Get an API key from Google (Gemini)

Go to aistudio.google.com and sign in with a Google account.
Click Get API key → Create API key and copy it.
In Tentaku: Settings → Your AI → choose “Google Gemini — API key” → paste the key → Save → Test.

Pay-as-you-go, separate from ChatGPT Plus / Claude Pro. Tentaku’s default (Balanced) model for this provider is gemini-3.5-flash-lite, which keeps a lecture to cents; Best uses gemini-3.8-flash.

Using Google’s free tier (advanced)

A key from Google AI Studio works without adding a card, within daily limits Google sets per account and can change at any time. It’s the quickest way to try AI notes. Before you use it, know the trade-offs:

Google can use what you send. On the free tier, Google uses your requests to improve its products, and human reviewers may read them. Google’s own terms say not to send personal information to the free tier — and lecture transcripts can include what classmates said. For anything sensitive, use a paid key, another provider, or Local AI.
18 or older. Google’s terms require it, and so do ours.
Limits. If you hit the daily limit, Tentaku tells you; try again the next day or add billing in Google AI Studio, which turns off Google’s use of your data for product improvement.
Your key, your account. You accept Google’s Gemini API terms when you create the key. Keep it private.

Details: Gemini API terms.

Treat the key like a password: it’s stored encrypted on your computer and only ever sent to the provider.

Still stuck? Email [email protected] — include which tab you were on and what you pressed.