Handle resolver outages in SMILES to Name tab

app.py

@@ -2,6 +2,7 @@ import gradio as gr
 from rdkit import Chem
 from rdkit.Chem import Descriptors, Draw, AllChem
 import cirpy
+from urllib.error import HTTPError, URLError
 
 
 # RDKit API with multiple endpoints
@@ -51,19 +52,21 @@ def name_to_smiles(name: str) -> str:
 
 
 def smiles_to_name(smiles: str) -> str:
-    """Convert SMILES string to chemical name using Chemical Identifier Resolver (CIR)"""
+    """Convert SMILES string to chemical name using Chemical Identifier Resolver (CIR)."""
+    mol = _mol_from_smiles(smiles)
+
     try:
-        # First validate the SMILES
-        mol = _mol_from_smiles(smiles)
-        
-        # Try to resolve SMILES to a chemical name
-        name = cirpy.resolve(smiles, 'name')
-        if name is None:
-            # If no name found, return the canonical SMILES
-            return Chem.MolToSmiles(mol)
-        return name
+        name = cirpy.resolve(smiles, "name")
+    except (HTTPError, URLError) as network_error:
+        # Gracefully degrade when the resolver service is unavailable.
+        return f"Resolver unavailable ({network_error}). Canonical SMILES: {Chem.MolToSmiles(mol)}"
     except Exception as e:
-        raise gr.Error(f"Error converting SMILES to name: {str(e)}")
+        return f"Unable to resolve to name ({e}). Canonical SMILES: {Chem.MolToSmiles(mol)}"
+
+    if not name:
+        return f"No name found. Canonical SMILES: {Chem.MolToSmiles(mol)}"
+
+    return name
 
 
 def name_to_3d_molecule(name: str) -> str: