> ## Documentation Index
> Fetch the complete documentation index at: https://to11.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.
# Models
> How a connected provider's model list works in to11, and how models are chosen when you build a routing rule.
A model is a single LLM offered by a connected provider — `gpt-4o`, `claude-sonnet-4-6`, `text-embedding-3-small`, and so on. Each provider you connect exposes a list of the models it serves, and that list is what to11 routes against.
## The provider model list
When you connect a provider in **Project → AI Gateway → Providers**, to11 discovers the models the upstream API offers. You choose which of those models the provider exposes to your project — its allow-list. Only models on a provider's allow-list can be routed to.
You can revisit a provider later, from the **Providers** list, to add or remove models from its allow-list as your usage changes.
## How models are chosen in routing
A model name is the thing every routing decision keys on:
* In **passthrough** (L1), you call the gateway with a model name and to11 forwards the request to whichever connected provider serves that model.
* In a **route** (L2), you pick the model the route matches on, and the route's [targets](/docs/deploy/concepts/targets) each pair a model with a stored credential. The models you can pick are the ones your connected providers expose.
* In a **function** (L3), the named task resolves to a route or to a model; the model still has to be one a connected provider serves.
When you build a routing rule under **Project → AI Gateway → Routing**, the model picker is populated from the allow-lists of your connected providers. A model that no connected provider serves is unknown to the gateway and returns a `404`.
Models are identified by name across all three routing layers. The same model name resolves the same way whether it arrives via passthrough, a route, or a function.
## Next steps
Connecting a provider and what it exposes.
How a route maps a model name to a strategy and targets.