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

# Models and regions

<Info>
  **Labs**

  This feature is in [Labs](/docs/astro/feature-previews).
</Info>

Otto and the AI features in the [Astro IDE](/docs/astro/ide-overview) access models from OpenAI, Anthropic, and Google through the Astronomer Gateway. Astronomer hosts these models on Azure OpenAI Service and Google Cloud Vertex AI rather than calling the model providers directly.

This document is the source of truth for the specific models and hosting regions currently in use. Astronomer updates it as the available models change.

## Azure OpenAI Service

These models run in the East US 2 region.

| Model provider | Model               |
| -------------- | ------------------- |
| OpenAI         | `gpt-5.5`           |
| OpenAI         | `gpt-5.4`           |
| OpenAI         | `gpt-5.4-mini`      |
| OpenAI         | `gpt-5.4-nano`      |
| OpenAI         | `gpt-5.3-codex`     |
| Anthropic      | `claude-opus-4-8`   |
| Anthropic      | `claude-opus-4-7`   |
| Anthropic      | `claude-opus-4-6`   |
| Anthropic      | `claude-sonnet-4-6` |
| Anthropic      | `claude-haiku-4-5`  |

## Google Cloud Vertex AI

These models run with the location set to `global`, which routes each request to whichever regional resource is available.

| Model provider | Model                           |
| -------------- | ------------------------------- |
| Anthropic      | `claude-opus-4-7`               |
| Anthropic      | `claude-opus-4-6`               |
| Anthropic      | `claude-sonnet-4-6`             |
| Anthropic      | `claude-haiku-4-5`              |
| Google         | `google/gemini-3.1-pro-preview` |
| Google         | `google/gemini-3.5-flash`       |
| Google         | `google/gemini-3-flash-preview` |
| Google         | `google/gemini-2.5-pro`         |

## Choose a model

To select a model for an Otto session, run `/model` in an interactive session to browse what's available to you, or pass `--model <id>` to pin a model at launch. See [Customize Otto](/docs/astro/customize-otto#choose-a-model) and [`astro otto` model selection](/docs/cli/v1.43/astro-otto#model-selection).