AAI is a common authentication and authorization infrastructure for Swiss institutions of higher education.
An Ad fontes account is still required for users logging in via AAI. After registering with your AAI credentials for the first time, your AAI info can be linked to your Ad fontes account.
You have logged in to Ad fontes via AAI for the first time. If you already have an Ad fontes account, you can link it to your AAI account. Otherwise, you can now create a new Ad fontes account.