leon

Built with privacy and extensibility as core principles, Leon gives developers a self-hosted alternative to cloud-based AI assistants like Alexa, Google Assistant, and Siri, with full visibility into the code handling their commands and data.

Leon's capability is extended through a module system where each module handles a specific domain time and calendar management, web search, media playback, smart home control, note-taking, and developer utilities.

Modules are written in JavaScript and Python, making them accessible to developers with web or scripting backgrounds. The assistant supports multiple natural language understanding backends and can be configured to use local speech recognition models, keeping all audio processing on-device for maximum privacy.

Leon is open-source under the MIT license and actively maintained with regular releases adding new capabilities and improving language understanding accuracy.

It is particularly valued by privacy-conscious users who want AI assistant functionality without contributing usage data to technology companies, and by developers who want a hackable assistant they can extend with custom modules for specific personal or organizational workflows.

Deployment is straightforward via Docker or direct installation on Linux, macOS, or Windows.