> For the complete documentation index, see [llms.txt](https://docs.geode.fi/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.geode.fi/key-concepts/staking-derivatives/g-derivatives.md).

# G-Derivatives

### G-Derivatives are *Databases* of <mark style="color:purple;">Balances</mark> and <mark style="color:purple;">Prices</mark> with extra <mark style="color:purple;">Scalability (interfaces).</mark>

<figure><img src="/files/JulC0qj7i5HOmLLU8Vp1" alt=""><figcaption><p>a special ERC1155 contract</p></figcaption></figure>

## <mark style="color:purple;">Balances</mark>

Acts as a **Database** for the amount of staked Ether that is represented by multiple Maintainers.

Balances for the depositors are tracked with a predetermined ID. IDs are the main separators of the different types of gETH, thus different maintainers.&#x20;

```solidity
mapping(uint256 => mapping(address => uint256)) private _balances;
```

{% hint style="warning" %}
Balances can be directly changed by **Interfaces.**
{% endhint %}

{% hint style="success" %}
Anyone can disable the access of the interfaces by simply using the **avoidInterfaces** function!
{% endhint %}

## <mark style="color:purple;">Pricing</mark>

The balance of users, doesn’t change while the amount of the underlying tokens increase over time thanks to **Staking Rewards**.

Every different ID of gETH has a different *\_pricePerShare* value.&#x20;

```solidity
mapping(uint256 => uint256) private _pricePerShare;
```

### **\_pricePerShare**

Basically, a variable that represents the equivalent of 1 gETH, in terms of underlying Ether.&#x20;

*\_pricePerShare* is used by Geode on minting / burning operations, *and* can be used by other contracts with peace of mind.&#x20;

It's value is updated by an Oracle.

{% content-ref url="/pages/mSbBs4vOrv18Q1994rDO" %}
[Oracles](/key-concepts/oracles.md)
{% endcontent-ref %}

{% hint style="info" %}
The **\_pricePerShare** parameter is one of the key components that supports DeFi.
{% endhint %}

## <mark style="color:purple;">Interfaces</mark>

> **Interfaces** are one of the most important concepts introduced by Geode.fi.

ERC-1155 tokens are not compatible within the DeFi ecosystem, thus they need to be mutated for public usage.&#x20;

**Every Derivative has a different use-case, depending on the represented Protocol, therefore it doesn’t come with a preset implementation.**

Interfaces are external contracts used to manage the underlying assets for different purposes. Unlocking infinite flexibility!

{% hint style="success" %}
There can be multiple Interfaces for one gETH ID.

However, Portal doesn't currently allow that.
{% endhint %}

```solidity
mapping(uint256 => mapping(address => bool)) private _interfaces;
```

{% hint style="success" %}
Transactions that are conducted with Interfaces can bypass the [ERC1155 requirements](https://eips.ethereum.org/EIPS/eip-1155#erc-1155-token-receiver), while other non-compatible contracts cannot receive them.
{% endhint %}

```solidity
  function _doSafeTransferAcceptanceCheck(...) private {
    if (to.isContract() && !isInterface(operator, id)) 
    {
    ...
    }
```

#### Learn more about other cool gETH functionalities:

{% content-ref url="/pages/MsaaugV6L8LFYtBZIQuv" %}
[gETH vs gAVAX](/key-concepts/staking-derivatives/g-derivatives/geth-vs-gavax.md)
{% endcontent-ref %}

#### See our case studies about some interfaces here: &#x20;

{% content-ref url="/pages/NMzvFXpWn6oyM78TmdkQ" %}
[Current Interfaces](/key-concepts/permissionless-configurable-staking-pools/current-interfaces.md)
{% endcontent-ref %}