There are many coding agents, but this one is
(dpc's) Tau is a process-oriented LLM coding agent harness built for command line nerds and Linux hackers. Like Pi, but twice as much.
Tau builds on top of the most venerable, powerful, and ubiquitous runtime there is: Unix itself. It embraces the Unix philosophy to its full potential.
It is built by devoted, experienced Unix users who want coding agents to become first-class modern Unix tooling: composable, inspectable, scriptable, and comfortable in the terminal.
All components (UI, harness, LLM API, extensions) run as standalone POSIX processes, communicating over stdio. No Node. No npm. Just processes, pipes and sockets.
For a tour of concrete features — built-in extensions, key bindings, slash commands, and configuration — see FEATURES.md.
Extensions are just executables. Write in the language of your choice.
Each component can be individually sandboxed with bubblewrap, Docker, Landlock, or jails—matched to its actual needs.
Running a component on another machine is as simple as prefixing
its command with ssh user@host -c.
Components can be packaged and managed by your OS. Pairs naturally with NixOS, Guix, and traditional package managers.
Ships as one unified binary containing CLI, agent, and built-in extensions. No runtime dependencies.
Native binary that starts instantly and requires very little memory. Initial measurements show just 4MB of memory use.
Typed event logs preserve sessions, agent transcripts, branch trees, rewinds, detach, and resume across restarts.
Configure roles, models, reasoning effort, verbosity, thinking summaries, service tier, and per-role tool access.
Slash commands, path completion, prompt history, fzf-powered insertion, custom key bindings, and editor-based prompt editing.
Shell and filesystem tools, web search, notifications, provider backends, and PIM extensions for controlled email and calendar access.
Agents can delegate to isolated sub-agents, message agents or users, and keep long-running tool work in the background.
Inline diffs, reasoning rendering, cache stats, turn stats, policy gates, approval logs, and shell/filesystem access locks keep agent work inspectable.
See the full FEATURES.md for details and configuration examples.
Tau owes its design to Pi and aims to copy every single thing that Pi does well, staying as close to its design as possible within a dogmatic Unix philosophy.
Tau is still under heavy development, but it has been a productive daily driver for its developers for weeks. It already has features and design choices that are stronger than those in popular coding agents, while the Unix-centric UX keeps improving quickly.
There are many big plans ahead: more process-oriented integrations, stronger multi-agent workflows, and Unix-native features no other coding harness has today.
Patchmark
is a diff-aware language server for Markdown and plain-text review notes.
It pairs nicely with Tau's prompt-editing flow: open the prompt in
$EDITOR, review diffs with
language-server help, and leave precise feedback for agents from the editor
you already use.
Because the author is not very original and forgot to do prior research, and Tau is just such a good name, there are other coding harnesses called "Tau", like:
When you want to be specific, you can call this one dpc's Tau coding agent.