> For the complete documentation index, see [llms.txt](https://craig-branscom.gitbook.io/marble-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://craig-branscom.gitbook.io/marble-docs/contract-standard/marble-core.md).

# Marble Core

## Core Interface

The **Marble Core Interface** consists of the **config**, **groups**, **behaviors**, and **items** features. All Marble Contracts, at a minimum, must include the Marble Core Interface in order to be considered a valid Marble Digital Item contract.

Other additional plugin-like features, called Marble Layers, are optional and not required to be a valid Marble contract, but do add exceptional capabilities on top of the Marble Core Interface.

## Config :control\_knobs: 

The Marble Config is a table in the contract that tracks administrative information like the contract name, version, admin, and serial counter.

{% content-ref url="/pages/-LvNO4sfNy-hWEnRuu4k" %}
[Config](/marble-docs/contract-standard/marble-core/config.md)
{% endcontent-ref %}

## Groups :busts\_in\_silhouette: 

Groups are sets of items that share behaviors and collective supply mechanics. The assigned group manager can also adjust group behaviors through standardized contract actions and is allowed to create new items within a group.

{% content-ref url="/pages/-Lv1gfC7gvxi8ySEjZ\_w" %}
[Groups](/marble-docs/contract-standard/marble-core/groups.md)
{% endcontent-ref %}

## Behaviors :chess\_pawn: 

Behaviors define the different actions a given item can perform such as **transfer**, **activate**, **consume**, or **destroy**. Group managers can turn behaviors on or off to best match their use case.

{% content-ref url="/pages/-M8bHa4YfFzOZtA45KQT" %}
[Behaviors](/marble-docs/contract-standard/marble-core/behaviors.md)
{% endcontent-ref %}

## Items :blue\_circle: 

Items are the individual ownable objects stored in the contract. Every item created is given a unique contract-wide serial number that's used to identify it among all other items in the contract. Most Marble Layers add additional functionality on top of the base Items feature.

{% content-ref url="/pages/-Lv1gaUjvi62mDH39xdb" %}
[Items](/marble-docs/contract-standard/marble-core/items.md)
{% endcontent-ref %}


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://craig-branscom.gitbook.io/marble-docs/contract-standard/marble-core.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.