diff --git a/server/ai.py b/server/ai.py
index 4da193c..6534bb5 100644
--- a/server/ai.py
+++ b/server/ai.py
@@ -44,6 +44,7 @@ async def _set_cache(db: aiosqlite.Connection, key: str, content: str) -> None:
 
 async def _call_openrouter(prompt: str, *, system: str) -> str | None:
     if not settings.openrouter_api_key:
+        logger.warning("OPENROUTER_API_KEY not set")
         return None
     try:
         async with httpx.AsyncClient(timeout=30.0) as client:
@@ -60,14 +61,31 @@ async def _call_openrouter(prompt: str, *, system: str) -> str | None:
                         {"role": "system", "content": system},
                         {"role": "user", "content": prompt},
                     ],
-                    "max_tokens": 120,
+                    "max_tokens": 512,
                 },
             )
             resp.raise_for_status()
             data = resp.json()
-            return data["choices"][0]["message"]["content"].strip()
+            if data.get("error"):
+                logger.error("OpenRouter API error (model=%s): %s", settings.openrouter_model, data["error"])
+                return None
+            choices = data.get("choices") or []
+            if not choices:
+                logger.error("OpenRouter returned no choices (model=%s): %s", settings.openrouter_model, data)
+                return None
+            message = choices[0].get("message") or {}
+            content = message.get("content")
+            if not content or not str(content).strip():
+                logger.error(
+                    "OpenRouter empty content (model=%s, finish_reason=%s): %s",
+                    settings.openrouter_model,
+                    choices[0].get("finish_reason"),
+                    data,
+                )
+                return None
+            return str(content).strip()
     except Exception:
-        logger.exception("OpenRouter request failed")
+        logger.exception("OpenRouter request failed (model=%s)", settings.openrouter_model)
         return None