flutter_libmwc

MWC wallet bindings for Dart 3.13+ and Flutter 3.47+. APIs are in lib/lib.dart and lib/mwc.dart; Flutter bundles the native library automatically. Nothing beyond Flutter is needed to use the package: the build hook downloads the Rust library built for this version and checks its hash.

Native library

The hook obtains the Rust library in one of three modes, chosen with the build user define in the consuming app's root pubspec.yaml (the workspace root for pub workspaces), or for this checkout with a .dnix-build file holding the mode:

hooks:
  user_defines:
    flutter_libmwc:
      build: prebuilt   # the default; or source, or dev

• prebuilt downloads the library of the release dnix.lock names and verifies it against the hash recorded there. A mismatch is an error, never a fallback. Downloads are cached by hash and need public HTTPS.
• source builds the library with Nix, the same build CI uses, and verifies it against the same hash. Needs Nix on Linux or an Apple Silicon Mac; the Apple targets need Xcode 27.0. OpenSSL is compiled from source inside that build.
• dev builds with Nix but skips the Xcode pin and the hash check, for working on the Rust code. The hook notices a .dnix-build file from its next run on, so touch dnix.json after creating it.

Only dynamic libraries are provided, without sanitizers:

Platform	Targets	Minimum
Linux	arm64, x64	glibc 2.28; no musl/Alpine
Windows	x64	MSVC runtime
macOS	arm64, x64	macOS 11
Android	armv7, arm64, x64	API 21; C++ runtime linked statically
iOS	arm64 device; arm64/x64 simulator	iOS 13; arm64 simulator 14

The floors, the Rust and Xcode versions, the location of the Rust workspace, and the LMDB flags for Apple targets live in dnix.json.

Releases

dnix.lock records the hash of every library the Rust source builds to and names the GitHub release, native-<release>, that holds those bytes. After changing the Rust code, run dart tool/update_lock.dart on a Mac with Nix and Xcode 27.0 and commit the lock with the change; without a Mac, push and copy the lock CI prints once every host is green. CI (.github/workflows/native.yml) builds on four hosts, fails if any host or the lock disagrees, and publishes the release when the lock reaches the default branch. Nothing is committed by CI, and old releases stay.

Anyone can rebuild one platform with Nix and compare: dart tool/verify_release.dart linux (or android, windows, macos, ios, or a target triple), on Windows inside WSL2 for the non-Apple platforms. The build comes from the shared dnix package, whose documentation explains how the bytes stay identical across hosts.

Tests

flutter test runs the Dart tests against the bundled library. Before the lock's release is published, or to test local Rust changes, they need the library built from source: echo dev > .dnix-build with Nix installed (source to also check the hash).