> ## 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.

# Phone

> Kotlin Data Class

**Data Class**

```kotlin theme={null}
data class Phone(val phoneNumber: String, val expiresAt: Long? = null) : DelegatedSigner
```

## Constructors

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

## Properties

### expiresAt

```kotlin theme={null}
open override val expiresAt: Long? = null
```

Optional expiration timestamp in milliseconds since Unix epoch. If set, the delegated signer will expire at this time.

### phoneNumber

```kotlin theme={null}
val phoneNumber: String
```