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

# Concepts Overview

> Core ideas for understanding APIXO before using endpoint details

Start here when you want to understand APIXO's API families, authentication model, async generation flow, and routing options before reading endpoint details.

<CardGroup>
  <Card title="How APIXO Works" href="/docs/concepts/how-apixo-works">
    Compare async Generation APIs with direct LLM Gateway calls.
  </Card>

  <Card title="Authentication" href="/docs/concepts/authentication">
    Get an API key and send it correctly with each request.
  </Card>

  <Card title="Async Workflow" href="/docs/concepts/async-workflow">
    Submit generation tasks, poll status, or receive webhooks.
  </Card>

  <Card title="Routing Strategies" href="/docs/concepts/routing-strategies">
    Choose Auto, Value, or Official routing for your API keys.
  </Card>
</CardGroup>

## Recommended reading order

1. Read [How APIXO Works](/docs/concepts/how-apixo-works) to choose between Generation APIs and the LLM Gateway.
2. Set up [Authentication](/docs/concepts/authentication) before sending requests.
3. Use [Async Workflow](/docs/concepts/async-workflow) for image, video, and audio generation tasks.
4. Review [Routing Strategies](/docs/concepts/routing-strategies) when you need cost, quality, or provider-key control.

## API families

| Area            | Use it for                                  | Start here                               |
| --------------- | ------------------------------------------- | ---------------------------------------- |
| Generation APIs | Image, video, and audio generation          | [Generation API Overview](/docs/models)       |
| LLM Gateway     | Claude, OpenAI, and Gemini compatible calls | [LLM Gateway Overview](/docs/llm)             |
| Operations      | Balance, routing, errors, and reliability   | [Best Practices](/docs/guides/best-practices) |