codex-cli.nvim

Lightweight Neovim integration for Codex CLI via tmux send-keys or an embedded terminal UI.

• Prompt from Neovim, send to a running Codex CLI pane
• If no Codex CLI pane is found, open a local terminal split
• Visual selection adds file/line context
• Auto-reload buffers when Codex edits files

Requirements

• Neovim >= 0.8
• Codex CLI available in PATH
• tmux (optional, for sending to an existing tmux pane)

Installation (lazy.nvim)

{
  "dukjjang/codex-cli.nvim",
  config = function()
    require("codex_cli").setup()
  end,
}

Usage

• Normal mode: <leader>aa opens a prompt and sends:
  • Context: <current-file>
  • your prompt on the next line
• Visual mode: <leader>aa does the same but includes the selected range:
  • Context: <current-file> lines <start>-<end>
  • your prompt on the next line
• Optional: set keymaps.visual to a different key if you want a separate visual-only mapping.

Commands:

• :CodexSend
• :CodexAsk
• :CodexToggle

Configuration

require("codex_cli").setup({
  tmux = {
    command = "codex", -- match process name for pane detection
  },
  split = {
    command = "codex", -- command used to launch Codex CLI
    direction = "right", -- "right" or "below"
    size = 0.4,
  },
  keymaps = {
    enabled = true,
    ask = "<leader>aa",
    visual = "<leader>aa",
    toggle = "<leader>at",
  },
  command = "CodexSend",
  command_ask = "CodexAsk",
  command_toggle = "CodexToggle",
})

Notes

• Pane detection searches the current tmux session and looks for a codex process in the pane's child process tree.
• If no tmux pane is found, Codex CLI starts in a terminal split.
• Buffers auto-reload on focus/enter/cursor hold via checktime.
• Invalid configuration values fall back to defaults and emit a warning once.

Troubleshooting

• No codex pane found: set tmux.command to match the process name you see in ps.
• Not in tmux: tmux integration is optional; the split terminal still works.