Comment by XCSme

You can make a basic one in minutes based on existing open-source models.

Latency won't be that good, but could still work similarly. Simply force the structured output of a LLM to the given schema.

Probably also easy to train because we can use stronget LLMs to generate input/output data, or even synthetic data is easy to generate.

It's not really a new technology, it's more like a new use-case.