Internal precompile binaries hook

.github/workflows/ci.yml

@@ -2,7 +2,7 @@ name: CI
 
 on:
   push:
-    branches: [main, "**"]
+    branches: [main]
   pull_request:
     branches: [main]
 
@@ -62,3 +62,11 @@ jobs:
       - name: Run tests
         run: |
           dart test
+
+  precompile-binaries:
+    needs: build-and-test
+    if: github.event_name == 'push' && github.ref == 'refs/heads/main'
+    permissions:
+      contents: write
+    uses: ./.github/workflows/precompile_binaries.yml
+    secrets: inherit

.github/workflows/precompile_binaries.yml

@@ -0,0 +1,88 @@
+name: Precompile Binaries
+
+on:
+  workflow_call:
+    secrets:
+      PRECOMPILED_PRIVATE_KEY:
+        required: true
+  workflow_dispatch:
+
+permissions:
+  contents: write
+
+env:
+  CRATE_DIR: "native"
+  CRATE_PACKAGE: "bdk_dart_ffi"
+
+jobs:
+  precompile_macos_ios:
+    runs-on: macos-latest
+    env:
+      PRIVATE_KEY: ${{ secrets.PRECOMPILED_PRIVATE_KEY }}
+      GH_TOKEN: ${{ github.token }}
+      GITHUB_TOKEN: ${{ github.token }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: stable
+          override: true
+      - uses: dart-lang/setup-dart@v1
+      - uses: subosito/flutter-action@v2
+        with:
+          channel: "stable"
+      - name: Pub get
+        run: dart pub get
+      - name: Precompile (macOS + iOS)
+        run: |
+          set -euo pipefail
+          dart run bin/build_tool.dart precompile-binaries \
+            -v \
+            --os=macos \
+            --manifest-dir="${CRATE_DIR}" \
+            --crate-package="${CRATE_PACKAGE}" \
+            --repository="${GITHUB_REPOSITORY}"
+
+  precompile_android:
+    runs-on: ubuntu-latest
+    env:
+      PRIVATE_KEY: ${{ secrets.PRECOMPILED_PRIVATE_KEY }}
+      GH_TOKEN: ${{ github.token }}
+      GITHUB_TOKEN: ${{ github.token }}
+      ANDROID_NDK_VERSION: "26.3.11579264"
+      ANDROID_MIN_SDK: "23"
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: stable
+          override: true
+      - uses: dart-lang/setup-dart@v1
+      - name: Set up Android SDK
+        uses: android-actions/setup-android@v3
+      - name: Install NDK
+        run: |
+          set -euo pipefail
+          sdkmanager --install "ndk;${ANDROID_NDK_VERSION}"
+      - name: Install cargo-ndk
+        run: cargo install cargo-ndk --locked
+      - name: Pub get
+        run: dart pub get
+      - name: Precompile (Android)
+        env:
+          ANDROID_SDK_ROOT: ${{ env.ANDROID_SDK_ROOT }}
+        run: |
+          set -euo pipefail
+          ANDROID_SDK_ROOT="${ANDROID_SDK_ROOT:-$ANDROID_HOME}"
+          dart run bin/build_tool.dart precompile-binaries \
+            -v \
+            --os=android \
+            --manifest-dir="${CRATE_DIR}" \
+            --crate-package="${CRATE_PACKAGE}" \
+            --repository="${GITHUB_REPOSITORY}" \
+            --android-sdk-location="${ANDROID_SDK_ROOT}" \
+            --android-ndk-version="${ANDROID_NDK_VERSION}" \
+            --android-min-sdk-version="${ANDROID_MIN_SDK}"
+

.gitignore

@@ -2,7 +2,6 @@
 /target
 native/target/
 **/*.rs.bk
-Cargo.lock
 
 # Flutter/Dart
 **/build/

README.md

@@ -59,6 +59,28 @@ If you have the Rust toolchain installed, the native library will be automatical
 As a user of the package, you don't need to worry about building the native library or bindings yourself.
 Only if you want to contribute to the bindings or modify the native code yourself, you can follow the instructions in [development](#development) below.
 
+## Precompiled binaries
+
+This plugin adds a precompiled-binary layer on top of the standard Native Assets approach.
+When enabled, the build hook tries to download a signed precompiled binary for your target first.
+If no matching binary is available or verification fails, it falls back to building from scratch via the Flutter/Dart build hook.
+This gives consumers a choice between using published binaries or building locally.
+
+### pubspec.yaml configuration
+
+In your app's `pubspec.yaml`, add the `bdk_dart` section at the top level (next to `dependencies`), like:
+
+```yaml
+bdk_dart:
+  precompiled_binaries:
+    mode: auto # auto | always | never
+```
+
+`mode` controls when the precompiled path is used:
+- `auto` prefers precompiled binaries when available, otherwise builds locally
+- `always` requires precompiled binaries and skips local builds
+- `never` always builds from source via the build hook
+
 ## Development
 
 ### Generating bindings
@@ -80,6 +102,10 @@ Dart test suite, which covers wallet creation, persistence, offline behavior, an
 dart test
 ```
 
+### Precompiled binaries (maintainers)
+
+See `docs/precompiled_binaries.md` for CI details, manual release steps, and configuration.
+
 ## License
 
 The Rust crate and generated bindings are dual-licensed under MIT or Apache 2.0 per the

bin/build_tool.dart

@@ -0,0 +1,6 @@
+import 'package:bdk_dart/src/precompiled/cli/cli.dart';
+
+Future<void> main(List<String> args) async {
+  await runCli(args);
+}
+

docs/precompiled_binaries.md

@@ -0,0 +1,83 @@
+# Precompiled binaries (maintainers)
+
+This document describes how precompiled binaries are built, signed, and published for the plugin.
+
+## Overview
+
+- CI builds and uploads precompiled binaries via `.github/workflows/precompile_binaries.yml`.
+- Artifacts are tagged by the crate hash and uploaded to a GitHub release.
+- Each binary is signed with an Ed25519 key; the public key is embedded in `pubspec.yaml`.
+- The build hook tries to download a verified binary first and falls back to a local build if needed.
+
+## CI workflow
+
+The workflow runs on `push` to `main` and on manual dispatch. It invokes:
+
+```
+dart run bin/build_tool.dart precompile-binaries ...
+```
+
+It currently builds macOS/iOS and Android targets.
+
+## Release expectations
+
+- The workflow creates/releases a GitHub release named `precompiled_<crateHash>` where `<crateHash>` comes from the verified crate sources and config.
+- If the release already exists, the workflow uploads missing assets without rebuilding anything already present.
+- If `gh release view precompiled_<crateHash>` fails locally, rerun `dart run bin/build_tool.dart precompile-binaries ...` with the same crate hash to recreate or update the release.
+
+## How the download works
+
+- The crate hash is computed from the Rust crate sources plus the plugin's `precompiled_binaries` config.
+- The release tag is `precompiled_<crateHash>`.
+- Assets are named `<targetTriple>_<libraryFileName>` with a matching `.sig` file.
+- Each binary is paired with the `.sig` file that the hook uses to verify the download before applying it.
+- The hook chooses the correct `lib$cratePackage` (or `lib$cratePackage.so`) artifact by matching the target triple and link mode from the Dart build config.
+- On build, the hook downloads the signature and binary, verifies it, then places it in the build output.
+- If any step fails (missing asset, bad signature), the hook builds locally via the standard build hook.
+
+## Manual release (local)
+
+Use this when debugging CI or producing artifacts manually.
+
+Required environment variables:
+
+- `PRIVATE_KEY` (Ed25519 private key, hex-encoded, 64 bytes)
+- `GH_TOKEN` or `GITHUB_TOKEN` (GitHub token with release upload permissions)
+
+Example:
+
+```
+dart run bin/build_tool.dart precompile-binaries \
+  --manifest-dir="native" \
+  --crate-package="bdk_dart_ffi" \
+  --repository="owner/repo" \
+  --os=macos
+```
+
+## Troubleshooting & ops tips
+
+- If `gh release view precompiled_<crateHash>` shows a release without the expected `<targetTriple>_` assets, rerun the build locally to regenerate them.
+- A stale crate hash (because sources or `precompiled_binaries` config changed) will point to a release that either doesn’t exist yet or lacks current binaries; re-run `dart run bin/build_tool.dart hash --manifest-dir=native` to confirm the hash and rebuild with the same inputs.
+- Use `gh release view precompiled_<crateHash> --json assets --jq '.assets[].name'` to inspect what’s uploaded and verify `.sig` coverage.
+- When debugging download failures, set `BDK_DART_PRECOMPILED_VERBOSE=1` to see why the hook skipped an asset.
+
+## Configuration knobs
+
+- `rust-toolchain.toml` controls the Rust channel and target list.
+- `pubspec.yaml` under `bdk_dart.precompiled_binaries` must include:
+  - `artifact_host` (owner/repo)
+  - `public_key` (Ed25519 public key, hex-encoded, 32 bytes)
+
+## Environment, keys, and secrets
+
+- `PRIVATE_KEY`: 64-byte hex string (Ed25519 private key). This must be set locally or as a GitHub Actions secret before running `precompile-binaries`. Keep it out of source control.
+- `PUBLIC_KEY`: Add the matching 32-byte hex public key to `pubspec.yaml` so consumers can verify downloads.
+- `GH_TOKEN` / `GITHUB_TOKEN`: release upload permissions (already used in the CI workflow).
+- `BDK_DART_PRECOMPILED_VERBOSE=1`: optional; shows download and verification details when debugging consumer builds.
+
+Generate a keypair with `dart run bin/build_tool.dart gen-key` and copy the printed `PRIVATE_KEY`/`PUBLIC_KEY` values. Rotate the pair if you ever suspect the signing key was exposed, and update every release’s config accordingly.
+
+## Security reminder
+
+- Treat the `PRIVATE_KEY` used for signing as highly sensitive; do not commit it to version control and rotate it immediately if you suspect compromise.
+- Update the public key in `pubspec.yaml` if the private key is rotated so consumers can still verify downloads.

hook/build.dart

@@ -1,10 +1,25 @@
+import 'package:bdk_dart/src/precompiled/precompiled_builder.dart';
 import 'package:hooks/hooks.dart';
-import 'package:native_toolchain_rust/native_toolchain_rust.dart';
+import 'package:native_toolchain_rust/native_toolchain_rust.dart' as ntr;
 
 void main(List<String> args) async {
   await build(args, (input, output) async {
-    await const RustBuilder(
+    final builder = PrecompiledBuilder(
       assetName: 'uniffi:bdk_dart_ffi',
-    ).run(input: input, output: output);
+      buildModeName: ntr.BuildMode.release.name,
+      fallback: (input, output, assetRouting, logger) async {
+        final rustBuilder = ntr.RustBuilder(
+          assetName: 'uniffi:bdk_dart_ffi',
+          buildMode: ntr.BuildMode.release,
+        );
+        await rustBuilder.run(
+          input: input,
+          output: output,
+          assetRouting: assetRouting,
+          logger: logger,
+        );
+      },
+    );
+    await builder.run(input: input, output: output);
   });
 }