Originally published on LLM Gateway .

A decision model answers questions you define with probabilities instead of generated text: 0.98 that a ticket is urgent, 0.88 that it belongs to billing, a churn risk that lands on "imminent". That is exactly what a routing or moderation step needs, and since October LLM Gateway serves them on an OpenAI-compatible /v1/decisions endpoint .

What was missing was a way to try one. Chat models have had a chat window since day one; a decision model had a JSON schema and a curl example. To see whether microsoft-decision-1 agrees with your support team on a real ticket, you wrote the request by hand, read the probabilities out of the raw response, edited a question, and ran it again. Decision Studio , new in Lounge , is the window for decision models.

Build the questions in the browser

The studio has two parts: the input and the questions.…