Is there a way to pass additional parameters to open ai model with AI Agent

Questions
1

At my work, we are could only use self hosted open AI models that requires a user parameter along with messages and model. This user param is used for multiple reasons such as tracking the usages, cost and other analytics etc.,

I cannot find a way to pass the user param to the open AI model and hence getting this error

You must pass a ‘user’ json field to your request

If I cannot pass the user param, I cannot use my org AI model and will be forced use LangChain+Python code approach. I really like the way n8n workflows are implemented so I would prefer n8n route. Today is my first hands on with n8n so please go easy on me if I am missing something obvious here.

2

Have you looked at using OpenRouter? You can use a base url as far as I understand from which you could prob add the parameter you need? I have not tried this myself.

What model are you guys using in the company?