Generation: use only OpenRouter when OPENROUTER_API_KEY set (no Gemini fallback)

rag_engine.py

@@ -682,15 +682,25 @@ class RAGEngine:
             return None
 
     def _call_api_with_backoff(self, system_prompt: str, prompt: str, models: List[str]):
-        """Try OpenRouter first (fast), then Gemini API with retry + backoff."""
+        """When OPENROUTER_API_KEY is set: use only OpenRouter (no Gemini). Else: use Gemini with backoff."""
         PIPELINE_LOG.info("_call_api_with_backoff START models=%s prompt_len=%d", models, len(prompt))
 
-        # Try OpenRouter first for speed (when key is set)
-        openrouter_result = self._call_openrouter(system_prompt, prompt)
-        if openrouter_result:
-            return openrouter_result
+        openrouter_key = self._get_openrouter_key()
+        if openrouter_key:
+            # Generation: use only OpenRouter when key is set (avoid Gemini rate limit)
+            PIPELINE_LOG.info("OpenRouter key present - using OpenRouter only for generation (no Gemini)")
+            for attempt in range(2):
+                result = self._call_openrouter(system_prompt, prompt, timeout_seconds=35)
+                if result:
+                    return result
+                PIPELINE_LOG.warning("OpenRouter attempt %d failed, retrying...", attempt + 1)
+            return (
+                "❌ OpenRouter request failed after retries. Check OPENROUTER_API_KEY and OPENROUTER_MODEL in Space secrets. "
+                "See logs for details."
+            )
 
-        # Fall back to Gemini
+        # No OpenRouter key: use Gemini
+        PIPELINE_LOG.info("OpenRouter key not set - using Gemini for generation")
         max_attempts_per_model = 8
         max_rate_limit_wait_s = 180  # wait up to 3 minutes per attempt before retry