Buddy 2.1 is an open-source Android application that allows Claude Code, Codex, or OpenCode to run directly on a smartphone. Released under the Apache 2.0 license, the software operates without requiring a PC, root access, ADB, or an API key.
The app creates a small Alpine Linux environment using proot within its own internal storage. To function, the software requires a 64-bit phone running Android 11 or a newer version.
Buddy utilizes the accessibility system of Android to provide phone-control tools through a local MCP server. Version 2.1 introduces per-app safety levels categorised as Trust, Hard, and Smart, while including an approval system for actions with real consequences.
Voice input is supported via the phone’s speech recognizer, Claude Code’s dictation capability, or ChatGPT voice through Codex. An optional developer mode allows users to create and modify files inside the app’s Linux environment.
Documentation for Buddy identifies prompt injection as a primary concern because the agent reads text displayed by other applications. The developer warns that no model is perfect regarding security risks.
