fix: fill missing NPC keys with defaults instead of failing validation

model_engine.py

@@ -177,23 +177,37 @@ def parse_json_safe(text: str) -> dict:
 
 
 def _validate_npc_payload(payload: dict) -> dict:
-    """Validate the NPC payload shape required by the UI."""
-    missing = REQUIRED_NPC_KEYS - payload.keys()
-    if missing:
-        raise ValueError(f"NPC payload missing keys: {sorted(missing)}")
+    """Validate the NPC payload shape, filling in missing keys from DEFAULT_NPC."""
+    # Fill any missing top-level keys with defaults so a partial response still works
+    for key in REQUIRED_NPC_KEYS:
+        if key not in payload:
+            print(f"[NPCverse] NPC payload missing key '{key}', using default.")
+            payload[key] = DEFAULT_NPC[key]
 
     stats = payload.get("stats")
     if not isinstance(stats, dict):
-        raise ValueError("NPC stats must be a dictionary.")
+        print("[NPCverse] NPC stats invalid, using defaults.")
+        payload["stats"] = dict(DEFAULT_NPC["stats"])
+        stats = payload["stats"]
 
-    missing_stats = REQUIRED_STAT_KEYS - stats.keys()
-    if missing_stats:
-        raise ValueError(f"NPC stats missing keys: {sorted(missing_stats)}")
+    # Fill any missing stat keys with defaults
+    for key in REQUIRED_STAT_KEYS:
+        if key not in stats:
+            print(f"[NPCverse] NPC stat '{key}' missing, using default.")
+            stats[key] = DEFAULT_NPC["stats"][key]
 
-    payload["level"] = int(payload["level"])
+    payload["level"] = int(payload.get("level") or DEFAULT_NPC["level"])
     for key in REQUIRED_STAT_KEYS:
         stats[key] = max(1, min(100, int(stats[key])))
 
+    # Ensure quests is a list of dicts
+    if not isinstance(payload.get("quests"), list) or len(payload["quests"]) == 0:
+        payload["quests"] = DEFAULT_NPC["quests"]
+
+    # Ensure secrets is a list of strings
+    if not isinstance(payload.get("secrets"), list) or len(payload["secrets"]) == 0:
+        payload["secrets"] = DEFAULT_NPC["secrets"]
+
     return payload