fix(ai): normalize OpenAI stream edge cases and add inline think parsing control

src/crates/core/src/infrastructure/ai/client.rs

@@ -1365,7 +1365,12 @@ impl AIClient {
             let (tx, rx) = mpsc::unbounded_channel();
             let (tx_raw, rx_raw) = mpsc::unbounded_channel();
 
-            tokio::spawn(handle_openai_stream(response, tx, Some(tx_raw)));
+            tokio::spawn(handle_openai_stream(
+                response,
+                tx,
+                Some(tx_raw),
+                self.config.inline_think_in_text,
+            ));
 
             return Ok(StreamResponse {
                 stream: Box::pin(tokio_stream::wrappers::UnboundedReceiverStream::new(rx)),
@@ -2092,6 +2097,7 @@ mod tests {
             top_p: None,
             enable_thinking_process: false,
             support_preserved_thinking: false,
+            inline_think_in_text: false,
             custom_headers: None,
             custom_headers_mode: None,
             skip_ssl_verify: false,
@@ -2115,6 +2121,7 @@ mod tests {
             top_p: None,
             enable_thinking_process: false,
             support_preserved_thinking: false,
+            inline_think_in_text: false,
             custom_headers: None,
             custom_headers_mode: None,
             skip_ssl_verify: false,
@@ -2143,6 +2150,7 @@ mod tests {
             top_p: None,
             enable_thinking_process: false,
             support_preserved_thinking: false,
+            inline_think_in_text: false,
             custom_headers: None,
             custom_headers_mode: None,
             skip_ssl_verify: false,
@@ -2172,6 +2180,7 @@ mod tests {
             top_p: Some(0.8),
             enable_thinking_process: true,
             support_preserved_thinking: true,
+            inline_think_in_text: false,
             custom_headers: None,
             custom_headers_mode: None,
             skip_ssl_verify: false,
@@ -2250,6 +2259,7 @@ mod tests {
             top_p: None,
             enable_thinking_process: false,
             support_preserved_thinking: true,
+            inline_think_in_text: false,
             custom_headers: None,
             custom_headers_mode: None,
             skip_ssl_verify: false,

src/crates/core/src/service/config/types.rs

@@ -785,6 +785,11 @@ pub struct AIModelConfig {
     #[serde(default)]
     pub support_preserved_thinking: bool,
 
+    /// Whether to parse OpenAI-compatible text chunks containing `<think>...</think>` into
+    /// streaming reasoning content.
+    #[serde(default)]
+    pub inline_think_in_text: bool,
+
     /// Custom HTTP request headers.
     #[serde(default)]
     pub custom_headers: Option<std::collections::HashMap<String, String>>,
@@ -1196,6 +1201,7 @@ impl Default for AIModelConfig {
             metadata: None,
             enable_thinking_process: false,
             support_preserved_thinking: false,
+            inline_think_in_text: false,
             custom_headers: None,
             custom_headers_mode: None,
             skip_ssl_verify: false,

src/crates/core/src/util/types/config.rs

@@ -82,6 +82,7 @@ pub struct AIConfig {
     pub top_p: Option<f64>,
     pub enable_thinking_process: bool,
     pub support_preserved_thinking: bool,
+    pub inline_think_in_text: bool,
     pub custom_headers: Option<std::collections::HashMap<String, String>>,
     /// "replace" (default) or "merge" (defaults first, then custom)
     pub custom_headers_mode: Option<String>,
@@ -209,6 +210,7 @@ impl TryFrom<AIModelConfig> for AIConfig {
             top_p: other.top_p,
             enable_thinking_process: other.enable_thinking_process,
             support_preserved_thinking: other.support_preserved_thinking,
+            inline_think_in_text: other.inline_think_in_text,
             custom_headers: other.custom_headers,
             custom_headers_mode: other.custom_headers_mode,
             skip_ssl_verify: other.skip_ssl_verify,

src/web-ui/src/features/onboarding/components/steps/ModelConfigStep.tsx

@@ -156,6 +156,7 @@ export const ModelConfigStep: React.FC<ModelConfigStepProps> = ({ onSkipForNow }
       max_tokens: 8192,
       enable_thinking_process: false,
       support_preserved_thinking: false,
+      inline_think_in_text: false,
       skip_ssl_verify: skipSslVerify,
       custom_headers: Object.keys(customHeaders).length > 0 ? customHeaders : undefined,
       custom_headers_mode: Object.keys(customHeaders).length > 0 ? customHeadersMode : undefined,

src/web-ui/src/features/onboarding/services/OnboardingService.ts

@@ -206,6 +206,7 @@ class OnboardingServiceClass {
         max_tokens: 8192,
         category: 'general_chat',
         capabilities: ['text_chat', 'function_calling'],
+        inline_think_in_text: false,
         custom_request_body: modelConfig.customRequestBody || undefined,
         skip_ssl_verify: modelConfig.skipSslVerify || undefined,
         custom_headers: modelConfig.customHeaders || undefined,

src/web-ui/src/flow_chat/components/modern/ExploreGroupRenderer.tsx

@@ -30,6 +30,7 @@ export const ExploreGroupRenderer: React.FC<ExploreGroupRendererProps> = ({
   const { 
     exploreGroupStates, 
     onExploreGroupToggle, 
+    onExpandGroup,
     onCollapseGroup 
   } = useFlowChatContext();
 
@@ -40,6 +41,7 @@ export const ExploreGroupRenderer: React.FC<ExploreGroupRendererProps> = ({
     isGroupStreaming,
     isLastGroupInTurn
   } = data;
+  const wasStreamingRef = useRef(isGroupStreaming);
   const {
     cardRootRef,
     applyExpandedState,
@@ -53,8 +55,39 @@ export const ExploreGroupRenderer: React.FC<ExploreGroupRendererProps> = ({
     ),
   });
 
-  const isExpanded = exploreGroupStates?.get(groupId) ?? false;
+  const hasExplicitState = exploreGroupStates?.has(groupId) ?? false;
+  const explicitExpanded = exploreGroupStates?.get(groupId) ?? false;
+  const isExpanded = hasExplicitState ? explicitExpanded : isGroupStreaming;
   const isCollapsed = !isExpanded;
+  const allowManualToggle = !isGroupStreaming;
+
+  useEffect(() => {
+    if (isGroupStreaming && !hasExplicitState) {
+      applyExpandedState(false, true, () => {
+        onExpandGroup?.(groupId);
+      });
+      wasStreamingRef.current = true;
+      return;
+    }
+
+    if (wasStreamingRef.current && !isGroupStreaming && isExpanded) {
+      applyExpandedState(true, false, () => {
+        onCollapseGroup?.(groupId);
+      }, {
+        reason: 'auto',
+      });
+    }
+
+    wasStreamingRef.current = isGroupStreaming;
+  }, [
+    applyExpandedState,
+    groupId,
+    hasExplicitState,
+    isExpanded,
+    isGroupStreaming,
+    onCollapseGroup,
+    onExpandGroup,
+  ]);
 
   // Auto-scroll to bottom during streaming.
   useEffect(() => {
@@ -105,7 +138,7 @@ export const ExploreGroupRenderer: React.FC<ExploreGroupRendererProps> = ({
   // Build class list.
   const className = [
     'explore-region',
-    'explore-region--collapsible',
+    allowManualToggle ? 'explore-region--collapsible' : null,
     isCollapsed ? 'explore-region--collapsed' : 'explore-region--expanded',
     isGroupStreaming ? 'explore-region--streaming' : null,
   ].filter(Boolean).join(' ');
@@ -115,10 +148,12 @@ export const ExploreGroupRenderer: React.FC<ExploreGroupRendererProps> = ({
       data-tool-card-id={groupId}
       className={className}
     >
-      <div className="explore-region__header" onClick={handleToggle}>
-        <ChevronRight size={14} className="explore-region__icon" />
-        <span className="explore-region__summary">{displaySummary}</span>
-      </div>
+      {allowManualToggle && (
+        <div className="explore-region__header" onClick={handleToggle}>
+          <ChevronRight size={14} className="explore-region__icon" />
+          <span className="explore-region__summary">{displaySummary}</span>
+        </div>
+      )}
       <div className="explore-region__content-wrapper">
         <div className="explore-region__content-inner">
           <div ref={containerRef} className="explore-region__content">

src/web-ui/src/flow_chat/components/modern/FlowChatContext.tsx

@@ -37,6 +37,11 @@ export interface FlowChatContextValue {
    */
   onExploreGroupToggle?: (groupId: string) => void;
 
+  /**
+   * Expand the specified explore group.
+   */
+  onExpandGroup?: (groupId: string) => void;
+
   /**
    * Expand all explore groups within a turn.
    */

src/web-ui/src/flow_chat/components/modern/ModernFlowChatContainer.tsx

@@ -51,6 +51,7 @@ export const ModernFlowChatContainer: React.FC<ModernFlowChatContainerProps> = (
   const {
     exploreGroupStates,
     onExploreGroupToggle: handleExploreGroupToggle,
+    onExpandGroup: handleExpandGroup,
     onExpandAllInTurn: handleExpandAllInTurn,
     onCollapseGroup: handleCollapseGroup,
   } = useExploreGroupState(virtualItems);
@@ -89,6 +90,7 @@ export const ModernFlowChatContainer: React.FC<ModernFlowChatContainerProps> = (
     },
     exploreGroupStates,
     onExploreGroupToggle: handleExploreGroupToggle,
+    onExpandGroup: handleExpandGroup,
     onExpandAllInTurn: handleExpandAllInTurn,
     onCollapseGroup: handleCollapseGroup,
   }), [
@@ -102,6 +104,7 @@ export const ModernFlowChatContainer: React.FC<ModernFlowChatContainerProps> = (
     config,
     exploreGroupStates,
     handleExploreGroupToggle,
+    handleExpandGroup,
     handleExpandAllInTurn,
     handleCollapseGroup,
   ]);

src/web-ui/src/flow_chat/components/modern/useExploreGroupState.ts

@@ -14,6 +14,7 @@ interface UseExploreGroupStateResult {
    */
   exploreGroupStates: Map<string, boolean>;
   onExploreGroupToggle: (groupId: string) => void;
+  onExpandGroup: (groupId: string) => void;
   onExpandAllInTurn: (turnId: string) => void;
   onCollapseGroup: (groupId: string) => void;
 }
@@ -32,6 +33,17 @@ export function useExploreGroupState(
     });
   }, []);
 
+  const onExpandGroup = useCallback((groupId: string) => {
+    setExploreGroupStates(prev => {
+      if (prev.get(groupId) === true) {
+        return prev;
+      }
+      const next = new Map(prev);
+      next.set(groupId, true);
+      return next;
+    });
+  }, []);
+
   const onExpandAllInTurn = useCallback((turnId: string) => {
     const groupIds = virtualItems
       .filter((item): item is ExploreGroupVirtualItem => (
@@ -57,6 +69,7 @@ export function useExploreGroupState(
   return {
     exploreGroupStates,
     onExploreGroupToggle,
+    onExpandGroup,
     onExpandAllInTurn,
     onCollapseGroup,
   };

src/web-ui/src/infrastructure/config/components/AIModelConfig.tsx

@@ -407,6 +407,7 @@ const AIModelConfig: React.FC = () => {
       metadata: config.metadata || {},
       enable_thinking_process: config.enable_thinking_process ?? false,
       support_preserved_thinking: config.support_preserved_thinking ?? false,
+      inline_think_in_text: config.inline_think_in_text ?? false,
       reasoning_effort: config.reasoning_effort,
       custom_headers: config.custom_headers,
       custom_headers_mode: config.custom_headers_mode,
@@ -420,6 +421,7 @@ const AIModelConfig: React.FC = () => {
     base_url: config.base_url,
     api_key: config.api_key,
     model_name: config.model_name,
+    inline_think_in_text: config.inline_think_in_text ?? false,
     skip_ssl_verify: config.skip_ssl_verify ?? false,
     custom_headers_mode: config.custom_headers_mode || null,
     custom_headers: config.custom_headers || null,
@@ -527,7 +529,8 @@ const AIModelConfig: React.FC = () => {
       category: 'general_chat',
       capabilities: ['text_chat', 'function_calling'],
       recommended_for: [],
-      metadata: {}
+      metadata: {},
+      inline_think_in_text: false,
     });
     setSelectedModelDrafts(
       configuredProviderModels.length > 0
@@ -563,7 +566,8 @@ const AIModelConfig: React.FC = () => {
       category: 'general_chat',
       capabilities: ['text_chat'],
       recommended_for: [],
-      metadata: {}
+      metadata: {},
+      inline_think_in_text: false,
     });
     setSelectedModelDrafts([]);
     setShowAdvancedSettings(false);  
@@ -597,6 +601,7 @@ const AIModelConfig: React.FC = () => {
       metadata: config.metadata || {},
       enable_thinking_process: config.enable_thinking_process ?? false,
       support_preserved_thinking: config.support_preserved_thinking ?? false,
+      inline_think_in_text: config.inline_think_in_text ?? false,
       reasoning_effort: config.reasoning_effort,
       custom_headers: config.custom_headers,
       custom_headers_mode: config.custom_headers_mode,
@@ -605,6 +610,7 @@ const AIModelConfig: React.FC = () => {
     });
     setSelectedModelDrafts(createDraftsFromConfigs(configuredProviderModels));
     setShowAdvancedSettings(
+      !!config.inline_think_in_text ||
       !!config.skip_ssl_verify ||
       (!!config.custom_request_body && config.custom_request_body.trim() !== '') ||
       (!!config.custom_headers && Object.keys(config.custom_headers).length > 0)
@@ -628,7 +634,12 @@ const AIModelConfig: React.FC = () => {
 
     const hasCustomHeaders = !!config.custom_headers && Object.keys(config.custom_headers).length > 0;
     const hasCustomBody = !!config.custom_request_body && config.custom_request_body.trim() !== '';
-    setShowAdvancedSettings(hasCustomHeaders || hasCustomBody || !!config.skip_ssl_verify);
+    setShowAdvancedSettings(
+      hasCustomHeaders ||
+      hasCustomBody ||
+      !!config.skip_ssl_verify ||
+      !!config.inline_think_in_text
+    );
     setIsEditing(true);
   };
 
@@ -680,6 +691,7 @@ const AIModelConfig: React.FC = () => {
           metadata: editingConfig.metadata,
           enable_thinking_process: draft.enableThinking,
           support_preserved_thinking: editingConfig.support_preserved_thinking ?? false,
+          inline_think_in_text: editingConfig.inline_think_in_text ?? false,
           reasoning_effort: editingConfig.reasoning_effort,
           custom_headers: editingConfig.custom_headers,
           custom_headers_mode: editingConfig.custom_headers_mode,
@@ -1378,6 +1390,7 @@ const AIModelConfig: React.FC = () => {
                           ...prev,
                           provider,
                           request_url: resolveRequestUrl(prev?.base_url || '', provider, prev?.model_name || ''),
+                          inline_think_in_text: provider === 'openai' ? (prev?.inline_think_in_text ?? false) : false,
                           reasoning_effort: isResponsesProvider(provider) ? (prev?.reasoning_effort || 'medium') : undefined,
                         }));
                       }} placeholder={t('form.providerPlaceholder')} options={requestFormatOptions} size="small" />
@@ -1458,9 +1471,13 @@ const AIModelConfig: React.FC = () => {
 
             {showAdvancedSettings && (
               <>
-                {editingConfig.enable_thinking_process && (
-                  <ConfigPageRow label={t('thinking.preserve')} description={t('thinking.preserveHint')} align="center">
-                    <Switch checked={editingConfig.support_preserved_thinking ?? false} onChange={(e) => setEditingConfig(prev => ({ ...prev, support_preserved_thinking: e.target.checked }))} size="small" />
+                {editingConfig.provider === 'openai' && (
+                  <ConfigPageRow label={t('advancedSettings.inlineThinkInText.label')} description={t('advancedSettings.inlineThinkInText.hint')} align="center">
+                    <Switch
+                      checked={editingConfig.inline_think_in_text ?? false}
+                      onChange={(e) => setEditingConfig(prev => ({ ...prev, inline_think_in_text: e.target.checked }))}
+                      size="small"
+                    />
                   </ConfigPageRow>
                 )}
                 <ConfigPageRow label={t('advancedSettings.skipSslVerify.label')} align="center">

src/web-ui/src/infrastructure/config/schemas/ai-models.json

@@ -391,6 +391,20 @@
                     "title": "高级设置",
                     "icon": "cog",
                     "fields": [
+                      {
+                        "type": "switch",
+                        "dataType": "boolean",
+                        "key": "inline_think_in_text",
+                        "title": "解析文本中的 <think> 标签",
+                        "description": "将 OpenAI 兼容文本流中的 <think>...</think> 实时拆分为 reasoning 内容，默认关闭",
+                        "default": false,
+                        "conditional": {
+                          "when": "provider",
+                          "operator": "equals",
+                          "value": "openai",
+                          "show": true
+                        }
+                      },
                       {
                         "type": "number",
                         "dataType": "number",

src/web-ui/src/infrastructure/config/types/index.ts

@@ -130,6 +130,9 @@ export interface AIModelConfig {
 
   support_preserved_thinking?: boolean;
 
+  /** Parse `<think>...</think>` text chunks into streaming reasoning content. */
+  inline_think_in_text?: boolean;
+
   /** Reasoning effort for OpenAI Responses API ("low" | "medium" | "high" | "xhigh") */
   reasoning_effort?: string;
 }

src/web-ui/src/locales/en-US/settings/ai-model.json

@@ -255,6 +255,10 @@
   },
   "advancedSettings": {
     "title": "Advanced Settings",
+    "inlineThinkInText": {
+      "label": "Parse <think> Tags In Text",
+      "hint": "Split OpenAI-compatible text streams containing <think>...</think> into live reasoning content. Disabled by default."
+    },
     "skipSslVerify": {
       "label": "Skip SSL Certificate Verification",
       "warning": "Skipping SSL verification is a security risk, use only in test or internal network environments!"