# Use Nosmai Effects with LiveKit on iOS

> Publish Nosmai's processed iOS pixel buffers through a LiveKit buffer track while keeping Nosmai as the camera owner.

> For AI agents: the complete documentation index is at https://nosmai.com/llms/effects.txt

Product: Nosmai Effects
Group: integrations
Source: https://nosmai.com/docs/effects/integrations/livekit/ios/

## Streaming path

![Nosmai processes iOS camera frames before LiveKit publishes them](/images/docs/livekit-streaming-flow-v1.svg)

Nosmai owns the camera and local preview. LiveKit publishes processed
`CVPixelBuffer` output through a `BufferCapturer`. iOS does not need an EGL
share-context step.

## Prerequisites

- iOS 15 or later on a physical arm64 device
- The `NosmaiCameraSDK` and `LiveKitClient` pods
- A LiveKit server URL and participant token
- Camera and microphone permission

```ruby
pod 'NosmaiCameraSDK', '~> 3.0.4'
pod 'LiveKitClient', '~> 2.0'
```

## Start capture and processing

Both operations are required. `startCapture` opens the camera;
`startProcessing` starts the effects pipeline.

```swift
NosmaiCore.shared().camera?.attach(to: previewView)

guard NosmaiCore.shared().camera?.startCapture() == true else {
    NSLog("Nosmai camera failed to start")
    return
}

NosmaiSDK.sharedInstance()?.startProcessing()
```

## Create a LiveKit buffer track

```swift
let room = Room(roomOptions: RoomOptions(
    defaultVideoPublishOptions: VideoPublishOptions(simulcast: false)
))

try await room.connect(url: liveKitURL, token: liveKitToken)

let track = LocalVideoTrack.createBufferTrack(
    name: "nosmai",
    source: .camera
)

guard let capturer = track.capturer as? BufferCapturer else {
    NSLog("LiveKit returned an unexpected capturer type")
    return
}
```

## Push processed buffers

Assign `liveFrameStreamCallback`, not the SDK singleton's lower-level pixel
buffer callback. `NosmaiCore` uses its callback fan-out for recording and live
output together.

```swift
NosmaiCore.shared().liveFrameStreamCallback = {
    pixelBuffer, timestamp in

    capturer.capture(
        pixelBuffer,
        timeStampNs: Int64(timestamp * 1_000_000_000)
    )
}

try await room.localParticipant.publish(videoTrack: track)
```

Keep the callback fast. It runs on Nosmai's render thread, and LiveKit retains
the IOSurface-backed buffer it needs.

## Stop in the correct order

```swift
NosmaiCore.shared().liveFrameStreamCallback = nil
await room.disconnect()
```

Clear frame production before disconnecting the room, then release the stored
track and capturer references owned by your screen or streaming coordinator.

## Common errors

| Symptom | Cause | Fix |
| --- | --- | --- |
| Preview is visible but no frame is published | Capture started without `startProcessing` | Start capture and processing before creating the track |
| Filters report success but are not visible | The effects queue is not being drained | Call `startProcessing` after camera capture starts |
| Recording stops receiving frames | The lower-level SDK callback replaced `NosmaiCore` fan-out | Use `liveFrameStreamCallback` only |

## Verify it worked

Apply a visible filter and confirm a remote participant sees it. Test a camera
switch and a second join after teardown.

## Complete example

The [native iOS LiveKit example](https://github.com/nosmai/nosmai-livekit-ios-example)
contains permission handling, capture, buffer publishing, filters, and teardown.

## Next steps

- [Compare live-streaming routes](/docs/effects/integrations/live-streaming/)
- [Render frames off-screen on iOS](/docs/effects/guides/streaming/render-frames-off-screen/ios/)
- [Review iOS requirements](/docs/effects/platforms/ios/)

## References

- [Nosmai LiveKit iOS example](https://github.com/nosmai/nosmai-livekit-ios-example)
- [LiveKit Swift SDK](https://github.com/livekit/client-sdk-swift)