# Enabling ad ID signaling for sessions
<a name="ad-id-session-state"></a>

The ad ID signaling feature must be enabled during session initialization. The process to enable the feature differs from creating sessions using the HLS/DASH playback prefix (implicit session initialization), versus the session initialization prefix (explicit session initialization).

**To enable ad ID for the session using HLS/DASH playback prefixes**
+ From the player, initialize a new MediaTailor playback session using a request in one of the following formats, according to your protocol:
  + Example: HLS format

    ```
    GET {{<mediatailorURL>}}/v1/master/{{<hashed-account-id>}}/{{<origin-id>}}/{{<asset-id>}}?aws.adSignalingEnabled=true
    ```
  + Example: DASH format

    ```
    GET {{<mediatailorURL>}}/v1/dash/{{<hashed-account-id>}}/{{<origin-id>}}/{{<asset-id>}}?aws.adSignalingEnabled=true
    ```

**To enable ad ID for the session using the session initialization prefix**
+ On the player, construct a JSON message body for the session initialization request to MediaTailor: 
  + Inside an `adsParams` object, provide any parameters that MediaTailor should pass to the ADS. These parameters correspond to `[player_params.param]` settings in the ADS template URL of the MediaTailor configuration. 
  + To enable ad ID signaling, add an `adSignaling` object as a top level object, and inside, add a parameter called `enabled` and value of `true`. The default `adSignaling` value is `disabled`.
  + Example: HLS format

    ```
    POST master.m3u8
        {
           "adsParams": {
               "deviceType": "ipad"
           },
           "adSignaling": {
               "enabled": "true"
           },
           "reportingMode": "client"
        }
    ```
  + Example: DASH format

    ```
    POST manifest.mpd
        {
            "adsParams": {
               "deviceType": "ipad"
           },
           "adSignaling": {
                "enabled": "true"
            },
            "reportingMode": "client"
        }
    ```