Update Streamlit UI to send messages to FastAPI chat endpoint

app.py

@@ -40,6 +40,20 @@ else:
         if user_input.strip() == "":
             st.warning("Please enter a message.")
         else:
-            # TODO: Send to backend and get response
+            # Display user message
             st.markdown(f"**You:** {user_input}")
-            st.markdown(f"**AI Coach:** [Response will appear here after backend integration.]")
+
+            # Send to backend
+            with st.spinner("AI Coach is thinking..."):
+                try:
+                    response = requests.post(
+                        "http://localhost:8000/api/chat",
+                        json={"user_id": user, "message": user_input}
+                    )
+                    if response.status_code == 200:
+                        ai_response = response.text  # Adjust based on actual response format
+                        st.markdown(f"**AI Coach:** {ai_response}")
+                    else:
+                        st.error("Failed to get response from AI Coach.")
+                except Exception as e:
+                    st.error(f"Connection error: {e}")