# Getting started with CMCD on iOS

Media player clients can transmit useful information to Content Delivery Networks (CDNs) with each object request. This implementation supports Common Media Client Data (CMCD) as defined in [CTA-5004](https://cdn.cta.tech/cta/media/media/resources/standards/pdfs/cta-5004-final.pdf), published in September 2020.

## Usage

To enable CMCD, developers can set the `cmcd` parameter inside a SourceDescription.

```swift
let typedSource = TypedSource(src: "<HLS_STREAM_URL>", type: "application/x-mpegurl", cmcd: true)
let sourceDescription = SourceDescription(source: typedSource)
theoplayer.source = sourceDescription
```

## Remarks

Note that CMCD is only supported on iOS 18.0+.