# Licensing (https://docs.open-e2ee.dev/licensing.md)



`@open-e2ee/signal-protocol-sdk` is dual-licensed under the [MIT License](https://github.com/open-e2ee/signal-protocol-js/blob/main/LICENSE-MIT) or the [Apache License 2.0](https://github.com/open-e2ee/signal-protocol-js/blob/main/LICENSE-APACHE), at your option. The SPDX expression is `MIT OR Apache-2.0`.

| License    | What it permits                                                      | What it asks                                         |
| ---------- | -------------------------------------------------------------------- | ---------------------------------------------------- |
| MIT        | Use, copy, modify, and redistribute, in open or proprietary products | Keep the copyright and license notice                |
| Apache-2.0 | The same rights, with an express patent grant from contributors      | Keep the notices and state your changes to the files |

Choose the one that fits your product. Neither requires a fee, a signed agreement, or a console account, and neither requires you to publish your own source.

> **The license file controls**
>
> This page summarizes the two licenses and is not legal advice. The license files in the repository control the grant.

## Commercial licenses [#commercial-licenses]

The console does not sell SDK commercial licenses. A signed license record, when one exists, can be checked offline against a published key: see [verify a license record](https://docs.open-e2ee.dev/licensing/verify-a-license-record.md).

> **No SDK phone-home requirement**
>
> The SDK does not need to contact the console during normal cryptographic operation.