Update audience data and refresh ads

When you create a custom audience, you can specify some or all of the custom audience metadata. This information can be passed directly when creating a CustomAudience object. The CustomAudience.Builder also supports a dailyUpdateUri field which can both supply and update the metadata. The platform will run a background job every 24 hours to fetch updated metadata from the dailyUpdateUri, or every four hours if the custom audience doesn't yet have the AdData needed to participate in an auction. The platform can update the following pieces of custom audience metadata:

• User bidding signals
• Trusted bidding data
• AdData list

To update this metadata, a daily background update process queries against the dailyUpdateUri defined in the custom audience which may return a JSON response.

• The JSON response may contain any of the supported metadata fields that need to be updated.
• Each JSON field is validated independently. The client ignores any malformed fields, which results in no updates to that particular field in the response.
• An empty HTTP response or an empty JSON object "{}" results in no metadata updates.
• The response message size must be limited to 10 KB.
• All URIs are required to use HTTPS.
• trusted_bidding_uri must share the same ETLD+1 as the buyer.

Example: JSON response for background daily update

{
    "user_bidding_signals" : { ... },  // Valid JSON object
    "trusted_bidding_data" : {
        "trusted_bidding_uri" : "example-dsp1-key-value-service.com",
        "trusted_bidding_keys" : [ "campaign123", "campaign456", ... ]
    },
    "ads" : [
        {
            "render_uri" : "www.example-dsp1.com/.../campaign123.html",
            "metadata" : { ... }  // Valid JSON object
        },
        {
            "render_uri" : "www.example-dsp1.com/.../campaign456.html",
            "metadata" : { ... }  // Valid JSON object
        },
        ...
    ]
}

See this mock server definition for an example of the kind of data that might be included in the response.