# Getting started: LiveObjects in Swift

<Aside data-type='note'>
**Building with LiveObjects?** Help shape its future by [sharing your use case](https://44qpp.share.hsforms.com/2fZobHQA1ToyRfB9xqZYQmQ).
</Aside>

This guide shows how to integrate Ably LiveObjects into your Swift application.

You will learn how to:

* Create an Ably account and get an API key for authentication.
* Install the Ably Pub/Sub SDK.
* Create a channel with LiveObjects functionality enabled.
* Use the [PathObject API](https://ably.com/docs/liveobjects/concepts/path-object.md) to access objects on a channel.
* Create, update and subscribe to changes on LiveObjects data structures: [LiveMap](https://ably.com/docs/liveobjects/map.md) and [LiveCounter](https://ably.com/docs/liveobjects/counter.md).

## Authentication 

An [API key](https://ably.com/docs/auth.md#api-keys) is required to authenticate with Ably. API keys are used either to authenticate directly with Ably using [basic authentication](https://ably.com/docs/auth/basic.md), or to generate tokens for untrusted clients using [token authentication](https://ably.com/docs/auth/token.md).

<Aside data-type='important'>
The examples use [basic authentication](https://ably.com/docs/auth/basic.md) to demonstrate features for convenience. In your own applications, basic authentication should never be used on the client-side as it exposes your Ably API key. Instead use [token authentication](https://ably.com/docs/auth/token.md).
</Aside>

[Sign up](https://ably.com/sign-up) for a free account and create your own API key in the [dashboard](https://ably.com/dashboard) or use the [Control API](https://ably.com/docs/platform/account/control-api.md) to create an API key programmatically.

API keys and tokens have a set of [capabilities](https://ably.com/docs/auth/capabilities.md) assigned to them that specify which operations can be performed on which resources. The following capabilities are available for LiveObjects:

* `object-subscribe` - grants clients read access to LiveObjects, allowing them to get the channel object and subscribe to updates.
* `object-publish` - grants clients write access to LiveObjects, allowing them to perform mutation operations on objects.

To use LiveObjects, an API key must have at least the `object-subscribe` capability. With only this capability, clients will have read-only access, preventing them from calling mutation methods on LiveObjects.

For the purposes of this guide, make sure your API key includes both `object-subscribe` and `object-publish` [capabilities](https://ably.com/docs/auth/capabilities.md) to allow full read and write access.

## Install Ably Pub/Sub SDK 

LiveObjects is available as part of the Ably Pub/Sub SDK via the dedicated LiveObjects plugin. The plugin ships as the `AblyLiveObjects` product of the `ably-cocoa` package from version 1.3.0 onwards, and is available through Swift Package Manager only. There is no separate package or version to install: the plugin is versioned and released as part of `ably-cocoa`.

The LiveObjects plugin requires a minimum deployment target of iOS 14, macOS 11, or tvOS 14, and Xcode 16.3 or later.

<Aside data-type='note'>
To follow this guide in Xcode, create a new iOS project with the SwiftUI App template. All code can be added directly to your `ContentView.swift` file, inside the `ContentView` struct. Use the `.task` modifier with a `do { … } catch { … }` inside to run the Ably code when the view appears. No additional files or setup are needed. All `print` output will appear in Xcode's debug console (View > Debug Area > Activate Console, or press Cmd+Shift+C).
</Aside>

Add the Ably SDK and the LiveObjects plugin to your Xcode project:

1. Select File → Add Package Dependencies.
2. Paste `https://github.com/ably/ably-cocoa` in the search box.
3. Set the dependency rule to version 1.4.0 or later.
4. Add both the `Ably` and `AblyLiveObjects` products to your target.

To install the plugin in another Swift package instead, add both products to your target's dependencies in `Package.swift`:

<Code>

### Swift

```
dependencies: [
    .package(url: "https://github.com/ably/ably-cocoa", from: "1.4.0"),
],
targets: [
    .target(
        name: "MyTarget",
        dependencies: [
            .product(name: "Ably", package: "ably-cocoa"),
            .product(name: "AblyLiveObjects", package: "ably-cocoa"),
        ]
    ),
]
```
</Code>

For the complete installation notes, platform requirements, usage overview and example app, see the [LiveObjects section of the ably-cocoa README](https://github.com/ably/ably-cocoa#liveobjects).

Import the SDK and the LiveObjects plugin into your project:

<Code>

### Swift

```
import Ably
import AblyLiveObjects
```
</Code>

## Instantiate a client 

Instantiate an Ably Realtime client from the Pub/Sub SDK, providing the LiveObjects plugin:

<Code>

### Swift

```
let clientOptions = ARTClientOptions(key: "your-api-key")
clientOptions.plugins = [.liveObjects: AblyLiveObjects.Plugin.self]

let realtime = ARTRealtime(options: clientOptions)
```
</Code>

A [`ClientOptions`](https://ably.com/docs/api/realtime-sdk.md#client-options) object may be passed to the Pub/Sub SDK instance to further customize the connection, however at a minimum you must set an API key and register the LiveObjects plugin through `clientOptions.plugins` so that the client can use LiveObjects functionality.

## Create a channel 

LiveObjects is managed and persisted on [channels](https://ably.com/docs/channels.md). To use LiveObjects, you must first create a channel with the correct [channel mode flags](https://ably.com/docs/channels/options.md#modes):

* `OBJECT_SUBSCRIBE` - required to access objects on a channel.
* `OBJECT_PUBLISH` - required to create and modify objects on a channel.

<Aside data-type='note'>
When you provide an explicit `modes` property for a channel, you override the set of [default modes](https://ably.com/docs/channels/options.md#modes) used for that channel. So, if you're using the channel for anything in addition to LiveObjects, you need to ensure that you also include the other modes required by the features you are using.
</Aside>

<Code>

### Swift

```
let channelOptions = ARTRealtimeChannelOptions()
channelOptions.modes = [.objectPublish, .objectSubscribe]
let channel = realtime.channels.get("test-channel", options: channelOptions)
```
</Code>

## Get the channel object 

The [`channel.object`](https://ably.com/docs/api/realtime-sdk/channels.md#object) property gives access to the LiveObjects API for a channel.

Use `channel.object.get()` to obtain the channel object. The channel object is a [`LiveMap`](https://ably.com/docs/liveobjects/map.md) that always exists on a channel and acts as the top-level entry point for accessing and persisting objects. It is returned as a [`LiveMapPathObject`](https://ably.com/docs/liveobjects/concepts/path-object.md#get), which provides a path-based API for accessing and manipulating the object hierarchy.

`channel.object.get()` is an `async` function that suspends with `try await` until the LiveObjects state is synchronized with the Ably system. Reads are synchronous and local:

<Code>

### Swift

```
let rootObject = try await channel.object.get()
```
</Code>

<Aside data-type='important'>
Mutations and `channel.object.get()` are asynchronous: they suspend with `try await` until the operation completes. Reads, navigation and casts are synchronous and run locally, so they need no `await`. There are no blocking variants of these calls. Subscription callbacks fire on ably-cocoa's callback queue, which is the main queue by default, so you can update your UI directly from them without hopping queues. If you set a custom `dispatchQueue` on `ARTClientOptions`, hop back to the main actor yourself before touching UI.
</Aside>

<Aside data-type='note'>
Calling `channel.object.get()` implicitly attaches to the channel if it's not already attached. You don't need to manually call `channel.attach()` before getting the object.
</Aside>

## Create and assign objects 

You can create and assign objects using the `LiveMap.create()` and `LiveCounter.create()` static methods. These methods return a blueprint describing the object to create; the actual object is created when you assign it to a key with `set()`. Wrap a blueprint in `.liveCounter(...)` or `.liveMap(...)` when passing it to `set()`, while primitive values such as strings and numbers can be passed directly:

<Code>

### Swift

```
// Create a LiveCounter with initial value 0
let visits = LiveCounter.create(initialCount: 0)

// Assign it to the 'visits' key on the channel object
try await rootObject.set(key: "visits", value: .liveCounter(visits))

// Create a LiveMap with initial entries
let reactions = LiveMap.create(entries: [
    "likes": 0,
    "hearts": 0,
])

// Assign it to the 'reactions' key on the channel object
try await rootObject.set(key: "reactions", value: .liveMap(reactions))

// Infer types for the assigned objects
let visitsCounter = rootObject.get(key: "visits").asLiveCounter()
let reactionsMap = rootObject.get(key: "reactions").asLiveMap()
```
</Code>

`rootObject.get(key:)` returns a general [`PathObject`](https://ably.com/docs/liveobjects/concepts/path-object.md) that doesn't yet know the type of the value it points to. Call one of the `as*` methods, such as `asLiveCounter()` or `asLiveMap()`, to work with the value as a specific type. These casts are always safe to call: they never throw, even if the value at the path has a different type. Learn more about [Type inference](https://ably.com/docs/liveobjects/typing.md#type-inference).

<Aside data-type='note'>
You can create deeply nested structures in a single operation by nesting `LiveMap.create()` and `LiveCounter.create()` calls.
</Aside>

## Subscribe to updates 

Subscribe to realtime updates using the `subscribe()` method on a `PathObject`. You will be notified when the object at that path is updated by other clients or by you:

<Code>

### Swift

```
// Subscribe to counter updates
let counterSubscription = try visitsCounter.subscribe { event in
    guard let value = try? event.object.asLiveCounter().value() else { return }
    print("Visits counter updated: \(value)")
}

// Subscribe to map updates
let mapSubscription = try reactionsMap.subscribe { event in
    guard let json = try? event.object.compactJson() else { return }
    print("Reactions updated: \(json)")
}
```
</Code>

The subscription callback receives an event that exposes:
- `object`: A `PathObject` pointing to the path where the change occurred.
- `message`: The `ObjectMessage` that carried the operation that led to the change (nullable).

The `subscribe()` method also returns a `Subscription` object. When you no longer want to receive updates, call `unsubscribe()` on it:

<Code>

### Swift

```
// Keep the Subscription returned by subscribe()
let subscription = try visitsCounter.subscribe { event in
    guard let value = try? event.object.asLiveCounter().value() else { return }
    print("Visits counter updated: \(value)")
}

// Later, stop receiving updates
subscription.unsubscribe()
```
</Code>

Every `PathObject` also exposes an `events()` [`AsyncStream`](https://developer.apple.com/documentation/swift/asyncstream), so you can consume updates with `for await`, which is often the more idiomatic pattern in Swift. Breaking out of the loop, or cancelling the enclosing task, automatically unsubscribes:

<Code>

### Swift

```
for await event in try visitsCounter.events() {
    guard let value = try? event.object.asLiveCounter().value() else { continue }
    print("Visits counter updated: \(value)")
}
```
</Code>

## Update objects 

Update objects using mutation methods on `PathObject`. All subscribers (including you) will be notified of the changes:

<Code>

### Swift

```
// Update counter
try await visitsCounter.increment(amount: 5)
// console: Visits counter updated: 5.0

try await visitsCounter.decrement(amount: 2)
// console: Visits counter updated: 3.0

// Update map
try await reactionsMap.set(key: "likes", value: 10)
// console: Reactions updated: {"likes":10.0,"hearts":0.0}

try await reactionsMap.set(key: "hearts", value: 5)
// console: Reactions updated: {"likes":10.0,"hearts":5.0}

try await reactionsMap.remove(key: "likes")
// console: Reactions updated: {"hearts":5.0}
```
</Code>

<Aside data-type='note'>
Mutation methods send operations to the Ably system and apply changes locally as soon as the operations are acknowledged. Once the `await` completes, the operation has been applied locally and you can read the updated state immediately. You will also be notified via subscription when the object is updated.
</Aside>

## Next steps 

This quickstart introduced the basic concepts of LiveObjects and demonstrated how the path-based API works. The next steps are to:

* Learn about the [PathObject](https://ably.com/docs/liveobjects/concepts/path-object.md) and [Instance](https://ably.com/docs/liveobjects/concepts/instance.md) APIs.
* Read more about [LiveCounter](https://ably.com/docs/liveobjects/counter.md) and [LiveMap](https://ably.com/docs/liveobjects/map.md).
* Learn about [Objects Lifecycle Events](https://ably.com/docs/liveobjects/lifecycle.md).
* Learn about [Type inference](https://ably.com/docs/liveobjects/typing.md) for your LiveObjects.

## Related Topics

- [JavaScript](https://ably.com/docs/liveobjects/quickstart/javascript.md): A getting started guide to learn the basics of integrating the Ably LiveObjects product into your JavaScript application.
- [Java](https://ably.com/docs/liveobjects/quickstart/java.md): A quickstart guide to learn the basics of integrating the Ably LiveObjects product into your Java application.

## Documentation Index

To discover additional Ably documentation:

1. Fetch [llms.txt](https://ably.com/llms.txt) for the canonical list of available pages.
2. Identify relevant URLs from that index.
3. Fetch target pages as needed.

Avoid using assumed or outdated documentation paths.