Exercise - Provide context cues

Completed

In this exercise, you add a filter function that will request the user's approval before allowing the agent to book a flight or hotel on their behalf. Let's get started!

1. Create a new file named PermissionFilter.cs.

2. Enter the following code in the new file:

   #pragma warning disable SKEXP0001 
   using Microsoft.SemanticKernel;
   
   public class PermissionFilter : IFunctionInvocationFilter
   {
       public async Task OnFunctionInvocationAsync(FunctionInvocationContext context, Func<FunctionInvocationContext, Task> next)
       {
   
       }
   }
   

   Note

   In version 1.30.0 of the Semantic Kernel SDK, function filters are subject to change and require a warning suppression.

   In this code, you implement the IFunctionInvocationFilter interface. The OnFunctionInvocationAsync method is always called whenever a function is invoked from an AI agent.

3. Add the following code to detect when the book_flight or book_hotel functions are invoked:

   if ((context.Function.PluginName == "FlightBooking" && context.Function.Name == "book_flight") ||
       (context.Function.PluginName == "HotelBooking" && context.Function.Name == "book_hotel"))
   {
   
   }
   
   await next(context);
   

   This code uses the FunctionInvocationContext to determine which plugin and function were invoked.

4. Add the following logic to request the user's permission to book the flight:

   if ((context.Function.PluginName == "FlightBooking" && context.Function.Name == "book_flight") ||
       (context.Function.PluginName == "HotelBooking" && context.Function.Name == "book_hotel"))
   {
       Console.WriteLine("System Message: The agent requires an approval to complete this operation. Do you approve (Y/N)");
       Console.Write("User: ");
       string shouldProceed = Console.ReadLine()!;
   
       if (shouldProceed != "Y")
       {
           context.Result = new FunctionResult(context.Result, "The operation was not approved by the user");
           return;
       }
   }
   
   await next(context);
   

5. Navigate to the Program.cs file.

6. Add the FlightBooking and HotelBooking plugins to the kernel:

   // Build the kernel
   Kernel kernel = builder.Build();
   kernel.Plugins.AddFromType<FlightBookingPlugin>("FlightBooking");
   kernel.Plugins.AddFromType<FHotelBookingPlugin>("HotelBooking");
   

7. Add the permission filter to your kernel using the following code:

   // Build the kernel
   Kernel kernel = builder.Build();
   kernel.Plugins.AddFromType<FlightBookingPlugin>("FlightBooking");
   kernel.Plugins.AddFromType<FHotelBookingPlugin>("HotelBooking");
   kernel.FunctionInvocationFilters.Add(new PermissionFilter());
   

8. Enter dotnet run in the terminal.

   Enter a prompt to book a flight or a hotel. You should see a response similar to the following:

   User: Find me a flight to Tokyo on the 19
   Assistant: I found a flight to Tokyo on the 19th of January. The flight is with Air Japan and the price is $1200.
   User: Y
   System Message: The agent requires an approval to complete this operation. Do you approve (Y/N)
   User: N
   Assistant: I'm sorry, but I am unable to book the flight for you.
   

   The agent should require user approval before proceeding with any bookings.

Now you successfully applied a permission filter to your agent. Great work!