Update app.py

app.py

@@ -2,7 +2,6 @@ import gradio as gr # type: ignore
 import requests # type: ignore
 import io
 import random
-import os
 import time
 from PIL import Image
 import json
@@ -41,13 +40,11 @@ def query_with_auto_routing(prompt, model, custom_lora, is_negative=False, steps
         if oauth_token is not None and getattr(oauth_token, "token", None):
             api_key = oauth_token.token
             print("Using OAuth token from signed-in user for inference.")
-        else:
-            api_key = os.getenv("HF_READ_TOKEN")
-            if api_key:
-                print("Using HF_READ_TOKEN environment variable for inference.")
 
         if not api_key:
-            raise gr.Error("No Hugging Face token available. Sign in with Hugging Face or set HF_READ_TOKEN.")
+            raise gr.Error(
+                "No Hugging Face session detected. Please sign in with your Hugging Face account before running generation."
+            )
 
         # Initialize client with automatic provider selection (default is "auto")
         client = InferenceClient(token=api_key)
@@ -76,10 +73,34 @@ def query_with_auto_routing(prompt, model, custom_lora, is_negative=False, steps
         
         print(f'Generation {key} completed with automatic routing!')
         return image
-        
+
+    except HfHubHTTPError as e:
+        status = getattr(e.response, "status_code", None)
+        detail_hint = None
+        if status == 401:
+            detail_hint = (
+                "Your Hugging Face session is missing the 'Make calls to Inference Providers' permission. "
+                "Generate a fine-grained token with that permission in your Hugging Face settings and "
+                "re-authorize the Space so the updated token can be used."
+            )
+        elif status == 403:
+            detail_hint = (
+                "The signed-in account did not grant the 'inference-api' scope. Sign out, then sign back in "
+                "and approve the requested permissions so your token can access Inference Providers."
+            )
+
+        print(f"Error with automatic routing: {e}")
+        if detail_hint:
+            raise gr.Error(
+                "Failed to generate image: "
+                f"{e}.\n\nTroubleshooting tip: {detail_hint}"
+            ) from e
+
+        raise gr.Error(f"Failed to generate image: {str(e)}") from e
+
     except Exception as e:
         print(f"Error with automatic routing: {e}")
-        raise gr.Error(f"Failed to generate image: {str(e)}")
+        raise gr.Error(f"Failed to generate image: {str(e)}") from e
 
 def get_model_id_from_name(model_name):
     """