---
title: "Custom Attributes"
slug: "mapp-engage-ios-sdk-custom-attributes"
updated: 2026-05-07T09:31:17Z
published: 2026-05-07T09:31:17Z
canonical: "docs.mapp.com/mapp-engage-ios-sdk-custom-attributes"
---

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

# Custom Attributes

## Overview

Custom Attributes in iOS enable developers to store and use user-specific information such as preferences, demographics, or activity data. These attributes enhance user engagement by allowing targeted and personalized communication.

---

## Use Case

1. **Purpose**:
  - Store user-specific data for personalized engagement.
  - Create user segments for tailored campaigns.
2. **Benefits**:
  - Improve user satisfaction with relevant content and offers.
  - Facilitate data-driven insights for marketing and analytics.

---

## Implementation Details

> [!WARNING]
> Warning:
> 
> The bulk-set selector exported by the SDK is `setCustomAttributtes:withCompletionHandler:` — the public header has a typo (`Attributtes` with a double `t`). Use the symbol exactly as shown; otherwise the call will not link. The matching getter `getCustomAttributes:withCompletionHandler:` is spelled correctly.

### Set Individual Custom Attributes

Assign user-specific values such as strings, numbers, or dates. Each setter takes an `AppoxeeCompletionHandler` block of type `^(NSError * _Nullable error, id _Nullable data)`.

**Swift**

```swift
Appoxee.shared()?.setStringValue("JohnDoe", forKey: "userName") { error, data in
    if error == nil { print("String attribute set successfully.") }
}

Appoxee.shared()?.setNumberValue(150, forKey: "userScore") { error, data in
    if error == nil { print("Numeric attribute set successfully.") }
}

Appoxee.shared()?.setDateValue(Date(), forKey: "userBirthday") { error, data in
    if error == nil { print("Date attribute set successfully.") }
}
```

**Objective-C**

```objectivec
// String value
[[Appoxee shared] setStringValue:@"JohnDoe"
                          forKey:@"userName"
           withCompletionHandler:^(NSError * _Nullable error, id _Nullable data) {
    if (!error) {
        NSLog(@"String attribute set successfully.");
    }
}];

// Numeric value
[[Appoxee shared] setNumberValue:@150
                          forKey:@"userScore"
           withCompletionHandler:^(NSError * _Nullable error, id _Nullable data) {
    if (!error) {
        NSLog(@"Numeric attribute set successfully.");
    }
}];

// Date value
[[Appoxee shared] setDateValue:[NSDate date]
                        forKey:@"userBirthday"
         withCompletionHandler:^(NSError * _Nullable error, id _Nullable data) {
    if (!error) {
        NSLog(@"Date attribute set successfully.");
    }
}];
```

### Set Multiple Custom Attributes at Once

Use the bulk-set selector to send several key/value pairs in a single call.

**Swift**

```swift
Appoxee.shared()?.setCustomAttributtes([
    "userName": "JohnDoe",
    "userScore": 150,
    "userBirthday": Date()
]) { error, data in
    if error == nil {
        print("Custom attributes updated successfully (bulk).")
    }
}
```

**Objective-C**

```objectivec
[[Appoxee shared] setCustomAttributtes:@{
    @"userName": @"JohnDoe",
    @"userScore": @150,
    @"userBirthday": [NSDate date]
} withCompletionHandler:^(NSError * _Nullable error, id _Nullable data) {
    if (!error) {
        NSLog(@"Custom attributes updated successfully (bulk).");
    }
}];
```

### Retrieve Custom Attributes

Fetch a single attribute by key, or fetch all stored attributes at once.

**Swift**

```swift
Appoxee.shared()?.fetchCustomField(byKey: "userName") { error, data in
    if error == nil {
        print("Fetched Attribute: \(data ?? "None")")
    }
}

Appoxee.shared()?.getCustomAttributes(nil) { error, data in
    if error == nil, let attributes = data as? [String: Any] {
        print("All attributes: \(attributes)")
    }
}
```

**Objective-C**

```objectivec
// Fetch a single attribute by key
[[Appoxee shared] fetchCustomFieldByKey:@"userName"
                  withCompletionHandler:^(NSError * _Nullable error, id _Nullable data) {
    if (!error) {
        NSLog(@"Fetched Attribute: %@", data);
    }
}];

// Fetch all custom attributes
[[Appoxee shared] getCustomAttributes:nil
                withCompletionHandler:^(NSError * _Nullable error, id _Nullable data) {
    if (!error) {
        NSDictionary *attributes = (NSDictionary *)data;
        NSLog(@"All attributes: %@", attributes);
    }
}];
```

### Increment Numeric Attributes

Update numeric values dynamically. The `byNumericValue` parameter takes an `NSNumber` — pass any integer or floating-point literal in Swift, or use the `@(...)` boxing syntax in Objective-C.

**Swift**

```swift
Appoxee.shared()?.incrementNumericKey("userScore", byNumericValue: 10) { error, data in
    if error == nil {
        print("Numeric attribute incremented successfully.")
    }
}
```

**Objective-C**

```objectivec
[[Appoxee shared] incrementNumericKey:@"userScore"
                        byNumericValue:@10
                 withCompletionHandler:^(NSError * _Nullable error, id _Nullable data) {
    if (!error) {
        NSLog(@"Numeric attribute incremented successfully.");
    }
}];
```

---

## Parameter Behaviour

- `key` — The attribute name. Use stable keys that are consistent across platforms.
- `value` — The attribute value (string, number, or date depending on the setter).
- `attributes` — Dictionary of attribute key/value pairs to set in one call (bulk setter).
- `withCompletionHandler` — `AppoxeeCompletionHandler` block of type `^(NSError * _Nullable error, id _Nullable data)`. Inspect `error` for failure; `data` carries response payload (for example, the requested attribute value for getters) and may be `nil` for setters.

> [!NOTE]
> Keep in mind:
> 
> - Custom attributes can be used as targeting criteria for dynamic and personalized push messages.
> - Use keys that are consistent across iOS, Android, and Web for uniform data handling.
> - Test attribute setters and getters under different app states (foreground, background, terminated) for accuracy.
> - To re-sync all locally stored attributes with the backend after setting a new alias, see [Set User Identifier](/v1/docs/mapp-engage-ios-sdk-set-user-identifier) and the `withResendAttributes` parameter.