Umbra, a new open-source AI agent for Android, is doing what most of us thought was impossible: it operates your phone’s apps in the background while you keep using the device. Released on November 4, 2026, by developer chengmatt416, Umbra uses an invisible display to tap, type, and scroll through apps, all while you’re browsing or texting. It’s not just a screen reader; it’s a full autonomous agent that builds code, checks its work, and asks for permission before doing anything risky.

A Linux Machine in Your Pocket

What makes Umbra stand out in the crowded AI agent space is its integration of a real Debian Linux environment directly on the Android device. The agent can run bash, git, Python, and Bun to build and test software, with files shared between the Linux side and the Android apps. This isn’t a cloud simulation; it’s a local chroot or proot environment (depending on whether you have root access) that lets the agent compile code and run tests without leaving your phone.

You Stay in Control

Umbra is built on omp, a coding agent framework, and extends it with Android-specific tools. But the developer is clear: you’re the boss. Risky actions like payments, sending messages, or changing security settings always require your approval, whether via a floating control, a notification, or the app itself. The agent can’t approve its own requests, and there’s a full audit history of every action and approval. Plus, a one-tap "Stop and take back" option revokes all access, kills running tasks, and deletes the history if things go sideways.

Key Takeaways

  • Umbra runs tasks in an invisible background display, so you keep using your phone normally.
  • It includes a full Debian Linux environment (2GB) for building and testing code locally.
  • All risky actions (payments, messages, deletions) require explicit user approval.
  • It supports multiple LLM providers, including Anthropic, OpenAI, Google, and OpenRouter.
  • The agent is open-source (MIT license) and requires Android 16 (API 36) to run.

The Bottom Line

Umbra isn’t just another chatbot wrapper; it’s a serious attempt to put a fully autonomous, code-capable agent on your phone without sacrificing user control. The invisible display trick is the killer feature here—finally, an AI agent that doesn’t demand your full attention. If the dev can keep the approval system tight, this could be the template for how mobile agents should work.

How to Get Started

Umbra is currently distributed as a sideloaded APK (no Play Store build) and requires you to provide your own API keys for the language model. The setup walks you through enabling accessibility services and initializing the Linux environment. You can also pair external computers (macOS or Linux) as execution nodes using umbra-node, which lets the phone offload heavy jobs to your desktop while keeping the agent’s logic and approvals on mobile. The whole interface is available in English and Traditional Chinese.