Legal document · effective June 16, 2026

Terms of Sale

These Terms of Sale (the "Terms") govern any paid subscription to the Keystro Service. They are concluded between Boris Molton, sole proprietor operating under the Keystro brand (the "Provider"), and the user subscribing to a paid plan (the "Customer").

1. Identification of the Provider

• Boris Molton — Sole proprietor (entrepreneur individuel / micro-entreprise)
• SIREN: 105 659 270 — SIRET: 10565927000018
• Registered with the French National Business Register (RNE) on June 2, 2026
• Address: 530 avenue de Grasse, 06370 Mouans-Sartoux, France
• VAT: not applicable — French CGI Article 293 B (small business VAT exemption)
• Contact: contact@keystro.ai — Billing questions: billing@keystro.ai

2. Scope and acceptance

These Terms apply to any subscription to the Pro or Pro+ plan (or any future paid plan) of the Keystro Service. By clicking "Subscribe" in the checkout flow, the Customer expressly accepts these Terms together with the Terms of Use and the Privacy Policy.

These Terms apply both to consumer users (B2C) and to professional users (B2B). Where a provision applies only to one category, this is explicitly stated.

3. Plans, features, and prices

The available plans, their features, and their prices are described on our pricing page, which forms an integral part of these Terms. As of the effective date:

• Free plan — 50 AI requests per rolling month, no payment, no time limit. Not subject to these Terms of Sale (see Terms of Use only).
• Pro plan — paid monthly subscription, full feature set for individual users.
• Pro+ plan — paid monthly subscription with higher monthly limits and expanded personalization capacity (prompt library and personal vocabulary), for individual users.

Prices are displayed in Euros (€) on the pricing page. While the Provider benefits from the French VAT exemption (Article 293 B CGI), prices are displayed and invoiced excluding VAT and the mention "TVA non applicable, art. 293 B du CGI" appears on each invoice. Should the Provider become subject to VAT, prices and invoices will be adjusted accordingly with appropriate prior notice.

Prices may be revised. Existing subscribers will be notified at least 30 days before a price increase takes effect. The new price applies to the next renewal; the Customer may cancel before that date if they do not wish to continue at the new price.

4. Order process

1. The Customer creates a Keystro account (via the authentication provider Clerk).
2. The Customer selects a paid plan on the pricing page.
3. The Customer is redirected to Stripe Checkout to enter payment details (we never see or store full card data).
4. The Customer reviews the order summary, accepts these Terms by checking the relevant box, and confirms the order.
5. A confirmation email is sent. Access to the paid features is enabled immediately upon successful payment authorization.
6. An invoice is generated and made available in the customer dashboard.

5. Payment

• Payments are processed by Stripe Payments Europe Ltd (Ireland), a PCI-DSS certified payment service provider.
• Accepted methods: major credit and debit cards. Other methods may be added over time.
• The first charge occurs at the time of subscription. Subsequent charges occur automatically on the renewal date until cancellation.
• If a payment fails, Stripe will retry over a 7-day grace period. If recovery fails, paid features are suspended; the account remains in Free mode until payment is updated.
• The Customer is responsible for keeping their payment method up to date. Payment methods can be managed via the Stripe Customer Portal accessible from the dashboard.

6. Term, renewal, and cancellation

• The Pro and Pro+ plans are billed monthly. The initial term is one (1) month from the date of subscription.
• The subscription renews automatically for successive one-month periods until cancelled by the Customer.
• The Customer may cancel at any time from the dashboard (Manage Subscription) or by writing to billing@keystro.ai. Cancellation takes effect at the end of the current billing period; access to paid features continues until that date.
• For B2C consumer users in France: where a plan is offered with a fixed-term commitment longer than one month, French Consumer Code Article L.215-1 applies and the Customer will be reminded by email of the upcoming tacit renewal between three (3) and one (1) month before the renewal date, with a clear option to cancel without penalty. As of the effective date, no such fixed-term plan is offered.

7. Right of withdrawal (B2C consumers, EU)

Pursuant to French Consumer Code Article L.221-18, consumers have a fourteen (14)-day right of withdrawal from the conclusion of the contract for distance services, free of charge and without giving reasons.

Express waiver: the Service is digital content and online services, delivered immediately upon subscription. By checking the dedicated box at checkout ("I expressly request immediate access to the Service and acknowledge that I will lose my right of withdrawal once the Service has been fully performed during the 14-day period"), the Customer waives the right of withdrawal for the portion of the Service already supplied at the time the withdrawal would be exercised, in accordance with French Consumer Code Article L.221-28-13°.

Where the Customer has not consumed any AI request and is still within the 14-day period, they may exercise the right of withdrawal by sending an unambiguous statement to billing@keystro.ai. A model withdrawal form is available below.

For Customers acting in a professional capacity (B2B), the right of withdrawal does not apply.

8. Refunds

• Beyond the right of withdrawal described in section 7, paid subscriptions are not refundable on a pro-rata basis when cancelled mid-cycle.
• The Customer remains entitled to all paid features until the end of the current billing period.
• Where required by mandatory consumer law (e.g., conformity defect, lack of legally required feature), the Customer may request a refund through billing@keystro.ai. Refunds are processed back to the original payment method within fourteen (14) days from acceptance of the request.

9. Service availability and quality

• The Provider commits to a best-effort 99% monthly uptime for paid plans, measured excluding scheduled maintenance windows announced in advance and downtime caused by third parties (notably the AI provider, the hosting provider, and the authentication provider).
• No financial compensation, credit, or refund is automatically due in the event of an outage on the Free or Pro plans. Pro+ plan customers may request a service credit for confirmed downtime exceeding 1% of the monthly billing period, on written request.
• The Provider may perform scheduled maintenance, with reasonable advance notice when practical.

10. Suspension for breach

Without prejudice to any other rights, the Provider may suspend access to the paid Service if the Customer breaches the Terms of Use, applicable law, or fails to pay an invoice. Suspension is notified by email and remains in place until the breach is remedied. No refund is due for periods of suspension caused by the Customer's breach.

11. Personal data

The processing of the Customer's personal data in connection with the subscription is described in the Privacy Policy. For B2B Customers, a Data Processing Agreement (DPA) compliant with GDPR Article 28 is available on request at privacy@keystro.ai.

12. Limitation of liability

The monetary cap in this section applies only to Customers acting for professional purposes (B2B). It does not apply to consumers within the meaning of the preliminary article of the French Consumer Code, who are not bound by it and retain the full extent of the rights and remedies granted to them by mandatory law.

For professional Customers, the Provider's aggregate liability arising out of or relating to the paid Service shall not exceed the greater of (i) the amount paid by the Customer in the twelve (12) months preceding the event giving rise to the claim, or (ii) one hundred (100) euros.

The Provider shall not be liable for indirect or consequential damages, lost profits, lost revenue, lost data, or business interruption. The full liability provisions of Section 12 of the Terms of Use apply.

13. Force majeure

Neither party is liable for any failure or delay in performance caused by an event of force majeure (including the failure of essential third-party services), as defined in French Civil Code Article 1218.

14. Termination by the Provider

The Provider may terminate the subscription with thirty (30) days' notice for convenience, with pro-rata refund of the unused portion of any prepaid period. The Provider may terminate immediately for material breach by the Customer that has not been remedied within fourteen (14) days of written notice.

15. Modification of these Terms

These Terms may be updated. Material changes will be notified to the Customer at least thirty (30) days before the effective date. The Customer may terminate the subscription before the effective date if they do not accept the changes; otherwise, continued use after the effective date constitutes acceptance.

16. Governing law, mediation, and jurisdiction

These Terms are governed by French law. Any dispute shall first be addressed amicably between the parties.

For consumer Customers, in the absence of an amicable resolution and pursuant to French Consumer Code Articles L.611-1 et seq., the Customer may refer the dispute, free of charge, to the designated consumer mediator: [Mediator name and contact — to be confirmed before opening paid plans to the public]. Consumers in the EU may also use the European Online Dispute Resolution platform: ec.europa.eu/consumers/odr.

Failing amicable resolution and mediation, the dispute shall be submitted to the competent French courts. Consumer Customers may also bring proceedings before the courts of the EU Member State in which they are domiciled.

For B2B Customers, exclusive jurisdiction is granted to the French courts.

17. Model withdrawal form (B2C consumers, EU)

To exercise the right of withdrawal where applicable, copy the following text into an email to billing@keystro.ai:

To: Boris Molton — Keystro — billing@keystro.ai

I, the undersigned, hereby give notice of my withdrawal from the
contract for the subscription to the Keystro Service:

— Subscription date: [date]
— Account email: [email]
— Plan: [Pro / Pro+]
— Customer name: [name]
— Date of this notice: [date]

See also: Terms of Use · Privacy Policy · Mentions légales (FR)