Anvil

A terminal-native IDE that orchestrates multiple AI coding agents inside tmux.

No browser. No GUI. Everything lives in your terminal: a file explorer on the left, neovim in the center, your AI agents on the right, and a bash terminal at the bottom. Agents edit files on disk, neovim's autoread picks up the changes live, and you stay in full control without leaving the keyboard.

Requirements

• tmux
• nvim
• yazi (or broot/ranger, if you change file_explorer in config)
• whichever agent CLIs you want to run (e.g. claude, opencode)
• Python 3.10+

Install

pip install -e .

Usage

cd your-project
anvil init      # scaffold .anvil/config.yaml
anvil start     # spin up the 4-pane layout and attach
anvil stop      # kill the session and all its processes

Config

.anvil/config.yaml, created by anvil init:

editor: nvim
file_explorer: yazi

agents:
  - name: opencode
    command: opencode
  - name: claude
    command: claude

layout:
  left_width: 20
  right_width: 25
  bottom_height: 8

Add or remove entries under agents to change how many agent panes get launched on the right.

Development

pip install -e ".[dev]"
pytest

layout.py drives a real tmux server, so it's best exercised with a manual smoke test rather than unit tests:

cd /tmp && mkdir demo && cd demo
anvil init && anvil start