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

# Engine

> A Cludo engine groups the index, crawler, ranking, and configuration that powers one search experience. Learn how engines map to your sites and APIs.

An **engine** is the unit of configuration that powers one search experience. It owns the indexed content, the search behavior (page rankings, synonyms, banners, AI features), and the credentials clients use to query it. Most accounts have one engine per site or property; you can have several when different audiences need different content or relevance tuning.

Every API call that returns or scores documents takes an `engineId` in the path — see the [Search](/api-reference/v4/search/search) reference for the standard request shape. The engine ID is also embedded in [SiteKey](/authentication) tokens, so a SiteKey is always tied to one specific engine.

Engines are created and configured in [MyCludo](https://my.cludo.com) under **Engines**.