Multipaz

This repository contains libraries and applications for working with real-world identity. The initial focus for this work was mdoc/mDL according to ISO/IEC 18013-5:2021 and related standards but the current scope also include other credential formats and presentment protocols.

Multipaz Libraries

The project provides libraries written in Kotlin Multiplatform:

• multipaz provides the core building blocks it works on Android, iOS, and in server-side environments. The library includes support for ISO mdoc and IETF SD-JWT VC credential formats and also implements proximity presentment using ISO/IEC 18013-5:2021 (for ISO mdoc credentials) and presentment to applications using the W3C Digital Credentials API.
• multipaz-models is a Kotlin Multiplatform library with stateful models with business logic intended to be used by graphical applications. The code is written in a way so it's not tied to a particular UI framework, for example Compose, SwiftUI, or other frameworks.
• multipaz-compose provides rich UI elements to be used in Compose applications.
• multipaz-android-legacy contains an older version of the APIs for applications not yet migrated to the newer libraries. At some point this library will be removed. Unlike the other libraries and applications, this library is in Java, not Kotlin, and only supports Android.
• multipaz-doctypes contains known credential document types (for example ISO/IEC 18013-5:2021 mDL and EU PID) along with human-readable descriptions of claims / data elements, sample data, and sample requests. This is packaged separately from the core multipaz library because its size is non-negligible and not all applications need this or they may bring their own.

A command-line tool multipazctl is also included which can be used to generate ISO/IEC 18013-5:2021 IACA certificates among other things. Use ./gradlew --quiet runMultipazCtl --args "help" for documentation on supported verbs and options.

Library releases, Versioning, and Stability

Libraries are released on GMaven with a two-month cadence and Semantic Versioning is used. At this time we're in pre-1.0 territory but we expect to hit 1.0 around early 2026.

At this point both API interfaces and data stored on disk is subject to change but we expect to provide stability guarantees post 1.0. We only expect minor changes for example conversion from ByteArray to ByteString and similar things.

Getting involved

We have resources for people already involved and people wishing to get involved

• CONTRIBUTING.md for how to get involved with the project and send PRs.
• CODING-STYLE.md for guidelines on writing code to be included in the project.
• TESTING.md explains our approach to unit and manual testing.

Examples / Samples

For a fully-fledged mDL wallet or reader application, the current answer is to use the samples/testapp module which works on both Android and iOS. This application is intended for developers and as such has a lot of options and settings. It's intended to exercise all code in the libraries.

To see how to use the Multipaz libraries from another project, see MpzSecureAreaSample for a minimal Compose Multiplatform app using the SecureArea abstraction. This application works on both Android and iOS.

For a sample using the legacy library, see SimpleVerifierStandalone which is a simple Android mDL reader application.

We intend to provide production-quality wallet and reader applications in separate repositories later in 2025. This will be based on what is currently in the wallet module, converted to Compose Multiplatform.

Note

This is not an official or supported Google product.