Function Calling

In a previous episode, we looked at structured outputs where we could get a language model to respond in a shape that our application understands.

But there's still a hard limit.

The model only knows what it is trained on.

Ask it about the data in your database without providing it in the context and it will happily make something up.

In this episode, we're flipping the direction.

Instead of our application asking the model for information, we're going to let the model ask our application.

This is called function calling, or tool use, and it's the foundation for building any kind of AI assistant or agent on top of your Rails application.