Terms of service

Last updated: 22 September 2026

1. Introduction

These Terms of Service (“Terms”) govern your use of Project Hollow (“Hollow”). Hollow is operated by Soulstack (“we”, “us”, “our”). Contact address for legal correspondence: Office One, 1 Coldbath Square, Farringdon, London, EC1R 5HL, England. By accessing or using Hollow, you agree to be bound by these Terms.

If you do not agree to these Terms, do not use Hollow.

2. The service

Hollow is a private, invite-only, AI-native workspace suite: chat, notes, tasks, files, spreadsheets, slides, diagrams, budgets, contacts, a recipe planner, calendar, Yap messaging, mail, no-code automation, and Lumen monitoring, sharing one account, one shell and one AI assistant.

3. Eligibility and invite-only access

• You must be at least 16 years old to create a Hollow account.
• Hollow is currently invite-only. Creating an account requires a valid invite code.
• We may restrict access to accounts we have not approved, even after successful sign-in, while Hollow is in early access.
• By registering, you confirm that the information you provide is accurate and complete.

4. Accounts

• You are responsible for maintaining the confidentiality of your account credentials.
• You must notify us promptly of any unauthorised use of your account.
• You can review and revoke individual active sessions at any time from Account settings.
• You may delete your account at any time from Account settings. Deletion permanently removes your associated workspace data and cannot be undone.
• We reserve the right to suspend or terminate accounts that violate these Terms.

5. Your content

You retain ownership of the content you create or upload in Hollow - notes, files, messages, diagrams, and everything else. You grant us a licence to host, store, process, transmit and display that content solely as needed to provide Hollow to you and to anyone you explicitly share it with.

Your workspace content is not used to train third-party foundation models without your explicit opt-in. See our Privacy Policy for how AI requests are processed.

6. Hollow AI

• Hollow AI can read workspace data automatically, but any action that would change your data - creating, editing or deleting something - is presented as a proposal you must explicitly approve before it runs.
• AI-generated output can be inaccurate. You are responsible for reviewing anything Hollow AI produces before relying on it.
• Daily AI usage is metered against a quota shown in Account settings; we may adjust quotas, the available models, or which model providers we use, at any time.
• Cascade automation steps you build run on your behalf; you are responsible for the actions your automations take, including any external systems (via connectors, webhooks or MCP servers) they reach.

7. Illegal and harmful content

Hollow hosts user-generated content across notes, Yap messages, files, cookbook entries and more. You must not upload, post, share or transmit content that is unlawful under the laws of England and Wales or that we reasonably consider harmful, including content that is fraudulent, threatening, harassing, defamatory, hateful, infringes another person’s intellectual-property rights, encourages or depicts illegal acts, sexually exploits any person, or promotes terrorism. If you encounter such content, contact support@projecthollow.com. We may remove content, suspend or terminate accounts, and, where required by law, refer matters to the appropriate authorities.

8. Acceptable use

You must not:

• Use Hollow for any unlawful purpose.
• Attempt to gain unauthorised access to any part of the service, other accounts, or connected systems.
• Interfere with or disrupt Hollow or the infrastructure it runs on.
• Scrape, harvest or collect data from Hollow without our consent.
• Impersonate another person or entity, or misuse an invite intended for someone else.
• Use Hollow AI to generate content that would itself breach section 7.

9. Third-party integrations

Connecting a Cascade connector, an MCP server, a GitHub repository, or a Mail account is your own choice and is governed by that third party’s own terms. We are not responsible for the availability, content or conduct of any connected third-party service.

10. Intellectual property

All Hollow software, trademarks, logos and branding are owned by or licensed to Soulstack. You may not copy, modify, distribute or reverse-engineer any part of Hollow without our prior written consent.

11. Service changes and availability

Hollow is in early access and under active development. We may add, change, deprecate or remove features at any time, and access is not guaranteed while Hollow remains invite-only. We do not currently offer a paid tier or a service-level uptime commitment.

12. Limitation of liability

To the fullest extent permitted by law:

• Hollow is provided “as is” and “as available”, without warranties of any kind, whether express or implied.
• We are not liable for any indirect, incidental, special or consequential damages arising from your use of Hollow.
• We are not responsible for the accuracy of AI-generated output, or for actions taken by an automation you configured.
• Nothing in these Terms excludes or limits liability for death or personal injury caused by negligence, fraud, or any other liability that cannot lawfully be excluded or limited under the laws of England and Wales.

13. Termination

We may suspend or terminate your access to Hollow at any time, without prior notice, for conduct that we believe violates these Terms or is harmful to other users, us, or third parties. You may terminate your account at any time from Account settings or by contacting support@projecthollow.com.

14. Governing law and jurisdiction

These Terms are governed by the laws of England and Wales. Any disputes are subject to the exclusive jurisdiction of the courts of England and Wales, without prejudice to your rights as a consumer under applicable law.

15. Changes to the Terms

We may revise these Terms at any time. Material changes will be notified to the email address on your account. Continued use of Hollow after changes take effect constitutes acceptance of the revised Terms.

16. Contact

Questions about these Terms: email legal@projecthollow.com, or write to Soulstack, Office One, 1 Coldbath Square, Farringdon, London, EC1R 5HL, England.