GitHub - benthamite/codex: Emacs integration for OpenAI Codex CLI

codex.el provides an Emacs interface to the OpenAI Codex CLI, embedding the full Codex agent TUI inside an Emacs terminal emulator buffer. You can interact with Codex without leaving your editor — start sessions, send commands, review output, and manage multiple instances across projects.

The package supports two terminal backends — eat (default, recommended) and vterm — and is modeled after claude-code.el, sharing a similar architecture and workflow.

Key capabilities include:

Session management — start Codex in the current project, resume or fork previous sessions, run multiple named instances, kill instances individually or in bulk.
Sending commands and context — send freeform prompts, prompts annotated with file/line context, the active region or entire buffer, file paths, images, and error-at-point requests.
TUI interaction — send return, escape, digits, Tab (follow-up), and other key sequences to the Codex TUI from any buffer.
Window and buffer management — toggle the Codex window, switch between instances, read-only mode for navigating output.
Hooks and notifications — auto-configures the Codex CLI hooks system so Emacs receives lifecycle events; desktop notifications when Codex awaits input.
Transient menus — a main command menu and a slash commands menu for quick keyboard access.
Live configuration — change model, reasoning effort, sandbox mode, approval policy, and profile on the fly via transient infixes.

Installation

Requires Emacs 30.0 or later.

package-vc (built-in since Emacs 30)

(package-vc-install "https://github.com/benthamite/codex")

Elpaca

(use-package codex
  :ensure (codex :host github :repo "benthamite/codex"))

straight.el

(straight-use-package
 '(codex :type git :host github :repo "benthamite/codex"))

Dependencies

transient (>= 0.9.3)
inheritenv (>= 0.2)
One of: eat (default backend) or vterm
The Codex CLI must be installed and available in your PATH.

Quick start

;; Enable the minor mode (auto-configures CLI hooks)
(codex-mode 1)

;; Bind the command map to a prefix of your choice
(global-set-key (kbd "C-c x") codex-command-map)

;; Start Codex in the current project
;; C-c x c  — or M-x codex

;; Send a command from any buffer
;; C-c x s  — or M-x codex-send-command

;; Toggle the Codex window
;; C-c x t  — or M-x codex-toggle

;; Open the transient menu for all commands
;; C-c x m  — or M-x codex-transient

Documentation

For a comprehensive description of all user options, commands, and functions, see the manual.