Create a Snapchat Ads custom audience from a Mobile App audience (app event retargeting) via the Marketing API

Steps

1. Authenticate to the Snap Marketing API using the OAuth 2.0 authorization code flow and obtain an access token with the snapchat-marketing-api scope
2. POST to the /v1/adaccounts/{ad_account_id}/audiences endpoint to create an audience of type SAM_RETARGETING (Mobile App Custom Audience), specifying the retention_in_days and source_type as APP_EVENTS
3. Configure the audience rules by specifying the app ID (from Snap App ID registered in Snap Ads Manager), event name (e.g. PURCHASE or ADD_TO_CART), and any event property filters
4. Retrieve the audience ID and check audience status via a GET request until status shows ACTIVE and the size estimate is populated
5. Include the audience ID in the targeting specification of an ad set by adding it to the audience object when POSTing to the /v1/adsquads endpoint for a new ad squad
6. Set up audience exclusions by adding exclude audience IDs to the targeting spec to suppress existing converters from the retargeting campaign