> ## Documentation Index
> Fetch the complete documentation index at: https://mux-mike-server-self-update.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Models

> Select and configure AI models in Xum

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

## First-class Models

Xum 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 5.1              | anthropic:claude-fable-5-1    | `fable`                                                      |         |
| Mythos 5.1             | anthropic:claude-mythos-5-1   | `mythos`                                                     |         |
| Opus 5                 | anthropic:claude-opus-5       | `opus`                                                       | ✓       |
| Sonnet 5               | anthropic:claude-sonnet-5     | `sonnet`                                                     |         |
| Haiku 4.5              | anthropic:claude-haiku-4-5    | `haiku`                                                      |         |
| GPT-5.6 Sol            | openai:gpt-5.6-sol            | `gpt`, `sol`                                                 |         |
| GPT-5.6 Terra          | openai:gpt-5.6-terra          | `terra`                                                      |         |
| GPT-5.6 Luna           | openai:gpt-5.6-luna           | `luna`                                                       |         |
| GPT-6 Astra            | openai:gpt-6-astra            | `astra`, `gpt-6-astra`                                       |         |
| 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 3.8 Flash       | google:gemini-3.8-flash       | `gemini-flash`                                               |         |
| Grok 4.6               | xai:grok-4.6                  | `grok`, `grok-4.6`                                           |         |
| 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`                        |         |
| Kimi K3                | moonshotai:kimi-k3            | `kimi`, `k3`, `kimi-k3`                                      |         |
| GLM 5.3 Flash          | zai:glm-5.3-flash             | `glm`, `glm-flash`, `glm-5.3-flash`                          |         |

### Pro reasoning mode (GPT-5.6 and GPT-6 Astra)

GPT-6 Astra and every GPT-5.6 model (Sol, Terra, and Luna) support OpenAI's pro reasoning mode. Open the reasoning selector next to the model picker and enable **Pro mode** (or run "Toggle Pro Reasoning Mode" from the Command Palette) to send `reasoning.mode: "pro"` with each request. The setting is saved per workspace. Pro mode can consume more tokens and responses can take noticeably longer. Pro is available on supported direct OpenAI Responses API routes. Gateway routes, Chat Completions, and Codex OAuth use standard mode.

For advisor calls, enable the Advisor Tool experiment and use its **Reasoning** picker under **Settings → Experiments**. Advisor Pro mode is saved independently of reasoning effort and the calling chat’s mode.

## 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 `xum run` CLI accepts the same thinking levels via `--thinking`:

```bash theme={null}
xum run -t 0 "Quick fix"          # Lowest thinking for the model
xum 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>