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

# Storage

> Auto-generated API documentation

[**@tevm/voltaire**](index.mdx)

***

[@tevm/voltaire](index.mdx) / Storage

# Storage

Storage Layout Utilities

## See

* [https://eips.ethereum.org/EIPS/eip-7201](https://eips.ethereum.org/EIPS/eip-7201) - Namespaced Storage Layout
* [https://eips.ethereum.org/EIPS/eip-8042](https://eips.ethereum.org/EIPS/eip-8042) - Diamond Storage

## Type Aliases

### StorageSlotType

> **StorageSlotType** = `Uint8Array` & `object`

Defined in: [src/primitives/Storage/StorageType.ts:7](https://github.com/evmts/voltaire/blob/bd6ec34405c15ad8cd51d11579d495dc53813482/src/primitives/Storage/StorageType.ts#L7)

Storage slot type (32 bytes)
Represents a storage location in Ethereum contract storage

#### Type Declaration

##### \[brand]

> `readonly` **\[brand]**: `"StorageSlot"`

## Functions

### calculateErc7201()

> **calculateErc7201**(`keccak256`, `id`): `Uint8Array`\<`ArrayBufferLike`>

Defined in: [src/primitives/Storage/calculateErc7201.js:10](https://github.com/evmts/voltaire/blob/bd6ec34405c15ad8cd51d11579d495dc53813482/src/primitives/Storage/calculateErc7201.js#L10)

Calculate ERC-7201 namespaced storage slot
Formula: keccak256(keccak256(id) - 1) & \~0xff
The result has the last byte cleared (set to 0x00)

#### Parameters

##### keccak256

(`data`) => `Uint8Array`

Keccak256 hash function

##### id

`string`

Namespace identifier string

#### Returns

`Uint8Array`\<`ArrayBufferLike`>

32-byte storage slot

#### See

[https://eips.ethereum.org/EIPS/eip-7201](https://eips.ethereum.org/EIPS/eip-7201)

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### calculateErc8042()

> **calculateErc8042**(`keccak256`, `id`): `Uint8Array`\<`ArrayBufferLike`>

Defined in: [src/primitives/Storage/calculateErc8042.js:10](https://github.com/evmts/voltaire/blob/bd6ec34405c15ad8cd51d11579d495dc53813482/src/primitives/Storage/calculateErc8042.js#L10)

Calculate ERC-8042 (Diamond Storage) storage slot
Formula: keccak256(id)
Simpler than ERC-7201, just the direct hash of the identifier

#### Parameters

##### keccak256

(`data`) => `Uint8Array`

Keccak256 hash function

##### id

`string`

Storage namespace identifier string

#### Returns

`Uint8Array`\<`ArrayBufferLike`>

32-byte storage slot

#### See

[https://eips.ethereum.org/EIPS/eip-8042](https://eips.ethereum.org/EIPS/eip-8042)