OpenAI function calling provides a means of producing valid JSON from a function signature, or a simplified version of a JSON schema definition; however, it has two big downsides:

1. it doesn't work with open-source models, and 2. sometimes the JSON it produces will not even parse.

A similar interface was recently merged into our open-source project Outlines. The approach can be extended to any open-source model and it can guarantee that the output will be parsable JSON.

Constructive feedback, bug reports, feature requests, and questions are greatly appreciated!