diff --git a/.gitignore b/.gitignore
index ed4133d..ab7a975 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,43 +1,61 @@
 # dependencies (bun install)
-node_modules
+node_modules/
+.bun/
 
 # output
-out
-dist
+out/
+dist/
+build/
+release/
 *.tgz
+*.tsbuildinfo
+
+# vendor binaries (downloaded / generated)
+vendor/
+apps/electron/vendor/
 
 # code coverage
-coverage
+coverage/
 *.lcov
+.nyc_output/
+
+# test outputs
+test-results/
+playwright-report/
+reports/
 
 # logs
-logs
-_.log
+logs/
+*.log
+*.tmp
+*.swp
 report.[0-9]_.[0-9]_.[0-9]_.[0-9]_.json
 
 # dotenv environment variable files
 .env
-.env.development.local
-.env.test.local
-.env.production.local
-.env.local
+.env.*
 
 # caches
 .eslintcache
-.cache
-*.tsbuildinfo
+.cache/
 
 # IntelliJ based IDEs
-.idea
+.idea/
+
+# VSCode
+.vscode/
 
 # Finder (MacOS) folder config
 .DS_Store
+Thumbs.db
 
-# ignore craft-agents-oss folder
-craft-agents-oss
+# Codex local workspace state
+.codex/
 
-# ignore what_are_humans_thinking folder
-what_are_humans_thinking
+# --- AI/Agent local instructions (do not commit) ---
+AGENTS.md
+CLAUDE.md
 
-# vendor binaries
-vendor
\ No newline at end of file
+# ignore local scratch folders
+craft-agents-oss/
+what_are_humans_thinking/
diff --git a/apps/electron/src/main/lib/agent-orchestrator.ts b/apps/electron/src/main/lib/agent-orchestrator.ts
index acd0b39..c917172 100644
--- a/apps/electron/src/main/lib/agent-orchestrator.ts
+++ b/apps/electron/src/main/lib/agent-orchestrator.ts
@@ -28,7 +28,7 @@ import type { ClaudeAgentQueryOptions } from './adapters/claude-agent-adapter'
 import { isPromptTooLongError } from './adapters/claude-agent-adapter'
 import { AgentEventBus } from './agent-event-bus'
 import { decryptApiKey, getChannelById, listChannels } from './channel-manager'
-import { getAdapter, fetchTitle, normalizeAnthropicBaseUrlForSdk } from '@proma/core'
+import { getAdapter, fetchTitle, normalizeAnthropicBaseUrlForSdk, normalizeOpenAIBaseUrl } from '@proma/core'
 import { getFetchFn } from './proxy-fetch'
 import { getEffectiveProxyUrl } from './proxy-settings-service'
 import { appendAgentMessage, updateAgentSessionMeta, getAgentSessionMeta, getAgentSessionMessages } from './agent-session-manager'
@@ -564,9 +564,16 @@ export class AgentOrchestrator {
       const apiKey = decryptApiKey(channelId)
       const providerAdapter = getAdapter(channel.provider)
       const request = providerAdapter.buildTitleRequest({
-        baseUrl: channel.baseUrl,
+        baseUrl:
+          channel.provider === 'openai'
+            ? normalizeOpenAIBaseUrl(channel.baseUrl)
+            : channel.baseUrl,
         apiKey,
         modelId,
+        apiFormat:
+          channel.provider === 'openai' || channel.provider === 'custom'
+            ? channel.apiFormat
+            : 'chat_completions',
         prompt: TITLE_PROMPT + userMessage,
       })
 
@@ -1461,4 +1468,4 @@ export class AgentOrchestrator {
     this.adapter.dispose()
     this.activeSessions.clear()
   }
-}
\ No newline at end of file
+}
diff --git a/apps/electron/src/main/lib/channel-manager.ts b/apps/electron/src/main/lib/channel-manager.ts
index 83a7630..809275e 100644
--- a/apps/electron/src/main/lib/channel-manager.ts
+++ b/apps/electron/src/main/lib/channel-manager.ts
@@ -23,7 +23,7 @@ import type {
 } from '@proma/shared'
 import { getFetchFn } from './proxy-fetch'
 import { getEffectiveProxyUrl } from './proxy-settings-service'
-import { normalizeAnthropicBaseUrl, normalizeBaseUrl } from '@proma/core'
+import { normalizeAnthropicBaseUrl, normalizeBaseUrl, normalizeOpenAIBaseUrl, probeOpenAICompatibleModelsBaseUrl } from '@proma/core'
 
 /** 当前配置版本 */
 const CONFIG_VERSION = 1
@@ -132,11 +132,17 @@ export function createChannel(input: ChannelCreateInput): Channel {
   const config = readConfig()
   const now = Date.now()
 
+  const effectiveApiFormat =
+    input.provider === 'openai' || input.provider === 'custom'
+      ? input.apiFormat
+      : undefined
+
   const channel: Channel = {
     id: randomUUID(),
     name: input.name,
     provider: input.provider,
     baseUrl: input.baseUrl,
+    apiFormat: effectiveApiFormat,
     apiKey: encryptApiKey(input.apiKey),
     models: input.models,
     enabled: input.enabled,
@@ -168,11 +174,18 @@ export function updateChannel(id: string, input: ChannelUpdateInput): Channel {
 
   const existing = config.channels[index]!
 
+  const nextProvider = input.provider ?? existing.provider
+  const effectiveApiFormat =
+    nextProvider === 'openai' || nextProvider === 'custom'
+      ? (input.apiFormat ?? existing.apiFormat)
+      : undefined
+
   const updated: Channel = {
     ...existing,
     name: input.name ?? existing.name,
-    provider: input.provider ?? existing.provider,
+    provider: nextProvider,
     baseUrl: input.baseUrl ?? existing.baseUrl,
+    apiFormat: effectiveApiFormat,
     apiKey: input.apiKey ? encryptApiKey(input.apiKey) : existing.apiKey,
     models: input.models ?? existing.models,
     enabled: input.enabled ?? existing.enabled,
@@ -240,14 +253,16 @@ export async function testChannel(channelId: string): Promise<ChannelTestResult>
       case 'anthropic':
         return await testAnthropic(channel.baseUrl, apiKey, proxyUrl)
       case 'openai':
+        return await testOpenAICompatible(channel.baseUrl, apiKey, proxyUrl, true)
       case 'deepseek':
       case 'moonshot':
       case 'zhipu':
       case 'minimax':
       case 'doubao':
       case 'qwen':
-      case 'custom':
         return await testOpenAICompatible(channel.baseUrl, apiKey, proxyUrl)
+      case 'custom':
+        return await testCustomOpenAICompatible(channel.baseUrl, apiKey, proxyUrl)
       case 'google':
         return await testGoogle(channel.baseUrl, apiKey, proxyUrl)
       default:
@@ -297,8 +312,13 @@ async function testAnthropic(baseUrl: string, apiKey: string, proxyUrl?: string)
 /**
  * 测试 OpenAI 兼容 API 连接（OpenAI / DeepSeek / Custom）
  */
-async function testOpenAICompatible(baseUrl: string, apiKey: string, proxyUrl?: string): Promise<ChannelTestResult> {
-  const url = normalizeBaseUrl(baseUrl)
+async function testOpenAICompatible(
+  baseUrl: string,
+  apiKey: string,
+  proxyUrl?: string,
+  ensureV1: boolean = false,
+): Promise<ChannelTestResult> {
+  const url = ensureV1 ? normalizeOpenAIBaseUrl(baseUrl) : normalizeBaseUrl(baseUrl)
   const fetchFn = getFetchFn(proxyUrl)
 
   const response = await fetchFn(`${url}/models`, {
@@ -320,6 +340,60 @@ async function testOpenAICompatible(baseUrl: string, apiKey: string, proxyUrl?:
   return { success: false, message: `请求失败 (${response.status}): ${text.slice(0, 200)}` }
 }
 
+/**
+ * 测试 OpenAI 兼容 API 连接（Custom 专用：自动探测是否需要 /v1）
+ *
+ * 同时探测：
+ * - {baseUrl}/models
+ * - {baseUrl}/v1/models
+ *
+ * 以探测结果决定推荐的 Base URL（优先选择 /v1）。
+ */
+async function testCustomOpenAICompatible(baseUrl: string, apiKey: string, proxyUrl?: string): Promise<ChannelTestResult> {
+  const fetchFn = getFetchFn(proxyUrl)
+  const baseNoV1 = normalizeBaseUrl(baseUrl)
+  const baseV1 = normalizeOpenAIBaseUrl(baseUrl)
+
+  const { best, probes, resolvedBaseUrl } = await probeOpenAICompatibleModelsBaseUrl({
+    baseUrl,
+    apiKey,
+    fetchFn,
+  })
+  const suffixHint = resolvedBaseUrl && resolvedBaseUrl === baseV1 && baseV1 !== baseNoV1
+    ? '（已自动补全 /v1）'
+    : ''
+
+  if (best.ok) {
+    return { success: true, message: `连接成功${suffixHint}`, resolvedBaseUrl }
+  }
+
+  if (best.status === 401) {
+    return { success: false, message: `API Key 无效${suffixHint}`, resolvedBaseUrl }
+  }
+
+  if (best.status === 404 && probes.every((p) => p.status === 404)) {
+    return {
+      success: false,
+      message: '请求失败 (404): 未找到 /models 或 /v1/models，请检查 Base URL 是否正确',
+      resolvedBaseUrl,
+    }
+  }
+
+  if (best.status > 0) {
+    return {
+      success: false,
+      message: `请求失败 (${best.status})${best.bodyPreview ? `: ${best.bodyPreview}` : ''}${suffixHint}`,
+      resolvedBaseUrl,
+    }
+  }
+
+  return {
+    success: false,
+    message: `连接测试失败: ${best.error ?? '未知错误'}${suffixHint}`,
+    resolvedBaseUrl,
+  }
+}
+
 /**
  * 测试 Google Generative AI API 连接
  */
@@ -359,14 +433,16 @@ export async function testChannelDirect(input: FetchModelsInput): Promise<Channe
       case 'anthropic':
         return await testAnthropic(input.baseUrl, input.apiKey, proxyUrl)
       case 'openai':
+        return await testOpenAICompatible(input.baseUrl, input.apiKey, proxyUrl, true)
       case 'deepseek':
       case 'moonshot':
       case 'zhipu':
       case 'minimax':
       case 'doubao':
       case 'qwen':
-      case 'custom':
         return await testOpenAICompatible(input.baseUrl, input.apiKey, proxyUrl)
+      case 'custom':
+        return await testCustomOpenAICompatible(input.baseUrl, input.apiKey, proxyUrl)
       case 'google':
         return await testGoogle(input.baseUrl, input.apiKey, proxyUrl)
       default:
@@ -394,14 +470,16 @@ export async function fetchModels(input: FetchModelsInput): Promise<FetchModelsR
       case 'anthropic':
         return await fetchAnthropicModels(input.baseUrl, input.apiKey, proxyUrl)
       case 'openai':
+        return await fetchOpenAICompatibleModels(input.baseUrl, input.apiKey, proxyUrl, true)
       case 'deepseek':
       case 'moonshot':
       case 'zhipu':
       case 'minimax':
       case 'doubao':
       case 'qwen':
-      case 'custom':
         return await fetchOpenAICompatibleModels(input.baseUrl, input.apiKey, proxyUrl)
+      case 'custom':
+        return await fetchCustomOpenAICompatibleModels(input.baseUrl, input.apiKey, proxyUrl)
       case 'google':
         return await fetchGoogleModels(input.baseUrl, input.apiKey, proxyUrl)
       default:
@@ -482,8 +560,13 @@ interface OpenAIModelItem {
  * API: GET {baseUrl}/models
  * 通用 OpenAI 兼容格式，适用于大部分第三方供应商。
  */
-async function fetchOpenAICompatibleModels(baseUrl: string, apiKey: string, proxyUrl?: string): Promise<FetchModelsResult> {
-  const url = normalizeBaseUrl(baseUrl)
+async function fetchOpenAICompatibleModels(
+  baseUrl: string,
+  apiKey: string,
+  proxyUrl?: string,
+  ensureV1: boolean = false,
+): Promise<FetchModelsResult> {
+  const url = ensureV1 ? normalizeOpenAIBaseUrl(baseUrl) : normalizeBaseUrl(baseUrl)
   const fetchFn = getFetchFn(proxyUrl)
 
   const response = await fetchFn(`${url}/models`, {
@@ -521,6 +604,50 @@ async function fetchOpenAICompatibleModels(baseUrl: string, apiKey: string, prox
   }
 }
 
+/**
+ * 从 OpenAI 兼容服务拉取模型列表（Custom：自动探测是否需要 /v1）
+ *
+ * 对于第三方 OpenAI 兼容服务，用户可能输入：
+ * - https://host
+ * - https://host/v1
+ *
+ * 这里复用探测逻辑，优先选择更合适的 Base URL，再发起 /models 请求，
+ * 以提升“未先点测试连接就直接拉取模型”的成功率。
+ */
+async function fetchCustomOpenAICompatibleModels(
+  baseUrl: string,
+  apiKey: string,
+  proxyUrl?: string,
+): Promise<FetchModelsResult> {
+  const fetchFn = getFetchFn(proxyUrl)
+  const baseNoV1 = normalizeBaseUrl(baseUrl)
+  const baseV1 = normalizeOpenAIBaseUrl(baseUrl)
+
+  const { best, probes, resolvedBaseUrl } = await probeOpenAICompatibleModelsBaseUrl({
+    baseUrl,
+    apiKey,
+    fetchFn,
+  })
+
+  const suffixHint = resolvedBaseUrl === baseV1 && baseV1 !== baseNoV1
+    ? '（已自动补全 /v1）'
+    : ''
+
+  if (best.status === 404 && probes.every((p) => p.status === 404)) {
+    return {
+      success: false,
+      message: `请求失败 (404): 未找到 /models 或 /v1/models，请检查 Base URL 是否正确${suffixHint}`,
+      models: [],
+    }
+  }
+
+  const result = await fetchOpenAICompatibleModels(resolvedBaseUrl, apiKey, proxyUrl, false)
+  return {
+    ...result,
+    message: `${result.message}${suffixHint}`,
+  }
+}
+
 /**
  * Google Generative AI 模型响应项
  */
diff --git a/apps/electron/src/main/lib/chat-service.ts b/apps/electron/src/main/lib/chat-service.ts
index 6fe592d..bf89f4f 100644
--- a/apps/electron/src/main/lib/chat-service.ts
+++ b/apps/electron/src/main/lib/chat-service.ts
@@ -15,11 +15,12 @@
 import { randomUUID } from 'node:crypto'
 import type { WebContents } from 'electron'
 import { CHAT_IPC_CHANNELS } from '@proma/shared'
-import type { ChatSendInput, ChatMessage, GenerateTitleInput, FileAttachment, ChatToolActivity } from '@proma/shared'
+import type { ChatSendInput, ChatMessage, GenerateTitleInput, FileAttachment, ChatToolActivity, ChannelApiFormat } from '@proma/shared'
 import {
   getAdapter,
   streamSSE,
   fetchTitle,
+  normalizeOpenAIBaseUrl,
 } from '@proma/core'
 import type { ImageAttachmentData, ContinuationMessage } from '@proma/core'
 import { listChannels, decryptApiKey } from './channel-manager'
@@ -268,9 +269,18 @@ export async function sendMessage(
 
     // 9. 工具续接循环
     let continuationMessages: ContinuationMessage[] = []
+    let previousResponseId: string | undefined
     let round = 0
     /** 标记最近一轮是否执行了工具（用于判断是否需要最终响应轮） */
     let pendingToolResults = false
+    let apiFormatForLoop: ChannelApiFormat =
+      channel.provider === 'openai' || channel.provider === 'custom'
+        ? (channel.apiFormat ?? 'chat_completions')
+        : 'chat_completions'
+    const effectiveBaseUrl =
+      channel.provider === 'openai'
+        ? normalizeOpenAIBaseUrl(channel.baseUrl)
+        : channel.baseUrl
 
     /** 流式事件处理器（工具轮和最终响应轮复用） */
     const handleStreamEvent = (event: { type: string; delta?: string; toolCallId?: string; toolName?: string }): void => {
@@ -309,9 +319,11 @@ export async function sendMessage(
       pendingToolResults = false
 
       const request = adapter.buildStreamRequest({
-        baseUrl: channel.baseUrl,
+        baseUrl: effectiveBaseUrl,
         apiKey,
         modelId,
+        apiFormat: apiFormatForLoop,
+        previousResponseId,
         history: enrichedHistory,
         userMessage: enrichedUserMessage,
         systemMessage: effectiveSystemMessage,
@@ -322,7 +334,7 @@ export async function sendMessage(
         continuationMessages: continuationMessages.length > 0 ? continuationMessages : undefined,
       })
 
-      const { content, toolCalls, stopReason } = await streamSSE({
+      const { content, toolCalls, stopReason, responseId } = await streamSSE({
         request,
         adapter,
         signal: controller.signal,
@@ -330,6 +342,24 @@ export async function sendMessage(
         onEvent: handleStreamEvent,
       })
 
+      if (responseId) {
+        previousResponseId = responseId
+      }
+
+      // Responses 模式下，如果需要继续 tool loop 但没拿到本轮 responseId，
+      // 下一轮无法可靠地通过 previous_response_id 续接。
+      // 为保证可用性，这里自动降级到 Chat Completions 继续循环。
+      if (
+        apiFormatForLoop === 'responses'
+        && stopReason === 'tool_use'
+        && toolCalls.length > 0
+        && !responseId
+      ) {
+        console.warn('[聊天服务] Responses 模式未收到 responseId，自动降级为 Chat Completions 继续 tool loop')
+        apiFormatForLoop = 'chat_completions'
+        previousResponseId = undefined
+      }
+
       // 如果没有工具调用或不是 tool_use 停止，退出循环
       if (!toolCalls || toolCalls.length === 0 || stopReason !== 'tool_use') {
         break
@@ -372,9 +402,11 @@ export async function sendMessage(
       console.log(`[聊天服务] 工具轮次已达上限 (${MAX_TOOL_ROUNDS})，发起最终响应轮`)
 
       const finalRequest = adapter.buildStreamRequest({
-        baseUrl: channel.baseUrl,
+        baseUrl: effectiveBaseUrl,
         apiKey,
         modelId,
+        apiFormat: apiFormatForLoop,
+        previousResponseId,
         history: enrichedHistory,
         userMessage: enrichedUserMessage,
         systemMessage: effectiveSystemMessage,
@@ -549,9 +581,16 @@ export async function generateTitle(input: GenerateTitleInput): Promise<string |
   try {
     const adapter = getAdapter(channel.provider)
     const request = adapter.buildTitleRequest({
-      baseUrl: channel.baseUrl,
+      baseUrl:
+        channel.provider === 'openai'
+          ? normalizeOpenAIBaseUrl(channel.baseUrl)
+          : channel.baseUrl,
       apiKey,
       modelId,
+      apiFormat:
+        channel.provider === 'openai' || channel.provider === 'custom'
+          ? channel.apiFormat
+          : 'chat_completions',
       prompt: TITLE_PROMPT + userMessage,
     })
 
diff --git a/apps/electron/src/renderer/components/settings/ChannelForm.tsx b/apps/electron/src/renderer/components/settings/ChannelForm.tsx
index c93612a..d58b3ef 100644
--- a/apps/electron/src/renderer/components/settings/ChannelForm.tsx
+++ b/apps/electron/src/renderer/components/settings/ChannelForm.tsx
@@ -30,9 +30,11 @@ import {
   PROVIDER_DEFAULT_URLS,
   PROVIDER_LABELS,
 } from '@proma/shared'
+import { normalizeOpenAIBaseUrl } from '@proma/core/providers'
 import type {
   Channel,
   ChannelCreateInput,
+  ChannelApiFormat,
   ChannelModel,
   ChannelTestResult,
   FetchModelsResult,
@@ -77,12 +79,18 @@ const PROVIDER_CHAT_PATHS: Record<ProviderType, string> = {
   custom: '/chat/completions',
 }
 
+/** OpenAI 兼容供应商的 API 格式选项 */
+const OPENAI_API_FORMAT_OPTIONS: Array<{ value: ChannelApiFormat; label: string }> = [
+  { value: 'chat_completions', label: 'Chat Completions（默认）' },
+  { value: 'responses', label: 'Responses（OpenAI）' },
+]
+
 /**
  * 生成 API 端点预览 URL
  *
  * Anthropic 特殊处理：如果 baseUrl 已包含 /v1，则不重复添加。
  */
-function buildPreviewUrl(baseUrl: string, provider: ProviderType): string {
+function buildPreviewUrl(baseUrl: string, provider: ProviderType, apiFormat: ChannelApiFormat): string {
   let trimmed = baseUrl.trim().replace(/\/+$/, '')
 
   if (provider === 'anthropic') {
@@ -94,6 +102,16 @@ function buildPreviewUrl(baseUrl: string, provider: ProviderType): string {
     return `${trimmed}/v1/messages`
   }
 
+  // OpenAI 官方：Base URL 约定包含 /v1
+  if (provider === 'openai') {
+    trimmed = normalizeOpenAIBaseUrl(trimmed)
+  }
+
+  // OpenAI / Custom：允许切换为 /responses
+  if ((provider === 'openai' || provider === 'custom') && apiFormat === 'responses') {
+    return `${trimmed}/responses`
+  }
+
   return `${trimmed}${PROVIDER_CHAT_PATHS[provider]}`
 }
 
@@ -104,6 +122,7 @@ export function ChannelForm({ channel, onSaved, onCancel }: ChannelFormProps): R
   const [name, setName] = React.useState(channel?.name ?? '')
   const [provider, setProvider] = React.useState<ProviderType>(channel?.provider ?? 'anthropic')
   const [baseUrl, setBaseUrl] = React.useState(channel?.baseUrl ?? PROVIDER_DEFAULT_URLS.anthropic)
+  const [apiFormat, setApiFormat] = React.useState<ChannelApiFormat>(channel?.apiFormat ?? 'chat_completions')
   const [apiKey, setApiKey] = React.useState('')
   const [showApiKey, setShowApiKey] = React.useState(false)
   const [models, setModels] = React.useState<ChannelModel[]>(channel?.models ?? [])
@@ -143,6 +162,14 @@ export function ChannelForm({ channel, onSaved, onCancel }: ChannelFormProps): R
     setProvider(p)
     setBaseUrl(PROVIDER_DEFAULT_URLS[p])
     setTestResult(null)
+    // 默认行为：
+    // - OpenAI：优先使用 Responses API
+    // - OpenAI 兼容格式 / 其他：默认使用 Chat Completions
+    if (p === 'openai') {
+      setApiFormat('responses')
+    } else {
+      setApiFormat('chat_completions')
+    }
   }
 
   /** 添加模型 */
@@ -219,6 +246,10 @@ export function ChannelForm({ channel, onSaved, onCancel }: ChannelFormProps): R
         apiKey,
       })
       setTestResult(result)
+      // OpenAI 兼容格式：连接测试时可能会探测并返回更合适的 Base URL（例如自动补全 /v1）
+      if (provider === 'custom' && result.resolvedBaseUrl && result.resolvedBaseUrl !== baseUrl.trim()) {
+        setBaseUrl(result.resolvedBaseUrl)
+      }
     } catch (error) {
       setTestResult({ success: false, message: '测试请求失败' })
     } finally {
@@ -228,11 +259,17 @@ export function ChannelForm({ channel, onSaved, onCancel }: ChannelFormProps): R
 
   /** 保存渠道 */
   const saveChannel = async (): Promise<void> => {
+    const effectiveApiFormat: ChannelApiFormat =
+      provider === 'openai' || provider === 'custom'
+        ? apiFormat
+        : 'chat_completions'
+
     if (isEdit && channel) {
       await window.electronAPI.updateChannel(channel.id, {
         name,
         provider,
         baseUrl,
+        apiFormat: effectiveApiFormat,
         apiKey: apiKey || undefined,
         models,
         enabled,
@@ -242,6 +279,7 @@ export function ChannelForm({ channel, onSaved, onCancel }: ChannelFormProps): R
         name,
         provider,
         baseUrl,
+        apiFormat: effectiveApiFormat,
         apiKey,
         models,
         enabled,
@@ -254,7 +292,7 @@ export function ChannelForm({ channel, onSaved, onCancel }: ChannelFormProps): R
   const handleSubmit = async (e: React.FormEvent): Promise<void> => {
     e.preventDefault()
 
-    if (!name.trim() || !apiKey.trim()) return
+    if (!name.trim() || (!isEdit && !apiKey.trim())) return
 
     setSaving(true)
     try {
@@ -332,8 +370,17 @@ export function ChannelForm({ channel, onSaved, onCancel }: ChannelFormProps): R
             value={baseUrl}
             onChange={setBaseUrl}
             placeholder="https://api.example.com"
-            description={baseUrl.trim() ? `预览：${buildPreviewUrl(baseUrl, provider)}` : undefined}
+            description={baseUrl.trim() ? `预览：${buildPreviewUrl(baseUrl, provider, apiFormat)}` : undefined}
           />
+          {(provider === 'openai' || provider === 'custom') && (
+            <SettingsSelect
+              label="API 格式"
+              description="仅对 OpenAI / 自定义渠道开放，第三方兼容服务可能不支持"
+              value={apiFormat}
+              onValueChange={(v) => setApiFormat(v as ChannelApiFormat)}
+              options={OPENAI_API_FORMAT_OPTIONS}
+            />
+          )}
           {/* API Key + 测试连接同行 */}
           <div className="px-4 py-3 space-y-2">
             <div className="flex items-center justify-between">
diff --git a/bun.lock b/bun.lock
index 8eef0a6..1fa0335 100644
--- a/bun.lock
+++ b/bun.lock
@@ -1,5 +1,6 @@
 {
   "lockfileVersion": 1,
+  "configVersion": 0,
   "workspaces": {
     "": {
       "name": "proma",
diff --git a/packages/core/src/providers/index.ts b/packages/core/src/providers/index.ts
index 8c6e1d1..3860511 100644
--- a/packages/core/src/providers/index.ts
+++ b/packages/core/src/providers/index.ts
@@ -15,6 +15,7 @@ import { GoogleAdapter } from './google-adapter.ts'
 export * from './types.ts'
 export * from './sse-reader.ts'
 export * from './url-utils.ts'
+export * from './openai-compat.ts'
 
 // 导出适配器类
 export { AnthropicAdapter } from './anthropic-adapter.ts'
diff --git a/packages/core/src/providers/openai-adapter.responses.test.ts b/packages/core/src/providers/openai-adapter.responses.test.ts
new file mode 100644
index 0000000..af8a500
--- /dev/null
+++ b/packages/core/src/providers/openai-adapter.responses.test.ts
@@ -0,0 +1,190 @@
+import { describe, expect, test } from 'bun:test'
+import type { ChatMessage, FileAttachment } from '@proma/shared'
+import type { ImageAttachmentData, StreamRequestInput, ToolDefinition } from './types.ts'
+import { OpenAIAdapter } from './openai-adapter.ts'
+
+function makeHistory(): ChatMessage[] {
+  const now = Date.now()
+  return [
+    { id: 'u1', role: 'user', content: '你好', createdAt: now - 2_000 },
+    { id: 'a1', role: 'assistant', content: '你好，有什么可以帮你？', createdAt: now - 1_000 },
+  ]
+}
+
+function makeImageAttachment(): FileAttachment {
+  return {
+    id: 'att_1',
+    filename: 'a.png',
+    mediaType: 'image/png',
+    localPath: 'c/att.png',
+    size: 123,
+  }
+}
+
+const readImageAttachments = (attachments?: FileAttachment[]): ImageAttachmentData[] => {
+  if (!attachments || attachments.length === 0) return []
+  return attachments.map((att) => ({
+    mediaType: att.mediaType,
+    data: 'AAAA',
+  }))
+}
+
+describe('OpenAIAdapter (Responses API)', () => {
+  test('Given apiFormat=responses When buildStreamRequest Then uses /responses', () => {
+    const adapter = new OpenAIAdapter()
+    const input: StreamRequestInput = {
+      baseUrl: 'https://api.openai.com/v1',
+      apiKey: 'k',
+      modelId: 'gpt-5',
+      apiFormat: 'responses',
+      history: makeHistory(),
+      userMessage: '请总结一下',
+      readImageAttachments,
+    }
+
+    const req = adapter.buildStreamRequest(input)
+    expect(req.url.endsWith('/responses')).toBe(true)
+  })
+
+  test('Given systemMessage When buildStreamRequest Then sets instructions', () => {
+    const adapter = new OpenAIAdapter()
+    const input: StreamRequestInput = {
+      baseUrl: 'https://api.openai.com/v1',
+      apiKey: 'k',
+      modelId: 'gpt-5',
+      apiFormat: 'responses',
+      history: makeHistory(),
+      userMessage: '请总结一下',
+      systemMessage: '你是一个严谨的助手',
+      readImageAttachments,
+    }
+
+    const req = adapter.buildStreamRequest(input)
+    const body = JSON.parse(req.body) as Record<string, unknown>
+    expect(body.instructions).toBe('你是一个严谨的助手')
+  })
+
+  test('Given tools When buildStreamRequest Then tools are flat (no function nesting)', () => {
+    const adapter = new OpenAIAdapter()
+    const tools: ToolDefinition[] = [
+      {
+        name: 'get_weather',
+        description: 'Get weather by city',
+        parameters: {
+          type: 'object',
+          properties: {
+            city: { type: 'string', description: 'City name' },
+          },
+          required: ['city'],
+        },
+      },
+    ]
+
+    const input: StreamRequestInput = {
+      baseUrl: 'https://api.openai.com/v1',
+      apiKey: 'k',
+      modelId: 'gpt-5',
+      apiFormat: 'responses',
+      history: makeHistory(),
+      userMessage: '上海天气？',
+      tools,
+      readImageAttachments,
+    }
+
+    const req = adapter.buildStreamRequest(input)
+    const body = JSON.parse(req.body) as Record<string, unknown>
+    const bodyTools = body.tools as Array<Record<string, unknown>>
+    expect(bodyTools[0]?.type).toBe('function')
+    expect(bodyTools[0]?.name).toBe('get_weather')
+    expect(bodyTools[0]?.description).toBe('Get weather by city')
+    expect(bodyTools[0]?.parameters).toBeTruthy()
+    expect((bodyTools[0] as Record<string, unknown>).function).toBeUndefined()
+  })
+
+  test('Given current message has image When buildStreamRequest Then includes input_image with data URL', () => {
+    const adapter = new OpenAIAdapter()
+    const attachments = [makeImageAttachment()]
+    const input: StreamRequestInput = {
+      baseUrl: 'https://api.openai.com/v1',
+      apiKey: 'k',
+      modelId: 'gpt-5',
+      apiFormat: 'responses',
+      history: makeHistory(),
+      userMessage: '这张图里是什么？',
+      attachments,
+      readImageAttachments,
+    }
+
+    const req = adapter.buildStreamRequest(input)
+    const body = JSON.parse(req.body) as Record<string, unknown>
+    const inputArr = body.input as Array<Record<string, unknown>>
+    const first = inputArr[0] as Record<string, unknown>
+    const content = first.content as Array<Record<string, unknown>>
+
+    const imageItem = content.find((c) => c.type === 'input_image')
+    expect(imageItem).toBeTruthy()
+    expect(typeof imageItem?.image_url).toBe('string')
+    expect((imageItem?.image_url as string).startsWith('data:image/png;base64,')).toBe(true)
+  })
+
+  test('Given response.output_text.delta When parseSSELine Then returns chunk', () => {
+    const adapter = new OpenAIAdapter()
+    const events = adapter.parseSSELine(JSON.stringify({ type: 'response.output_text.delta', delta: 'hi' }))
+    expect(events).toEqual([{ type: 'chunk', delta: 'hi' }])
+  })
+
+  test('Given response.output_item.added function_call When parseSSELine Then returns tool_call_start', () => {
+    const adapter = new OpenAIAdapter()
+    const events = adapter.parseSSELine(JSON.stringify({
+      type: 'response.output_item.added',
+      item: { type: 'function_call', call_id: 'call_1', name: 'my_tool' },
+    }))
+    expect(events).toEqual([{ type: 'tool_call_start', toolCallId: 'call_1', toolName: 'my_tool' }])
+  })
+
+  test('Given response.output_item.added with response_id When parseSSELine Then returns meta + tool_call_start', () => {
+    const adapter = new OpenAIAdapter()
+    const events = adapter.parseSSELine(JSON.stringify({
+      type: 'response.output_item.added',
+      response_id: 'resp_1',
+      item: { type: 'function_call', call_id: 'call_1', name: 'my_tool' },
+    }))
+    expect(events).toEqual([
+      { type: 'meta', responseId: 'resp_1' },
+      { type: 'tool_call_start', toolCallId: 'call_1', toolName: 'my_tool' },
+    ])
+  })
+
+  test('Given response.function_call_arguments.delta When parseSSELine Then returns tool_call_delta', () => {
+    const adapter = new OpenAIAdapter()
+    const events = adapter.parseSSELine(JSON.stringify({
+      type: 'response.function_call_arguments.delta',
+      call_id: 'call_1',
+      delta: '{"q":"x"}',
+    }))
+    expect(events).toEqual([{ type: 'tool_call_delta', toolCallId: 'call_1', argumentsDelta: '{"q":"x"}' }])
+  })
+
+  test('Given response.function_call_arguments.delta with response_id When parseSSELine Then returns meta + tool_call_delta', () => {
+    const adapter = new OpenAIAdapter()
+    const events = adapter.parseSSELine(JSON.stringify({
+      type: 'response.function_call_arguments.delta',
+      response_id: 'resp_1',
+      call_id: 'call_1',
+      delta: '{"q":"x"}',
+    }))
+    expect(events).toEqual([
+      { type: 'meta', responseId: 'resp_1' },
+      { type: 'tool_call_delta', toolCallId: 'call_1', argumentsDelta: '{"q":"x"}' },
+    ])
+  })
+
+  test('Given response.created When parseSSELine Then returns meta(responseId)', () => {
+    const adapter = new OpenAIAdapter()
+    const events = adapter.parseSSELine(JSON.stringify({
+      type: 'response.created',
+      response: { id: 'resp_1' },
+    }))
+    expect(events).toEqual([{ type: 'meta', responseId: 'resp_1' }])
+  })
+})
diff --git a/packages/core/src/providers/openai-adapter.ts b/packages/core/src/providers/openai-adapter.ts
index 0bc0157..71f6207 100644
--- a/packages/core/src/providers/openai-adapter.ts
+++ b/packages/core/src/providers/openai-adapter.ts
@@ -1,7 +1,7 @@
 /**
  * OpenAI 兼容供应商适配器
  *
- * 实现 OpenAI Chat Completions API 的消息转换、请求构建和 SSE 解析。
+ * 实现 OpenAI Chat Completions 与 Responses API 的消息转换、请求构建和 SSE 解析。
  * 同时适用于 OpenAI、DeepSeek 和自定义 OpenAI 兼容 API。
  * 特点：
  * - 角色：system / user / assistant / tool
@@ -10,6 +10,7 @@
  * - 认证：Authorization: Bearer
  */
 
+import type { ChatMessage } from '@proma/shared'
 import type {
   ProviderAdapter,
   ProviderRequest,
@@ -67,6 +68,35 @@ interface OpenAITitleResponse {
   choices?: Array<{ message?: { content?: string } }>
 }
 
+// ===== Responses API 相关类型（最小子集） =====
+
+/** Responses SSE 数据块（最小字段集，按需扩展） */
+interface OpenAIResponsesChunkData {
+  type?: string
+  delta?: string
+  id?: string
+  response_id?: string
+  response?: { id?: string }
+  output_index?: number
+  call_id?: string
+  item?: {
+    type?: string
+    id?: string
+    call_id?: string
+    name?: string
+    arguments?: string
+  }
+}
+
+/** Responses 标题响应（最小字段集） */
+interface OpenAIResponsesTitleResponse {
+  output_text?: string
+  output?: Array<{
+    type?: string
+    content?: Array<{ type?: string; text?: string }>
+  }>
+}
+
 // ===== 消息转换 =====
 
 /**
@@ -135,6 +165,26 @@ function toOpenAIMessages(input: StreamRequestInput): OpenAIMessage[] {
   return messages
 }
 
+/**
+ * 将历史消息 + 当前用户消息拼接为转录文本（用于 Responses API）
+ *
+ * 注意：Responses 的 message input item role 不包含 assistant，
+ * 这里通过单条 user message 的 input_text 承载历史上下文。
+ */
+function toTranscriptText(history: ChatMessage[], userMessage: string): string {
+  const lines: string[] = []
+  for (const msg of history) {
+    if (msg.role === 'system') continue
+    if (msg.role === 'user') {
+      lines.push(`User: ${msg.content}`)
+    } else if (msg.role === 'assistant') {
+      lines.push(`Assistant: ${msg.content}`)
+    }
+  }
+  lines.push(`User: ${userMessage}`)
+  return lines.join('\n\n')
+}
+
 /**
  * 将工具定义转换为 OpenAI 格式
  */
@@ -149,6 +199,53 @@ function toOpenAITools(tools: ToolDefinition[]): Array<Record<string, unknown>>
   }))
 }
 
+/**
+ * 将工具定义转换为 OpenAI Responses API 格式（扁平 function tool）
+ *
+ * 参考：/responses/create 中 tools 示例为 { type:'function', name, description, parameters, strict }。
+ */
+function toOpenAIResponsesTools(tools: ToolDefinition[]): Array<Record<string, unknown>> {
+  return tools.map((tool) => ({
+    type: 'function',
+    name: tool.name,
+    description: tool.description,
+    parameters: tool.parameters,
+  }))
+}
+
+/**
+ * 从 continuationMessages 中提取最近一次的工具结果（避免重复发送历史 tool outputs）
+ */
+function getLatestToolResults(
+  continuationMessages: ContinuationMessage[] | undefined,
+): Array<{ toolCallId: string; content: string; isError?: boolean }> | null {
+  if (!continuationMessages || continuationMessages.length === 0) return null
+  for (let i = continuationMessages.length - 1; i >= 0; i--) {
+    const msg = continuationMessages[i]!
+    if (msg.role === 'tool') {
+      return msg.results
+    }
+  }
+  return null
+}
+
+/**
+ * 构建 Responses API 的 input message content 列表（input_text + input_image）
+ */
+function buildResponsesMessageContent(
+  text: string,
+  imageData: ImageAttachmentData[],
+): Array<Record<string, unknown>> {
+  const content: Array<Record<string, unknown>> = [{ type: 'input_text', text }]
+  for (const img of imageData) {
+    content.push({
+      type: 'input_image',
+      image_url: `data:${img.mediaType};base64,${img.data}`,
+    })
+  }
+  return content
+}
+
 /**
  * 将续接消息追加到 OpenAI 消息列表
  */
@@ -186,6 +283,60 @@ export class OpenAIAdapter implements ProviderAdapter {
 
   buildStreamRequest(input: StreamRequestInput): ProviderRequest {
     const url = normalizeBaseUrl(input.baseUrl)
+
+    // ===== Responses API =====
+    if (input.apiFormat === 'responses') {
+      const latestToolResults = getLatestToolResults(input.continuationMessages)
+
+      const bodyObj: Record<string, unknown> = {
+        model: input.modelId,
+        stream: true,
+      }
+
+      // systemMessage 映射到 instructions（保持每轮一致，避免依赖服务端链式继承）
+      if (input.systemMessage) {
+        bodyObj.instructions = input.systemMessage
+      }
+
+      // 工具定义（Responses: 扁平 function tool）
+      if (input.tools && input.tools.length > 0) {
+        bodyObj.tools = toOpenAIResponsesTools(input.tools)
+      }
+
+      // tool loop：仅发送最近一次 tool outputs，并通过 previous_response_id 续接
+      if (latestToolResults && latestToolResults.length > 0) {
+        if (input.previousResponseId) {
+          bodyObj.previous_response_id = input.previousResponseId
+        }
+        bodyObj.input = latestToolResults.map((tr) => ({
+          type: 'function_call_output',
+          call_id: tr.toolCallId,
+          output: tr.content,
+        }))
+      } else {
+        // 首轮：发送转录文本 + 当前消息图片（仅当前轮图片附件）
+        const transcript = toTranscriptText(input.history, input.userMessage)
+        const currentImages = input.readImageAttachments(input.attachments)
+        bodyObj.input = [
+          {
+            type: 'message',
+            role: 'user',
+            content: buildResponsesMessageContent(transcript, currentImages),
+          },
+        ]
+      }
+
+      return {
+        url: `${url}/responses`,
+        headers: {
+          Authorization: `Bearer ${input.apiKey}`,
+          'content-type': 'application/json',
+        },
+        body: JSON.stringify(bodyObj),
+      }
+    }
+
+    // ===== Chat Completions（兼容） =====
     const messages = toOpenAIMessages(input)
 
     const bodyObj: Record<string, unknown> = {
@@ -216,7 +367,78 @@ export class OpenAIAdapter implements ProviderAdapter {
 
   parseSSELine(jsonLine: string): StreamEvent[] {
     try {
-      const chunk = JSON.parse(jsonLine) as OpenAIChunkData
+      const parsed = JSON.parse(jsonLine) as OpenAIChunkData & OpenAIResponsesChunkData
+      const eventType = typeof parsed.type === 'string' ? parsed.type : null
+
+      // ===== Responses SSE 事件 =====
+      if (eventType && eventType.startsWith('response.')) {
+        const maybeResponseId =
+          parsed.response?.id
+          || parsed.response_id
+          || parsed.id
+        const events: StreamEvent[] = []
+
+        if (eventType === 'response.created') {
+          const responseId =
+            parsed.response?.id
+            || parsed.response_id
+            || parsed.id
+          if (responseId) {
+            events.push({ type: 'meta', responseId })
+          }
+          return events
+        }
+
+        if (eventType === 'response.output_text.delta' && parsed.delta) {
+          events.push({ type: 'chunk', delta: parsed.delta })
+          return events
+        }
+
+        if (eventType === 'response.output_item.added' && parsed.item?.type === 'function_call') {
+          const toolCallId = parsed.item.call_id || parsed.item.id || `tc_${String(parsed.output_index ?? 0)}`
+          const toolName = parsed.item.name || 'unknown_tool'
+
+          // 兼容实现：有些服务可能不发 response.created，而是在其它事件里携带 response_id
+          if (maybeResponseId) {
+            events.push({ type: 'meta', responseId: maybeResponseId })
+          }
+
+          events.push({
+            type: 'tool_call_start',
+            toolCallId,
+            toolName,
+          })
+
+          // 某些实现可能在 added 事件中直接携带完整 arguments
+          if (parsed.item.arguments) {
+            events.push({
+              type: 'tool_call_delta',
+              toolCallId,
+              argumentsDelta: parsed.item.arguments,
+            })
+          }
+
+          return events
+        }
+
+        if (eventType === 'response.function_call_arguments.delta' && parsed.delta) {
+          // 兼容实现：有些服务可能不发 response.created，而是在其它事件里携带 response_id
+          if (maybeResponseId) {
+            events.push({ type: 'meta', responseId: maybeResponseId })
+          }
+          events.push({
+            type: 'tool_call_delta',
+            toolCallId: parsed.call_id || parsed.item?.call_id || '',
+            argumentsDelta: parsed.delta,
+          })
+          return events
+        }
+
+        return []
+      }
+
+      // ===== Chat Completions SSE 数据 =====
+      const chunk = parsed as OpenAIChunkData
       const delta = chunk.choices?.[0]?.delta
       const events: StreamEvent[] = []
 
@@ -266,6 +488,22 @@ export class OpenAIAdapter implements ProviderAdapter {
   buildTitleRequest(input: TitleRequestInput): ProviderRequest {
     const url = normalizeBaseUrl(input.baseUrl)
 
+    // Responses API：非流式生成标题
+    if (input.apiFormat === 'responses') {
+      return {
+        url: `${url}/responses`,
+        headers: {
+          Authorization: `Bearer ${input.apiKey}`,
+          'content-type': 'application/json',
+        },
+        body: JSON.stringify({
+          model: input.modelId,
+          input: input.prompt,
+          max_output_tokens: 60,
+        }),
+      }
+    }
+
     return {
       url: `${url}/chat/completions`,
       headers: {
@@ -281,6 +519,20 @@ export class OpenAIAdapter implements ProviderAdapter {
   }
 
   parseTitleResponse(responseBody: unknown): string | null {
+    const maybeResponses = responseBody as OpenAIResponsesTitleResponse
+    if (typeof maybeResponses.output_text === 'string') {
+      return maybeResponses.output_text
+    }
+
+    // fallback：从 output message 中提取第一段 output_text
+    const firstText = maybeResponses.output
+      ?.find((it) => it.type === 'message')
+      ?.content?.find((c) => c.type === 'output_text')
+      ?.text
+    if (typeof firstText === 'string') {
+      return firstText
+    }
+
     const data = responseBody as OpenAITitleResponse
     return data.choices?.[0]?.message?.content ?? null
   }
diff --git a/packages/core/src/providers/openai-compat.test.ts b/packages/core/src/providers/openai-compat.test.ts
new file mode 100644
index 0000000..7749b40
--- /dev/null
+++ b/packages/core/src/providers/openai-compat.test.ts
@@ -0,0 +1,77 @@
+import { describe, expect, test } from 'bun:test'
+import { probeOpenAICompatibleModelsBaseUrl } from './openai-compat.ts'
+
+function makeFetch(map: Record<string, number | 'throw'>): typeof fetch {
+  return (async (input: RequestInfo | URL) => {
+    const url = typeof input === 'string' ? input : input.toString()
+    const hit = map[url]
+    if (hit === 'throw') {
+      throw new Error('network error')
+    }
+    const status = typeof hit === 'number' ? hit : 404
+    const body = status === 200 ? '{"data":[]}' : `status ${status}`
+    return new Response(body, { status })
+  }) as unknown as typeof fetch
+}
+
+describe('probeOpenAICompatibleModelsBaseUrl', () => {
+  test('Given /models ok and /v1/models 404 When probe Then chooses non-v1 baseUrl', async () => {
+    const baseUrl = 'https://api.example.com'
+    const fetchFn = makeFetch({
+      'https://api.example.com/models': 200,
+      'https://api.example.com/v1/models': 404,
+    })
+
+    const result = await probeOpenAICompatibleModelsBaseUrl({ baseUrl, apiKey: 'k', fetchFn })
+    expect(result.resolvedBaseUrl).toBe('https://api.example.com')
+    expect(result.best.ok).toBe(true)
+  })
+
+  test('Given /models 404 and /v1/models ok When probe Then chooses /v1 baseUrl', async () => {
+    const baseUrl = 'https://api.example.com'
+    const fetchFn = makeFetch({
+      'https://api.example.com/models': 404,
+      'https://api.example.com/v1/models': 200,
+    })
+
+    const result = await probeOpenAICompatibleModelsBaseUrl({ baseUrl, apiKey: 'k', fetchFn })
+    expect(result.resolvedBaseUrl).toBe('https://api.example.com/v1')
+    expect(result.best.ok).toBe(true)
+  })
+
+  test('Given both endpoints 401 When probe Then prefers /v1 baseUrl', async () => {
+    const baseUrl = 'https://api.example.com'
+    const fetchFn = makeFetch({
+      'https://api.example.com/models': 401,
+      'https://api.example.com/v1/models': 401,
+    })
+
+    const result = await probeOpenAICompatibleModelsBaseUrl({ baseUrl, apiKey: 'bad', fetchFn })
+    expect(result.resolvedBaseUrl).toBe('https://api.example.com/v1')
+    expect(result.best.status).toBe(401)
+  })
+
+  test('Given both endpoints 403 When probe Then prefers /v1 baseUrl', async () => {
+    const baseUrl = 'https://api.example.com'
+    const fetchFn = makeFetch({
+      'https://api.example.com/models': 403,
+      'https://api.example.com/v1/models': 403,
+    })
+
+    const result = await probeOpenAICompatibleModelsBaseUrl({ baseUrl, apiKey: 'bad', fetchFn })
+    expect(result.resolvedBaseUrl).toBe('https://api.example.com/v1')
+    expect(result.best.status).toBe(403)
+  })
+
+  test('Given /models throws and /v1/models 404 When probe Then chooses /v1 baseUrl (less bad)', async () => {
+    const baseUrl = 'https://api.example.com'
+    const fetchFn = makeFetch({
+      'https://api.example.com/models': 'throw',
+      'https://api.example.com/v1/models': 404,
+    })
+
+    const result = await probeOpenAICompatibleModelsBaseUrl({ baseUrl, apiKey: 'k', fetchFn })
+    expect(result.resolvedBaseUrl).toBe('https://api.example.com/v1')
+    expect(result.probes).toHaveLength(2)
+  })
+})
diff --git a/packages/core/src/providers/openai-compat.ts b/packages/core/src/providers/openai-compat.ts
new file mode 100644
index 0000000..aa2a4bd
--- /dev/null
+++ b/packages/core/src/providers/openai-compat.ts
@@ -0,0 +1,110 @@
+/**
+ * OpenAI 兼容服务探测工具
+ *
+ * 主要用于第三方 OpenAI 兼容服务的 Base URL 兼容性探测：
+ * - 有的服务以 https://host/v1 作为根路径（OpenAI 官方）
+ * - 有的服务以 https://host 作为根路径（不带 /v1）
+ *
+ * 这里提供一个轻量探测：并发请求 /models 与 /v1/models，通过结果选择更合适的 Base URL。
+ * 仅用于“连接测试/辅助回填”，不影响实际请求构建逻辑。
+ */
+
+import { normalizeBaseUrl, normalizeOpenAIBaseUrl } from './url-utils.ts'
+
+/** /models 探测结果（最小字段集） */
+export interface OpenAIModelsProbe {
+  baseUrl: string
+  ok: boolean
+  status: number
+  bodyPreview?: string
+  error?: string
+}
+
+/** 探测汇总结果 */
+export interface OpenAIModelsProbeResult {
+  /** 探测到的候选 baseUrl（去重后） */
+  probes: OpenAIModelsProbe[]
+  /** 最优探测结果 */
+  best: OpenAIModelsProbe
+  /** 推荐使用的 baseUrl */
+  resolvedBaseUrl: string
+}
+
+export function scoreOpenAIModelsProbe(probe: OpenAIModelsProbe): number {
+  if (probe.ok) return 3
+  // 401/403：鉴权失败但 endpoint 存在，可用于判断 baseUrl 是否正确
+  if (probe.status === 401 || probe.status === 403) return 2
+  if (probe.status === 404) return 0
+  if (probe.status > 0) return 1
+  return -1
+}
+
+export function chooseBestOpenAIModelsProbe(
+  probes: OpenAIModelsProbe[],
+  preferBaseUrl?: string,
+): OpenAIModelsProbe {
+  if (probes.length === 0) {
+    throw new Error('No probes provided')
+  }
+
+  return probes.reduce((prev, cur) => {
+    const sPrev = scoreOpenAIModelsProbe(prev)
+    const sCur = scoreOpenAIModelsProbe(cur)
+    if (sCur !== sPrev) return sCur > sPrev ? cur : prev
+    if (preferBaseUrl && cur.baseUrl === preferBaseUrl && prev.baseUrl !== preferBaseUrl) return cur
+    return prev
+  })
+}
+
+async function probeOpenAIModels(
+  baseUrl: string,
+  apiKey: string,
+  fetchFn: typeof globalThis.fetch,
+): Promise<OpenAIModelsProbe> {
+  try {
+    const response = await fetchFn(`${baseUrl}/models`, {
+      method: 'GET',
+      headers: {
+        Authorization: `Bearer ${apiKey}`,
+      },
+    })
+
+    const bodyPreview = response.ok
+      ? undefined
+      : (await response.text().catch(() => '')).slice(0, 200)
+
+    return { baseUrl, ok: response.ok, status: response.status, bodyPreview }
+  } catch (error) {
+    const msg = error instanceof Error ? error.message : '未知错误'
+    return { baseUrl, ok: false, status: -1, error: msg }
+  }
+}
+
+/**
+ * 探测 OpenAI 兼容服务 Base URL（/models 与 /v1/models）
+ *
+ * @param baseUrl 用户输入的 Base URL（可能带/不带 /v1）
+ * @param apiKey API Key（用于鉴权，401 也能用来判断 endpoint 存在）
+ * @param fetchFn 可注入 fetch（默认使用全局 fetch）
+ */
+export async function probeOpenAICompatibleModelsBaseUrl(options: {
+  baseUrl: string
+  apiKey: string
+  fetchFn?: typeof globalThis.fetch
+}): Promise<OpenAIModelsProbeResult> {
+  const { baseUrl, apiKey, fetchFn = fetch } = options
+  const baseNoV1 = normalizeBaseUrl(baseUrl)
+  const baseV1 = normalizeOpenAIBaseUrl(baseUrl)
+
+  const candidates = Array.from(new Set([baseNoV1, baseV1]))
+  const probes = await Promise.all(candidates.map((b) => probeOpenAIModels(b, apiKey, fetchFn)))
+
+  // 同分时优先 /v1（baseV1）
+  const best = chooseBestOpenAIModelsProbe(probes, baseV1)
+
+  return {
+    probes,
+    best,
+    resolvedBaseUrl: best.baseUrl,
+  }
+}
diff --git a/packages/core/src/providers/sse-reader.responses.test.ts b/packages/core/src/providers/sse-reader.responses.test.ts
new file mode 100644
index 0000000..5f01c9f
--- /dev/null
+++ b/packages/core/src/providers/sse-reader.responses.test.ts
@@ -0,0 +1,96 @@
+import { describe, expect, test } from 'bun:test'
+import { streamSSE } from './sse-reader.ts'
+import { OpenAIAdapter } from './openai-adapter.ts'
+
+function makeSSEStream(chunks: string[]): ReadableStream<Uint8Array> {
+  const encoder = new TextEncoder()
+  return new ReadableStream<Uint8Array>({
+    start(controller) {
+      for (const chunk of chunks) {
+        controller.enqueue(encoder.encode(chunk))
+      }
+      controller.close()
+    },
+  })
+}
+
+describe('streamSSE (Responses API aggregation)', () => {
+  test('Given Responses SSE with responseId/content/toolCalls When streamSSE Then aggregates responseId/toolCalls/stopReason', async () => {
+    const adapter = new OpenAIAdapter()
+
+    const sseLines = [
+      `data: ${JSON.stringify({ type: 'response.created', response: { id: 'resp_123' } })}\n\n`,
+      `data: ${JSON.stringify({ type: 'response.output_text.delta', delta: 'Hello' })}\n`,
+      `data: ${JSON.stringify({ type: 'response.output_text.delta', delta: ' world' })}\n\n`,
+      `data: ${JSON.stringify({
+        type: 'response.output_item.added',
+        item: { type: 'function_call', call_id: 'call_1', name: 'my_tool' },
+      })}\n`,
+      `data: ${JSON.stringify({
+        type: 'response.function_call_arguments.delta',
+        call_id: 'call_1',
+        delta: '{"q":"x"}',
+      })}\n\n`,
+      `data: [DONE]\n\n`,
+    ]
+
+    const response = new Response(makeSSEStream([sseLines.join('')]), { status: 200 })
+    const fetchFn: typeof fetch = async (_input, _init) => response
+
+    const events: Array<{ type: string }> = []
+    const result = await streamSSE({
+      request: { url: 'https://example.com/responses', headers: {}, body: '{}' },
+      adapter,
+      fetchFn,
+      onEvent: (e) => events.push({ type: e.type }),
+    })
+
+    expect(result.responseId).toBe('resp_123')
+    expect(result.content).toBe('Hello world')
+    expect(result.toolCalls).toHaveLength(1)
+    expect(result.toolCalls[0]?.id).toBe('call_1')
+    expect(result.toolCalls[0]?.name).toBe('my_tool')
+    expect(result.toolCalls[0]?.arguments).toEqual({ q: 'x' })
+    expect(result.stopReason).toBe('tool_use')
+
+    // 保底：done 事件必然触发（无论服务端是否显式给出 stopReason）
+    expect(events.some((e) => e.type === 'done')).toBe(true)
+  })
+
+  test('Given adapter emits done When streamSSE Then forwards done only once', async () => {
+    const adapter = new OpenAIAdapter()
+
+    // Chat Completions：finish_reason=tool_calls 会被 adapter 解析为 done(tool_use)
+    const sseLines = [
+      `data: ${JSON.stringify({
+        choices: [
+          {
+            delta: {
+              tool_calls: [
+                { index: 0, id: 'call_1', function: { name: 'my_tool', arguments: '{"q":"x"}' } },
+              ],
+            },
+            finish_reason: 'tool_calls',
+          },
+        ],
+      })}\n\n`,
+      `data: [DONE]\n\n`,
+    ]
+
+    const response = new Response(makeSSEStream([sseLines.join('')]), { status: 200 })
+    const fetchFn: typeof fetch = async (_input, _init) => response
+
+    const events: Array<{ type: string }> = []
+    const result = await streamSSE({
+      request: { url: 'https://example.com/chat/completions', headers: {}, body: '{}' },
+      adapter,
+      fetchFn,
+      onEvent: (e) => events.push({ type: e.type }),
+    })
+
+    const doneCount = events.filter((e) => e.type === 'done').length
+    expect(doneCount).toBe(1)
+    expect(result.stopReason).toBe('tool_use')
+    expect(result.toolCalls[0]?.id).toBe('call_1')
+  })
+})
diff --git a/packages/core/src/providers/sse-reader.ts b/packages/core/src/providers/sse-reader.ts
index 0bbb7ac..4c9cf8f 100644
--- a/packages/core/src/providers/sse-reader.ts
+++ b/packages/core/src/providers/sse-reader.ts
@@ -38,6 +38,8 @@ export interface StreamSSEResult {
   toolCalls: ToolCall[]
   /** 停止原因（'tool_use' 表示需要执行工具后继续） */
   stopReason?: string
+  /** Responses API 的 response.id（如有） */
+  responseId?: string
 }
 
 /**
@@ -77,6 +79,7 @@ export async function streamSSE(options: StreamSSEOptions): Promise<StreamSSERes
   let content = ''
   let reasoning = ''
   let stopReason: string | undefined
+  let responseId: string | undefined
   const reader = response.body.getReader()
   const decoder = new TextDecoder()
   let buffer = ''
@@ -105,6 +108,16 @@ export async function streamSSE(options: StreamSSEOptions): Promise<StreamSSERes
         const events = adapter.parseSSELine(data)
 
         for (const event of events) {
+          // 适配器可能会发出 done（例如 Chat Completions 的 tool_calls finish_reason）。
+          // 为避免上层收到重复 done，这里只记录 stopReason，不直接转发 done，
+          // 最终由 streamSSE 在函数末尾统一发出一次 done。
+          if (event.type === 'done') {
+            if (event.stopReason) {
+              stopReason = event.stopReason
+            }
+            continue
+          }
+
           if (event.type === 'chunk') {
             content += event.delta
           } else if (event.type === 'reasoning') {
@@ -117,6 +130,8 @@ export async function streamSSE(options: StreamSSEOptions): Promise<StreamSSERes
               args: '',
               metadata: event.metadata,
             })
+          } else if (event.type === 'meta' && event.responseId) {
+            responseId = event.responseId
           } else if (event.type === 'tool_call_delta') {
             const tcId = event.toolCallId || currentToolCallId
             if (tcId) {
@@ -125,8 +140,6 @@ export async function streamSSE(options: StreamSSEOptions): Promise<StreamSSERes
                 pending.args += event.argumentsDelta
               }
             }
-          } else if (event.type === 'done' && event.stopReason) {
-            stopReason = event.stopReason
           }
           onEvent(event)
         }
@@ -163,7 +176,7 @@ export async function streamSSE(options: StreamSSEOptions): Promise<StreamSSERes
   }
 
   onEvent({ type: 'done', stopReason })
-  return { content, reasoning, toolCalls, stopReason }
+  return { content, reasoning, toolCalls, stopReason, responseId }
 }
 
 // ===== 非流式标题请求 =====
diff --git a/packages/core/src/providers/types.ts b/packages/core/src/providers/types.ts
index 2354077..bd591ce 100644
--- a/packages/core/src/providers/types.ts
+++ b/packages/core/src/providers/types.ts
@@ -6,7 +6,7 @@
  * core 层不依赖 Electron / Node fs，通过注入函数访问平台能力。
  */
 
-import type { ChatMessage, FileAttachment, ProviderType } from '@proma/shared'
+import type { ChatMessage, ChannelApiFormat, FileAttachment, ProviderType } from '@proma/shared'
 
 // ===== 图片附件数据 =====
 
@@ -107,6 +107,12 @@ export interface StreamDoneEvent {
   stopReason?: 'end_turn' | 'tool_use' | string
 }
 
+/** 元信息事件（如 Responses API 的 response.id） */
+export interface StreamMetaEvent {
+  type: 'meta'
+  responseId?: string
+}
+
 /** 工具调用开始事件 */
 export interface StreamToolCallStartEvent {
   type: 'tool_call_start'
@@ -129,6 +135,7 @@ export type StreamEvent =
   | StreamReasoningEvent
   | StreamErrorEvent
   | StreamDoneEvent
+  | StreamMetaEvent
   | StreamToolCallStartEvent
   | StreamToolCallDeltaEvent
 
@@ -157,6 +164,14 @@ export interface StreamRequestInput {
   apiKey: string
   /** 模型 ID */
   modelId: string
+  /** API 格式（OpenAI 兼容供应商可选，缺省为 chat_completions） */
+  apiFormat?: ChannelApiFormat
+  /**
+   * 上一轮 Responses 的 response.id（仅用于 tool loop 续接）
+   *
+   * 对于 Chat Completions 会被忽略。
+   */
+  previousResponseId?: string
   /** 经过裁剪的历史消息（不含当前用户消息） */
   history: ChatMessage[]
   /** 当前用户消息文本 */
@@ -183,6 +198,8 @@ export interface TitleRequestInput {
   apiKey: string
   /** 模型 ID */
   modelId: string
+  /** API 格式（OpenAI 兼容供应商可选，缺省为 chat_completions） */
+  apiFormat?: ChannelApiFormat
   /** 标题生成 prompt（已包含用户消息） */
   prompt: string
 }
diff --git a/packages/core/src/providers/url-utils.test.ts b/packages/core/src/providers/url-utils.test.ts
new file mode 100644
index 0000000..e1ce0bc
--- /dev/null
+++ b/packages/core/src/providers/url-utils.test.ts
@@ -0,0 +1,19 @@
+import { describe, expect, test } from 'bun:test'
+import { normalizeOpenAIBaseUrl } from './url-utils.ts'
+
+describe('normalizeOpenAIBaseUrl', () => {
+  test('Given baseUrl without version When normalize Then appends /v1', () => {
+    expect(normalizeOpenAIBaseUrl('https://api.openai.com')).toBe('https://api.openai.com/v1')
+  })
+
+  test('Given baseUrl already endsWith /v1 When normalize Then keeps /v1', () => {
+    expect(normalizeOpenAIBaseUrl('https://api.openai.com/v1')).toBe('https://api.openai.com/v1')
+  })
+
+  test('Given baseUrl endsWith endpoint suffix When normalize Then strips suffix and ensures version', () => {
+    expect(normalizeOpenAIBaseUrl('https://example.com/v1/chat/completions')).toBe('https://example.com/v1')
+    expect(normalizeOpenAIBaseUrl('https://example.com/v1/responses')).toBe('https://example.com/v1')
+    expect(normalizeOpenAIBaseUrl('https://example.com/v1/models')).toBe('https://example.com/v1')
+  })
+})
+
diff --git a/packages/core/src/providers/url-utils.ts b/packages/core/src/providers/url-utils.ts
index e32d690..b2150ea 100644
--- a/packages/core/src/providers/url-utils.ts
+++ b/packages/core/src/providers/url-utils.ts
@@ -56,3 +56,25 @@ export function normalizeAnthropicBaseUrlForSdk(baseUrl: string): string {
 export function normalizeBaseUrl(baseUrl: string): string {
   return baseUrl.trim().replace(/\/+$/, '')
 }
+
+/**
+ * 规范化 OpenAI Base URL
+ *
+ * OpenAI 官方 API 约定 Base URL 末尾包含版本号（通常为 /v1）。
+ * 这里在不改变用户输入语义的前提下做容错：
+ * - 去除尾部斜杠
+ * - 去除误填的终端路径（/chat/completions、/responses、/models）
+ * - 若末尾不含 /v{n}，则自动追加 /v1
+ */
+export function normalizeOpenAIBaseUrl(baseUrl: string): string {
+  let url = normalizeBaseUrl(baseUrl)
+  url = url
+    .replace(/\/chat\/completions$/, '')
+    .replace(/\/responses$/, '')
+    .replace(/\/models$/, '')
+
+  if (!url.match(/\/v\d+$/)) {
+    url = `${url}/v1`
+  }
+  return url
+}
diff --git a/packages/core/tsconfig.json b/packages/core/tsconfig.json
index 22d81b9..9ef6e06 100644
--- a/packages/core/tsconfig.json
+++ b/packages/core/tsconfig.json
@@ -11,5 +11,6 @@
     "noEmit": true,
     "types": []
   },
-  "include": ["src/**/*"]
+  "include": ["src/**/*"],
+  "exclude": ["src/**/*.test.ts", "src/**/*.spec.ts"]
 }
diff --git a/packages/shared/src/types/channel.ts b/packages/shared/src/types/channel.ts
index f522058..2319d06 100644
--- a/packages/shared/src/types/channel.ts
+++ b/packages/shared/src/types/channel.ts
@@ -20,6 +20,14 @@ export type ProviderType =
   | 'qwen'
   | 'custom'
 
+/**
+ * OpenAI 兼容供应商的 API 格式
+ *
+ * - chat_completions: 兼容 /chat/completions（默认）
+ * - responses: OpenAI /responses 格式（仅对 OpenAI / 自定义渠道开放）
+ */
+export type ChannelApiFormat = 'chat_completions' | 'responses'
+
 /**
  * 各供应商的默认 Base URL
  */
@@ -78,6 +86,8 @@ export interface Channel {
   provider: ProviderType
   /** API Base URL */
   baseUrl: string
+  /** OpenAI 兼容供应商的 API 格式（缺省为 chat_completions） */
+  apiFormat?: ChannelApiFormat
   /** 加密后的 API Key（base64 编码） */
   apiKey: string
   /** 可用模型列表 */
@@ -97,6 +107,8 @@ export interface ChannelCreateInput {
   name: string
   provider: ProviderType
   baseUrl: string
+  /** OpenAI 兼容供应商的 API 格式（可选，缺省为 chat_completions） */
+  apiFormat?: ChannelApiFormat
   /** 明文 API Key，主进程会加密后存储 */
   apiKey: string
   models: ChannelModel[]
@@ -110,6 +122,8 @@ export interface ChannelUpdateInput {
   name?: string
   provider?: ProviderType
   baseUrl?: string
+  /** OpenAI 兼容供应商的 API 格式（可选） */
+  apiFormat?: ChannelApiFormat
   /** 明文 API Key，为空字符串表示不更新 */
   apiKey?: string
   models?: ChannelModel[]
@@ -134,6 +148,13 @@ export interface ChannelTestResult {
   success: boolean
   /** 结果消息 */
   message: string
+  /**
+   * 探测/规范化后的 Base URL（可选）
+   *
+   * 主要用于 OpenAI 兼容服务的路径探测（例如自动判断是否需要 /v1）。
+   * 调用方可据此自动回填表单 Base URL，避免用户手动修正。
+   */
+  resolvedBaseUrl?: string
 }
 
 /**