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

# Overview

> Where to start with ION's GraphQL API

## What's in this section

<CardGroup cols={2}>
  <Card title="Getting started" icon="rocket" href="/api-reference/getting-started">
    Make your first authenticated GraphQL request.
  </Card>

  <Card title="Authentication" icon="lock" href="/api-reference/authentication/overview">
    Authenticate a system or a user with API keys or OAuth.
  </Card>

  <Card title="Sandbox" icon="flask" href="/api-reference/sandbox">
    Test against an isolated sandbox tenant.
  </Card>

  <Card title="Playground" icon="terminal" href="/api-reference/playground">
    Explore the schema and run live queries.
  </Card>

  <Card title="Data model" icon="diagram-project" href="/api-reference/data-model">
    Understand the core entities and how they relate.
  </Card>

  <Card title="Example requests" icon="code" href="/api-reference/examples">
    Copy common queries and mutations.
  </Card>

  <Card title="Error codes" icon="triangle-exclamation" href="/api-reference/error-codes">
    Handle API errors and status codes.
  </Card>

  <Card title="Guides" icon="graduation-cap" href="/api-reference/guides/build-a-production-integration">
    Follow end-to-end integration guides.
  </Card>

  <Card title="MCP server" icon="robot" href="/api-reference/mcp-server">
    Use ION from an AI agent like OpenAI Codex, Claude, or Cursor.
  </Card>

  <Card title="API change policy" icon="file-contract" href="/api-reference/api-change-policy">
    Understand how the API evolves and deprecates.
  </Card>

  <Card title="Changelog" icon="clock-rotate-left" href="/api-reference/changelog">
    See recent changes to the API.
  </Card>
</CardGroup>