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OPENProof

Terms of Service

By using OpenProof, you agree to these terms. Last updated: July 4, 2026.

1. Acceptance of Terms

By accessing or using OpenProof (the “App”), you agree to be bound by these Terms of Service. If you do not agree, do not use the App. The App is available at proof.kovina.org and its source code is at github.com/sparshsam/openproof.

2. License

The OpenProof source code is licensed under the GNU Affero General Public License v3.0 only (AGPL-3.0-only). You are free to use, modify, and distribute the software under the terms of that license. The receipt schema is additionally available under the MIT license.

This license applies to the software only. Proof receipts you generate, files you hash, and blockchain transactions you submit are your own data and are not subject to the software license.

3. No Legal Advice

OpenProof is a tool for timestamping file fingerprints (SHA-256 hashes) on a blockchain. It does not provide legal advice, legal certification, or any legally binding timestamp or notarization service. Proofs registered on the Base Sepolia testnet have no guarantee of permanence — testnets may be reset, paused, or deprecated. Consult a qualified legal professional for any evidentiary, regulatory, or compliance matters.

4. No Warranty

OpenProof is provided “as is” and “as available,” without any warranty of any kind, express or implied. This includes, but is not limited to, warranties of merchantability, fitness for a particular purpose, non-infringement, title, or availability. The entire risk arising out of use or performance of the App remains with you. No oral or written information or advice given by the maintainers creates a warranty.

5. Data Responsibility

Local receipts: Proof receipts are generated locally and offered as downloads. You are solely responsible for backing up and securing your receipts. OpenProof does not store receipts on any server.

Blockchain permanence: Once a transaction is submitted to the Base Sepolia blockchain, it is public and permanent by design. The transaction cannot be reversed, deleted, or modified by OpenProof or any party. You should not register hashes of content you may later need to keep private, as the onchain presence of a hash may reveal that a particular file existed at a particular time.

Wallet and keys: You are solely responsible for securing your wallet, private keys, and any associated seed phrases. OpenProof never has access to your private keys. Lost keys or compromised wallets may result in permanent loss of access to your proofs.

6. Service Availability

OpenProof is a fully static web application hosted on Vercel. There is no backend, database, or API server. The App does not guarantee uninterrupted availability. The Base Sepolia testnet is a third-party network that may experience downtime, resets, or deprecation. OpenProof has no control over testnet operations and is not responsible for any resulting loss of access to onchain data.

7. User Conduct

You agree not to use OpenProof for any unlawful purpose or in violation of any applicable laws or regulations. You also agree not to:

  • Submit files you do not have the right to hash.
  • Use the App to register hashes of illegal content.
  • Attempt to reverse-engineer, decompile, or bypass any aspect of the App (beyond what the open-source license explicitly permits).
  • Interfere with or disrupt the App's operation or the Base Sepolia network.

8. Changes to Terms

These terms may be updated from time to time. The “Last updated” date at the top of this page will reflect the most recent revision. Material changes will be noted in the repository changelog. Continued use of OpenProof after changes take effect constitutes acceptance of the updated terms.

9. Contact

For questions about these terms, open an issue on GitHub or contact sparshsam@gmail.com.