understanding POST /completion: Given a prompt, it returns the predicted completion

[siddhsql]

i am trying to understand this endpoint. Questions:

1. what are slots? i thought slots would map to users. each user would be assigned a slot and to get a chat completion the request has to go to appropriate slot but the /POST endpoint does not take slot as parameter.
   id_slot: Assign the completion task to an specific slot. If is -1 the task will be assigned to a Idle slot. Default: -1
2. if same /POST endpoint is serving multiple users then their history and conversation is getting mixed up which can't be right.
3. is the /POST endpoint stateless meaning it does not remember the chat history?