diff --git a/chat.go b/chat.go
index ce24fa3..d05fc8e 100644
--- a/chat.go
+++ b/chat.go
@@ -261,7 +261,8 @@ type ChatCompletionRequest struct {
 	// Controls effort on reasoning for reasoning models. It can be set to "low", "medium", or "high".
 	ReasoningEffort string `json:"reasoning_effort,omitempty"`
 	// Metadata to store with the completion.
-	Metadata map[string]string `json:"metadata,omitempty"`
+	Metadata         map[string]string `json:"metadata,omitempty"`
+	IncludeReasoning *bool             `json:"include_reasoning,omitempty"`
 }
 
 type StreamOptions struct {