  // Cancel codex OAuth with Escape
+  useKeybinding(
+    'confirm:no',
+    () => {
+      setShowCodexPastePrompt(false)
+      setCodexPastedCode('')
+      setOAuthStatus({ state: 'idle' })
+    },
+    {
+      context: 'Confirmation',
+      isActive: oauthStatus.state === 'codex_oauth_waiting',
+    },
+  )
+
   // Cleanup OAuth service when component unmounts
   useEffect(() => {
     return () => {
@@ -399,6 +527,13 @@ export function ConsoleOAuthFlow({
           setOAuthStatus={setOAuthStatus}
           setLoginWithClaudeAi={setLoginWithClaudeAi}
           onDone={onDone}
+          showCodexPastePrompt={showCodexPastePrompt}
+          codexUrlCopied={codexUrlCopied}
+          codexPastedCode={codexPastedCode}
+          setCodexPastedCode={setCodexPastedCode}
+          codexPastedCursor={codexPastedCursor}
+          setCodexPastedCursor={setCodexPastedCursor}
+          handleCodexPasteSubmit={handleCodexPasteSubmit}
         />
       </Box>
     </Box>
@@ -420,6 +555,14 @@ type OAuthStatusMessageProps = {
   handleSubmitCode: (value: string, url: string) => void
   setOAuthStatus: (status: OAuthStatus) => void
   setLoginWithClaudeAi: (value: boolean) => void
+  // Codex ChatGPT OAuth props
+  showCodexPastePrompt: boolean
+  codexUrlCopied: boolean
+  codexPastedCode: string
+  setCodexPastedCode: (value: string) => void
+  codexPastedCursor: number
+  setCodexPastedCursor: (offset: number) => void
+  handleCodexPasteSubmit: (value: string) => void
 }
 
 function OAuthStatusMessage({
@@ -437,6 +580,13 @@ function OAuthStatusMessage({
   setOAuthStatus,
   setLoginWithClaudeAi,
   onDone,
+  showCodexPastePrompt,
+  codexUrlCopied,
+  codexPastedCode,
+  setCodexPastedCode,
+  codexPastedCursor,
+  setCodexPastedCursor,
+  handleCodexPasteSubmit,
 }: OAuthStatusMessageProps): React.ReactNode {
   switch (oauthStatus.state) {
     case 'idle':
@@ -475,6 +625,16 @@ function OAuthStatusMessage({
                   ),
                   value: 'openai_chat_api',
                 },
+                {
+                  label: (
+                    <Text>
+                      OpenAI Codex (ChatGPT Subscription) -{' '}
+                      <Text dimColor>Login with ChatGPT Plus/Pro</Text>
+                      {'\n'}
+                    </Text>
+                  ),
+                  value: 'codex_chatgpt',
+                },
                 {
                   label: (
                     <Text>
@@ -552,6 +712,39 @@ function OAuthStatusMessage({
                     opusModel: process.env.OPENAI_DEFAULT_OPUS_MODEL ?? '',
                     activeField: 'base_url',
                   })
+                } else if (value === 'codex_chatgpt') {
+                  logEvent('tengu_codex_chatgpt_selected', {})
+                  // Skip OAuth if already authenticated — go straight to model config
+                  const settings = getSettings_DEPRECATED()
+                  const hasToken = !!(
+                    process.env.CODEX_ACCESS_TOKEN ||
+                    settings?.env?.CODEX_ACCESS_TOKEN
+                  )
+                  if (hasToken) {
+                    setOAuthStatus({
+                      state: 'codex_models',
+                      haikuModel:
+                        process.env.CODEX_DEFAULT_HAIKU_MODEL ||
+                        settings?.env?.CODEX_DEFAULT_HAIKU_MODEL ||
+                        'gpt-5.4-mini',
+                      sonnetModel:
+                        process.env.CODEX_DEFAULT_SONNET_MODEL ||
+                        settings?.env?.CODEX_DEFAULT_SONNET_MODEL ||
+                        'gpt-5.4-mini',
+                      opusModel:
+                        process.env.CODEX_DEFAULT_OPUS_MODEL ||
+                        settings?.env?.CODEX_DEFAULT_OPUS_MODEL ||
+                        'gpt-5.5',
+                      activeField: 'haiku_model',
+                      codexResult: {
+                        apiKey: process.env.CODEX_API_KEY || null,
+                        accessToken: process.env.CODEX_ACCESS_TOKEN || '',
+                        refreshToken: process.env.CODEX_REFRESH_TOKEN || '',
+                      },
+                    })
+                  } else {
+                    setOAuthStatus({ state: 'codex_oauth_start' })
+                  }
                 } else if (value === 'gemini_api') {
                   logEvent('tengu_gemini_api_selected', {})
                   setOAuthStatus({
@@ -1275,6 +1468,282 @@ function OAuthStatusMessage({
         )
       }
 
+    case 'codex_oauth_waiting': {
+      const { url } = oauthStatus as { state: 'codex_oauth_waiting'; url: string }
+      const codexPasteColumns = useTerminalSize().columns - PASTE_HERE_MSG.length - 1
+      return (
+        <Box flexDirection="column" gap={1}>
+          {!showCodexPastePrompt && (
+            <Box>
+              <Spinner />
+              <Text>Opening browser for ChatGPT login...</Text>
+            </Box>
+          )}
+          {showCodexPastePrompt && (
+            <Box flexDirection="column" gap={1}>
+              <Box paddingX={1}>
+                <Text dimColor>
+                  Browser didn&apos;t open? Use the url below to sign in{' '}
+                </Text>
+                {codexUrlCopied ? (
+                  <Text color="success">(Copied!)</Text>
+                ) : (
+                  <Text dimColor>
+                    <KeyboardShortcutHint shortcut="c" action="copy" parens />
+                  </Text>
+                )}
+              </Box>
+              <Link url={url}>
+                <Text dimColor>{url}</Text>
+              </Link>
+            </Box>
+          )}
+          {showCodexPastePrompt && (
+            <Box>
+              <Text>{PASTE_HERE_MSG}</Text>
+              <TextInput
+                value={codexPastedCode}
+                onChange={setCodexPastedCode}
+                onSubmit={handleCodexPasteSubmit}
+                cursorOffset={codexPastedCursor}
+                onChangeCursorOffset={setCodexPastedCursor}
+                columns={codexPasteColumns}
+                mask="*"
+              />
+            </Box>
+          )}
+          <Text dimColor>
+            Press <Text bold>Esc</Text> to cancel
+          </Text>
+        </Box>
+      )
+    }
+
+    case 'codex_models': {
+      type CodexField = 'haiku_model' | 'sonnet_model' | 'opus_model'
+      const CODEX_FIELDS: CodexField[] = ['haiku_model', 'sonnet_model', 'opus_model']
+      const cm = oauthStatus as {
+        state: 'codex_models'
+        activeField: CodexField
+        haikuModel: string
+        sonnetModel: string
+        opusModel: string
+        codexResult: { apiKey: string | null; accessToken: string; refreshToken: string }
+      }
+      const { activeField, haikuModel, sonnetModel, opusModel, codexResult } = cm
+      const codexDisplayValues: Record<CodexField, string> = {
+        haiku_model: haikuModel,
+        sonnet_model: sonnetModel,
+        opus_model: opusModel,
+      }
+
+      const [codexModelInput, setCodexModelInput] = useState(
+        () => codexDisplayValues[activeField],
+      )
+      const [codexModelCursor, setCodexModelCursor] = useState(
+        () => codexDisplayValues[activeField].length,
+      )
+
+      const buildCodexModelState = useCallback(
+        (field: CodexField, value: string, newActive?: CodexField) => {
+          const s = {
+            state: 'codex_models' as const,
+            activeField: newActive ?? activeField,
+            haikuModel,
+            sonnetModel,
+            opusModel,
+            codexResult,
+          }
+          switch (field) {
+            case 'haiku_model':
+              return { ...s, haikuModel: value }
+            case 'sonnet_model':
+              return { ...s, sonnetModel: value }
+            case 'opus_model':
+              return { ...s, opusModel: value }
+          }
+        },
+        [activeField, haikuModel, sonnetModel, opusModel, codexResult],
+      )
+
+      const doCodexModelSave = useCallback(() => {
+        const finalVals = { ...codexDisplayValues, [activeField]: codexModelInput }
+        const env: Record<string, string | undefined> = {
+          CODEX_API_KEY: codexResult.apiKey ?? undefined,
+          CODEX_ACCESS_TOKEN: codexResult.accessToken,
+          CODEX_REFRESH_TOKEN: codexResult.refreshToken,
+          CODEX_LOGIN_METHOD: 'chatgpt_subscription',
+          CODEX_DEFAULT_HAIKU_MODEL: finalVals.haiku_model,
+          CODEX_DEFAULT_SONNET_MODEL: finalVals.sonnet_model,
+          CODEX_DEFAULT_OPUS_MODEL: finalVals.opus_model,
+        }
+        const { error } = updateSettingsForSource('userSettings', {
+          modelType: 'codex' as any,
+          env,
+        } as any)
+        if (error) {
+          setOAuthStatus({
+            state: 'error',
+            message: 'Failed to save settings. Please try again.',
+            toRetry: {
+              state: 'codex_models',
+              haikuModel: finalVals.haiku_model,
+              sonnetModel: finalVals.sonnet_model,
+              opusModel: finalVals.opus_model,
+              activeField: 'haiku_model',
+              codexResult,
+            },
+          })
+        } else {
+          for (const [k, v] of Object.entries(env)) {
+            if (v !== undefined) {
+              process.env[k] = v
+            }
+          }
+          setOAuthStatus({ state: 'success' })
+          void onDone()
+        }
+      }, [activeField, codexModelInput, codexDisplayValues, codexResult, setOAuthStatus, onDone])
+
+      const handleCodexModelEnter = useCallback(() => {
+        const idx = CODEX_FIELDS.indexOf(activeField)
+        if (idx === CODEX_FIELDS.length - 1) {
+          setOAuthStatus(buildCodexModelState(activeField, codexModelInput))
+          doCodexModelSave()
+        } else {
+          const next = CODEX_FIELDS[idx + 1]!
+          setOAuthStatus(buildCodexModelState(activeField, codexModelInput, next))
+          setCodexModelInput(codexDisplayValues[next] ?? '')
+          setCodexModelCursor((codexDisplayValues[next] ?? '').length)
+        }
+      }, [
+        activeField,
+        codexModelInput,
+        buildCodexModelState,
+        doCodexModelSave,
+        codexDisplayValues,
+        setOAuthStatus,
+      ])
+
+      useKeybinding(
+        'tabs:next',
+        () => {
+          const idx = CODEX_FIELDS.indexOf(activeField)
+          if (idx < CODEX_FIELDS.length - 1) {
+            setOAuthStatus(
+              buildCodexModelState(activeField, codexModelInput, CODEX_FIELDS[idx + 1]),
+            )
+            setCodexModelInput(codexDisplayValues[CODEX_FIELDS[idx + 1]!] ?? '')
+            setCodexModelCursor((codexDisplayValues[CODEX_FIELDS[idx + 1]!] ?? '').length)
+          }
+        },
+        { context: 'FormField' },
+      )
+      useKeybinding(
+        'tabs:previous',
+        () => {
+          const idx = CODEX_FIELDS.indexOf(activeField)
+          if (idx > 0) {
+            setOAuthStatus(
+              buildCodexModelState(activeField, codexModelInput, CODEX_FIELDS[idx - 1]),
+            )
+            setCodexModelInput(codexDisplayValues[CODEX_FIELDS[idx - 1]!] ?? '')
+            setCodexModelCursor((codexDisplayValues[CODEX_FIELDS[idx - 1]!] ?? '').length)
+          }
+        },
+        { context: 'FormField' },
+      )
+      useKeybinding(
+        'confirm:no',
+        () => {
+          setOAuthStatus({ state: 'idle' })
+        },
+        { context: 'Confirmation' },
+      )
+
+      // Ctrl+D: clear codex login state and re-login
+      useKeybinding(
+        'oauth:codex-relogin',
+        () => {
+          // Clear codex credentials from process.env
+          delete process.env.CODEX_ACCESS_TOKEN
+          delete process.env.CODEX_REFRESH_TOKEN
+          delete process.env.CODEX_API_KEY
+          delete process.env.CODEX_LOGIN_METHOD
+          delete process.env.CODEX_DEFAULT_HAIKU_MODEL
+          delete process.env.CODEX_DEFAULT_SONNET_MODEL
+          delete process.env.CODEX_DEFAULT_OPUS_MODEL
+          // Clear from settings.json
+          updateSettingsForSource('userSettings', {
+            modelType: undefined,
+            env: {
+              CODEX_ACCESS_TOKEN: undefined,
+              CODEX_REFRESH_TOKEN: undefined,
+              CODEX_API_KEY: undefined,
+              CODEX_LOGIN_METHOD: undefined,
+              CODEX_DEFAULT_HAIKU_MODEL: undefined,
+              CODEX_DEFAULT_SONNET_MODEL: undefined,
+              CODEX_DEFAULT_OPUS_MODEL: undefined,
+            },
+          } as any)
+          // Restart OAuth flow
+          setOAuthStatus({ state: 'codex_oauth_start' })
+        },
+        { context: 'FormField' },
+      )
+
+      const codexModelColumns = useTerminalSize().columns - 20
+
+      const renderCodexModelRow = (
+        field: CodexField,
+        label: string,
+      ) => {
+        const active = activeField === field
+        const val = codexDisplayValues[field]
+        return (
+          <Box>
+            <Text
+              backgroundColor={active ? 'suggestion' : undefined}
+              color={active ? 'inverseText' : undefined}
+            >
+              {` ${label} `}
+            </Text>
+            <Text> </Text>
+            {active ? (
+              <TextInput
+                value={codexModelInput}
+                onChange={setCodexModelInput}
+                onSubmit={handleCodexModelEnter}
+                cursorOffset={codexModelCursor}
+                onChangeCursorOffset={setCodexModelCursor}
+                columns={codexModelColumns}
+                focus={true}
+              />
+            ) : val ? (
+              <Text color="success">{val}</Text>
+            ) : null}
+          </Box>
+        )
+      }
+
+      return (
+        <Box flexDirection="column" gap={1}>
+          <Text bold>Codex Model Configuration</Text>
+          <Text dimColor>
+            ChatGPT login successful. Configure model names (press Enter on last field to save).
+          </Text>
+          <Box flexDirection="column" gap={1}>
+            {renderCodexModelRow('haiku_model', 'Haiku    ')}
+            {renderCodexModelRow('sonnet_model', 'Sonnet   ')}
+            {renderCodexModelRow('opus_model', 'Opus     ')}
+          </Box>
+          <Text dimColor>
+            ↑↓/Tab to switch · Enter on last field to save · Ctrl+R to re-login · Esc to go back
+          </Text>
+        </Box>
+      )
+    }
+
     case 'platform_setup':
       return (
         <Box flexDirection="column" gap={1} marginTop={1}>

src/keybindings/defaultBindings.ts

@@ -156,6 +156,8 @@ export const DEFAULT_BINDINGS: KeybindingBlock[] = [
       'shift+tab': 'tabs:previous',
       up: 'tabs:previous',
       down: 'tabs:next',
+      // Re-login: clear codex credentials and restart OAuth
+      'ctrl+r': 'oauth:codex-relogin',
     },
   },
   {

src/keybindings/schema.ts

@@ -109,6 +109,8 @@ export const KEYBINDING_ACTIONS = [
   // Tabs navigation actions
   'tabs:next',
   'tabs:previous',
+  // OAuth re-login action (codex model config panel)
+  'oauth:codex-relogin',
   // Transcript viewer actions
   'transcript:toggleShowAll',
   'transcript:exit',

src/services/api/claude.ts

@@ -1347,6 +1347,12 @@ async function* queryModel(
     return
   }
 
+  if (getAPIProvider() === 'codex') {
+    const { queryModelCodex } = await import('./codex/index.js')
+    yield* queryModelCodex(messagesForAPI, systemPrompt, filteredTools, signal, options)
+    return
+  }
+
   if (getAPIProvider() === 'gemini') {
     const { queryModelGemini } = await import('./gemini/index.js')
     yield* queryModelGemini(

src/services/api/codex/client.ts

@@ -0,0 +1,57 @@
+import OpenAI from 'openai'
+import { openaiAdapter } from 'src/services/providerUsage/adapters/openai.js'
+import { updateProviderBuckets } from 'src/services/providerUsage/store.js'
+import { getProxyFetchOptions } from 'src/utils/proxy.js'
+
+export const DEFAULT_CODEX_BASE_URL = 'https://api.openai.com/v1'
+
+let cachedClient: OpenAI | null = null
+
+function wrapFetchForUsage(base: typeof fetch): typeof fetch {
+  const wrapped = async (
+    ...args: Parameters<typeof fetch>
+  ): Promise<Response> => {
+    const res = await base(...args)
+    try {
+      updateProviderBuckets('codex', openaiAdapter.parseHeaders(res.headers))
+    } catch {
+      // Usage tracking must not affect the request path.
+    }
+    return res
+  }
+  return wrapped as unknown as typeof fetch
+}
+
+export function getCodexClient(options?: {
+  maxRetries?: number
+  fetchOverride?: typeof fetch
+}): OpenAI {
+  if (cachedClient && !options?.fetchOverride) {
+    return cachedClient
+  }
+
+  const apiKey = process.env.CODEX_API_KEY || process.env.CODEX_ACCESS_TOKEN || ''
+  const baseURL = process.env.CODEX_BASE_URL || DEFAULT_CODEX_BASE_URL
+  const baseFetch = options?.fetchOverride ?? (globalThis.fetch as typeof fetch)
+  const wrappedFetch = wrapFetchForUsage(baseFetch)
+
+  const client = new OpenAI({
+    apiKey,
+    baseURL,
+    maxRetries: options?.maxRetries ?? 0,
+    timeout: parseInt(process.env.API_TIMEOUT_MS || String(600 * 1000), 10),
+    dangerouslyAllowBrowser: true,
+    fetchOptions: getProxyFetchOptions({ forAnthropicAPI: false }),
+    fetch: wrappedFetch,
+  })
+
+  if (!options?.fetchOverride) {
+    cachedClient = client
+  }
+
+  return client
+}
+
+export function clearCodexClientCache(): void {
+  cachedClient = null
+}

src/services/api/codex/errors.ts

@@ -0,0 +1,115 @@
+import type { SDKAssistantMessageError } from '../../../entrypoints/agentSdkTypes.js'
+
+type CodexErrorLike = {
+  status?: unknown
+  message?: unknown
+  error?: {
+    message?: unknown
+  }
+}
+
+export type NormalizedCodexError = {
+  content: string
+  error: SDKAssistantMessageError
+}
+
+function readErrorStatus(error: unknown): number | null {
+  if (
+    typeof error === 'object' &&
+    error !== null &&
+    typeof (error as CodexErrorLike).status === 'number'
+  ) {
+    return (error as CodexErrorLike).status as number
+  }
+
+  return null
+}
+
+function readErrorMessage(error: unknown): string {
+  if (error instanceof Error && error.message.length > 0) {
+    return error.message
+  }
+
+  if (typeof error === 'object' && error !== null) {
+    const value = error as CodexErrorLike
+    if (typeof value.message === 'string' && value.message.length > 0) {
+      return value.message
+    }
+    if (
+      typeof value.error?.message === 'string' &&
+      value.error.message.length > 0
+    ) {
+      return value.error.message
+    }
+  }
+
+  return String(error)
+}
+
+export function getCodexConfigurationError(): NormalizedCodexError | null {
+  if (!process.env.CODEX_API_KEY && !process.env.CODEX_ACCESS_TOKEN) {
+    return {
+      content:
+        'Missing CODEX_API_KEY or CODEX_ACCESS_TOKEN. Use /login (ChatGPT Subscription) or set manually.',
+      error: 'authentication_failed',
+    }
+  }
+
+  return null
+}
+
+export function normalizeCodexError(error: unknown): NormalizedCodexError {
+  const status = readErrorStatus(error)
+  const message = readErrorMessage(error)
+
+  if (/^Codex preflight:/i.test(message)) {
+    return {
+      content: message,
+      error: 'invalid_request',
+    }
+  }
+
+  if (status === 401 || status === 403) {
+
+    return {
+      content: `Codex authentication failed (${status}). ${message}`,
+      error: 'authentication_failed',
+    }
+  }
+
+  if (status === 404) {
+    return {
+      content:
+        'Codex endpoint not found (404). Verify CODEX_BASE_URL points to a Responses API root.',
+      error: 'invalid_request',
+    }
+  }
+
+  if (status === 429) {
+    return {
+      content:
+        'Codex rate limit reached (429). Retry shortly or reduce request volume.',
+      error: 'rate_limit',
+    }
+  }
+
+  if (status === 502 && /upstream request failed/i.test(message)) {
+    return {
+      content:
+        'Codex gateway returned 502 Upstream request failed. This usually means a transient gateway issue or incomplete Responses API compatibility during tool replay.',
+      error: 'server_error',
+    }
+  }
+
+  if (status !== null && status >= 500) {
+    return {
+      content: `Codex server error (${status}): ${message}`,
+      error: 'server_error',
+    }
+  }
+
+  return {
+    content: `API Error: ${message}`,
+    error: 'unknown',
+  }
+}

src/services/api/codex/imageUpload.ts

@@ -0,0 +1,132 @@
+import { createHash } from 'crypto'
+import { logForDebugging } from '../../../utils/debug.js'
+
+const resolvedImageUrls = new Map<string, string>()
+const DEFAULT_TIMEOUT_MS = 30_000
+const IMGBB_UPLOAD_URL = 'https://api.imgbb.com/1/upload'
+
+type ImgbbVariant = {
+  url?: unknown
+}
+
+type ImgbbPayload = {
+  data?: {
+    url?: unknown
+    display_url?: unknown
+    image?: ImgbbVariant
+    medium?: ImgbbVariant
+    thumb?: ImgbbVariant
+  }
+}
+
+function getUploadTimeoutMs(): number {
+  const raw =
+    process.env.CODEX_IMAGE_UPLOAD_TIMEOUT_MS ??
+    process.env.CODEX_IMAGE_URL_TIMEOUT_MS
+  if (!raw) {
+    return DEFAULT_TIMEOUT_MS
+  }
+
+  const parsed = Number.parseInt(raw, 10)
+  return Number.isFinite(parsed) && parsed > 0 ? parsed : DEFAULT_TIMEOUT_MS
+}
+
+function getCacheKey(prefix: string, value: string): string {
+  return `${prefix}:${createHash('sha256').update(value).digest('hex')}`
+}
+
+function getImgbbApiKey(): string | null {
+  const apiKey = process.env.CODEX_IMGBB_API_KEY?.trim()
+  return apiKey && apiKey.length > 0 ? apiKey : null
+}
+
+function pickImgbbImageUrl(payload: ImgbbPayload): string | null {
+  const candidates = [
+    payload.data?.medium?.url,
+    payload.data?.thumb?.url,
+    payload.data?.image?.url,
+    payload.data?.url,
+    payload.data?.display_url,
+  ]
+
+  for (const candidate of candidates) {
+    if (typeof candidate === 'string' && candidate.length > 0) {
+      return candidate
+    }
+  }
+
+  return null
+}
+
+async function withTimeout<T>(
+  run: (signal: AbortSignal) => Promise<T>,
+): Promise<T> {
+  const controller = new AbortController()
+  const timeout = setTimeout(() => controller.abort(), getUploadTimeoutMs())
+
+  try {
+    return await run(controller.signal)
+  } finally {
+    clearTimeout(timeout)
+  }
+}
+
+async function uploadToImgbb(
+  base64Image: string,
+): Promise<string | null> {
+  const apiKey = getImgbbApiKey()
+  if (!apiKey) {
+    return null
+  }
+
+  try {
+    const url = await withTimeout(async signal => {
+      const body = new FormData()
+      body.append('image', base64Image)
+
+      const response = await fetch(`${IMGBB_UPLOAD_URL}?key=${encodeURIComponent(apiKey)}`, {
+        method: 'POST',
+        body,
+        signal,
+      })
+
+      if (!response.ok) {
+        logForDebugging(
+          `[Codex] ImgBB upload failed: ${response.status} ${response.statusText}`,
+        )
+        return null
+      }
+
+      return pickImgbbImageUrl((await response.json()) as ImgbbPayload)
+    })
+
+    if (!url) {
+      logForDebugging('[Codex] ImgBB upload produced no usable URL.')
+      return null
+    }
+
+    return url
+  } catch (error) {
+    logForDebugging(`[Codex] Failed to upload image to ImgBB: ${error}`)
+    return null
+  }
+}
+
+export async function uploadCodexBase64Image(
+  data: string,
+  mediaType: string = 'image/png',
+): Promise<string | null> {
+  const cacheKey = getCacheKey('base64', `${mediaType}:${data}`)
+  const cached = resolvedImageUrls.get(cacheKey)
+  if (cached) {
+    return cached
+  }
+
+  const url = await uploadToImgbb(data)
+  if (!url) {
+    return null
+  }
+
+  resolvedImageUrls.set(cacheKey, url)
+  return url
+}

src/services/api/codex/index.ts

@@ -0,0 +1,304 @@
+import type { BetaToolUnion } from '@anthropic-ai/sdk/resources/beta/messages/messages.mjs'
+import type {
+  Response,
+  ResponseCreateParamsNonStreaming,
+} from 'openai/resources/responses/responses.mjs'
+import { appendFileSync } from 'fs'
+import type { SystemPrompt } from '../../../utils/systemPromptType.js'
+import type {
+  AssistantMessage,
+  Message,
+  StreamEvent,
+  SystemAPIErrorMessage,
+} from '../../../types/message.js'
+import type { Tools } from '../../../Tool.js'
+import type { SDKAssistantMessageError } from '../../../entrypoints/agentSdkTypes.js'
+import { toolToAPISchema } from '../../../utils/api.js'
+import {
+  createAssistantAPIErrorMessage,
+  normalizeMessagesForAPI,
+} from '../../../utils/messages.js'
+import { logForDebugging } from '../../../utils/debug.js'
+import { getModelMaxOutputTokens } from '../../../utils/context.js'
+import type { Options } from '../claude.js'
+import { recordLLMObservation } from '../../../services/langfuse/tracing.js'
+import {
+  convertMessagesToLangfuse,
+  convertOutputToLangfuse,
+  convertToolsToLangfuse,
+} from '../../../services/langfuse/convert.js'
+import {
+  anthropicMessagesToCodexInput,
+  anthropicToolsToCodex,
+  resolveCodexMaxTokens,
+  resolveCodexModel,
+} from '@ant/model-provider'
+import { getCodexClient } from './client.js'
+import { uploadCodexBase64Image } from './imageUpload.js'
+import {
+  getCodexConfigurationError,
+  normalizeCodexError,
+} from './errors.js'
+import { sanitizeCodexRequest } from './preflight.js'
+import {
+  addCodexUsage,
+  type CodexStreamResult,
+  type CodexUsage,
+  rawAssistantBlocksToAssistantMessage,
+  type RawAssistantBlock,
+  streamCodexAttempt,
+} from './streaming.js'
+
+const MAX_CODEX_CONTINUATIONS = 3
+
+function dumpCodexPayload(
+  body: ResponseCreateParamsNonStreaming,
+): void {
+  const path = process.env.CODEX_DEBUG_PAYLOADS
+  if (!path) {
+    return
+  }
+
+  appendFileSync(
+    path,
+    `${JSON.stringify({ timestamp: new Date().toISOString(), body }, null, 2)}\n`,
+  )
+}
+
+function appendRawAssistantBlocks(
+  target: RawAssistantBlock[],
+  source: RawAssistantBlock[],
+): void {
+  for (const block of source) {
+    const lastBlock = target.at(-1)
+
+    if (lastBlock?.type === 'text' && block.type === 'text') {
+      lastBlock.text += block.text
+      continue
+    }
+
+    if (
+      lastBlock?.type === 'tool_use' &&
+      block.type === 'tool_use' &&
+      lastBlock.id === block.id &&
+      lastBlock.name === block.name &&
+      block.input.startsWith(lastBlock.input)
+    ) {
+      lastBlock.input = block.input
+      continue
+    }
+
+    target.push({ ...block })
+  }
+}
+
+export async function* queryModelCodex(
+  messages: Message[],
+  systemPrompt: SystemPrompt,
+  tools: Tools,
+  signal: AbortSignal,
+  options: Options,
+): AsyncGenerator<
+  StreamEvent | AssistantMessage | SystemAPIErrorMessage,
+  void
+> {
+  try {
+    const configurationError = getCodexConfigurationError()
+    if (configurationError) {
+      yield createAssistantAPIErrorMessage({
+        content: configurationError.content,
+        apiError: 'api_error',
+        error: configurationError.error,
+      })
+      return
+    }
+
+    const model = resolveCodexModel(options.model)
+    const messagesForAPI = normalizeMessagesForAPI(messages, tools)
+    const toolSchemas = await Promise.all(
+      tools.map(tool =>
+        toolToAPISchema(tool, {
+          getToolPermissionContext: options.getToolPermissionContext,
+          tools,
+          agents: options.agents,
+          allowedAgentTypes: options.allowedAgentTypes,
+          model: options.model,
+        }),
+      ),
+    )
+    const codexTools = anthropicToolsToCodex(toolSchemas as BetaToolUnion[])
+    const { upperLimit } = getModelMaxOutputTokens(model)
+    const maxTokens = resolveCodexMaxTokens(
+      upperLimit,
+      options.maxOutputTokensOverride,
+    )
+
+    const client = getCodexClient({
+      maxRetries: 0,
+      fetchOverride: options.fetchOverride as typeof fetch | undefined,
+    })
+    const start = Date.now()
+    const collectedMessages: AssistantMessage[] = []
+    let totalUsage: CodexUsage = {
+      input_tokens: 0,
+      output_tokens: 0,
+      cache_creation_input_tokens: 0,
+      cache_read_input_tokens: 0,
+    }
+
+    const aggregateBlocks: RawAssistantBlock[] = []
+    let replayMessages = messagesForAPI
+    let partialMessage: AssistantMessage['message'] | undefined
+    let finalResponse: Response | undefined
+    let terminalIncompleteResponse: Response | undefined
+
+    for (
+      let attempt = 0;
+      attempt <= MAX_CODEX_CONTINUATIONS;
+      attempt += 1
+    ) {
+      const input = await anthropicMessagesToCodexInput(replayMessages, {
+        resolveBase64ImageUrl: uploadCodexBase64Image,
+      })
+      const requestBody = sanitizeCodexRequest({
+        model,
+        input,
+        store: false,
+        parallel_tool_calls: false,
+        max_output_tokens: maxTokens,
+        ...(systemPrompt.length > 0 && {
+          instructions: systemPrompt.join('\n\n'),
+        }),
+        ...(codexTools.length > 0 && {
+          tools: codexTools,
+        }),
+        ...(options.temperatureOverride !== undefined && {
+          temperature: options.temperatureOverride,
+        }),
+      } satisfies ResponseCreateParamsNonStreaming)
+
+      if (attempt === 0) {
+        logForDebugging(
+          `[Codex] Calling model=${model}, inputItems=${input.length}, tools=${codexTools.length}`,
+        )
+        dumpCodexPayload(requestBody)
+      } else {
+        logForDebugging(
+          `[Codex] Continuing incomplete response attempt ${attempt}/${MAX_CODEX_CONTINUATIONS}`,
+        )
+      }
+
+      const attemptStream = streamCodexAttempt({
+        client,
+        requestBody,
+        signal,
+        start,
+        emitPrimaryEvents: attempt === 0,
+      })
+
+      let attemptResult: CodexStreamResult | undefined
+      while (true) {
+        const next = await attemptStream.next()
+        if (next.done) {
+          attemptResult = next.value
+          break
+        }
+        yield next.value
+      }
+
+      if (!attemptResult?.response) {
+        continue
+      }
+
+      partialMessage = partialMessage ?? attemptResult.partialMessage
+      finalResponse = attemptResult.response
+      terminalIncompleteResponse = attemptResult.incompleteResponse
+      totalUsage = addCodexUsage(totalUsage, attemptResult.response)
+
+      if (attemptResult.assistantBlocks.length === 0) {
+        break
+      }
+
+      appendRawAssistantBlocks(aggregateBlocks, attemptResult.assistantBlocks)
+
+      const shouldContinue =
+        attemptResult.incompleteResponse !== undefined &&
+        attempt < MAX_CODEX_CONTINUATIONS
+
+      if (!shouldContinue) {
+        break
+      }
+
+      const continuationMessage = rawAssistantBlocksToAssistantMessage(
+        attemptResult.assistantBlocks,
+        attemptResult.response,
+        tools,
+        options.agentId,
+      )
+      replayMessages = [...replayMessages, continuationMessage]
+    }
+
+    if (finalResponse) {
+      if (aggregateBlocks.length === 0) {
+        yield createAssistantAPIErrorMessage({
+          content: 'Codex returned an empty streamed response.',
+          apiError: 'api_error',
+          error: 'unknown',
+        })
+        return
+      }
+
+      const assistantMessage = rawAssistantBlocksToAssistantMessage(
+        aggregateBlocks,
+        finalResponse,
+        tools,
+        options.agentId,
+      )
+      assistantMessage.message.usage = totalUsage as any
+      collectedMessages.push(assistantMessage)
+      yield assistantMessage
+
+      recordLLMObservation(options.langfuseTrace ?? null, {
+        model,
+        provider: process.env.CODEX_LOGIN_METHOD === 'chatgpt_subscription'
+          ? 'codex-chatgpt'
+          : 'codex',
+        input: convertMessagesToLangfuse(messagesForAPI, systemPrompt),
+        output: convertOutputToLangfuse(collectedMessages),
+        usage: totalUsage,
+        startTime: new Date(start),
+        endTime: new Date(),
+        completionStartTime:
+          partialMessage !== undefined ? new Date(start) : undefined,
+        tools: convertToolsToLangfuse(toolSchemas as unknown[]),
+      })
+    } else {
+      yield createAssistantAPIErrorMessage({
+        content: 'Codex returned an empty streamed response.',
+        apiError: 'api_error',
+        error: 'unknown',
+      })
+      return
+    }
+
+    if (
+      terminalIncompleteResponse?.incomplete_details?.reason ===
+      'max_output_tokens'
+    ) {
+      yield createAssistantAPIErrorMessage({
+        content: `Output truncated: response exceeded the ${maxTokens} token limit. Set CODEX_MAX_TOKENS or CLAUDE_CODE_MAX_OUTPUT_TOKENS to override.`,
+        apiError: 'max_output_tokens',
+        error: 'max_output_tokens' as unknown as SDKAssistantMessageError,
+      })
+    }
+  } catch (error) {
+    const errorMessage = error instanceof Error ? error.message : String(error)
+    const normalizedError = normalizeCodexError(error)
+    logForDebugging(`[Codex] Error: ${errorMessage}`, { level: 'error' })
+    yield createAssistantAPIErrorMessage({
+      content: normalizedError.content,
+      apiError: 'api_error',
+      error: normalizedError.error,
+    })
+  }
+}

src/services/api/codex/preflight.ts

@@ -0,0 +1,151 @@
+import type {
+  ResponseCreateParamsNonStreaming,
+  ResponseCreateParamsStreaming,
+  ResponseInputItem,
+  Tool,
+} from 'openai/resources/responses/responses.mjs'
+import { normalizeCodexCallId } from '@ant/model-provider'
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === 'object' && value !== null && !Array.isArray(value)
+}
+
+function assertString(value: unknown, label: string): string {
+  if (typeof value !== 'string') {
+    throw new Error(`Codex preflight: ${label} must be a string.`)
+  }
+
+  return value
+}
+
+function sanitizeMessageItem(item: Record<string, unknown>): ResponseInputItem {
+  const role = assertString(item.role, 'message.role')
+  const content = item.content
+
+  if ((role !== 'user' && role !== 'assistant') || !Array.isArray(content)) {
+    throw new Error('Codex preflight: message items require role and content array.')
+  }
+
+  return item as unknown as ResponseInputItem
+}
+
+function sanitizeFunctionCallItem(item: Record<string, unknown>): ResponseInputItem {
+  const callId = normalizeCodexCallId(item.call_id)
+  const name = assertString(item.name, 'function_call.name').trim()
+  const argumentsValue = item.arguments
+
+  if (!callId) {
+    throw new Error('Codex preflight: function_call.call_id is required.')
+  }
+  if (name.length === 0) {
+    throw new Error('Codex preflight: function_call.name is required.')
+  }
+  if (typeof argumentsValue !== 'string') {
+    throw new Error('Codex preflight: function_call.arguments must be a string.')
+  }
+
+  return {
+    ...item,
+    call_id: callId,
+    name,
+    arguments: argumentsValue,
+  } as ResponseInputItem
+}
+
+function sanitizeFunctionCallOutputItem(
+  item: Record<string, unknown>,
+): ResponseInputItem {
+  const callId = normalizeCodexCallId(item.call_id)
+  const output = item.output
+
+  if (!callId) {
+    throw new Error('Codex preflight: function_call_output.call_id is required.')
+  }
+  if (
+    typeof output !== 'string' &&
+    !(Array.isArray(output) && output.every(part => isRecord(part)))
+  ) {
+    throw new Error(
+      'Codex preflight: function_call_output.output must be a string or content array.',
+    )
+  }
+
+  return {
+    ...item,
+    call_id: callId,
+  } as ResponseInputItem
+}
+
+function sanitizeInputItem(item: unknown): ResponseInputItem {
+  if (!isRecord(item) || typeof item.type !== 'string') {
+    throw new Error('Codex preflight: each input item requires a type.')
+  }
+
+  switch (item.type) {
+    case 'message':
+      return sanitizeMessageItem(item)
+    case 'function_call':
+      return sanitizeFunctionCallItem(item)
+    case 'function_call_output':
+      return sanitizeFunctionCallOutputItem(item)
+    default:
+      throw new Error(`Codex preflight: unsupported input item type "${item.type}".`)
+  }
+}
+
+function sanitizeTool(tool: unknown): Tool {
+  if (!isRecord(tool) || tool.type !== 'function') {
+    throw new Error('Codex preflight: only function tools are supported.')
+  }
+
+  const name = assertString(tool.name, 'tool.name').trim()
+  const parameters = isRecord(tool.parameters) ? tool.parameters : {}
+
+  if (name.length === 0) {
+    throw new Error('Codex preflight: tool.name is required.')
+  }
+
+  return {
+    ...tool,
+    type: 'function',
+    name,
+    parameters,
+  } as Tool
+}
+
+export function sanitizeCodexRequest(
+  request: ResponseCreateParamsNonStreaming,
+): ResponseCreateParamsNonStreaming {
+  if (typeof request.model !== 'string' || request.model.trim().length === 0) {
+    throw new Error('Codex preflight: model is required.')
+  }
+
+  if (
+    request.instructions !== undefined &&
+    request.instructions !== null &&
+    typeof request.instructions !== 'string'
+  ) {
+    throw new Error('Codex preflight: instructions must be a string.')
+  }
+
+  if (!Array.isArray(request.input)) {
+    throw new Error('Codex preflight: input must be an array.')
+  }
+
+  return {
+    ...request,
+    model: request.model.trim(),
+    instructions: request.instructions?.trim() || undefined,
+    input: request.input.map(sanitizeInputItem),
+    tools: request.tools?.map(sanitizeTool),
+  }
+}
+
+export function toStreamingCodexRequest(
+  request: ResponseCreateParamsNonStreaming,
+): ResponseCreateParamsStreaming {
+  return {
+    ...request,
+    stream: true,
+  }
+}

src/services/api/codex/streaming.ts

@@ -0,0 +1,681 @@
+import { randomUUID } from 'crypto'
+import type {
+  Response,
+  ResponseCreateParamsNonStreaming,
+  ResponseFunctionToolCall,
+  ResponseOutputItem,
+  ResponseOutputMessage,
+  ResponseStreamEvent,
+} from 'openai/resources/responses/responses.mjs'
+import type { AssistantMessage, StreamEvent } from '../../../types/message.js'
+import type { Tools } from '../../../Tool.js'
+import {
+  createAssistantMessage,
+  normalizeContentFromAPI,
+} from '../../../utils/messages.js'
+import { getCodexClient } from './client.js'
+import { resolveCodexCallId } from '@ant/model-provider'
+import { toStreamingCodexRequest } from './preflight.js'
+
+export type RawAssistantBlock =
+  | { type: 'text'; text: string }
+  | { type: 'tool_use'; id: string; name: string; input: string }
+
+export type CodexUsage = {
+  input_tokens: number
+  output_tokens: number
+  cache_creation_input_tokens: number
+  cache_read_input_tokens: number
+}
+
+export type CodexStreamResult = {
+  response?: Response
+  incompleteResponse?: Response
+  partialMessage?: AssistantMessage['message']
+  assistantBlocks: RawAssistantBlock[]
+}
+
+type CodexStreamState = {
+  contentBlocks: Record<number, RawAssistantBlock>
+  completedBlocks: Array<RawAssistantBlock | undefined>
+  partialMessage?: AssistantMessage['message']
+  finalResponse?: Response
+  incompleteResponse?: Response
+  failedResponse?: Response
+}
+
+export function getCodexUsage(
+  response: Pick<Response, 'usage'> | null | undefined,
+): CodexUsage {
+  return {
+    input_tokens: response?.usage?.input_tokens ?? 0,
+    output_tokens: response?.usage?.output_tokens ?? 0,
+    cache_creation_input_tokens: 0,
+    cache_read_input_tokens:
+      response?.usage?.input_tokens_details.cached_tokens ?? 0,
+  }
+}
+
+export function addCodexUsage(
+  total: CodexUsage,
+  response: Pick<Response, 'usage'> | null | undefined,
+): CodexUsage {
+  const usage = getCodexUsage(response)
+
+  return {
+    input_tokens: total.input_tokens + usage.input_tokens,
+    output_tokens: total.output_tokens + usage.output_tokens,
+    cache_creation_input_tokens:
+      total.cache_creation_input_tokens + usage.cache_creation_input_tokens,
+    cache_read_input_tokens:
+      total.cache_read_input_tokens + usage.cache_read_input_tokens,
+  }
+}
+
+function createPartialAssistantMessage(
+  response: Response,
+): AssistantMessage['message'] {
+  return {
+    id: response.id,
+    type: 'message',
+    role: 'assistant',
+    content: [],
+    model: response.model,
+    stop_reason: null,
+    stop_sequence: null,
+    usage: getCodexUsage(response) as any,
+  } as AssistantMessage['message']
+}
+
+function createToolUseBlock(
+  item: Partial<ResponseFunctionToolCall> & { id?: string },
+): RawAssistantBlock {
+  return {
+    type: 'tool_use',
+    id: resolveCodexCallId(
+      item.call_id ?? item.id,
+      `tool:${item.name ?? ''}:${item.arguments ?? ''}:${item.id ?? ''}`,
+    ),
+    name: item.name ?? '',
+    input: item.arguments ?? '',
+  }
+}
+
+function getCompletedTextFromItem(item: ResponseOutputItem): string | null {
+  if (item.type !== 'message' || item.role !== 'assistant') {
+    return null
+  }
+
+  for (const content of (item as ResponseOutputMessage).content) {
+    if (content.type === 'output_text' && content.text.length > 0) {
+      return content.text
+    }
+    if (content.type === 'refusal' && content.refusal.length > 0) {
+      return content.refusal
+    }
+  }
+
+  return null
+}
+
+function getCompletedAssistantBlocks(
+  blocks: Array<RawAssistantBlock | undefined>,
+): RawAssistantBlock[] {
+  return blocks.filter(
+    (block): block is RawAssistantBlock => block !== undefined,
+  )
+}
+
+function getCodexStopReason(
+  response: Pick<Response, 'incomplete_details'>,
+  blocks: RawAssistantBlock[],
+): string {
+  if (response.incomplete_details?.reason === 'max_output_tokens') {
+    return 'max_tokens'
+  }
+
+  return blocks.some(block => block.type === 'tool_use') ? 'tool_use' : 'end_turn'
+}
+
+function emitTrailingTextDelta(
+  output: StreamEvent[],
+  index: number,
+  currentText: string,
+  finalText: string,
+): void {
+  if (!finalText.startsWith(currentText)) {
+    return
+  }
+
+  const delta = finalText.slice(currentText.length)
+  if (delta.length === 0) {
+    return
+  }
+
+  output.push({
+    type: 'stream_event',
+    event: {
+      type: 'content_block_delta',
+      index,
+      delta: {
+        type: 'text_delta',
+        text: delta,
+      },
+    } as any,
+  } as StreamEvent)
+}
+
+function emitTrailingToolDelta(
+  output: StreamEvent[],
+  index: number,
+  currentInput: string,
+  finalInput: string,
+): void {
+  if (!finalInput.startsWith(currentInput)) {
+    return
+  }
+
+  const delta = finalInput.slice(currentInput.length)
+  if (delta.length === 0) {
+    return
+  }
+
+  output.push({
+    type: 'stream_event',
+    event: {
+      type: 'content_block_delta',
+      index,
+      delta: {
+        type: 'input_json_delta',
+        partial_json: delta,
+      },
+    } as any,
+  } as StreamEvent)
+}
+
+function responseToRawAssistantBlocks(response: Response): RawAssistantBlock[] {
+  const blocks: RawAssistantBlock[] = []
+
+  for (const item of response.output) {
+    if (item.type === 'function_call') {
+      const functionCall = item as ResponseFunctionToolCall
+      blocks.push({
+        type: 'tool_use',
+        id: resolveCodexCallId(
+          functionCall.call_id,
+          `output:${functionCall.name}:${functionCall.arguments}`,
+        ),
+        name: functionCall.name,
+        input: functionCall.arguments,
+      })
+      continue
+    }
+
+    if (item.type !== 'message' || item.role !== 'assistant') {
+      continue
+    }
+
+    for (const content of (item as ResponseOutputMessage).content) {
+      if (content.type === 'output_text' && content.text.length > 0) {
+        blocks.push({
+          type: 'text',
+          text: content.text,
+        })
+      } else if (content.type === 'refusal' && content.refusal.length > 0) {
+        blocks.push({
+          type: 'text',
+          text: content.refusal,
+        })
+      }
+    }
+  }
+
+  if (
+    blocks.length === 0 &&
+    typeof response.output_text === 'string' &&
+    response.output_text.length > 0
+  ) {
+    blocks.push({
+      type: 'text',
+      text: response.output_text,
+    })
+  }
+
+  return blocks
+}
+
+export function rawAssistantBlocksToAssistantMessage(
+  rawBlocks: RawAssistantBlock[],
+  response: Pick<Response, 'id' | 'model' | 'usage' | 'incomplete_details'>,
+  tools: Tools,
+  agentId?: string,
+): AssistantMessage {
+  const content = normalizeContentFromAPI(
+    rawBlocks as any,
+    tools,
+    agentId as any,
+  )
+
+  const assistantMessage = createAssistantMessage({
+    content: content as any,
+    usage: {
+      input_tokens: response.usage?.input_tokens ?? 0,
+      output_tokens: response.usage?.output_tokens ?? 0,
+      cache_creation_input_tokens: 0,
+      cache_read_input_tokens:
+        response.usage?.input_tokens_details.cached_tokens ?? 0,
+    } as any,
+  })
+
+  assistantMessage.message.id = response.id
+  assistantMessage.message.model = response.model
+  assistantMessage.message.stop_reason = getCodexStopReason(response, rawBlocks) as any
+  assistantMessage.message.stop_sequence = null
+  assistantMessage.uuid = randomUUID()
+  assistantMessage.timestamp = new Date().toISOString()
+
+  return assistantMessage
+}
+
+function handleCodexStreamEvent(params: {
+  event: ResponseStreamEvent
+  partialMessage: AssistantMessage['message'] | undefined
+  contentBlocks: Record<number, RawAssistantBlock>
+  completedBlocks: Array<RawAssistantBlock | undefined>
+  start: number
+}): {
+  output: StreamEvent[]
+  partialMessage: AssistantMessage['message'] | undefined
+  finalResponse?: Response
+  failedResponse?: Response
+  incompleteResponse?: Response
+} {
+  const { event, start } = params
+  const output: StreamEvent[] = []
+  const contentBlocks = params.contentBlocks
+  const completedBlocks = params.completedBlocks
+  let partialMessage = params.partialMessage
+  let finalResponse: Response | undefined
+  let failedResponse: Response | undefined
+  let incompleteResponse: Response | undefined
+
+  const ensureMessageStart = (response: Response): void => {
+    if (partialMessage) {
+      return
+    }
+
+    partialMessage = createPartialAssistantMessage(response)
+    output.push({
+      type: 'stream_event',
+      event: {
+        type: 'message_start',
+        message: partialMessage,
+      } as any,
+      ttftMs: Date.now() - start,
+    } as StreamEvent)
+  }
+
+  const ensureTextBlock = (index: number): RawAssistantBlock => {
+    const existing = contentBlocks[index]
+    if (existing) {
+      return existing
+    }
+
+    const block: RawAssistantBlock = { type: 'text', text: '' }
+    contentBlocks[index] = block
+    output.push({
+      type: 'stream_event',
+      event: {
+        type: 'content_block_start',
+        index,
+        content_block: { type: 'text', text: '' },
+      } as any,
+    } as StreamEvent)
+    return block
+  }
+
+  const ensureToolUseBlock = (
+    index: number,
+    item?: Partial<ResponseFunctionToolCall> & { id?: string },
+  ): RawAssistantBlock => {
+    const existing = contentBlocks[index]
+    if (existing) {
+      return existing
+    }
+
+    const block = createToolUseBlock(item ?? {})
+    contentBlocks[index] = block
+    const toolBlock = block as Extract<RawAssistantBlock, { type: 'tool_use' }>
+    output.push({
+      type: 'stream_event',
+      event: {
+        type: 'content_block_start',
+        index,
+        content_block: {
+          type: 'tool_use',
+          id: toolBlock.id,
+          name: toolBlock.name,
+          input: '',
+        },
+      } as any,
+    } as StreamEvent)
+    return block
+  }
+
+  const emitCompletedBlock = (index: number): void => {
+    const block = contentBlocks[index]
+    if (!block) {
+      return
+    }
+    completedBlocks[index] = { ...block }
+    output.push({
+      type: 'stream_event',
+      event: {
+        type: 'content_block_stop',
+        index,
+      } as any,
+    } as StreamEvent)
+    delete contentBlocks[index]
+  }
+
+  switch (event.type) {
+    case 'response.created':
+    case 'response.in_progress':
+      ensureMessageStart(event.response)
+      break
+    case 'response.output_item.added':
+      if (event.item.type === 'function_call') {
+        ensureToolUseBlock(event.output_index, event.item)
+      } else if (event.item.type === 'message' && event.item.role === 'assistant') {
+        ensureTextBlock(event.output_index)
+      }
+      break
+    case 'response.output_text.delta':
+    case 'response.refusal.delta': {
+      const block = ensureTextBlock(event.output_index)
+      if (block.type === 'text') {
+        block.text += event.delta
+      }
+      output.push({
+        type: 'stream_event',
+        event: {
+          type: 'content_block_delta',
+          index: event.output_index,
+          delta: {
+            type: 'text_delta',
+            text: event.delta,
+          },
+        } as any,
+      } as StreamEvent)
+      break
+    }
+    case 'response.function_call_arguments.delta': {
+      const block = ensureToolUseBlock(event.output_index, { id: event.item_id })
+      if (block.type === 'tool_use') {
+        block.input += event.delta
+      }
+      output.push({
+        type: 'stream_event',
+        event: {
+          type: 'content_block_delta',
+          index: event.output_index,
+          delta: {
+            type: 'input_json_delta',
+            partial_json: event.delta,
+          },
+        } as any,
+      } as StreamEvent)
+      break
+    }
+    case 'response.output_text.done':
+    case 'response.refusal.done': {
+      const block = ensureTextBlock(event.output_index)
+      const finalText = event.type === 'response.output_text.done'
+        ? event.text
+        : event.refusal
+      if (block.type === 'text') {
+        emitTrailingTextDelta(output, event.output_index, block.text, finalText)
+        block.text = finalText
+      }
+      emitCompletedBlock(event.output_index)
+      break
+    }
+    case 'response.function_call_arguments.done': {
+      const block = ensureToolUseBlock(event.output_index, {
+        id: event.item_id,
+        name: event.name,
+      })
+      if (block.type === 'tool_use') {
+        if (event.name) {
+          block.name = event.name
+        }
+        emitTrailingToolDelta(output, event.output_index, block.input, event.arguments)
+        block.input = event.arguments
+      }
+      emitCompletedBlock(event.output_index)
+      break
+    }
+    case 'response.output_item.done':
+      if (
+        event.item.type === 'message' &&
+        event.item.role === 'assistant' &&
+        contentBlocks[event.output_index]
+      ) {
+        const finalText = getCompletedTextFromItem(event.item)
+        if (finalText !== null) {
+          const block = contentBlocks[event.output_index]
+          if (block.type === 'text') {
+            emitTrailingTextDelta(output, event.output_index, block.text, finalText)
+            block.text = finalText
+          }
+        }
+        emitCompletedBlock(event.output_index)
+      } else if (
+        event.item.type === 'function_call' &&
+        contentBlocks[event.output_index]
+      ) {
+        const block = contentBlocks[event.output_index]
+        if (block.type === 'tool_use') {
+          block.id = resolveCodexCallId(
+            event.item.call_id,
+            `done:${event.item.name}:${event.item.arguments}:${event.item.id}`,
+          )
+          block.name = event.item.name
+          emitTrailingToolDelta(
+            output,
+            event.output_index,
+            block.input,
+            event.item.arguments,
+          )
+          block.input = event.item.arguments
+        }
+        emitCompletedBlock(event.output_index)
+      }
+      break
+    case 'response.completed':
+    case 'response.incomplete': {
+      ensureMessageStart(event.response)
+      if (event.type === 'response.completed') {
+        finalResponse = event.response
+      } else {
+        incompleteResponse = event.response
+      }
+      const assistantBlocks = getCompletedAssistantBlocks(completedBlocks)
+      output.push({
+        type: 'stream_event',
+        event: {
+          type: 'message_delta',
+          delta: {
+            stop_reason: getCodexStopReason(event.response, assistantBlocks),
+            stop_sequence: null,
+          },
+          usage: getCodexUsage(event.response),
+        } as any,
+      } as StreamEvent)
+      output.push({
+        type: 'stream_event',
+        event: {
+          type: 'message_stop',
+        } as any,
+      } as StreamEvent)
+      break
+    }
+    case 'response.failed':
+      failedResponse = event.response
+      break
+    case 'error':
+      throw new Error(event.message)
+  }
+
+  return {
+    output,
+    partialMessage,
+    finalResponse,
+    failedResponse,
+    incompleteResponse,
+  }
+}
+
+function selectResponse(
+  state: CodexStreamState,
+  streamedResponse?: Response,
+): CodexStreamResult {
+  const response =
+    [streamedResponse, state.finalResponse, state.incompleteResponse, state.failedResponse]
+      .find(
+        candidate =>
+          candidate !== undefined &&
+          responseToRawAssistantBlocks(candidate).length > 0,
+      ) ??
+    streamedResponse ??
+    state.finalResponse ??
+    state.incompleteResponse ??
+    state.failedResponse
+
+  return {
+    response,
+    incompleteResponse: state.incompleteResponse,
+    partialMessage: state.partialMessage,
+    assistantBlocks:
+      response !== undefined && responseToRawAssistantBlocks(response).length > 0
+        ? responseToRawAssistantBlocks(response)
+        : getCompletedAssistantBlocks(state.completedBlocks),
+  }
+}
+
+async function consumeCodexStream(
+  events: AsyncIterable<ResponseStreamEvent>,
+  start: number,
+): Promise<CodexStreamState> {
+  const state: CodexStreamState = {
+    contentBlocks: {},
+    completedBlocks: [],
+  }
+
+  for await (const event of events) {
+    const handled = handleCodexStreamEvent({
+      event,
+      partialMessage: state.partialMessage,
+      contentBlocks: state.contentBlocks,
+      completedBlocks: state.completedBlocks,
+      start,
+    })
+
+    state.partialMessage = handled.partialMessage
+    state.finalResponse = handled.finalResponse ?? state.finalResponse
+    state.incompleteResponse =
+      handled.incompleteResponse ?? state.incompleteResponse
+    state.failedResponse = handled.failedResponse ?? state.failedResponse
+  }
+
+  return state
+}
+
+export async function* streamCodexAttempt(params: {
+  client: ReturnType<typeof getCodexClient>
+  requestBody: ResponseCreateParamsNonStreaming
+  signal: AbortSignal
+  start: number
+  emitPrimaryEvents?: boolean
+}): AsyncGenerator<StreamEvent, CodexStreamResult, void> {
+  let primaryError: unknown
+  let primaryResult: CodexStreamResult | undefined
+
+  try {
+    const stream = params.client.responses.stream(
+      params.requestBody as unknown as Parameters<
+        typeof params.client.responses.stream
+      >[0],
+      { signal: params.signal },
+    )
+
+    const state: CodexStreamState = {
+      contentBlocks: {},
+      completedBlocks: [],
+    }
+
+    for await (const event of stream) {
+      const handled = handleCodexStreamEvent({
+        event,
+        partialMessage: state.partialMessage,
+        contentBlocks: state.contentBlocks,
+        completedBlocks: state.completedBlocks,
+        start: params.start,
+      })
+
+      state.partialMessage = handled.partialMessage
+      state.finalResponse = handled.finalResponse ?? state.finalResponse
+      state.incompleteResponse =
+        handled.incompleteResponse ?? state.incompleteResponse
+      state.failedResponse = handled.failedResponse ?? state.failedResponse
+
+      if (params.emitPrimaryEvents !== false) {
+        yield* handled.output
+      }
+    }
+
+    let streamedResponse: Response | undefined
+    try {
+      streamedResponse = await stream.finalResponse()
+    } catch {
+      streamedResponse = undefined
+    }
+
+    primaryResult = selectResponse(state, streamedResponse)
+    if (primaryResult.assistantBlocks.length > 0 || primaryResult.response) {
+      return primaryResult
+    }
+  } catch (error) {
+    primaryError = error
+  }
+
+  try {
+    const fallbackStream = await params.client.responses.create(
+      toStreamingCodexRequest(params.requestBody),
+      { signal: params.signal },
+    )
+
+    const fallbackState = await consumeCodexStream(
+      fallbackStream as AsyncIterable<ResponseStreamEvent>,
+      params.start,
+    )
+    const fallbackResult = selectResponse(fallbackState)
+
+    if (fallbackResult.assistantBlocks.length > 0 || fallbackResult.response) {
+      return fallbackResult
+    }
+  } catch (fallbackError) {
+    if (primaryError) {
+      throw primaryError
+    }
+    throw fallbackError
+  }
+
+  if (primaryError) {
+    throw primaryError
+  }
+
+  return primaryResult ?? {
+    assistantBlocks: [],
+  }
+}

src/services/langfuse/tracing.ts

@@ -57,6 +57,8 @@ const PROVIDER_GENERATION_NAMES: Record<string, string> = {
   vertex: 'ChatVertexAnthropic',
   foundry: 'ChatFoundry',
   openai: 'ChatOpenAI',
+  codex: 'ChatCodex',
+  'codex-chatgpt': 'ChatCodex',
   gemini: 'ChatGoogleGenerativeAI',
   grok: 'ChatXAI',
 }

src/services/oauth/__tests__/openai-codex.test.ts

@@ -0,0 +1,238 @@
+import { describe, expect, test, mock, beforeEach, afterEach } from 'bun:test'
+import {
+  _internal,
+  performOpenAICodexLogin,
+} from '../openai-codex.js'
+
+describe('openai-codex OAuth', () => {
+  describe('constants', () => {
+    test('has correct OAuth endpoints', () => {
+      expect(_internal.CLIENT_ID).toBe('app_EMoamEEZ73f0CkXaXp7hrann')
+      expect(_internal.AUTHORIZE_URL).toBe('https://auth.openai.com/oauth/authorize')
+      expect(_internal.TOKEN_URL).toBe('https://auth.openai.com/oauth/token')
+      expect(_internal.REDIRECT_URI).toBe('http://localhost:1455/auth/callback')
+      expect(_internal.SCOPE).toBe('openid profile email offline_access api.connectors.read api.connectors.invoke')
+    })
+  })
+
+  describe('buildAuthorizeUrl', () => {
+    test('builds correct authorize URL with all parameters', () => {
+      const url = _internal.buildAuthorizeUrl('test-challenge', 'test-state')
+      const parsed = new URL(url)
+
+      expect(parsed.origin + parsed.pathname).toBe('https://auth.openai.com/oauth/authorize')
+      expect(parsed.searchParams.get('response_type')).toBe('code')
+      expect(parsed.searchParams.get('client_id')).toBe(_internal.CLIENT_ID)
+      expect(parsed.searchParams.get('redirect_uri')).toBe(_internal.REDIRECT_URI)
+      expect(parsed.searchParams.get('scope')).toBe(_internal.SCOPE)
+      expect(parsed.searchParams.get('code_challenge')).toBe('test-challenge')
+      expect(parsed.searchParams.get('code_challenge_method')).toBe('S256')
+      expect(parsed.searchParams.get('state')).toBe('test-state')
+      expect(parsed.searchParams.get('id_token_add_organizations')).toBe('true')
+      expect(parsed.searchParams.get('codex_cli_simplified_flow')).toBe('true')
+      expect(parsed.searchParams.get('originator')).toBe('claude-code')
+    })
+
+    test('uses custom redirect URI when provided', () => {
+      const url = _internal.buildAuthorizeUrl('challenge', 'state', 'http://localhost:9999/custom')
+      const parsed = new URL(url)
+      expect(parsed.searchParams.get('redirect_uri')).toBe('http://localhost:9999/custom')
+    })
+  })
+
+  describe('decodeJwt', () => {
+    test('decodes valid JWT payload', () => {
+      // Create a minimal JWT: header.payload.signature
+      const payload = Buffer.from(
+        JSON.stringify({
+          'https://api.openai.com/auth': { chatgpt_account_id: 'acc_12345' },
+          sub: 'user_123',
+        }),
+      ).toString('base64url')
+      const token = `eyJhbGciOiJSUzI1NiJ9.${payload}.signature`
+
+      const result = _internal.decodeJwt(token)
+      expect(result).not.toBeNull()
+      expect(result?.['https://api.openai.com/auth']?.chatgpt_account_id).toBe('acc_12345')
+    })
+
+    test('returns null for invalid JWT', () => {
+      expect(_internal.decodeJwt('not-a-jwt')).toBeNull()
+      expect(_internal.decodeJwt('a.b')).toBeNull()
+      expect(_internal.decodeJwt('')).toBeNull()
+    })
+  })
+
+  describe('getAccountId', () => {
+    test('extracts account ID from valid token', () => {
+      const payload = Buffer.from(
+        JSON.stringify({
+          'https://api.openai.com/auth': { chatgpt_account_id: 'acc_test123' },
+        }),
+      ).toString('base64url')
+      const token = `header.${payload}.sig`
+
+      expect(_internal.getAccountId(token)).toBe('acc_test123')
+    })
+
+    test('returns null when account ID is missing', () => {
+      const payload = Buffer.from(JSON.stringify({ sub: 'user_123' })).toString('base64url')
+      const token = `header.${payload}.sig`
+
+      expect(_internal.getAccountId(token)).toBeNull()
+    })
+
+    test('returns null for empty account ID', () => {
+      const payload = Buffer.from(
+        JSON.stringify({
+          'https://api.openai.com/auth': { chatgpt_account_id: '' },
+        }),
+      ).toString('base64url')
+      const token = `header.${payload}.sig`
+
+      expect(_internal.getAccountId(token)).toBeNull()
+    })
+
+    test('returns null for invalid token', () => {
+      expect(_internal.getAccountId('invalid')).toBeNull()
+    })
+  })
+
+  describe('exchangeCodeForTokens', () => {
+    const originalFetch = globalThis.fetch
+
+    afterEach(() => {
+      globalThis.fetch = originalFetch
+    })
+
+    test('exchanges code for tokens successfully', async () => {
+      globalThis.fetch = mock(() =>
+        Promise.resolve(
+          new Response(
+            JSON.stringify({
+              id_token: 'id_token_value',
+              access_token: 'access_value',
+              refresh_token: 'refresh_value',
+              expires_in: 3600,
+            }),
+            { status: 200, headers: { 'Content-Type': 'application/json' } },
+          ),
+        ),
+      ) as any
+
+      const result = await _internal.exchangeCodeForTokens('auth_code', 'verifier')
+      expect(result.access_token).toBe('access_value')
+      expect(result.refresh_token).toBe('refresh_value')
+      expect(result.id_token).toBe('id_token_value')
+    })
+
+    test('throws on non-200 response', async () => {
+      globalThis.fetch = mock(() =>
+        Promise.resolve(
+          new Response('Unauthorized', { status: 401 }),
+        ),
+      ) as any
+
+      await expect(
+        _internal.exchangeCodeForTokens('bad_code', 'verifier'),
+      ).rejects.toThrow('Token exchange failed (401)')
+    })
+
+    test('throws when response missing fields', async () => {
+      globalThis.fetch = mock(() =>
+        Promise.resolve(
+          new Response(JSON.stringify({ access_token: 'only_access' }), {
+            status: 200,
+            headers: { 'Content-Type': 'application/json' },
+          }),
+        ),
+      ) as any
+
+      await expect(
+        _internal.exchangeCodeForTokens('code', 'verifier'),
+      ).rejects.toThrow('missing required fields')
+    })
+
+    test('sends correct request body', async () => {
+      let capturedBody: string | null = null
+      globalThis.fetch = mock((url: string, opts: any) => {
+        capturedBody = opts.body
+        return Promise.resolve(
+          new Response(
+            JSON.stringify({
+              id_token: 'id',
+              access_token: 'acc',
+              refresh_token: 'ref',
+            }),
+            { status: 200, headers: { 'Content-Type': 'application/json' } },
+          ),
+        )
+      }) as any
+
+      await _internal.exchangeCodeForTokens('test_code', 'test_verifier', 'http://localhost:1455/auth/callback')
+
+      const params = new URLSearchParams(capturedBody!)
+      expect(params.get('grant_type')).toBe('authorization_code')
+      expect(params.get('client_id')).toBe(_internal.CLIENT_ID)
+      expect(params.get('code')).toBe('test_code')
+      expect(params.get('code_verifier')).toBe('test_verifier')
+      expect(params.get('redirect_uri')).toBe('http://localhost:1455/auth/callback')
+    })
+  })
+
+  describe('obtainApiKey', () => {
+    const originalFetch = globalThis.fetch
+
+    afterEach(() => {
+      globalThis.fetch = originalFetch
+    })
+
+    test('exchanges id_token for API key', async () => {
+      globalThis.fetch = mock(() =>
+        Promise.resolve(
+          new Response(
+            JSON.stringify({ access_token: 'sk-api-key-12345' }),
+            { status: 200, headers: { 'Content-Type': 'application/json' } },
+          ),
+        ),
+      ) as any
+
+      const apiKey = await _internal.obtainApiKey('id_token_value')
+      expect(apiKey).toBe('sk-api-key-12345')
+    })
+
+    test('throws on non-200 response', async () => {
+      globalThis.fetch = mock(() =>
+        Promise.resolve(
+          new Response('Forbidden', { status: 403 }),
+        ),
+      ) as any
+
+      await expect(
+        _internal.obtainApiKey('bad_token'),
+      ).rejects.toThrow('API key exchange failed (403)')
+    })
+
+    test('sends correct token exchange parameters', async () => {
+      let capturedBody: string | null = null
+      globalThis.fetch = mock((url: string, opts: any) => {
+        capturedBody = opts.body
+        return Promise.resolve(
+          new Response(
+            JSON.stringify({ access_token: 'key' }),
+            { status: 200, headers: { 'Content-Type': 'application/json' } },
+          ),
+        )
+      }) as any
+
+      await _internal.obtainApiKey('test_id_token')
+
+      const params = new URLSearchParams(capturedBody!)
+      expect(params.get('grant_type')).toBe('urn:ietf:params:oauth:grant-type:token-exchange')
+      expect(params.get('client_id')).toBe(_internal.CLIENT_ID)
+      expect(params.get('requested_token')).toBe('openai-api-key')
+      expect(params.get('subject_token')).toBe('test_id_token')
+      expect(params.get('subject_token_type')).toBe('urn:ietf:params:oauth:token-type:id_token')
+    })
+  })
+})

src/services/oauth/openai-codex.ts

@@ -0,0 +1,373 @@
+/**
+ * OpenAI Codex (ChatGPT) OAuth flow
+ *
+ * Implements the browser-based OAuth login for ChatGPT subscription access.
+ * Based on the official OpenAI Codex CLI implementation (codex-rs/login/src/server.rs).
+ *
+ * Flow:
+ * 1. Generate PKCE codes + state
+ * 2. Start local HTTP server on port 1455
+ * 3. Open browser to OpenAI authorize URL
+ * 4. Handle callback → exchange code for tokens
+ * 5. Token exchange: id_token → API key
+ */
+
+import { createServer, type Server, type IncomingMessage, type ServerResponse } from 'http'
+import { generateCodeVerifier, generateCodeChallenge, generateState } from './crypto.js'
+import { openBrowser } from '../../utils/browser.js'
+
+// ─── Constants ───────────────────────────────────────────────────────────────
+
+const CLIENT_ID = 'app_EMoamEEZ73f0CkXaXp7hrann'
+const AUTHORIZE_URL = 'https://auth.openai.com/oauth/authorize'
+const TOKEN_URL = 'https://auth.openai.com/oauth/token'
+const DEFAULT_PORT = 1455
+const CALLBACK_PATH = '/auth/callback'
+const REDIRECT_URI = `http://localhost:${DEFAULT_PORT}${CALLBACK_PATH}`
+const SCOPE = 'openid profile email offline_access api.connectors.read api.connectors.invoke'
+const JWT_CLAIM_PATH = 'https://api.openai.com/auth'
+
+// ─── Types ───────────────────────────────────────────────────────────────────
+
+export type CodexOAuthResult = {
+  apiKey: string | null
+  accessToken: string
+  refreshToken: string
+  accountId: string
+}
+
+type TokenResponse = {
+  id_token: string
+  access_token: string
+  refresh_token: string
+  expires_in?: number
+}
+
+type ExchangeResponse = {
+  access_token: string
+}
+
+type JwtPayload = {
+  [JWT_CLAIM_PATH]?: {
+    chatgpt_account_id?: string
+  }
+  [key: string]: unknown
+}
+
+// ─── JWT helpers ─────────────────────────────────────────────────────────────
+
+function decodeJwt(token: string): JwtPayload | null {
+  try {
+    const parts = token.split('.')
+    if (parts.length !== 3) return null
+    const payload = parts[1] ?? ''
+    const decoded = Buffer.from(payload, 'base64url').toString('utf-8')
+    return JSON.parse(decoded) as JwtPayload
+  } catch {
+    return null
+  }
+}
+
+function getAccountId(token: string): string | null {
+  const payload = decodeJwt(token)
+  const accountId = payload?.[JWT_CLAIM_PATH]?.chatgpt_account_id
+  return typeof accountId === 'string' && accountId.length > 0 ? accountId : null
+}
+
+// ─── URL building ────────────────────────────────────────────────────────────
+
+function buildAuthorizeUrl(
+  codeChallenge: string,
+  state: string,
+  redirectUri: string = REDIRECT_URI,
+): string {
+  const url = new URL(AUTHORIZE_URL)
+  url.searchParams.set('response_type', 'code')
+  url.searchParams.set('client_id', CLIENT_ID)
+  url.searchParams.set('redirect_uri', redirectUri)
+  url.searchParams.set('scope', SCOPE)
+  url.searchParams.set('code_challenge', codeChallenge)
+  url.searchParams.set('code_challenge_method', 'S256')
+  url.searchParams.set('state', state)
+  url.searchParams.set('id_token_add_organizations', 'true')
+  url.searchParams.set('codex_cli_simplified_flow', 'true')
+  url.searchParams.set('originator', 'claude-code')
+  return url.toString()
+}
+
+// ─── Token exchange ──────────────────────────────────────────────────────────
+
+async function exchangeCodeForTokens(
+  code: string,
+  codeVerifier: string,
+  redirectUri: string = REDIRECT_URI,
+): Promise<TokenResponse> {
+  const response = await fetch(TOKEN_URL, {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
+    body: new URLSearchParams({
+      grant_type: 'authorization_code',
+      client_id: CLIENT_ID,
+      code,
+      code_verifier: codeVerifier,
+      redirect_uri: redirectUri,
+    }),
+  })
+
+  if (!response.ok) {
+    const text = await response.text().catch(() => '')
+    throw new Error(`Token exchange failed (${response.status}): ${text}`)
+  }
+
+  const json = (await response.json()) as TokenResponse
+  if (!json.access_token || !json.refresh_token) {
+    throw new Error('Token response missing required fields')
+  }
+  return json
+}
+
+async function obtainApiKey(idToken: string): Promise<string> {
+  const response = await fetch(TOKEN_URL, {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
+    body: new URLSearchParams({
+      grant_type: 'urn:ietf:params:oauth:grant-type:token-exchange',
+      client_id: CLIENT_ID,
+      requested_token: 'openai-api-key',
+      subject_token: idToken,
+      subject_token_type: 'urn:ietf:params:oauth:token-type:id_token',
+    }),
+  })
+
+  if (!response.ok) {
+    const text = await response.text().catch(() => '')
+    throw new Error(`API key exchange failed (${response.status}): ${text}`)
+  }
+
+  const json = (await response.json()) as ExchangeResponse
+  if (!json.access_token) {
+    throw new Error('API key exchange response missing access_token')
+  }
+  return json.access_token
+}
+
+// ─── HTML responses ──────────────────────────────────────────────────────────
+
+const SUCCESS_HTML = `<!DOCTYPE html>
+<html><head><meta charset="utf-8"><title>Login Successful</title>
+<style>body{font-family:system-ui,sans-serif;display:flex;justify-content:center;align-items:center;height:100vh;margin:0;background:#1a1a2e;color:#eee}
+.card{text-align:center;padding:2rem;border-radius:12px;background:#16213e;box-shadow:0 4px 24px rgba(0,0,0,.3)}
+h1{color:#4ade80;font-size:1.5rem}p{color:#94a3b8;margin-top:.5rem}</style></head>
+<body><div class="card"><h1>Authentication Complete</h1><p>You can close this window.</p></div></body></html>`
+
+const ERROR_HTML = (msg: string) => `<!DOCTYPE html>
+<html><head><meta charset="utf-8"><title>Login Error</title>
+<style>body{font-family:system-ui,sans-serif;display:flex;justify-content:center;align-items:center;height:100vh;margin:0;background:#1a1a2e;color:#eee}
+.card{text-align:center;padding:2rem;border-radius:12px;background:#16213e;box-shadow:0 4px 24px rgba(0,0,0,.3)}
+h1{color:#f87171;font-size:1.5rem}p{color:#94a3b8;margin-top:.5rem}</style></head>
+<body><div class="card"><h1>Authentication Failed</h1><p>${msg}</p></div></body></html>`
+
+// ─── Local callback server ──────────────────────────────────────────────────
+
+function startCallbackServer(
+  state: string,
+  port: number,
+): Promise<{
+  waitForCode: () => Promise<string>
+  close: () => void
+}> {
+  let settlePromise: ((code: string) => void) | ((error: Error) => void) | null = null
+
+  const codePromise = new Promise<string>((resolve, reject) => {
+    settlePromise = resolve
+    // Also store reject for error cases
+    ;(settlePromise as any).__reject = reject
+  })
+
+  const server: Server = createServer((req: IncomingMessage, res: ServerResponse) => {
+    try {
+      const url = new URL(req.url || '', `http://localhost:${port}`)
+
+      if (url.pathname !== CALLBACK_PATH) {
+        res.writeHead(404, { 'Content-Type': 'text/html; charset=utf-8' })
+        res.end(ERROR_HTML('Not found'))
+        return
+      }
+
+      // Check for OAuth error
+      const error = url.searchParams.get('error')
+      if (error) {
+        const desc = url.searchParams.get('error_description') ?? error
+        res.writeHead(400, { 'Content-Type': 'text/html; charset=utf-8' })
+        res.end(ERROR_HTML(desc))
+        ;((settlePromise as any).__reject as (e: Error) => void)?.(new Error(`OAuth error: ${desc}`))
+        return
+      }
+
+      if (url.searchParams.get('state') !== state) {
+        res.writeHead(400, { 'Content-Type': 'text/html; charset=utf-8' })
+        res.end(ERROR_HTML('State mismatch'))
+        ;((settlePromise as any).__reject as (e: Error) => void)?.(new Error('State mismatch'))
+        return
+      }
+
+      const code = url.searchParams.get('code')
+      if (!code) {
+        res.writeHead(400, { 'Content-Type': 'text/html; charset=utf-8' })
+        res.end(ERROR_HTML('Missing authorization code'))
+        ;((settlePromise as any).__reject as (e: Error) => void)?.(new Error('Missing authorization code'))
+        return
+      }
+
+      res.writeHead(200, { 'Content-Type': 'text/html; charset=utf-8' })
+      res.end(SUCCESS_HTML)
+      ;(settlePromise as (code: string) => void)?.(code)
+    } catch {
+      res.writeHead(500, { 'Content-Type': 'text/html; charset=utf-8' })
+      res.end(ERROR_HTML('Internal error'))
+    }
+  })
+
+  return new Promise((resolve, reject) => {
+    server.listen(port, '127.0.0.1', () => {
+      resolve({
+        waitForCode: () => codePromise,
+        close: () => {
+          server.close()
+          server.removeAllListeners()
+        },
+      })
+    })
+    server.on('error', (err: Error & { code?: string }) => {
+      reject(new Error(`Failed to start callback server on port ${port}: ${err.message}`))
+    })
+  })
+}
+
+// ─── Manual code parsing ────────────────────────────────────────────────────
+
+/**
+ * Parse manual user input to extract an authorization code.
+ * Accepts:
+ * - A full redirect URL: http://localhost:1455/auth/callback?code=XXX&state=YYY
+ * - A raw authorization code: XXX
+ * - code#state format: XXX#YYY
+ */
+export function parseManualCodeInput(input: string): string | null {
+  const value = input.trim()
+  if (!value) return null
+
+  // Try as URL
+  try {
+    const url = new URL(value)
+    const code = url.searchParams.get('code')
+    return code ?? null
+  } catch {
+    // Not a URL, continue
+  }
+
+  // Try code#state format — return just the code part
+  if (value.includes('#')) {
+    const [code] = value.split('#', 2)
+    return code ?? null
+  }
+
+  // Return as raw code
+  return value
+}
+
+// ─── Public API ──────────────────────────────────────────────────────────────
+
+export type CodexLoginOptions = {
+  /** Called with the authorize URL when the flow starts */
+  onUrl: (url: string) => void
+  /** Optional: provide a manual authorization code (headless fallback) */
+  manualCode?: Promise<string>
+}
+
+/**
+ * Perform the complete OpenAI Codex OAuth login flow.
+ *
+ * 1. Starts local callback server on port 1455
+ * 2. Opens browser to OpenAI authorize URL
+ * 3. Exchanges authorization code for tokens
+ * 4. Performs token exchange to obtain an API key
+ * 5. Returns the API key and token information
+ */
+export async function performOpenAICodexLogin(
+  options: CodexLoginOptions,
+): Promise<CodexOAuthResult> {
+  const { onUrl, manualCode } = options
+
+  // Step 1: Generate PKCE + state
+  const codeVerifier = generateCodeVerifier()
+  const codeChallenge = generateCodeChallenge(codeVerifier)
+  const state = generateState()
+
+  // Step 2: Build authorize URL
+  const authUrl = buildAuthorizeUrl(codeChallenge, state)
+  onUrl(authUrl)
+
+  // Step 3: Start callback server
+  const server = await startCallbackServer(state, DEFAULT_PORT)
+
+  try {
+    // Step 4: Open browser
+    await openBrowser(authUrl)
+
+    // Step 5: Wait for code (from callback or manual input)
+    let code: string
+
+    if (manualCode) {
+      // Race between browser callback and manual input
+      const result = await Promise.race([
+        server.waitForCode().then(c => ({ source: 'callback' as const, code: c })),
+        manualCode.then(c => ({ source: 'manual' as const, code: c })),
+      ])
+      code = result.code
+    } else {
+      code = await server.waitForCode()
+    }
+
+    // Step 6: Exchange code for tokens
+    const tokens = await exchangeCodeForTokens(code, codeVerifier)
+
+    // Step 7: Extract account ID
+    const accountId = getAccountId(tokens.id_token)
+    if (!accountId) {
+      throw new Error('Failed to extract ChatGPT account ID from token')
+    }
+
+    // Step 8: Exchange id_token for API key (non-fatal: some accounts lack org, returning null)
+    let apiKey: string | null = null
+    try {
+      apiKey = await obtainApiKey(tokens.id_token)
+    } catch {
+      // API key exchange may fail if the ID token lacks organization_id.
+      // This is expected for some account types — login still succeeds.
+    }
+
+    return {
+      apiKey,
+      accessToken: tokens.access_token,
+      refreshToken: tokens.refresh_token,
+      accountId,
+    }
+  } finally {
+    server.close()
+  }
+}
+
+// Export helpers for testing
+export const _internal = {
+  CLIENT_ID,
+  AUTHORIZE_URL,
+  TOKEN_URL,
+  REDIRECT_URI,
+  SCOPE,
+  buildAuthorizeUrl,
+  decodeJwt,
+  getAccountId,
+  exchangeCodeForTokens,
+  obtainApiKey,
+}

src/utils/managedEnvConstants.ts

@@ -23,6 +23,7 @@ const PROVIDER_MANAGED_ENV_VARS = new Set([
   'CLAUDE_CODE_USE_VERTEX',
   'CLAUDE_CODE_USE_FOUNDRY',
   'CLAUDE_CODE_USE_GEMINI',
+  'CLAUDE_CODE_USE_CODEX',
   // Endpoint config (base URLs, project/resource identifiers)
   'ANTHROPIC_BASE_URL',
   'ANTHROPIC_BEDROCK_BASE_URL',
@@ -31,6 +32,7 @@ const PROVIDER_MANAGED_ENV_VARS = new Set([
   'ANTHROPIC_FOUNDRY_RESOURCE',
   'ANTHROPIC_VERTEX_PROJECT_ID',
   'GEMINI_BASE_URL',
+  'CODEX_BASE_URL',
   // Region routing (per-model VERTEX_REGION_CLAUDE_* handled by prefix below)
   'CLOUD_ML_REGION',
   // Auth
@@ -43,6 +45,7 @@ const PROVIDER_MANAGED_ENV_VARS = new Set([
   'CLAUDE_CODE_SKIP_VERTEX_AUTH',
   'CLAUDE_CODE_SKIP_FOUNDRY_AUTH',
   'GEMINI_API_KEY',
+  'CODEX_API_KEY',
   // Model defaults — often set to provider-specific ID formats
   'ANTHROPIC_MODEL',
   'ANTHROPIC_DEFAULT_HAIKU_MODEL',
@@ -92,6 +95,17 @@ const PROVIDER_MANAGED_ENV_VARS = new Set([
   'GEMINI_DEFAULT_SONNET_MODEL_DESCRIPTION',
   'GEMINI_DEFAULT_SONNET_MODEL_NAME',
   'GEMINI_DEFAULT_SONNET_MODEL_SUPPORTED_CAPABILITIES',
+  // Codex provider specific
+  'CODEX_BASE_URL',
+  'CODEX_API_KEY',
+  'CODEX_MODEL',
+  'CODEX_DEFAULT_HAIKU_MODEL',
+  'CODEX_DEFAULT_SONNET_MODEL',
+  'CODEX_DEFAULT_OPUS_MODEL',
+  'CODEX_IMGBB_API_KEY',
+  'CODEX_LOGIN_METHOD',
+  'CODEX_ACCESS_TOKEN',
+  'CODEX_REFRESH_TOKEN',
 ])
 
 const PROVIDER_MANAGED_ENV_PREFIXES = [
@@ -201,6 +215,7 @@ export const SAFE_ENV_VARS = new Set([
   'CLAUDE_CODE_USE_FOUNDRY',
   'CLAUDE_CODE_USE_GEMINI',
   'CLAUDE_CODE_USE_VERTEX',
+  'CLAUDE_CODE_USE_CODEX',
   'GEMINI_MODEL',
   'GEMINI_SMALL_FAST_MODEL',
   'GEMINI_DEFAULT_HAIKU_MODEL',
@@ -215,6 +230,11 @@ export const SAFE_ENV_VARS = new Set([
   'GEMINI_DEFAULT_SONNET_MODEL_DESCRIPTION',
   'GEMINI_DEFAULT_SONNET_MODEL_NAME',
   'GEMINI_DEFAULT_SONNET_MODEL_SUPPORTED_CAPABILITIES',
+  // Codex provider specific
+  'CODEX_DEFAULT_HAIKU_MODEL',
+  'CODEX_DEFAULT_SONNET_MODEL',
+  'CODEX_DEFAULT_OPUS_MODEL',
+  'CODEX_IMGBB_API_KEY',
   'DISABLE_AUTOUPDATER',
   'DISABLE_BUG_COMMAND',
   'DISABLE_COST_WARNINGS',

src/utils/model/configs.ts

@@ -13,6 +13,7 @@ export const CLAUDE_3_7_SONNET_CONFIG = {
   foundry: 'claude-3-7-sonnet',
   openai: 'claude-3-7-sonnet-20250219',
   gemini: 'claude-3-7-sonnet-20250219',
+  codex: 'gpt-5.4-mini',
   grok: 'claude-3-7-sonnet-20250219',
 } as const satisfies ModelConfig
 
@@ -23,6 +24,7 @@ export const CLAUDE_3_5_V2_SONNET_CONFIG = {
   foundry: 'claude-3-5-sonnet',
   openai: 'claude-3-5-sonnet-20241022',
   gemini: 'claude-3-5-sonnet-20241022',
+  codex: 'gpt-5.4-mini',
   grok: 'claude-3-5-sonnet-20241022',
 } as const satisfies ModelConfig
 
@@ -33,6 +35,7 @@ export const CLAUDE_3_5_HAIKU_CONFIG = {
   foundry: 'claude-3-5-haiku',
   openai: 'claude-3-5-haiku-20241022',
   gemini: 'claude-3-5-haiku-20241022',
+  codex: 'gpt-5.4-mini',
   grok: 'claude-3-5-haiku-20241022',
 } as const satisfies ModelConfig
 
@@ -43,6 +46,7 @@ export const CLAUDE_HAIKU_4_5_CONFIG = {
   foundry: 'claude-haiku-4-5',
   openai: 'claude-haiku-4-5-20251001',
   gemini: 'claude-haiku-4-5-20251001',
+  codex: 'gpt-5.4-mini',
   grok: 'claude-haiku-4-5-20251001',
 } as const satisfies ModelConfig
 
@@ -53,6 +57,7 @@ export const CLAUDE_SONNET_4_CONFIG = {
   foundry: 'claude-sonnet-4',
   openai: 'claude-sonnet-4-20250514',
   gemini: 'claude-sonnet-4-20250514',
+  codex: 'gpt-5.4-mini',
   grok: 'claude-sonnet-4-20250514',
 } as const satisfies ModelConfig
 
@@ -63,6 +68,7 @@ export const CLAUDE_SONNET_4_5_CONFIG = {
   foundry: 'claude-sonnet-4-5',
   openai: 'claude-sonnet-4-5-20250929',
   gemini: 'claude-sonnet-4-5-20250929',
+  codex: 'gpt-5.4-mini',
   grok: 'claude-sonnet-4-5-20250929',
 } as const satisfies ModelConfig
 
@@ -73,6 +79,7 @@ export const CLAUDE_OPUS_4_CONFIG = {
   foundry: 'claude-opus-4',
   openai: 'claude-opus-4-20250514',
   gemini: 'claude-opus-4-20250514',
+  codex: 'gpt-5.4',
   grok: 'claude-opus-4-20250514',
 } as const satisfies ModelConfig
 
@@ -83,6 +90,7 @@ export const CLAUDE_OPUS_4_1_CONFIG = {
   foundry: 'claude-opus-4-1',
   openai: 'claude-opus-4-1-20250805',
   gemini: 'claude-opus-4-1-20250805',
+  codex: 'gpt-5.4',
   grok: 'claude-opus-4-1-20250805',
 } as const satisfies ModelConfig
 
@@ -93,6 +101,7 @@ export const CLAUDE_OPUS_4_5_CONFIG = {
   foundry: 'claude-opus-4-5',
   openai: 'claude-opus-4-5-20251101',
   gemini: 'claude-opus-4-5-20251101',
+  codex: 'gpt-5.4',
   grok: 'claude-opus-4-5-20251101',
 } as const satisfies ModelConfig
 
@@ -103,6 +112,7 @@ export const CLAUDE_OPUS_4_6_CONFIG = {
   foundry: 'claude-opus-4-6',
   openai: 'claude-opus-4-6',
   gemini: 'claude-opus-4-6',
+  codex: 'gpt-5.4',
   grok: 'claude-opus-4-6',
 } as const satisfies ModelConfig
 
@@ -113,6 +123,7 @@ export const CLAUDE_OPUS_4_7_CONFIG = {
   foundry: 'claude-opus-4-7',
   openai: 'claude-opus-4-7',
   gemini: 'claude-opus-4-7',
+  codex: 'gpt-5.5',
   grok: 'claude-opus-4-7',
 } as const satisfies ModelConfig
 
@@ -123,6 +134,7 @@ export const CLAUDE_SONNET_4_6_CONFIG = {
   foundry: 'claude-sonnet-4-6',
   openai: 'claude-sonnet-4-6',
   gemini: 'claude-sonnet-4-6',
+  codex: 'gpt-5.4-mini',
   grok: 'claude-sonnet-4-6',
 } as const satisfies ModelConfig
 

src/utils/model/modelOptions.ts

@@ -83,7 +83,9 @@ function getCustomSonnetOption(): ModelOption | undefined {
       ? process.env.OPENAI_DEFAULT_SONNET_MODEL
       : provider === 'gemini'
         ? process.env.GEMINI_DEFAULT_SONNET_MODEL
-        : process.env.ANTHROPIC_DEFAULT_SONNET_MODEL
+        : provider === 'codex'
+          ? process.env.CODEX_DEFAULT_SONNET_MODEL
+          : process.env.ANTHROPIC_DEFAULT_SONNET_MODEL
   // When a 3P user has a custom sonnet model string, show it directly
   if (is3P && customSonnetModel) {
     const is1m = has1mContext(customSonnetModel)
@@ -93,13 +95,17 @@ function getCustomSonnetOption(): ModelOption | undefined {
         ? process.env.OPENAI_DEFAULT_SONNET_MODEL_NAME
         : provider === 'gemini'
           ? process.env.GEMINI_DEFAULT_SONNET_MODEL_NAME
-          : process.env.ANTHROPIC_DEFAULT_SONNET_MODEL_NAME
+          : provider === 'codex'
+            ? process.env.CODEX_DEFAULT_SONNET_MODEL_NAME
+            : process.env.ANTHROPIC_DEFAULT_SONNET_MODEL_NAME
     const descEnv =
       provider === 'openai'
         ? process.env.OPENAI_DEFAULT_SONNET_MODEL_DESCRIPTION
         : provider === 'gemini'
           ? process.env.GEMINI_DEFAULT_SONNET_MODEL_DESCRIPTION
-          : process.env.ANTHROPIC_DEFAULT_SONNET_MODEL_DESCRIPTION
+          : provider === 'codex'
+            ? process.env.CODEX_DEFAULT_SONNET_MODEL_DESCRIPTION
+            : process.env.ANTHROPIC_DEFAULT_SONNET_MODEL_DESCRIPTION
     return {
       value: 'sonnet',
       label: nameEnv ?? customSonnetModel,
@@ -132,7 +138,9 @@ function getCustomOpusOption(): ModelOption | undefined {
       ? process.env.OPENAI_DEFAULT_OPUS_MODEL
       : provider === 'gemini'
         ? process.env.GEMINI_DEFAULT_OPUS_MODEL
-        : process.env.ANTHROPIC_DEFAULT_OPUS_MODEL
+        : provider === 'codex'
+          ? process.env.CODEX_DEFAULT_OPUS_MODEL
+          : process.env.ANTHROPIC_DEFAULT_OPUS_MODEL
   // When a 3P user has a custom opus model string, show it directly
   if (is3P && customOpusModel) {
     const is1m = has1mContext(customOpusModel)
@@ -142,13 +150,17 @@ function getCustomOpusOption(): ModelOption | undefined {
         ? process.env.OPENAI_DEFAULT_OPUS_MODEL_NAME
         : provider === 'gemini'
           ? process.env.GEMINI_DEFAULT_OPUS_MODEL_NAME
-          : process.env.ANTHROPIC_DEFAULT_OPUS_MODEL_NAME
+          : provider === 'codex'
+            ? process.env.CODEX_DEFAULT_OPUS_MODEL_NAME
+            : process.env.ANTHROPIC_DEFAULT_OPUS_MODEL_NAME
     const descEnv =
       provider === 'openai'
         ? process.env.OPENAI_DEFAULT_OPUS_MODEL_DESCRIPTION
         : provider === 'gemini'
           ? process.env.GEMINI_DEFAULT_OPUS_MODEL_DESCRIPTION
-          : process.env.ANTHROPIC_DEFAULT_OPUS_MODEL_DESCRIPTION
+          : provider === 'codex'
+            ? process.env.CODEX_DEFAULT_OPUS_MODEL_DESCRIPTION
+            : process.env.ANTHROPIC_DEFAULT_OPUS_MODEL_DESCRIPTION
     return {
       value: 'opus',
       label: nameEnv ?? customOpusModel,
@@ -232,7 +244,9 @@ function getCustomHaikuOption(): ModelOption | undefined {
       ? process.env.OPENAI_DEFAULT_HAIKU_MODEL
       : provider === 'gemini'
         ? process.env.GEMINI_DEFAULT_HAIKU_MODEL
-        : process.env.ANTHROPIC_DEFAULT_HAIKU_MODEL
+        : provider === 'codex'
+          ? process.env.CODEX_DEFAULT_HAIKU_MODEL
+          : process.env.ANTHROPIC_DEFAULT_HAIKU_MODEL
   // When a 3P user has a custom haiku model string, show it directly
   if (is3P && customHaikuModel) {
     // Use appropriate NAME/DESCRIPTION env vars based on provider
@@ -241,13 +255,17 @@ function getCustomHaikuOption(): ModelOption | undefined {
         ? process.env.OPENAI_DEFAULT_HAIKU_MODEL_NAME
         : provider === 'gemini'
           ? process.env.GEMINI_DEFAULT_HAIKU_MODEL_NAME
-          : process.env.ANTHROPIC_DEFAULT_HAIKU_MODEL_NAME
+          : provider === 'codex'
+            ? process.env.CODEX_DEFAULT_HAIKU_MODEL_NAME
+            : process.env.ANTHROPIC_DEFAULT_HAIKU_MODEL_NAME
     const descEnv =
       provider === 'openai'
         ? process.env.OPENAI_DEFAULT_HAIKU_MODEL_DESCRIPTION
         : provider === 'gemini'
           ? process.env.GEMINI_DEFAULT_HAIKU_MODEL_DESCRIPTION
-          : process.env.ANTHROPIC_DEFAULT_HAIKU_MODEL_DESCRIPTION
+          : provider === 'codex'
+            ? process.env.CODEX_DEFAULT_HAIKU_MODEL_DESCRIPTION
+            : process.env.ANTHROPIC_DEFAULT_HAIKU_MODEL_DESCRIPTION
     return {
       value: 'haiku',
       label: nameEnv ?? customHaikuModel,

src/utils/model/providers.ts

@@ -8,12 +8,14 @@ export type APIProvider =
   | 'vertex'
   | 'foundry'
   | 'openai'
+  | 'codex'
   | 'gemini'
   | 'grok'
 
 export function getAPIProvider(): APIProvider {
   const modelType = getInitialSettings().modelType
   if (modelType === 'openai') return 'openai'
+  if (modelType === 'codex') return 'codex'
   if (modelType === 'gemini') return 'gemini'
   if (modelType === 'grok') return 'grok'
 
@@ -22,6 +24,7 @@ export function getAPIProvider(): APIProvider {
   if (isEnvTruthy(process.env.CLAUDE_CODE_USE_FOUNDRY)) return 'foundry'
 
   if (isEnvTruthy(process.env.CLAUDE_CODE_USE_OPENAI)) return 'openai'
+  if (isEnvTruthy(process.env.CLAUDE_CODE_USE_CODEX)) return 'codex'
   if (isEnvTruthy(process.env.CLAUDE_CODE_USE_GEMINI)) return 'gemini'
   if (isEnvTruthy(process.env.CLAUDE_CODE_USE_GROK)) return 'grok'
 

src/utils/settings/types.ts

@@ -369,11 +369,11 @@ export const SettingsSchema = lazySchema(() =>
         .optional()
         .describe('Tool usage permissions configuration'),
       modelType: z
-        .enum(['anthropic', 'openai', 'gemini', 'grok'])
+        .enum(['anthropic', 'openai', 'gemini', 'grok', 'codex'])
         .optional()
         .describe(
-          'API provider type. "anthropic" uses the Anthropic API (default), "openai" uses the OpenAI Chat Completions API, "gemini" uses the Gemini API, and "grok" uses the xAI Grok API (OpenAI-compatible). ' +
-            'When set to "openai", configure OPENAI_API_KEY, OPENAI_BASE_URL, and OPENAI_MODEL. When set to "gemini", configure GEMINI_API_KEY and optional GEMINI_BASE_URL. When set to "grok", configure GROK_API_KEY (or XAI_API_KEY), optional GROK_BASE_URL, GROK_MODEL, and GROK_MODEL_MAP.',
+          'API provider type. "anthropic" uses the Anthropic API (default), "openai" uses the OpenAI Chat Completions API, "gemini" uses the Gemini API, "grok" uses the xAI Grok API (OpenAI-compatible), and "codex" uses the OpenAI Responses API via ChatGPT subscription or API key. ' +
+            'When set to "openai", configure OPENAI_API_KEY, OPENAI_BASE_URL, and OPENAI_MODEL. When set to "gemini", configure GEMINI_API_KEY and optional GEMINI_BASE_URL. When set to "grok", configure GROK_API_KEY (or XAI_API_KEY), optional GROK_BASE_URL, GROK_MODEL, and GROK_MODEL_MAP. When set to "codex", configure CODEX_API_KEY and optional CODEX_BASE_URL.',
         ),
       model: z
         .string()

src/utils/status.tsx

@@ -342,6 +342,7 @@ export function buildAPIProviderProperties(): Property[] {
       gemini: 'Gemini API',
       grok: 'Grok API',
       openai: 'OpenAI API',
+      codex: 'Codex API',
     }[apiProvider]
     properties.push({
       label: 'API provider',