Create a TikTok Ads API customer file custom audience from a hashed contact list

Steps

1. Authenticate using an access token obtained via TikTok's OAuth 2.0 flow; the token must have the Audience Management permission scope.
2. Prepare the contact list file: hash each email or phone number individually using SHA-256; phone numbers should be normalized to E.164 format before hashing.
3. Use the audience file upload endpoint to upload the hashed file; specify file_type as CUSTOM_AUDIENCE_FILE and audience_type as CUSTOMER_FILE.
4. After upload, create the audience by calling the audience creation endpoint with the file_id returned from the upload step; set audience_type to CUSTOMER_FILE and select the matching identifier type (EMAIL or PHONE).
5. Wait for the audience status to transition to READY before attaching it to a campaign; poll the audience status endpoint or listen for a webhook event if available.
6. Attach the audience to an ad group in the audience targeting section using the audience_ids field in the ad group's targeting_spec.