Install llamadart

Requirements#

• Dart SDK >= 3.10.7
• Flutter SDK >= 3.38.0 (if you build Flutter apps)
• Flutter iOS apps: deployment target 16.4 or newer
• Flutter macOS apps: deployment target 14.0 or newer
• Windows: the latest Microsoft Visual C++ v14 Redistributable for the app's architecture (x64 or arm64) on every machine that runs the app, at least as new as the build tools of the bundled DLLs. Stock Windows Server lacks it; see Native library won't load.

Add the package#

dependencies:
  llamadart: ^0.13.1

Then resolve packages:

dart pub get
# or
flutter pub get

Flutter iOS and macOS setup#

Set the app's deployment target before running: iOS 16.4 or newer, macOS 14.0 or newer. In Xcode, set IPHONEOS_DEPLOYMENT_TARGET = 16.4 or MACOSX_DEPLOYMENT_TARGET = 14.0 for the Runner configurations. An iOS app that still uses CocoaPods also needs the Podfile platform:

platform :ios, '16.4'

The deployment target is a build requirement, not a tested floor for every runtime. LiteRT-LM has run on a device only on iOS 18.3.2; see Known limitations.

To link the Apple XCFrameworks through Swift Package Manager, add the runtime companion packages you need:

dependencies:
  llamadart: ^0.13.1
  llamadart_llama_cpp_flutter: ^0.13.0 # GGUF / llama.cpp
  llamadart_litert_lm_flutter: ^0.13.0 # Apple .litertlm / LiteRT-LM targets
  llamadart_stable_diffusion_flutter: ^0.13.0 # Apple image generation, opt-in

Companion versions released with core 0.13.0 and later share its MAJOR.MINOR, depend on llamadart, and constrain it to that core minor, so pub refuses a mismatched pair instead of the Apple build failing. Companion patch versions move independently of the core's.

The companions depend on the hosted llamadart, and pub ignores a dependency's own pubspec_overrides.yaml. An app that takes llamadart from git or a path, for example with a companion from the same checkout, therefore repeats that llamadart source under its own dependency_overrides:

dependencies:
  llamadart:
    git: https://github.com/leehack/llamadart.git
  llamadart_llama_cpp_flutter:
    git:
      url: https://github.com/leehack/llamadart.git
      path: packages/llamadart_llama_cpp_flutter

dependency_overrides:
  llamadart:
    git: https://github.com/leehack/llamadart.git

Pair companion 0.13.0 with core 0.13.1 and 0.13.0, and 0.0.23 with core 0.12.2; keep 0.0.22 with core 0.12.1 and 0.12.0, and 0.0.21 with core 0.11.1 and 0.11.0. The build checks the resolved llama.cpp and stable_diffusion companions' runtime pins and fails on a mismatch or on an unverified local Artifacts override; the llama.cpp error names the companion release of your core's minor to depend on, such as ^0.13.0 with core 0.13.0. That check also accepts, with a build warning, a companion whose pin is an earlier build of the same llama.cpp release: companion 0.0.22 (v0.6.0-2) still builds with core 0.12.2, 0.13.0 and 0.13.1, but its frameworks lack the minimum OS version keys that App Store validation checks, so move to the companion paired with your core before you ship. On macOS, llamadart_litert_lm_flutter links and embeds the complete LiteRT-LM runtime, including the GPU accelerators. The build uses it only when the resolved companion's Package.swift is the one this core release expects; any other companion keeps macOS LiteRT-LM in the hook cache with a build warning, and the app then needs the build phase below. Companion 0.0.15 is the exception: it pins v0.18.0 rather than this core's v0.18.0-1, but the app still embeds and loads the companion's complete macOS arm64 runtime and needs no build phase, so the build only warns to upgrade the companion to 0.0.16 or later, the releases pinning v0.18.0-1. On iOS the build does not check the LiteRT-LM companion pin. v0.18.0-1 rebuilds the same LiteRT-LM release with arm64-only macOS XCFrameworks.

The companion's macOS XCFrameworks are published for arm64 only, so a universal flutter build macos prints ld: warning: ignoring file ... found architecture 'arm64', required architecture 'x86_64' for each of them. The arm64-only build that Intel Macs describes removes those warnings.

Pair llamadart_stable_diffusion_flutter 0.13.0 with core 0.13.1 and 0.13.0, and 0.0.3 with core 0.12.2, 0.12.1 and 0.12.0. Keep 0.0.2 with core 0.11.1 and 0.11.0, and 0.0.1 with core 0.10.0; older cores, including 0.9.x, ignore it. Adding it opts iOS and macOS builds into the image generation runtime (about 37 MB per Apple target) on its own and leaves the other runtimes on their current path, so leave it out unless the app uses ImageGenerationEngine. An app that uses image generation without it gets the hook-bundled runtime, whose iOS framework MinimumOSVersion App Store Connect rejects; only Xcode and xcodebuild show the build warning about it.

An app bound for the App Store should use the companion for each runtime it ships, because an Apple privacy manifest reaches an app inside a companion's XCFramework and never through the hook path. The llama.cpp XCFramework has one from llamadart-native v0.5.0-1, and the stable_diffusion one from stable-diffusion-native v0.2.0-1. An app that runs llama.cpp or stable_diffusion on the hook path, or whose embedded llama.framework or stable_diffusion.framework has no PrivacyInfo.xcprivacy, declares the runtime's required-reason API use in its own PrivacyInfo.xcprivacy. The LiteRT-LM iOS frameworks have their own manifests from litert-lm-native v0.17.0-8; an app that runs LiteRT-LM on the hook path, or whose embedded LiteRT-LM frameworks have none, declares that runtime's three categories itself. Copy the categories and codes from Apple privacy manifest.

Intel Macs#

LiteRT-LM is not available on x86_64 macOS, on an Intel Mac or under Rosetta. From v0.18.0-1, litert-lm-native publishes macOS runtimes for arm64 only (litert-lm-native#72). llama.cpp runs on both architectures.

A universal Flutter macOS app that depends on llamadart_litert_lm_flutter builds and launches on x86_64. The build hook leaves LiteRT-LM out of the x86_64 slice and prints a warning: llamadart: build warning. On x86_64, loading a .litertlm model or LiteRT-LM speech recognition throws LlamaUnsupportedException. A Dart program on x86_64 macOS gets the same exception. The build fails only when a macos-x86_64 or macos-x64 entry in llamadart_native_runtimes names litert_lm. The same holds for an app without the companion that uses the build phase.

Building for arm64 only is optional. It only silences the ignoring file ... required architecture 'x86_64' linker warnings for the arm64-only LiteRT-LM XCFrameworks. To do it, add this line to macos/Runner/Configs/Release.xcconfig, which the Release and Profile configurations use:

EXCLUDED_ARCHS = x86_64

An Intel Mac then refuses to open the app. Debug builds already target only the build Mac's architecture. For a one-off build, FLUTTER_MACOS_ARM64_ONLY=true flutter build macos has the same effect.

Flutter macOS LiteRT-LM build phase#

A Flutter macOS app gets the LiteRT-LM runtime in its bundle only from a llamadart_litert_lm_flutter that matches the core. With llamadart 0.12.0 and earlier, with companion 0.0.14 or earlier, or without the companion, the build hook leaves the libraries in its cache inside the resolved llamadart package, and the app loads them from there only when it runs unsandboxed, on the build machine, from inside the project. Under the App Sandbox, which flutter create turns on, and in any copied or distributed app, the first LiteRT-LM generation on CPU or GPU throws Failed to load dynamic library 'libLiteRt.dylib', or 'libLiteRtMetalAccelerator.dylib' with llamadart 0.12.0 and a newer companion (#1029). llama.cpp is not affected.

Upgrade the core and the companion together. Until then, add a build phase that copies the runtime into the app:

1. Open macos/Runner.xcworkspace in Xcode and select the Runner target.
2. In Build Phases, add a New Run Script Phase and drag it to the end of the list, after Bundle Framework and Flutter's own script phase.
3. Set Shell to /bin/bash, clear Based on dependency analysis, and paste:

set -euo pipefail
config=
dir="$PROJECT_DIR"
while [ "$dir" != / ]; do
  if [ -f "$dir/.dart_tool/package_config.json" ]; then
    config="$dir/.dart_tool/package_config.json"
    break
  fi
  dir="$(dirname "$dir")"
done
if [ -z "$config" ]; then
  echo "error: no .dart_tool/package_config.json above $PROJECT_DIR; run flutter pub get" >&2
  exit 1
fi
root=
count="$(plutil -extract packages raw -o - "$config")"
for ((i = 0; i < count; i++)); do
  if [ "$(plutil -extract "packages.$i.name" raw -o - "$config")" = llamadart ]; then
    root="$(plutil -extract "packages.$i.rootUri" raw -o - "$config")"
    break
  fi
done
if [ -z "$root" ]; then
  echo "error: llamadart is not resolved in $config" >&2
  exit 1
fi
case "$root" in
  file://*) root="${root#file://}" ;;
  *) root="$(dirname "$config")/$root" ;;
esac
root="$(printf '%b' "${root//%/\\x}")"
bash "$root/tool/macos_litert_lm_prepare_app.sh" "$TARGET_BUILD_DIR/$WRAPPER_NAME"

The script finds the resolved llamadart package through .dart_tool/package_config.json, so it works for hosted, path and git dependencies and in pub workspaces, and runs that package's tool/macos_litert_lm_prepare_app.sh. That script copies the arm64 libraries into Contents/Frameworks/LiteRtLmRuntime and signs them with the build's signing identity. It picks the architecture from Xcode's ARCHS, or from the build Mac when ARCHS is unset, so a universal build on an Intel Mac gets the arm64 runtime. A build for x86_64 only, such as a Debug build on an Intel Mac, gets a warning: line naming litert-lm-native#72 and no LiteRT-LM runtime. Once the companion embeds the runtime, the script detects it and copies nothing, so the phase can be removed.

Web#

Web apps must load the WebGPU bridge script in their web/index.html; the package does not inject it. See Add the bridge to your app.

AI agent skills#

The package ships agent skills that teach coding agents llamadart's APIs. After pub get, run this from your app's root and pick the skills and agent to install them for:

dart run skills@ get

Rerun it after upgrading llamadart to update the installed skills.

Verify it works#

Run the Quickstart example with maxTokens: 1. If the runtime initializes and the model loads, your setup is complete.

What happens on first build#

On the first dart run / flutter run for a native target, llamadart:

1. Detects platform and architecture.
2. Resolves matching runtime artifacts from leehack/llamadart-native and leehack/litert-lm-native.
3. Wires them into your app through native assets. Flutter iOS builds use SwiftPM-linked XCFrameworks when the matching companion packages are present; without the LiteRT-LM companion, Flutter macOS LiteRT-LM keeps its libraries in the hook cache and needs the build phase in the app. The opt-in image generation runtime comes from leehack/stable-diffusion-native the same way.

No local C++ toolchain setup is required for consumers.

Customize native runtimes#

Native builds bundle every available runtime family. To ship only one model format, or to test another native build, set hooks.user_defines in your pubspec.yaml:

hooks:
  user_defines:
    llamadart:
      llamadart_native_runtimes: [llama_cpp] # or [litert_lm]
      # Compatibility testing only; omit to use the tested pin.
      # llamadart_native_tag: v0.6.0-3

A llamadart_native_backends request that names any backend module the target bundle lacks is discarded whole: the hook logs a warning and bundles the defaults instead.

Override tags name a leehack/llamadart-native release: stable vMAJOR.MINOR.PATCH, stable wrapper rebuilds vMAJOR.MINOR.PATCH-N, historical bNNNN, nightly wrapper rebuilds bNNNN-N, or consume-only bNNNN-llamadart.N. Nightly cores are written without leading zeros, and rebuild counters start at 1. Build-hook overrides must always name an explicit tag; latest is limited to maintainer synchronization and header/binding regeneration. An override does not regenerate the Dart bindings, so its binary must stay ABI-compatible with the default leehack/llamadart-native@v0.6.0-3 runtime.

Every key, per-target backend and Android CPU variant selection, local bundle paths, and fallback rules: Configuring native backend modules. How the hook resolves runtimes and the Apple SwiftPM path: Native build hooks.