pocketflow/cookbook/pocketflow-async-basic/README.md

PocketFlow Async Basic Example

This example demonstrates async operations using a simple Recipe Finder that:

1. Fetches recipes from an API (async HTTP)
2. Processes them with an LLM (async LLM)
3. Waits for user confirmation (async input)

What this Example Does

When you run the example:

1. You enter an ingredient (e.g., "chicken")
2. It searches for recipes (async API call)
3. It suggests a recipe (async LLM call)
4. You approve or reject the suggestion
5. If rejected, it tries again with a different recipe

How it Works

1. FetchRecipes (AsyncNode)

   async def prep_async(self, shared):
       ingredient = input("Enter ingredient: ")
       return ingredient
   
   async def exec_async(self, ingredient):
       # Async API call
       recipes = await fetch_recipes(ingredient)
       return recipes
   

2. SuggestRecipe (AsyncNode)

   async def exec_async(self, recipes):
       # Async LLM call
       suggestion = await call_llm_async(
           f"Choose best recipe from: {recipes}"
       )
       return suggestion
   

3. GetApproval (AsyncNode)

   async def post_async(self, shared, prep_res, suggestion):
       # Async user input
       answer = await get_user_input(
           f"Accept {suggestion}? (y/n): "
       )
       return "accept" if answer == "y" else "retry"
   

Running the Example

pip install -r requirements.txt
python main.py

Sample Interaction

Enter ingredient: chicken
Fetching recipes...
Found 3 recipes.

Suggesting best recipe...
How about: Grilled Chicken with Herbs

Accept this recipe? (y/n): n
Suggesting another recipe...
How about: Chicken Stir Fry

Accept this recipe? (y/n): y
Great choice! Here's your recipe...

Key Concepts

1. Async Operations: Using async/await for:

   • API calls (non-blocking I/O)
   • LLM calls (potentially slow)
   • User input (waiting for response)

2. AsyncNode Methods:

   • prep_async: Setup and data gathering
   • exec_async: Main async processing
   • post_async: Post-processing and decisions

3. Flow Control:

   • Actions ("accept"/"retry") control flow
   • Retry loop for rejected suggestions