MediaPipe is a cross-platform framework for building multimodal machine learning pipelines, primarily targeting on-device inference. It provides a graph-based execution model where modular 'calculators' process typed 'packets' through directed acyclic graphs. The framework includes a rich library of pre-built calculators for image processing, tensor manipulation, audio analysis, and ML inference, as well as high-level task APIs for vision (face/hand/pose landmarking, image classification, segmentation), text (classification, language detection), audio (classification), and generative AI (LLM inference). The architecture is layered: a core C++ framework (mediapipe/framework/) defines the graph runtime, stream handlers, and packet infrastructure; a calculator library (mediapipe/calculators/) provides reusable processing nodes; and task-specific APIs (mediapipe/tasks/) offer consistent interfaces across C++, Java, Python, iOS, Web, and C. The system relies on TensorFlow Lite (LiteRT) for model execution, OpenCV for image operations, protobuf for configuration, and Abseil for utilities. Key entry points include the Python package (mediapipe/__init__.py), the C++ task APIs (mediapipe/tasks/cc/), and the web TypeScript modules (mediapipe/web/). The codebase is large and actively developed, with ongoing migration from older API patterns to newer ones (api2/api3), and some deprecated components (legacy Python solutions, older calculator interfaces).

Google AI Edge Gallery is an Android application that serves as a showcase and playground for on-device AI models, primarily Gemma 4 and other LiteRT-compatible LLMs. It provides a rich set of interactive tasks including AI Chat, Prompt Lab, Ask Image, Audio Scribe, Tiny Garden (a mini-game powered by a 270M model), Mobile Actions (device control via function calling), and an Agent Skills system with MCP (Model Context Protocol) integration. The app manages the full lifecycle of on-device models: discovery (via HuggingFace), download, initialization, inference, and benchmarking. It features a plugin architecture via the CustomTask interface, allowing new tasks to be registered through Hilt dependency injection. Skills are defined as markdown instruction files paired with JavaScript functions executed in a WebView, enabling extensible tool use. The codebase is well-structured with Jetpack Compose UI, Proto DataStore persistence, Firebase Analytics, and a clean separation of concerns. It is a professional-grade demo application that demonstrates advanced on-device AI capabilities, though some areas (e.g., skill duplication, large ViewModels) show signs of rapid development.