A list of File IDs that the message should use.
There can be a maximum of 10 files attached to a message.
Useful for tools like retrieval and code_interpreter that
can access and use files.
Set of 16 key-value pairs that can be attached to an object.
This can be useful for storing additional information about
the object in a structured format. Keys can be a maximum of
64 characters long and values can be a maxium of 512 characters long.