Yes, Mixpanel still supports using Project Secret for API authentication, including for exporting data, but it is deprecated and new or updated integrations should use Service Accounts instead.
Project Secret auth is described as “in the process of being deprecated” but will continue to be supported for legacy customers so existing scripts don’t break. [Project secret]
Project Secret is used via HTTP Basic Auth, with the secret as the username and an empty password:
curl 'https://data.mixpanel.com/api/2.0/export?from_date=2026-01-10&to_date=2026-01-11' \
-u '<project_secret>:' \
--header 'accept: text/plain'
[Project secret]
