Pricing
Pay only for what you use.
During the Private Preview the monthly platform fee is on us. Your only cost is the AI your learner actually uses — metered per token, billed once a month, at the provider's list price plus a 10% service fee. No allowances, no bundles, no surprises.
Monthly platform fee
The platform fee covers your account, the parent and educator surfaces, support, and ongoing safety work. While the Private Preview runs, we waive it entirely — you will see it on your invoice at $0.
Usage rates
The models we sell — and use
LucaAIstein runs on four models, and we resell each at its provider's public list price plus 10%. Prices are in USD per 1 million tokens and pro-rate down to the single token — you are never billed for capacity you didn't use.
| Model & direction | Provider list (per 1M tokens) | Your price (+10%) |
|---|---|---|
| Anthropic Claude — the tutor's reasoning | ||
| Claude Sonnet — input | $3.00 | $3.30 |
| Claude Sonnet — output | $15.00 | $16.50 |
| Claude Opus — input | $5.00 | $5.50 |
| Claude Opus — output | $25.00 | $27.50 |
| Claude Fable — input | $10.00 | $11.00 |
| Claude Fable — output | $50.00 | $55.00 |
| Luca Air — our own open-model inference service | ||
| Luca Air — input | — | $1.65 |
| Luca Air — output | — | $8.25 |
| OpenAI GPT-Realtime-2 — the live voice | ||
| Voice — audio input | $32.00 | $35.20 |
| Voice — audio output | $64.00 | $70.40 |
| Voice — cached audio input | $0.40 | $0.44 |
| Voice — text input | $4.00 | $4.40 |
| Voice — text output | $24.00 | $26.40 |
The honest math: we resell Anthropic and OpenAI models at provider list price + 10%. That 10% is our fee — it funds the tutor, the psychometric and safety work, and support. When providers change their prices, ours change with them, same formula. Luca Air is different: it is our own open-model inference service, run on our own hardware, priced flat at half the Claude Sonnet rate — the budget-friendly choice for routine practice turns.
Billing
How billing works
- Card on file via Stripe. When your invitation is accepted, you receive a secure Stripe link to add a payment method. $0 is charged at sign-up.
- One monthly invoice. At the end of each billing month, Stripe invoices exactly the tokens your learners used, line by line, at the rates above — plus the platform fee at $0 while the Private Preview runs.
- Metered from the first token. There are no included allowances and nothing pre-purchased — small months cost little, quiet months cost nearly nothing.
- Cancel any time. Cancelling stops new usage immediately; your final invoice covers only what was already used. Data erasure is available on request (see the privacy section).
Cost control
Luca AI — the model router
Luca AI is our routing intelligence: on every turn it auto-decides which model serves the moment best. Claude Sonnet carries most turns; Claude Opus and Claude Fable step in only when a moment genuinely needs deeper reasoning; Luca Air — our own open-model service at half the Sonnet rate — handles routine practice; and voice speaks only when it is pedagogically valuable and consented. Auto is the default and the recommendation — or you can optionally prefer Luca Air in the app for budget-first learning. Parents see exactly which models ran on their invoice.
Join the Private Preview
The first 50 customers, by invitation. The monthly fee is on us — you pay only for the AI you use.
Request your invitation →Questions first? See the support page or the documentation library.