fix(schemas): add ExtraContent field to ChatStreamResponseChoiceDelta

core/schemas/chatcompletions.go

@@ -1547,13 +1547,14 @@ type ChatStreamResponseChoice struct {
 
 // ChatStreamResponseChoiceDelta represents a delta in the stream response
 type ChatStreamResponseChoiceDelta struct {
-	Role             *string                        `json:"role,omitempty"`      // Only in the first chunk
-	Content          *string                        `json:"content,omitempty"`   // May be empty string or null
-	Refusal          *string                        `json:"refusal,omitempty"`   // Refusal content if any
-	Audio            *ChatAudioMessageAudio         `json:"audio,omitempty"`     // Audio data if any
-	Reasoning        *string                        `json:"reasoning,omitempty"` // May be empty string or null
+	Role             *string                        `json:"role,omitempty"`          // Only in the first chunk
+	Content          *string                        `json:"content,omitempty"`       // May be empty string or null
+	Refusal          *string                        `json:"refusal,omitempty"`       // Refusal content if any
+	Audio            *ChatAudioMessageAudio         `json:"audio,omitempty"`         // Audio data if any
+	Reasoning        *string                        `json:"reasoning,omitempty"`     // May be empty string or null
 	ReasoningDetails []ChatReasoningDetails         `json:"reasoning_details,omitempty"`
-	ToolCalls        []ChatAssistantMessageToolCall `json:"tool_calls,omitempty"` // If tool calls used (supports incremental updates)
+	ToolCalls        []ChatAssistantMessageToolCall `json:"tool_calls,omitempty"`    // If tool calls used (supports incremental updates)
+	ExtraContent     json.RawMessage                `json:"extra_content,omitempty"` // Provider-specific metadata (e.g. Gemini thought markers, thought_signature)
 }
 
 // UnmarshalJSON implements custom unmarshalling for ChatStreamResponseChoiceDelta.

core/schemas/utils.go

@@ -760,9 +760,44 @@ func DeepCopyChatMessage(original ChatMessage) ChatMessage {
 					copyName := *toolCall.Function.Name
 					copyToolCall.Function.Name = &copyName
 				}
+				if len(toolCall.ExtraContent) > 0 {
+					copyToolCall.ExtraContent = append(json.RawMessage(nil), toolCall.ExtraContent...)
+				}
 				copy.ChatAssistantMessage.ToolCalls[i] = copyToolCall
 			}
 		}
+
+		// Deep copy ReasoningDetails
+		if original.ChatAssistantMessage.ReasoningDetails != nil {
+			copy.ChatAssistantMessage.ReasoningDetails = make([]ChatReasoningDetails, len(original.ChatAssistantMessage.ReasoningDetails))
+			for i, rd := range original.ChatAssistantMessage.ReasoningDetails {
+				copyRD := ChatReasoningDetails{
+					Index: rd.Index,
+					Type:  rd.Type,
+				}
+				if rd.ID != nil {
+					copyID := *rd.ID
+					copyRD.ID = &copyID
+				}
+				if rd.Summary != nil {
+					copySummary := *rd.Summary
+					copyRD.Summary = &copySummary
+				}
+				if rd.Text != nil {
+					copyText := *rd.Text
+					copyRD.Text = &copyText
+				}
+				if rd.Signature != nil {
+					copySig := *rd.Signature
+					copyRD.Signature = &copySig
+				}
+				if rd.Data != nil {
+					copyData := *rd.Data
+					copyRD.Data = &copyData
+				}
+				copy.ChatAssistantMessage.ReasoningDetails[i] = copyRD
+			}
+		}
 	}
 
 	return copy

plugins/jsonparser/utils.go

@@ -335,6 +335,39 @@ func (p *JsonParserPlugin) deepCopyChatStreamResponseChoiceDelta(original *schem
 		Reasoning: original.Reasoning, // Shallow copy
 		Refusal:   original.Refusal,   // Shallow copy
 		ToolCalls: original.ToolCalls, // Shallow copy - we don't modify tool calls
+		Audio:     original.Audio,     // Shallow copy
+	}
+
+	// Deep copy ReasoningDetails — elements contain pointer fields
+	if len(original.ReasoningDetails) > 0 {
+		result.ReasoningDetails = make([]schemas.ChatReasoningDetails, len(original.ReasoningDetails))
+		for i, rd := range original.ReasoningDetails {
+			copyRD := schemas.ChatReasoningDetails{
+				Index: rd.Index,
+				Type:  rd.Type,
+			}
+			if rd.ID != nil {
+				v := *rd.ID
+				copyRD.ID = &v
+			}
+			if rd.Summary != nil {
+				v := *rd.Summary
+				copyRD.Summary = &v
+			}
+			if rd.Text != nil {
+				v := *rd.Text
+				copyRD.Text = &v
+			}
+			if rd.Signature != nil {
+				v := *rd.Signature
+				copyRD.Signature = &v
+			}
+			if rd.Data != nil {
+				v := *rd.Data
+				copyRD.Data = &v
+			}
+			result.ReasoningDetails[i] = copyRD
+		}
 	}
 
 	// Deep copy Content pointer if it exists (this is what we modify)
@@ -343,5 +376,10 @@ func (p *JsonParserPlugin) deepCopyChatStreamResponseChoiceDelta(original *schem
 		result.Content = &contentCopy
 	}
 
+	// Copy ExtraContent (provider metadata like google.thought / thought_signature)
+	if len(original.ExtraContent) > 0 {
+		result.ExtraContent = append(json.RawMessage(nil), original.ExtraContent...)
+	}
+
 	return result
 }