Getting a Google API key

Create the key

1. Open aistudio.google.com/apikey and sign in. Use the Google account that should own the bill — a church or organisation account rather than someone's personal one, so the key doesn't leave with the volunteer who made it.
2. Accept the terms the first time Google asks.
3. Press Create API key. If it asks for a Google Cloud project, let it create a new one — any name will do, for example "Lithos Translate".
4. Copy the key. It is a long line starting with AIza. Keep the page open until it is safely pasted into Lithos.

Google's pages change their look from time to time; the button is sometimes labelled Get API key. The steps stay the same.

Put it into Lithos

• First run of the app: paste it in step 1 of the setup page and press Check key.
• Later, or to change it: the Operator tab → Setup & advanced → API keys → paste → Save → Test. The test opens a real translation session, so you know it works before Sunday.
• On a server you run yourself: put it in the environment as GEMINI_API_KEY=AIza… (the .env file, or /etc/lithos-server/server.env on a box) — see the always-on guide.

Lithos stores the key encrypted and never shows it again after you save it. To replace it, paste a new one over it.

Free tier or billing

A new key works straight away on Google's free tier. That is fine for trying Lithos out, with two things to know:

• Low limits. The free tier caps how much you can use in a minute and a day. A whole service in several languages can run into them — the translation then stops partway through.
• Your content. On the free tier, Google may use what is sent to it to improve its products. For a sermon that is usually fine; for a counselling conversation or a private class it may not be.

For real meetings, turn on billing: in AI Studio open Billing (or Set up billing beside your key) and add a payment method to the Google Cloud account. On the paid tier Google does not use your content to improve its models, and the limits are far higher. The same key keeps working — nothing changes in Lithos.

What it costs

About $0.037 a minute for each language while it is open — roughly $2.20 an hour per language. Three languages for a 90-minute service is about $10. You pay per language, not per listener: fifty phones on Spanish cost the same as one.

Rooms only open a language while someone is listening to it (or a room speaker is playing it), and nothing is billed once a room is stopped. The operator page shows a running estimate. The full picture — what opens and closes a stream, and the guards against a runaway bill — is in Costs & billing.

A budget alert

In the Google Cloud billing console, open Budgets & alerts and create a budget — for example $20 a month — with an email alert. It doesn't stop anything; it tells you before a room someone forgot to stop becomes a surprise.

Keeping it safe

• Anyone with the key can spend on your account. Don't email it, post it or put it in a shared document.
• Give Lithos its own key rather than sharing one with other projects, so you can see what Lithos costs and replace its key on its own.
• If it leaks, delete it in AI Studio and create a new one, then paste the new one into Lithos. The old one stops working at once.

When something's wrong