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

# DelegatedSigner.ApiKey

> Kotlin Data Class

**Data Class**

```kotlin theme={null}
data class ApiKey(val expiresAt: Long? = null) : DelegatedSigner
```

## Constructors

```kotlin theme={null}
constructor(expiresAt: Long? = null)
```

## Properties

| Property    | Type    | Description                                                                                                            |
| ----------- | ------- | ---------------------------------------------------------------------------------------------------------------------- |
| `expiresAt` | `Long?` | Optional expiration timestamp in milliseconds since Unix epoch. If set, the delegated signer will expire at this time. |