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

# Models

> How model choice works: Auto, MAX, or a specific model you pick

Summer gives you three ways to choose which model does the work:

* **[Auto](/auto-mode/auto)** — Summer picks for you. The default for new chats, available on every plan.
* **[MAX](/auto-mode/premium)** — Summer picks from the frontier models, billed at the API pricing of whatever it selects. Paid plans only.
* **A specific model** — you pick one yourself from the model selector.

## The selector is the list

The model selector in the chat composer is the source of truth for what you can
pick right now. It is rendered from the live model catalog, so it is current in a
way a documentation page cannot be. Open it and you will see every model, grouped
by provider, with its context window and any cost warning attached.

Models are added and retired regularly. Anything named on this page is a snapshot
of a moving list; the selector is not.

## What each plan can pick

|                | Models you can select                                                                     |
| -------------- | ----------------------------------------------------------------------------------------- |
| **Signed out** | Auto, plus one directly selectable OpenAI model (currently Luna Extra High)               |
| **Free plan**  | Auto, plus two directly selectable models (currently Luna Extra High and DeepSeek V4 Pro) |
| **Paid plans** | Auto, MAX, and every model in the selector                                                |

Auto is not the only thing a free account can use. The two concrete models are
selectable on purpose, for people who would rather name their model than hand the
choice to Auto's routing.

Models your plan does not cover still appear in the selector, muted and marked with
a lock. Picking one opens the upgrade prompt rather than switching your chat.

## Which providers are in the selector

On a paid plan you can pick directly from every provider represented in the
selector:

| Provider            | What it is good for                                              |
| ------------------- | ---------------------------------------------------------------- |
| **OpenAI**          | Everyday coding and agentic work, plus a coding-specialist model |
| **Anthropic**       | Hard coding, long-horizon agentic tasks, and planning            |
| **DeepSeek**        | Long-context coding when you want more building time per dollar  |
| **GLM (Z.ai)**      | Large projects and long-running agentic work at 1M context       |
| **Kimi (Moonshot)** | Long-context reasoning with native vision                        |
| **Grok (xAI)**      | Fast coding, knowledge work, and STEM reasoning                  |
| **Qwen (Alibaba)**  | Long-running agentic work and tool use                           |

Individual model names and versions live in the selector — hover one to see its
description, context window, and any cost warning. Some frontier models will burn a
\$20 plan quickly; those carry a "Higher cost" marker and an estimate of how many
messages your balance has left at that model's rate.

<Info>
  If you do not want to think about any of this, leave it on Auto. It is the
  default for a reason and it is what we recommend for most work.
</Info>