Update main.go

main.go

@@ -95,24 +95,20 @@ func resolveModel(requested string) string {
 }
 
 func injectSystemPrompt(messages []Message, modelID string) []Message {
-	prompt := loadSystemPrompt(modelID)
-	if prompt == "" {
-		return messages
+	// Strip any system messages from client - gateway prompt always wins
+	filtered := make([]Message, 0, len(messages))
+	for _, m := range messages {
+		if m.Role != "system" {
+			filtered = append(filtered, m)
+		}
 	}
 
-	// Check if first message is already a system message
-	if len(messages) > 0 && messages[0].Role == "system" {
-		existing := ""
-		switch v := messages[0].Content.(type) {
-		case string:
-			existing = v
-		}
-		messages[0].Content = prompt + "\n\n" + existing
-		return messages
+	prompt := loadSystemPrompt(modelID)
+	if prompt == "" {
+		return filtered
 	}
 
-	systemMsg := Message{Role: "system", Content: prompt}
-	return append([]Message{systemMsg}, messages...)
+	return append([]Message{{Role: "system", Content: prompt}}, filtered...)
 }
 
 func authenticate(r *http.Request) bool {
@@ -304,4 +300,4 @@ func main() {
 	if err := http.ListenAndServe(":"+port, mux); err != nil {
 		log.Fatal(err)
 	}
-}
+}