Here's the core of the message sent to the LLM: https://github.com/microsoft/TypeChat/blob/main/src/typechat...
You are basically getting a fixed prompt to return structured data with a small amount of automation and vendor lockin. All these LLM libraries are just crappy APIs to the underlying API. It is trivial to write a script that does the same and will be much more flexible as models and user needs evolve.
As an example, think about how you could change the prompt or use python classes instead. How much work would this be using a library like this versus something that lifts the API calls and text templating to the user like: https://github.com/hofstadter-io/hof/blob/_dev/flow/chat/llm...