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

# UserProfile

> Data model for user profile information in Divvy

The `UserProfile` model represents a user's basic profile information in the Divvy app.

## Data Class Definition

```kotlin UserProfile.kt theme={null}
package com.example.divvy.models

import kotlinx.serialization.Serializable

@Serializable
data class UserProfile(
    val id: String,
    val displayName: String,
    val email: String? = null
)
```

Source: UserProfile.kt

## Fields

<ParamField path="id" type="String" required>
  Unique identifier for the user
</ParamField>

<ParamField path="displayName" type="String" required>
  The user's display name shown throughout the app
</ParamField>

<ParamField path="email" type="String?" default="null">
  Optional email address for the user. Nullable field.
</ParamField>

## Usage Examples

### Creating a UserProfile

```kotlin theme={null}
val userProfile = UserProfile(
    id = "user_123",
    displayName = "Sarah Chen",
    email = "sarah@example.com"
)
```

### UserProfile Without Email

```kotlin theme={null}
val userProfile = UserProfile(
    id = "user_456",
    displayName = "Alex Johnson"
    // email is null by default
)
```

## Related Models

### GroupMember

A simplified representation of a user within a group context:

```kotlin GroupMember.kt theme={null}
@Serializable
data class GroupMember(
    val userId: String,
    val name: String
)
```

Source: \[GroupMember.kt:6]

The `GroupMember` model is used when displaying members in a group and only requires the user ID and name, not the full profile information.

### MemberBalance

Represents a user's balance within a specific group:

```kotlin MemberBalance.kt theme={null}
@Serializable
data class MemberBalance(
    val userId: String,
    val name: String,
    val balanceCents: Long   // positive = they owe you, negative = you owe them
)
```

Source: \[MemberBalance.kt:6]

## Serialization

The `UserProfile` model uses Kotlin Serialization with the `@Serializable` annotation. All fields are serialized with their property names (no custom `@SerialName` annotations).

## Usage in the App

User profiles are referenced throughout the app:

* **Group Creation**: The `createdBy` field in [Group](group) references a user ID
* **Expenses**: The `paidByUserId` field in [Expense](expense) indicates who paid
* **Ledger Entries**: The `paidByUserId` and `toUserId` fields in [LedgerEntry](ledger-entry) track transactions between users
* **Activity Feed**: User names and IDs are displayed in expense and settlement activities