Generate and activate a Criteo retail media audience from a retailer's shopper data

Steps

1. Authenticate to the Criteo API using the client credentials OAuth 2.0 flow against the Criteo identity endpoint to obtain a bearer token
2. POST to the retail media audiences endpoint to create an audience, specifying the account ID (brand or retailer account), name, description, and audience type (e.g. customer file or behavioral segment)
3. For customer file audiences, prepare a list of hashed emails (SHA-256, lowercase normalized) and POST them to the audience users endpoint using the returned audience ID, in batches respecting the API's size limits
4. Alternatively for behavioral segments, define the segment rules (e.g. viewed or purchased specific product categories in the past N days) using the segment query parameters on the audience creation request
5. Retrieve the audience status and estimated reach using a GET on the audience ID; wait for status to transition from PROCESSING to ACTIVE before targeting
6. Associate the audience with a retail media line item by including the audience ID in the targeting configuration when creating or updating a campaign line item via the campaigns endpoint