Update app.py

app.py

@@ -13,8 +13,15 @@ app = FastAPI()
 client = Groq(api_key=os.environ.get("GROQ_API_KEY"))
 
 # ── Persistent storage ──────────────────────────────────────────────────────
-DATA_DIR = Path(os.environ.get("DATA_DIR", "/data/pharma_chat"))
-DATA_DIR.mkdir(parents=True, exist_ok=True)
+# Use /data if persistent storage is mounted (HF Spaces), else fall back to home dir
+_preferred = Path("/data/pharma_chat")
+_fallback  = Path(os.environ.get("HOME", "/home/user")) / "pharma_chat"
+try:
+    _preferred.mkdir(parents=True, exist_ok=True)
+    DATA_DIR = _preferred
+except PermissionError:
+    _fallback.mkdir(parents=True, exist_ok=True)
+    DATA_DIR = _fallback
 THREADS_FILE = DATA_DIR / "threads.json"
 
 def load_threads() -> dict:
@@ -892,4 +899,4 @@ loadThreads();
 </template>
 
 </body>
-</html>"""
+</html>"""