fix(providers): add thinking and reasoning fallback for OpenAI-compatible providers (Ollama)

pkg/providers/common/common.go

@@ -73,6 +73,8 @@ type openaiMessage struct {
 	Role             string     `json:"role"`
 	Content          string     `json:"content"`
 	ReasoningContent string     `json:"reasoning_content,omitempty"`
+	Reasoning        string     `json:"reasoning,omitempty"`
+	Thinking         string     `json:"thinking,omitempty"`
 	ToolCalls        []ToolCall `json:"tool_calls,omitempty"`
 	ToolCallID       string     `json:"tool_call_id,omitempty"`
 }
@@ -89,6 +91,8 @@ func SerializeMessages(messages []Message) []any {
 				Role:             m.Role,
 				Content:          m.Content,
 				ReasoningContent: m.ReasoningContent,
+				Reasoning:        m.Reasoning,
+				Thinking:         m.Thinking,
 				ToolCalls:        m.ToolCalls,
 				ToolCallID:       m.ToolCallID,
 			})
@@ -127,6 +131,12 @@ func SerializeMessages(messages []Message) []any {
 		if m.ReasoningContent != "" {
 			msg["reasoning_content"] = m.ReasoningContent
 		}
+		if m.Reasoning != "" {
+			msg["reasoning"] = m.Reasoning
+		}
+		if m.Thinking != "" {
+			msg["thinking"] = m.Thinking
+		}
 		out = append(out, msg)
 	}
 	return out
@@ -142,6 +152,7 @@ func ParseResponse(body io.Reader) (*LLMResponse, error) {
 				Content          string            `json:"content"`
 				ReasoningContent string            `json:"reasoning_content"`
 				Reasoning        string            `json:"reasoning"`
+				Thinking         string            `json:"thinking"`
 				ReasoningDetails []ReasoningDetail `json:"reasoning_details"`
 				ToolCalls        []struct {
 					ID       string `json:"id"`
@@ -208,10 +219,22 @@ func ParseResponse(body io.Reader) (*LLMResponse, error) {
 		toolCalls = append(toolCalls, toolCall)
 	}
 
+	content := choice.Message.Content
+	if content == "" {
+		if choice.Message.Thinking != "" {
+			content = choice.Message.Thinking
+		} else if choice.Message.Reasoning != "" {
+			content = choice.Message.Reasoning
+		} else if choice.Message.ReasoningContent != "" {
+			content = choice.Message.ReasoningContent
+		}
+	}
+
 	return &LLMResponse{
-		Content:          choice.Message.Content,
+		Content:          content,
 		ReasoningContent: choice.Message.ReasoningContent,
 		Reasoning:        choice.Message.Reasoning,
+		Thinking:         choice.Message.Thinking,
 		ReasoningDetails: choice.Message.ReasoningDetails,
 		ToolCalls:        toolCalls,
 		FinishReason:     choice.FinishReason,

pkg/providers/openai_compat/provider.go

@@ -241,6 +241,9 @@ func parseStreamResponse(
 	onChunk func(accumulated string),
 ) (*LLMResponse, error) {
 	var textContent strings.Builder
+	var reasoningContent strings.Builder
+	var reasoning strings.Builder
+	var thinking strings.Builder
 	var finishReason string
 	var usage *UsageInfo
 
@@ -274,6 +277,9 @@ func parseStreamResponse(
 			Choices []struct {
 				Delta struct {
 					Content          string `json:"content"`
+					ReasoningContent string `json:"reasoning_content"`
+					Reasoning        string `json:"reasoning"`
+					Thinking         string `json:"thinking"`
 					ToolCalls        []struct {
 						Index    int    `json:"index"`
 						ID       string `json:"id"`
@@ -301,14 +307,25 @@ func parseStreamResponse(
 		}
 
 		choice := chunk.Choices[0]
+		delta := choice.Delta
+
+		// Accumulate text content with fallback to reasoning/thinking
+		if delta.Content != "" {
+			textContent.WriteString(delta.Content)
+		} else if delta.Thinking != "" {
+			thinking.WriteString(delta.Thinking)
+			textContent.WriteString(delta.Thinking) // Surface reasoning to user
+		} else if delta.Reasoning != "" {
+			reasoning.WriteString(delta.Reasoning)
+			textContent.WriteString(delta.Reasoning) // Surface reasoning to user
+		} else if delta.ReasoningContent != "" {
+			reasoningContent.WriteString(delta.ReasoningContent)
+			textContent.WriteString(delta.ReasoningContent) // Surface reasoning to user
+		}
 
-		// Accumulate text content
-		if choice.Delta.Content != "" {
-			textContent.WriteString(choice.Delta.Content)
 		if onChunk != nil {
 			onChunk(textContent.String())
 		}
-		}
 
 		// Accumulate tool call deltas
 		for _, tc := range choice.Delta.ToolCalls {
@@ -367,6 +384,9 @@ func parseStreamResponse(
 
 	return &LLMResponse{
 		Content:          textContent.String(),
+		ReasoningContent: reasoningContent.String(),
+		Reasoning:        reasoning.String(),
+		Thinking:         thinking.String(),
 		ToolCalls:        toolCalls,
 		FinishReason:     finishReason,
 		Usage:            usage,

pkg/providers/protocoltypes/types.go

@@ -27,10 +27,11 @@ type FunctionCall struct {
 type LLMResponse struct {
 	Content          string            `json:"content"`
 	ReasoningContent string            `json:"reasoning_content,omitempty"`
+	Reasoning        string            `json:"reasoning,omitempty"`
+	Thinking         string            `json:"thinking,omitempty"`
 	ToolCalls        []ToolCall        `json:"tool_calls,omitempty"`
 	FinishReason     string            `json:"finish_reason"`
 	Usage            *UsageInfo        `json:"usage,omitempty"`
-	Reasoning        string            `json:"reasoning"`
 	ReasoningDetails []ReasoningDetail `json:"reasoning_details"`
 }
 
@@ -67,6 +68,8 @@ type Message struct {
 	Content          string         `json:"content"`
 	Media            []string       `json:"media,omitempty"`
 	ReasoningContent string         `json:"reasoning_content,omitempty"`
+	Reasoning        string         `json:"reasoning,omitempty"`
+	Thinking         string         `json:"thinking,omitempty"`
 	SystemParts      []ContentBlock `json:"system_parts,omitempty"` // structured system blocks for cache-aware adapters
 	ToolCalls        []ToolCall     `json:"tool_calls,omitempty"`
 	ToolCallID       string         `json:"tool_call_id,omitempty"`