Codex Mobile - Local AI Agent APK for Android

Codex Mobile - Local AI Agent by Fr3 Man is an Android coding assistant designed to run large language models locally for code authoring, editing, and automation. The app uses GGUF-formatted models via llama.cpp to deliver on-device inference, agentic file system integration, and multi-project organization for managing separate work directories. Additional capabilities include system prompt customization, chain-of-thought visualization, context attachments, and a background execution option to prevent interruptions. The tool targets developers, AI researchers, and privacy-conscious users who need offline LLM workflows.

Acts as an on-device coding agent that edits and organizes projects

Codex gives the AI active control over project folders, allowing it to create, read, modify, and delete code files inside designated working directories. Multi-project management separates tasks into independent directories and the UI exposes system prompt settings for bespoke agent behavior. The interface also supports chain-of-thought visualization in expandable blocks and lets users attach specific files to chat messages to provide contextual project data.

How private are your coding sessions?

All model inference and data processing are handled on the device, so the app does not send project code to external servers. The developer designed it to operate without an active internet connection once a model is loaded, which keeps code and prompts on the phone during use. This local-first architecture is intended for users who prioritize retaining project data on-device rather than routing it through remote services.

Is it practical on typical Android hardware?

Performance depends on the device's CPU and available RAM; the documentation recommends small quantized models in the 1.5B to 8B parameter range for smoother runs. The app provides a background execution option that keeps the screen active during long generations to avoid interruptions. Users should expect that larger models require more memory, and preparing project folders and attaching context files benefits from a device with ample storage and processing headroom.

How do you add and manage AI models in the app?

The app supports the GGUF model format and exposes a 'Load GGUF Model' control in settings and project chat menus for importing models. Users bring their own models by downloading compatible GGUF files and loading them into a project. That BYOM approach gives control over model choice and versioning, and works within Android's app environment where model files and project directories remain under the user's control.

Best suited for developers who accept a hands-on model workflow

Codex is a practical option for developers and AI researchers who need direct control of models and project files on a device. Its design rewards users comfortable importing GGUF models and arranging project directories, while those seeking a plug-and-play cloud service may find the setup demanding. The app favors technical users who prioritize local control over remote convenience. Expect an environment tailored to experimentation rather than simple chat-based assistance.