Mercury – Open-source, local-first agentic harness for Android

Mercury is an open-source, local-first AI agent framework for Android that runs entirely on-device. It enables users to build and execute automated agents directly on their mobile devices without cloud dependencies, emphasizing privacy and offline functionality.

Background

- Mercury is an open-source Android app that lets users run AI agents locally on their phone, without sending data to cloud servers. - It's described as an "agentic harness" — meaning it gives the phone the ability to autonomously perform tasks (e.g., reading screenshots, replying to messages, controlling apps) using on-device AI models. - "Local-first" and "open-source" are key differentiators: most AI assistants (Siri, Google Assistant, ChatGPT app) rely on cloud processing, raising privacy and latency concerns. Mercury aims to keep everything on the device. - The project is early-stage (roughly a personal/experimental repo as of mid-2025), but taps into the broader trend of "on-device AI" and "agentic AI" — AI systems that not only answer questions but take actions on your behalf. - Android is a natural platform for this because it allows more background permissions and app control than iOS.