Concordium Swift SDK

An SDK for applications written in the Swift Programming Language to interact with the Concordium Blockchain.

The main purpose of the SDK is to facilitate development of mobile wallet apps for iOS devices.

Concordium specific cryptographic functions that are implemented in Rust are exposed as a separate Swift library ConcordiumWalletCrypto. That library used to merely host a SwiftPM package for exposing a single binary artifact of an older crypto library which is still used in the iOS reference wallet.

Once this SDK is ready for production, it will completely replace this old library.

Supported platforms

• iOS 15+
• macOS 10.15+ (macOS 12+ to build)

Usage

The SDK is available as a SwiftPM package hosted on GitHub as this repository. To include it as a dependency, add the following

.package(url: "https://github.com/Concordium/concordium-swift-sdk.git", from: "<version>")

where <version> is replaced by an actual version (see tags/releases on GitHub). Then add

.product(name: "Concordium", package: "concordium-swift-sdk")

to the dependencies list of the appropriate target.

Examples

The repository includes some example projects that show how to integrate the SDK into different kinds of applications:

• DocSnippets: Example snippets of code to be directly copied into documentation while being sure that they compile successfully.
• CLI: A simple client that demonstrates how to use the SDK in a terminal-based context. It's also used to exercise the gRPC client in ways that are hard to cover with unit tests.

An example wallet app is currently in development.

Documentation

See the developer documentation site for collected documentation of the various Wallet SDKs.

Development

Build Rust bindings

The Rust bindings are located in concordium-wallet-crypto-swift. which also hosts the Swift package ConcordiumWalletCrypto for exposing the compiled binaries to Swift. By default, this precompiled framework is downloaded from GitHub. Use the environment variable CONCORDIUM_WALLET_CRYPTO_PATH to use a local checkout of this project during development. This will also make it resolve the binary framework to the default target location when compiled locally (./generated/ConcordiumWalletCryptoUniffi.xcframework relative to the crypto project root). Use the environment variable CONCORDIUM_WALLET_CRYPTO_FRAMEWORK_PATH to override this location or define the variable with empty value to disable the behavior and not use a local framework.

In conclusion, assuming that concordium-wallet-crypto-swift is checkout out right next to this project (and make framework has been run), then the command

CONCORDIUM_WALLET_CRYPTO_PATH=../concordium-wallet-crypto-swift swift test

will build and test the project using the local crypto package and the binary framework compiled locally from it.

Build and test SDK

With the Rust bindings in place, the SDK is built and tests executed using swift test. It's not necessary to build the project in order to use it in other projects: Just declare a dependency as explained in usage. The SDK will get compiled as part of the build process of the executable.

Source code formatting

The source code is formatted according to the default rules of SwiftFormat.

The CI workflow Build and test checks that the code base is correctly formatted before PRs are merged.

The formatter has been integrated as a Swift Package Manager plugin. It's possible to run the tool in a variety of ways (see the previous link for all options). The easiest option is to run it on the command line via

make fmt

It may also be invoked directly from XCode by right-clicking on package root (i.e. concordium-swift-sdk) in the Project Navigator pane. The tool is then listed under "SwiftFormat" as "SwiftFormatPlugin" in the context menu for formatting the entire project.