National Center for Supercomputing Applications LLM Services

Lumen

LLM Services Lumen

A ready-to-use AI service, hosted by NCSA: a curated set of models you can use anytime — from the web chat or straight from your own code — behind a single Illinois login.

What it is

Lumen is a managed AI service that NCSA runs for you, so there is nothing to install or operate. It puts a curated set of models behind one Illinois login and makes them available two ways at once: a full web chat interface for everyday use, and an OpenAI-compatible API you can call from your own scripts and applications.

Because access, usage limits, metering, and reporting are handled centrally, you — and your programs — can start using models right away and switch freely between them, without provisioning any infrastructure of your own.

When to use it

Good fit

  • You want ready-to-use models without running any infrastructure yourself.
  • You want the same models from a chat UI and from your own code.
  • You want to sign in with your Illinois NetID (CILogon).
  • You want usage visibility and optional per-user or per-group usage limits.

Look elsewhere if

  • You need commercial models (GPT, Claude, Gemini) — see IllinoisChat.
  • You want document Q&A with citations — see IllinoisChat.
  • You need large offline batch jobs — see LLMFlux.
  • You just want to deploy an open model on HPC — see LLM Hub.

Key capabilities

Key capabilities
ModelsA curated set of open-weight models, all hosted on Illinois/NCSA. Choose whichever model fits your task — per conversation in the chat, or per request from your code — with no setup on your part.
Signing inSign in with your Illinois NetID (single sign-on); for scripts and apps, generate a personal API key. You’re placed in the right group automatically based on your campus affiliation, so the appropriate models and limits apply.
Your usageCheck your usage any time on a personal page — your remaining balance, the models you’ve used, and your API keys. Group administrators get aggregate dashboards showing usage across their team.
CostNo charge to use. Like other Illinois Computes resources, Lumen is provided to campus researchers at no cost — no money changes hands. Usage is metered in coins, a virtual allowance rather than currency: each model has a coin rate per 1M input/output tokens (and per audio-hour for speech), so admins can set fair per-user or per-group quotas.

Data & hosting note

Lumen serves only models hosted on Illinois/NCSA infrastructure — nothing is routed to an outside vendor — so your prompts and data stay within University control. That makes it a good choice for sensitive work, though you should still follow your unit’s data-classification guidance for regulated data (FERPA, HIPAA, export-controlled, and the like).

What’s recorded: only your web-chat conversations are saved — so you have a chat history — and you can delete them at any time. Anything you send through the API is not recorded: Lumen keeps only usage totals (tokens, cost, timing), never your prompts or the model’s replies.

Get started with Lumen

National Center for Supercomputing Applications LLM Services Guide
Illinois Computes University data classification & policy