SIGIL PROTOCOL COMMERCIAL LICENSE

Copyright (c) 2026 SIGIL Protocol — sigil-protocol.org
All rights reserved.

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## 1. Preamble

SIGIL Protocol is dual-licensed. The source code is available under the open-source
European Union Public Licence v1.2 (EUPL-1.2) for qualifying use cases. This
Commercial Licence governs all other use cases.

If you intend to use SIGIL Protocol in a proprietary, closed-source product or service,
you must obtain a Commercial Licence.

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## 2. Who Needs a Commercial Licence?

You need a Commercial Licence if you:

- Embed or integrate SIGIL Protocol into a **closed-source, proprietary product or SaaS**
  without releasing your derived source code under EUPL-1.2.
- Offer a **managed or hosted service** built on SIGIL Protocol to third parties.
- Distribute a **compiled binary** including SIGIL Protocol code without disclosing
  the corresponding source code.
- Use SIGIL Protocol in a **patent-restricted context** where you cannot comply with
  the patent grant provisions of EUPL-1.2.

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## 3. Who Does NOT Need a Commercial Licence?

You do NOT need a Commercial Licence if you:

- Use SIGIL Protocol in an **open-source project** published under a compatible
  open-source licence (see the EUPL-1.2 compatibility appendix: GPL, AGPL, MPL, LGPL, etc.)
- Use SIGIL Protocol for **personal experimentation, research, or internal evaluation**.
- Contribute to SIGIL Protocol under the EUPL-1.2 terms.

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## 4. Commercial Licence Terms

### 4.1 Grant of Rights
Subject to payment of the applicable licence fee and compliance with this Agreement,
SIGIL Protocol grants you a non-exclusive, non-transferable, worldwide licence to:

- Use, reproduce, and distribute SIGIL Protocol in your proprietary products.
- Deploy SIGIL Protocol in production environments without open-sourcing your application.

### 4.2 Restrictions
You may not:

- Sublicense, resell, or transfer the Commercial Licence to any third party.
- Use the SIGIL name, brand, or logo without separate written permission.
- Remove or obscure any copyright notices.

### 4.3 Patent Rights
This Commercial Licence includes a limited grant of patent rights for the methods
described in the SIGIL Protocol specification (the `_sigil` envelope, per-message
DID-based policy verdict system). Patent rights are granted solely for use within
the scope of this Commercial Licence and do not extend beyond the duration of the
licence agreement.

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## 5. Warranty and Liability

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED.
SIGIL PROTOCOL SHALL NOT BE LIABLE FOR ANY DAMAGES ARISING FROM THE USE OF THE SOFTWARE.

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## 6. Obtaining a Commercial Licence

To obtain a Commercial Licence, contact:

**SIGIL Protocol**
📧 info@sigil-protocol.org
🌐 https://sigil-protocol.org

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*This licence is governed by the laws of the European Union and the applicable law
of the country where the Licensor is registered.*
