diff --git a/pkg/agent/loop.go b/pkg/agent/loop.go
index cd4276155..870a62234 100644
--- a/pkg/agent/loop.go
+++ b/pkg/agent/loop.go
@@ -616,8 +616,9 @@ func (al *AgentLoop) runLLMIteration(ctx context.Context, messages []providers.M
 
 		// Build assistant message with tool calls
 		assistantMsg := providers.Message{
-			Role:    "assistant",
-			Content: response.Content,
+			Role:             "assistant",
+			Content:          response.Content,
+			ReasoningContent: response.ReasoningContent, // Preserve for thinking models (e.g., GLM-Z1)
 		}
 		for _, tc := range response.ToolCalls {
 			argumentsJSON, _ := json.Marshal(tc.Arguments)
diff --git a/pkg/providers/http_provider.go b/pkg/providers/http_provider.go
index 4cf2c6db2..611ee7971 100644
--- a/pkg/providers/http_provider.go
+++ b/pkg/providers/http_provider.go
@@ -127,7 +127,8 @@ func (p *HTTPProvider) parseResponse(body []byte) (*LLMResponse, error) {
 	var apiResponse struct {
 		Choices []struct {
 			Message struct {
-				Content   string `json:"content"`
+				Content          string `json:"content"`
+				ReasoningContent string `json:"reasoning_content"` // For thinking models (e.g., GLM-Z1)
 				ToolCalls []struct {
 					ID       string `json:"id"`
 					Type     string `json:"type"`
@@ -186,10 +187,11 @@ func (p *HTTPProvider) parseResponse(body []byte) (*LLMResponse, error) {
 	}
 
 	return &LLMResponse{
-		Content:      choice.Message.Content,
-		ToolCalls:    toolCalls,
-		FinishReason: choice.FinishReason,
-		Usage:        apiResponse.Usage,
+		Content:          choice.Message.Content,
+		ReasoningContent: choice.Message.ReasoningContent,
+		ToolCalls:        toolCalls,
+		FinishReason:     choice.FinishReason,
+		Usage:            apiResponse.Usage,
 	}, nil
 }
 
diff --git a/pkg/providers/types.go b/pkg/providers/types.go
index 88b62e975..11917806b 100644
--- a/pkg/providers/types.go
+++ b/pkg/providers/types.go
@@ -16,10 +16,11 @@ type FunctionCall struct {
 }
 
 type LLMResponse struct {
-	Content      string     `json:"content"`
-	ToolCalls    []ToolCall `json:"tool_calls,omitempty"`
-	FinishReason string     `json:"finish_reason"`
-	Usage        *UsageInfo `json:"usage,omitempty"`
+	Content          string     `json:"content"`
+	ReasoningContent string     `json:"reasoning_content,omitempty"` // For thinking models (e.g., GLM-Z1)
+	ToolCalls        []ToolCall `json:"tool_calls,omitempty"`
+	FinishReason     string     `json:"finish_reason"`
+	Usage            *UsageInfo `json:"usage,omitempty"`
 }
 
 type UsageInfo struct {
@@ -29,10 +30,11 @@ type UsageInfo struct {
 }
 
 type Message struct {
-	Role       string     `json:"role"`
-	Content    string     `json:"content"`
-	ToolCalls  []ToolCall `json:"tool_calls,omitempty"`
-	ToolCallID string     `json:"tool_call_id,omitempty"`
+	Role             string     `json:"role"`
+	Content          string     `json:"content"`
+	ReasoningContent string     `json:"reasoning_content,omitempty"` // For thinking models (e.g., GLM-Z1)
+	ToolCalls        []ToolCall `json:"tool_calls,omitempty"`
+	ToolCallID       string     `json:"tool_call_id,omitempty"`
 }
 
 type LLMProvider interface {
diff --git a/pkg/tools/toolloop.go b/pkg/tools/toolloop.go
index 1302079b4..e63361342 100644
--- a/pkg/tools/toolloop.go
+++ b/pkg/tools/toolloop.go
@@ -97,8 +97,9 @@ func RunToolLoop(ctx context.Context, config ToolLoopConfig, messages []provider
 
 		// 6. Build assistant message with tool calls
 		assistantMsg := providers.Message{
-			Role:    "assistant",
-			Content: response.Content,
+			Role:             "assistant",
+			Content:          response.Content,
+			ReasoningContent: response.ReasoningContent, // Preserve for thinking models (e.g., GLM-Z1)
 		}
 		for _, tc := range response.ToolCalls {
 			argumentsJSON, _ := json.Marshal(tc.Arguments)