# cast.[framework](https://developers.google.com/cast/docs/reference/web_receiver/cast.framework).[messages](https://developers.google.com/cast/docs/reference/web_receiver/cast.framework.messages).RequestData

class static

Media event request data.

## Constructor

### RequestData

new
RequestData(type)

| #### Parameter ||
|---|---|
| type | [cast.framework.messages.MessageType](https://developers.google.com/cast/docs/reference/web_receiver/cast.framework.messages#.MessageType) Request type. Value must not be null. |

## Properties

### customData

(non-null Object or undefined)

Application-specific data for this request. It enables the sender and
receiver to easily extend the media protocol without having to use a new
namespace with custom messages.

### mediaSessionId

(number or undefined)

Id of the media session that the request applies to.

### requestId

number

Id of the request, used to correlate request/response.

### sequenceNumber

(number or undefined)

A number to synchronize all queue commands.
If provided for a queue command, the SDK will verify the queue latest
sequence number match the request.
Current sequenceNumber is provided as part of outgoing queue changed
messages.