Thin facade over Wire's Kalium SDK offering a streamlined API for secure citizen-to-government messaging, with a core SDK and a CLI reference implementation.
Natrium is a Kotlin Multiplatform library that wraps Wire's Kalium SDK to provide a simplified API for secure citizen-to-government communication.
Natrium is not a rewrite of Kalium. It is a thin facade that exposes only what partners need to build secure messaging clients.
natrium/
natrium-core/ KMP library (the SDK) — see natrium-core/docs/ for SDK documentation
natrium-cli/ JVM CLI app (Clikt), reference implementation
All shared code lives in natrium-core/src/commonMain/ and must compile for all three targets.
Prerequisites: JDK 17+, Android SDK (compileSdk 36).
# Build all targets
./gradlew buildAdd natrium-core as a dependency from Maven Central:
// build.gradle.kts
dependencies {
implementation("schwarz.opensource.natrium:natrium-core:<version>")
}See natrium-core/README.md for API usage and code examples.
See natrium-core/README.md for the complete documentation index and design overview.
The Natrium SDK (the wrapper code in this repository) is licensed under the European Union Public Licence v. 1.2 only (EUPL-1.2). See LICENSE for the full licence text and NOTICE for attribution.
Natrium depends on Wire’s Kalium SDK
(currently the Maven artifact schwarz.opensource.natrium:logic). No portion
of the Kalium SDK is licensed under the EUPL-1.2, either as a standalone
component or as incorporated in Natrium.
The Kalium SDK may only be used under:
Linking or combining Natrium with the Kalium SDK does not cause any copyleft effect of the EUPL-1.2 to extend to Kalium. Recipients who use Kalium without a commercial licence from Wire remain subject to the GPL-3.0 and to the licences of Kalium’s third-party dependencies.
Publication of Natrium under the EUPL-1.2 is authorised by a commercial licence agreement between Schwarz Digits and Wire Swiss GmbH. That agreement does not grant any Kalium rights to recipients of Natrium.
Natrium is a Kotlin Multiplatform library that wraps Wire's Kalium SDK to provide a simplified API for secure citizen-to-government communication.
Natrium is not a rewrite of Kalium. It is a thin facade that exposes only what partners need to build secure messaging clients.
natrium/
natrium-core/ KMP library (the SDK) — see natrium-core/docs/ for SDK documentation
natrium-cli/ JVM CLI app (Clikt), reference implementation
All shared code lives in natrium-core/src/commonMain/ and must compile for all three targets.
Prerequisites: JDK 17+, Android SDK (compileSdk 36).
# Build all targets
./gradlew buildAdd natrium-core as a dependency from Maven Central:
// build.gradle.kts
dependencies {
implementation("schwarz.opensource.natrium:natrium-core:<version>")
}See natrium-core/README.md for API usage and code examples.
See natrium-core/README.md for the complete documentation index and design overview.
The Natrium SDK (the wrapper code in this repository) is licensed under the European Union Public Licence v. 1.2 only (EUPL-1.2). See LICENSE for the full licence text and NOTICE for attribution.
Natrium depends on Wire’s Kalium SDK
(currently the Maven artifact schwarz.opensource.natrium:logic). No portion
of the Kalium SDK is licensed under the EUPL-1.2, either as a standalone
component or as incorporated in Natrium.
The Kalium SDK may only be used under:
Linking or combining Natrium with the Kalium SDK does not cause any copyleft effect of the EUPL-1.2 to extend to Kalium. Recipients who use Kalium without a commercial licence from Wire remain subject to the GPL-3.0 and to the licences of Kalium’s third-party dependencies.
Publication of Natrium under the EUPL-1.2 is authorised by a commercial licence agreement between Schwarz Digits and Wire Swiss GmbH. That agreement does not grant any Kalium rights to recipients of Natrium.