> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sint.gg/llms.txt
> Use this file to discover all available pages before exploring further.

# Licenses

> Apache-2.0 for code. CC BY 4.0 for the specification. What you can do with each.

SINT splits its licensing between code and specification. The two licenses are chosen to give implementers and integrators the maximum freedom while keeping the specification open and citable.

## Apache-2.0 for code

All code in `github.com/sint-ai/sint-protocol` and SINT Labs' other public repositories is licensed under **Apache License 2.0**.

### You can

* Use the code commercially
* Modify it
* Distribute it
* Patent it (the Apache 2.0 grant includes a patent license)
* Use it privately
* Sublicense it

### You must

* Include the LICENSE file in distributions
* Note significant modifications
* Include the NOTICE file if one exists
* Include copyright notices

### You cannot

* Use SINT Labs' trademarks (the SINT name, logos) without permission
* Hold SINT Labs liable for damages

Full text: [Apache License 2.0](https://www.apache.org/licenses/LICENSE-2.0).

## CC BY 4.0 for the specification

The SINT Protocol specification, whitepaper, architecture diagrams, and this documentation are licensed under **Creative Commons Attribution 4.0 International (CC BY 4.0)**.

### You can

* Share the specification
* Adapt and build on it
* Use it commercially
* Reproduce it in academic papers

### You must

* Give appropriate credit (cite SINT Labs as the source)
* Provide a link to the license
* Indicate if you've modified the specification

Full text: [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/).

## Why split licenses

Apache-2.0 is the industry-standard permissive license for open-source infrastructure code. It's compatible with most commercial use cases, includes a patent grant, and has strong enterprise acceptance.

CC BY 4.0 is the correct license for a *specification*. A specification isn't code — it's a normative document that implementers derive from. CC BY 4.0 ensures that anyone can read, cite, and implement the specification without license friction, while requiring attribution.

## Implementation licensing

If you build an independent implementation of SINT Protocol, you can license *your implementation* under any license you choose — including proprietary. The specification license (CC BY 4.0) governs the spec itself, not your derived work.

Contribution back to `sint-ai/sint-protocol` is Apache-2.0.

## Trademark

"SINT", "SINT Labs", "SINT Protocol", "SINT OS", and related marks are trademarks of PSHKV Inc. You may reference them in descriptive or comparative contexts. You may not use them in a way that implies endorsement or sponsorship by SINT Labs.

If you're building something on the SINT Protocol and want to use the SINT name or logo, email [i@pshkv.com](mailto:i@pshkv.com). We're generous with trademark usage for legitimate integrations.

## Questions

* License questions: [i@pshkv.com](mailto:i@pshkv.com)
* Trademark questions: [i@pshkv.com](mailto:i@pshkv.com)
* Security disclosures: see [security](/legal/security)