rate limit chcek

backend/main.py

@@ -187,7 +187,31 @@ def call_groq_with_backoff(client: Groq, messages: list) -> str:
             if "413" in err or "too large" in err.lower() or "rate_limit_exceeded" in err.lower():
                 attempt += 1
                 if attempt >= len(word_limits):
-                    raise ValueError("Request too large even after maximum reductions.,"+err[:100])
+                    if "429" in err:
+
+                        retry_after = None
+        
+                        try:
+                            # Try to read headers if available
+                            if hasattr(e, "response") and e.response:
+        
+                                headers = getattr(e.response, "headers", {})
+        
+                                retry_after = headers.get("retry-after")
+        
+                        except Exception:
+                            pass
+        
+                        if retry_after:
+                            raise ValueError(
+                                f"Rate limit exceeded. Retry after {retry_after} seconds."
+                            )
+        
+                        else:
+                            raise ValueError(
+                                "Rate limit exceeded. Retry later."
+                            )
+                    raise ValueError("Request too large even after maximum reductions.")
                 new_limit = word_limits[attempt]
                 for msg in messages:
                     if msg["role"] == "user":