Fix API endpoint: Add named 'chat' endpoint to Gradio ChatInterface and update frontend API calls

app.py

@@ -183,6 +183,7 @@ def create_enhanced_medical_interface():
             ],
             cache_examples=False
         )
+        chatbot.api_name = "chat"
         
         # Footer with technical info
         gr.Markdown("""

frontend/src/lib/api.ts

@@ -20,20 +20,25 @@ export async function queryAPI(input: string, history: ChatMessage[] = []): Prom
       throw new Error('HF_API_URL is not configured');
     }
 
-    // Convert history to Gradio format
-    const gradioHistory = history.map(msg => [
-      msg.role === 'user' ? msg.content : '',
-      msg.role === 'assistant' ? msg.content : ''
-    ]).filter(pair => pair[0] || pair[1]);
+    // Convert history to Gradio's chat format: a list of [user, assistant] pairs.
+    const gradioHistory: [string | null, string | null][] = [];
+    for (let i = 0; i < history.length; i += 2) {
+      if (i + 1 < history.length && history[i].role === 'user' && history[i+1].role === 'assistant') {
+        gradioHistory.push([history[i].content, history[i+1].content]);
+      }
+    }
 
-    // Use Gradio API format - try the basic predict endpoint
-    const response = await fetch(`${HF_API_URL}/predict`, {
+    // Use the specific Gradio API endpoint as per the documentation
+    const response = await fetch(`${HF_API_URL}/chat`, {
       method: 'POST',
       headers: {
         'Content-Type': 'application/json',
       },
       body: JSON.stringify({
-        data: [input, gradioHistory]
+        data: [
+          input,
+          gradioHistory
+        ]
       }),
     });
 
@@ -44,7 +49,7 @@ export async function queryAPI(input: string, history: ChatMessage[] = []): Prom
     const result = await response.json();
     
     return {
-      answer: result?.data?.[0] || result?.[0] || 'No response received from the medical assistant.',
+      answer: result?.data?.[0] || 'No response received from the medical assistant.',
       sources: [], // Enhanced backend provides sources within the response text
     };
   } catch (error) {