Using actions in assistant API

Hello! Currently, it’s possible to create GPTs with actions, but is this not available in the API/Playground? I’m using an external assistant and need to enable an action, but I can’t find how to do this using the assistant API.
I’m considering using an initial prompt with a standard GPT chat to retrieve a JSON and then use that locally to execute an ‘action’ in my app, not in the assistant.

@antonio.g I don’t suppose its possible directly with the assistants. I am working on the same thing and from what i have found uptil now is that create a proxy server that can connect to your database ( my case i wanna query my database)