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

# What is 4D OS?

Fourth Dimension Operating System (4D OS) is a platform that provides organizations with a comprehensive
set of tools to manage fan engagement, loyalty, rewards, consent, and more.
Your organization brings its members; 4D gives you one place to hold their identity, track how they engage,
reward that engagement with XP, and respect their consent choices throughout -
with an on-chain XP token settling behind the scenes.

You integrate through our [REST API](/api-reference/overview),
authenticated with an organization API key, and there is a lightweight
[engagement SDK](/sdk/engagement-sdk) for browser event tracking. Everything
your key touches is scoped to your organization: your members, your events,
your XP economy.

## The pieces

* **Tenants and members** - your organization is a tenant; each person in your
  member base is a member of it. One person can hold a single 4D identity
  across many organizations. See
  [Tenants and members](/concepts/tenants-and-members).
* **Events** - engagement events flow in from your sites and apps (a
  publishable tracking key, batched browser events) and drive everything
  downstream. See [Events](/concepts/events).
* **XP** - a double-entry loyalty ledger. Rules turn events into XP awards;
  tiers rank members; balances settle to an on-chain token. See
  [XP](/concepts/xp).
* **Consent** - append-only consent records gate what the platform does with
  member data. See [Consent](/concepts/consent).

## Start here

<CardGroup cols={2}>
  <Card title="Quickstart" icon="rocket" href="/quickstart">
    Make your first authenticated call in five minutes.
  </Card>

  <Card title="Create a user" icon="user-plus" href="/walkthroughs/create-a-user">
    Add a member to your organization, idempotently.
  </Card>

  <Card title="Trigger an event" icon="bolt" href="/walkthroughs/trigger-an-event">
    Track engagement from a browser with a publishable key.
  </Card>

  <Card title="Migrate an existing member base" icon="database" href="/walkthroughs/migrate-existing-members">
    Bulk-import your current members - never overwrites, never emails, never deletes.
  </Card>
</CardGroup>

## API reference

The [API reference](/api-reference/overview) is generated live from the same
schemas the server validates against, so it cannot drift from what the API
actually accepts.