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

# VerifierModule

## Overview

`VerifierModule` is an abstract extension of `BaseModule` designed to provide standardized access to a `Verifier` contract. It manages internal storage using a deterministic slot derived via `SlotLibrary`, supporting secure modular composition across multiple vault systems.

## Constructor

```solidity theme={null}
constructor(string memory name_, uint256 version_)
```

Computes and stores the custom storage slot used for verifier configuration based on a unique `(name_, version_)` pair.

**Parameters:**

* `name_` — Unique identifier used to namespace the storage slot.
* `version_` — Version number used for slot derivation.

## Public & External Functions

### `verifier()`

```solidity theme={null}
function verifier() public view returns (IVerifier)
```

Returns the address of the configured `Verifier` contract. It is retrieved from internal storage using a fixed slot.

**Returns:**

* `IVerifier` — The verifier contract associated with the module.

## Internal Functions

### `__VerifierModule_init(address verifier_)`

```solidity theme={null}
function __VerifierModule_init(address verifier_) internal onlyInitializing
```

Initializes the verifier module with the given verifier contract address. Validates non-zero address to prevent misconfiguration.

**Parameters:**

* `verifier_` — Address of the verifier contract.

**Reverts:**

* `ZeroAddress()` if verifier address is zero.

## Private Functions

### `_verifierModuleStorage()`

```solidity theme={null}
function _verifierModuleStorage() private view returns (VerifierModuleStorage storage)
```

Internal function to access the `VerifierModuleStorage` struct using the precomputed custom slot. Utilizes inline assembly for direct storage access.

**Returns:**

* `VerifierModuleStorage` — Storage struct holding verifier address.