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

# Models

> Select and configure AI models in Mux

Mux supports multiple AI providers. Configure provider API keys in **Settings → Providers** — see [Providers](/config/providers) for setup.

## First-class Models

Mux ships with curated models kept up to date with the frontier. Use any custom model with `/model <provider:model_id>`.

| Model                  | ID                            | Aliases                                                      | Default |
| ---------------------- | ----------------------------- | ------------------------------------------------------------ | ------- |
| Fable 5                | anthropic:claude-fable-5      | `fable`                                                      |         |
| Opus 4.8               | anthropic:claude-opus-4-8     | `opus`                                                       | ✓       |
| Sonnet 4.6             | anthropic:claude-sonnet-4-6   | `sonnet`                                                     |         |
| Haiku 4.5              | anthropic:claude-haiku-4-5    | `haiku`                                                      |         |
| GPT-5.5                | openai:gpt-5.5                | `gpt`, `gpt-5.5`                                             |         |
| GPT-5.5 Pro            | openai:gpt-5.5-pro            | `gpt-pro`, `gpt-5.5-pro`                                     |         |
| GPT-5.4 Mini           | openai:gpt-5.4-mini           | `gpt-mini`                                                   |         |
| GPT-5.4 Nano           | openai:gpt-5.4-nano           | `gpt-nano`                                                   |         |
| Codex 5.3              | openai:gpt-5.3-codex          | `codex`, `codex-5.3`                                         |         |
| Spark 5.3              | openai:gpt-5.3-codex-spark    | `spark`                                                      |         |
| Codex Mini 5.1         | openai:gpt-5.1-codex-mini     | `codex-mini`                                                 |         |
| Codex Max 5.1          | openai:gpt-5.1-codex-max      | `codex-max`                                                  |         |
| Gemini 3.1 Pro Preview | google:gemini-3.1-pro-preview | `gemini`, `gemini-pro`                                       |         |
| Gemini 3.5 Flash       | google:gemini-3.5-flash       | `gemini-flash`                                               |         |
| Grok 4 1 Fast          | xai:grok-4-1-fast             | `grok`, `grok-4`, `grok-4.1`, `grok-4-1`                     |         |
| Grok Code Fast 1       | xai:grok-code-fast-1          | `grok-code`                                                  |         |
| DeepSeek V4 Pro        | deepseek:deepseek-v4-pro      | `deepseek`, `deepseek-pro`, `deepseek-v4`, `deepseek-v4-pro` |         |
| DeepSeek V4 Flash      | deepseek:deepseek-v4-flash    | `deepseek-flash`, `deepseek-v4-flash`                        |         |

## Model Selection

Keyboard shortcuts:

* **Cycle models**
  * **macOS:** `Cmd+/`
  * **Windows/Linux:** `Ctrl+/`

To *choose* a specific model, click the model pill in the chat footer.

Alternatively, use the Command Palette (`Cmd+Shift+P` / `Ctrl+Shift+P`):

1. Type "model"
2. Select "Change Model"
3. Choose from available models

Models are specified in the format: `provider:model-name`

## One-shot Overrides

Override the model or thinking level for a single message using slash commands. The override applies only to that message — workspace settings stay unchanged.

### Syntax

| Command                     | Effect                                   |
| --------------------------- | ---------------------------------------- |
| `/sonnet explain this code` | Use Sonnet for one message               |
| `/opus+high deep review`    | Use Opus with high thinking              |
| `/haiku+0 quick answer`     | Use Haiku at its lowest thinking level   |
| `/+2 analyze this`          | Keep current model, set thinking level 2 |

### Thinking levels

Append `+level` to any model alias. Levels can be **named** (`off`, `low`, `medium`/`med`, `high`, `max`) or **numeric** (`0`–`9`).

Numeric levels are **model-relative** — they map to the model's allowed thinking range:

* `0` = model's lowest allowed level (e.g., `off` for Sonnet, `medium` for GPT-5.5 Pro)
* Higher numbers select progressively higher levels, clamped to the model's maximum

This means `/sonnet+0` disables thinking while `/gpt-pro+0` sets thinking to medium (GPT-5.5 Pro's minimum).

Use `/+level` (no model) to override thinking on the current model: `/+0 quick answer`

### CLI

The `mux run` CLI accepts the same thinking levels via `--thinking`:

```bash theme={null}
mux run -t 0 "Quick fix"          # Lowest thinking for the model
mux run -t high "Deep analysis"   # Named level
```

## Next Steps

<Card title="Configure Providers" icon="key" href="/config/providers">
  Set up API keys for Anthropic, OpenAI, Google, and other providers.
</Card>