---
title: "Probing and model discovery"
description: "How Noket asks an upstream which models it serves, and what it does not do."
---

> Documentation Index
> Fetch the complete documentation index at: https://docs.noket.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Probing and model discovery

When you add an upstream interactively, Noket asks the server which models it serves so you can pick
from a list instead of typing ids. The same probe backs `noket upstream test` and the console's
Add upstream form.

## The request

The probe is a `GET` to `{base_url}/v1/models`.

- A base URL that already ends in `/v1` is not given a second one.
- The request uses the upstream's key and headers, so a protected server answers the same way it would
  for a real call.
- It times out after 10 seconds and reads at most 1 MiB of the response body.

## Reading the answer

Different servers describe their models differently, and Noket handles the two common shapes:

- OpenAI-style: `{"data": [{"id": "..."}, ...]}`.
- Ollama's legacy list: `{"models": [{"name": "...", "model": "..."}]}`.

What the probe returns is a list of model id strings. The picker shows those ids; selecting one adds it
to the upstream's model list.

## What a probe is not

- **It is not a generation test.** No prompt is sent, no tokens are billed by your provider beyond any
  list request, and the model's quality is not checked.
- **It does not write anything.** A probe from `noket upstream test` or from the console's form does not
  change `config.toml`. Only saving does.
- **It does not prove calls will work.** A server can list a model and still fail a completion, for
  example when the model is not loaded or the account lacks access.

## When the probe fails

A failing probe does not block you from saving. The form lets you save and type model ids by hand, which
is what you need when:

- the server does not implement `/v1/models`;
- the server requires a key you have not entered yet;
- the server is temporarily down but you want to configure it now;
- you want to expose an id the list endpoint omits.

If the probe succeeds but a call later fails with `model_not_found`, the id in the request does not
match any id an upstream lists. Compare it with `noket upstream list`.

## Console versus CLI probing

Both ask the node's connector to make the request, so the probe runs from the machine that can reach the
server, not from the cloud. The console's form can probe with a key you have typed but not saved; when
you edit an upstream and leave the key blank while keeping the base URL, it reuses the stored key.

## Next

- [Upstreams](https://docs.noket.dev/concepts/upstreams/)
- [`noket upstream test`](https://docs.noket.dev/reference/cli/upstream/test/)

Source: https://docs.noket.dev/concepts/probing-and-model-discovery/index.mdx