Integrate initial uniffi rust core

.changes/uniffi-rust-core-dev-wiring

@@ -0,0 +1 @@
+patch type="added" "Wire in the livekit_uniffi Rust core behind a native-only facade, delivered as a bundled cdylib via Native Assets"

AGENTS.md

@@ -32,6 +32,28 @@ CI (`build.yaml`) runs all of the above plus example-app builds for every platfo
 
 Web/native divergence is handled with conditional imports (e.g. `track/processor_native.dart` vs `processor_web.dart`) — new platform-specific code should follow that pattern.
 
+## The Rust core (`livekit_uniffi`)
+
+`lib/src/uniffi/` wraps `livekit_uniffi`, a Dart package generated from the `livekit-uniffi` crate in the sibling `rust-sdks` repo. It reaches Rust through Dart's Native Assets: the package's `hook/build.dart` bundles a `cdylib` into the host app and the generated bindings call into it with `@Native`. This is why the SDK requires Flutter >= 3.38 / Dart >= 3.10.
+
+There is no dynamic library to load on the web, so `uniffi.dart` splits native/web the same way the rest of the SDK does. **`uniffi_io.dart` is the only file allowed to import `package:livekit_uniffi/...`** — importing it from anywhere reachable on web pulls `dart:ffi` into a web compile and breaks `flutter build web`/`--wasm`. Guard calls with `LiveKitUniffi.isAvailable`.
+
+### Local development loop
+
+`livekit_uniffi` is not on pub.dev yet, so both `pubspec.yaml` and `example/pubspec.yaml` override it to a path in a sibling `rust-sdks` checkout (overrides don't propagate from a dependency, hence both). To produce or refresh it:
+
+```sh
+cd ../rust-sdks/livekit-uniffi
+cargo make dart-package    # generates packages/dart/: bindings, pubspec, build hook, host cdylib
+cd -
+flutter pub get
+flutter test test/uniffi/  # smoke test: calls buildVersion() across the FFI boundary
+```
+
+Requires `cargo-make`, `protoc` and `tera`. Re-run `cargo make dart-package` whenever the crate's exported surface changes — the build hook tracks the copied library, so a stale one won't be silently reused.
+
+Two things to know about that hook: it picks the locally built library purely on target *OS*, not architecture, so a host build can be bundled into an iOS or Android build by mistake — verify the desktop target first when debugging. And its download mode (used when no local library is present) fetches `build-<triple>.zip` from a `livekit-uniffi` GitHub release; no release currently carries those assets, so download mode fails until the `cdylib` job is re-enabled in `rust-sdks`.
+
 ## Common pitfalls (from issue history)
 
 - `flutter_webrtc` is pinned to an exact version on purpose: livekit_client and flutter_webrtc must agree on the same WebRTC-SDK native pods, and mismatches break user builds (CocoaPods conflicts). Bump it only in sync with a matching WebRTC-SDK version.

analysis_options.yaml

@@ -22,12 +22,14 @@ analyzer:
     avoid_print: ignore
     deprecated_member_use_from_same_package: ignore
 
-  # Exclude protobuf files
+  # Exclude generated files: protobuf, and json_serializable output. Neither is
+  # hand-edited, so lint hits there can only be fixed by changing the generator.
   exclude:
     - "**/*.pb.dart"
     - "**/*.pbenum.dart"
     - "**/*.pbjson.dart"
     - "**/*.pbserver.dart"
+    - "**/*.g.dart"
     # - 'web/*.dart'
     # Xcode vendors Swift package checkouts under build when Swift Package
     # Manager is enabled and this package ships Package.swift.

example/pubspec.yaml

@@ -25,6 +25,13 @@ dependencies:
   livekit_client:
     path: ../
 
+dependency_overrides:
+  # Overrides do not propagate from a dependency, so livekit_client's override of
+  # livekit_uniffi has to be repeated here. Drop both once it is on pub.dev.
+  livekit_uniffi:
+    path: ../../rust-sdks/livekit-uniffi/packages/dart
+
+
 dev_dependencies:
   flutter_test:
     sdk: flutter

lib/src/uniffi/uniffi.dart

@@ -0,0 +1,45 @@
+// Copyright 2026 LiveKit, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import 'uniffi_io.dart' if (dart.library.js_interop) 'uniffi_web.dart' as impl;
+
+/// Facade over the Rust core exposed by the `livekit_uniffi` package.
+///
+/// `livekit_uniffi` reaches Rust through Dart's Native Assets: its build hook
+/// bundles a `cdylib` into the host app and the generated bindings call into it
+/// with `@Native`. None of that exists on the web, where there is no dynamic
+/// library to load, so every entry point here is split native/web through the
+/// same conditional-import pattern the rest of the SDK uses (see
+/// `support/platform.dart`). Web builds must never reach the generated
+/// bindings -- importing them at all would break `dart compile js`/`wasm`.
+///
+/// Callers get [isAvailable] to branch on, and platform-specific code paths
+/// stay out of the public API surface.
+abstract final class LiveKitUniffi {
+  /// Whether the Rust core can be called on this platform.
+  ///
+  /// False on web. Every other member throws [UnsupportedError] when this is
+  /// false, rather than returning a silently wrong value.
+  static bool get isAvailable => impl.isAvailable;
+
+  /// Version string reported by the Rust core.
+  ///
+  /// The simplest possible round trip -- a synchronous, argument-free call
+  /// returning a string -- so it doubles as the smoke test that the whole
+  /// chain is wired up: build hook resolved the library, `@Native` bound the
+  /// symbol, and a value came back across the FFI boundary.
+  ///
+  /// Throws [UnsupportedError] on web.
+  static String get buildVersion => impl.buildVersion();
+}

lib/src/uniffi/uniffi_io.dart

@@ -0,0 +1,23 @@
+// Copyright 2026 LiveKit, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import 'package:livekit_uniffi/livekit_uniffi.dart' as uniffi;
+
+/// Native implementation of [LiveKitUniffi]. See `uniffi.dart`.
+///
+/// This is the only file in the SDK that may import the generated bindings:
+/// the conditional import in `uniffi.dart` keeps it out of web builds.
+const bool isAvailable = true;
+
+String buildVersion() => uniffi.buildVersion();

lib/src/uniffi/uniffi_web.dart

@@ -0,0 +1,27 @@
+// Copyright 2026 LiveKit, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/// Web implementation of [LiveKitUniffi]. See `uniffi.dart`.
+///
+/// Native Assets bundles a `cdylib`, which the web has no way to load, so the
+/// Rust core is simply absent here. This file deliberately does not import
+/// `package:livekit_uniffi/...` -- doing so would pull `dart:ffi` into a web
+/// compile and fail the build.
+const bool isAvailable = false;
+
+Never buildVersion() => throw UnsupportedError(
+  'LiveKitUniffi.buildVersion is not available on web: the Rust core is '
+  'delivered as a native library. Guard calls with '
+  'LiveKitUniffi.isAvailable.',
+);

pubspec.lock

@@ -17,6 +17,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "13.0.0"
+  archive:
+    dependency: transitive
+    description:
+      name: archive
+      sha256: a96e8b390886ee8abb49b7bd3ac8df6f451c621619f52a26e815fdcf568959ff
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.0.9"
   args:
     dependency: transitive
     description:
@@ -432,6 +440,13 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "6.1.0"
+  livekit_uniffi:
+    dependency: "direct main"
+    description:
+      path: "../rust-sdks/livekit-uniffi/packages/dart"
+      relative: true
+    source: path
+    version: "0.1.8"
   logger:
     dependency: transitive
     description:
@@ -616,6 +631,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.5.2"
+  posix:
+    dependency: transitive
+    description:
+      name: posix
+      sha256: bc1bad54ad2b735816e31f8d4600cfde6c7839975085ddfbca48b6c9f7c4044e
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.5.2"
   protobuf:
     dependency: "direct main"
     description:

pubspec.yaml

@@ -57,6 +57,17 @@ dependencies:
   flutter_webrtc: 1.6.0
   dart_webrtc: ^1.8.0
 
+  # Rust core (livekit-uniffi), delivered as a bundled cdylib via Native Assets.
+  # Native platforms only — see lib/src/uniffi/.
+  livekit_uniffi: ^0.1.7
+
+# livekit_uniffi is not published to pub.dev yet, so it resolves out of a sibling
+# rust-sdks checkout produced by `cargo make dart-package`. See AGENTS.md. Drop
+# this once the package is published.
+dependency_overrides:
+  livekit_uniffi:
+    path: ../rust-sdks/livekit-uniffi/packages/dart
+
 dev_dependencies:
   flutter_test:
     sdk: flutter

test/uniffi/uniffi_test.dart

@@ -0,0 +1,40 @@
+// Copyright 2026 LiveKit, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+@TestOn('vm')
+library;
+
+import 'package:flutter_test/flutter_test.dart';
+
+import 'package:livekit_client/src/uniffi/uniffi.dart';
+
+void main() {
+  // Exercises the whole delivery chain rather than any particular API: the
+  // build hook resolved a cdylib for this target, Native Assets bundled it,
+  // `@Native` bound the symbol, and a value crossed back from Rust. If the
+  // bindgen or the hook regresses, this is what fails first.
+  group('livekit_uniffi', () {
+    test('is available on native platforms', () {
+      expect(LiveKitUniffi.isAvailable, isTrue);
+    });
+
+    test('buildVersion returns the Rust core version', () {
+      final version = LiveKitUniffi.buildVersion;
+      expect(version, isNotEmpty);
+      // The crate stamps its own semver, so assert the shape rather than a
+      // literal that would need bumping on every livekit-uniffi release.
+      expect(version, matches(RegExp(r'^\d+\.\d+\.\d+')));
+    });
+  });
+}