Terms of Service

Last updated: 2026-10-06 · Language: English · Deutsche Version

1. Scope & provider

These terms govern your use of Tuba (web app). Provider: Christian Fischer, Austria (address: see Imprint). Austrian law applies, except where mandatory consumer-protection rules of your habitual residence conflict.

2. Service

The app transcribes uploaded image content and produces correction suggestions, error analyses, grading and feedback via Anthropic Claude Sonnet. Results are recommendations — the final call is made by the reviewer (typically the teacher). We do not guarantee error-free AI output.

3. Eligibility

• Minimum age: 18 (or your jurisdiction's age of majority)
• Truthful registration data
• No sharing of credentials

4. Red pens & purchases

In the app the unit of account is called red pen (internally: credit). Red pens are purchased via Stripe Checkout in the web app. On registration you receive 12 free red pens to start. All prices are final prices; as a small business under § 6(1)(27) of the Austrian VAT Act, we do not charge VAT.

Right of withdrawal: As a consumer you may withdraw from a purchase within 14 days without giving reasons (an email to info@tuba.school is enough). If you requested immediate crediting and confirmed that your right of withdrawal then lapses, it lapses once you use red pens from the pack (Austrian FAGG § 18(1)(11)). You receive this confirmation with your payment confirmation by email.

Unused red pens remain valid indefinitely. Except in the case of a withdrawal, they are not paid out in cash.

5. Your obligations

• Remove or redact student names and personal details before uploading
• Do not upload texts revealing special categories of personal data (Art. 9 GDPR, e.g. health, religion, ethnic origin), or redact those passages
• Make sure you are allowed to process work by students and other third parties (e.g. as part of your teaching)
• Do not submit unlawful or offensive content
• No automated bulk API use without express permission

6. Confidentiality

Uploaded content is transmitted to Anthropic in the US for analysis — details in our Privacy Policy. Tuba does not store original images on its servers.

7. Liability

We are liable only for intent and gross negligence, except where mandatory consumer-protection rules say otherwise. We accept no liability for consequences of incorrect or incomplete AI output.

8. Availability

We aim for high availability but make no uptime guarantee. Maintenance windows are announced where possible.

9. Termination

You may delete your account at any time via Settings → Delete account irreversibly. We may suspend or delete accounts that violate these terms, with reasonable notice.

10. Changes

We announce changes to these terms at least 30 days before they take effect by email. Material changes to your disadvantage apply only once you accept them (e.g. in the app); without your acceptance the previous terms continue to apply to you. You can delete your account at any time.

11. Disputes

Consumer venue: place of habitual residence. We are not obliged or willing to participate in consumer arbitration.

12. Data processing on your behalf (Art. 28 GDPR)

Where you upload third-party content (notably student work), we process it as your processor. This agreement applies to you or your school as the controller.

• Subject and duration: transcription, correction and storage of results until you delete them or your account.
• Data and data subjects: image content, transcribed text, corrections and assessments; students and other authors of the texts.
• Instructions: we process the data only on your instructions, given by using the app features, and not for our own purposes.
• Confidentiality and security: everyone involved is bound to confidentiality. We apply technical and organisational measures under Art. 32 GDPR (including encryption, access only through authenticated accounts, data storage in the EU, no storage of original images).
• Assistance: we assist you with data-subject requests and personal data breaches and inform you without undue delay if we become aware of a breach.
• Deletion: data is deleted when you delete it, at the latest when you delete your account; for backups see the Privacy Policy.
• Evidence: on request we provide the information needed to demonstrate compliance.
• Sub-processors: you authorise the providers listed under Processors. We notify new ones 30 days in advance by email; you may object and delete your account.