How to use a planner

  • 7 minutes

Planners are an excellent tool to help you automatically run your functions and prompts. To use the Handlebars planner, first you need to install the add-on package:

dotnet add package Microsoft.SemanticKernel.Planners.Handlebars --version 1.2.0-preview

Afterwards, you create a new planner object using CreatePlanAsync and pass it a goal. The goal is a string that describes the desired outcome. The planner then creates a plan to accomplish the goal. CreatePlanAsync returns a HandlebarsPlan object that you can use to invoke and run the plan.

For example, suppose you have some ingredient plugins that support the following functions:

- `GetIngredients`: Gets a list of the user's available ingredients
- `GetRecipe`: Gets a list of ingredients for a given recipe
- `GetMissingIngredients`: Gets a list of ingredients that are missing from the user's kitchen for a given recipe

To use a planner, you create a new HandlebarsPlanner object, create the plan, and then invoke it.

var planner = new HandlebarsPlanner(new HandlebarsPlannerOptions() { AllowLoops = true });

string goal = @"What ingredients is the user missing from their 
   current ingredients list to make a recipe for blueberry muffins";

var plan = await planner.CreatePlanAsync(kernel, goal);
var result = await plan.InvokeAsync(kernel);
Console.WriteLine(result);

The output may be similar to the following result:

Based on the list of ingredients for blueberry muffins, you are missing blueberries and salt from your available ingredients.

You can also save the generated plan and reload it later, for example:

var plan = await planner.CreatePlanAsync(kernel, goal);
var serializedPlan = plan.ToString();

HandlebarsPlan reloadedPlan = new HandlebarsPlan(serializedPlan);

var result = await reloadedPlan.InvokeAsync(kernel);
Console.WriteLine($"Results: {result}");

The Handlebars planner is a powerful feature that can help developers create dynamic applications and handle complex scenarios with less code. In the next unit, you'll learn how to create and run your own plan!