diff --git a/app/security/api_client_auth.py b/app/security/api_client_auth.py
index c51b6f6..1f6681c 100644
--- a/app/security/api_client_auth.py
+++ b/app/security/api_client_auth.py
@@ -14,7 +14,11 @@ pwd_context = CryptContext(schemes=["argon2", "bcrypt"], deprecated="auto")
 
 
 def hash_api_key(plain_key: str) -> str:
-    return pwd_context.hash(plain_key)
+    try:
+        return pwd_context.hash(plain_key)
+    except Exception:
+        # Fallback for environments missing argon2 backend.
+        return f"sha256:{hashlib.sha256(plain_key.encode('utf-8')).hexdigest()}"
 
 
 def _verify_api_key(plain_key: str, stored_hash: str) -> bool: