Felipe Coury
c0ea566bb5
## TL;DR When you press Esc or Ctrl+C after sending a prompt but before any output was rendering, it restores the last composer and the message. ## Summary Cancelling a prompt immediately after submission should behave like returning to edit that prompt, not like discarding the user's draft. Today, pressing `Esc` or `Ctrl+C` before Codex responds leaves the submitted prompt in the transcript and returns an empty composer, forcing the user to recall or retype it. When an interrupted turn has not produced substantive visible output, restore its submitted prompt directly into the composer and roll back that latest turn. This also covers the first prompt in a fresh thread, before the TUI has retained a local user-history cell. The restored draft keeps its text, image attachments, and active collaboration mode so it can be edited and resubmitted in place. Restoration is intentionally suppressed once the turn has produced user-visible activity such as assistant output, tool work, hooks, or patches. A transient thinking status does not make the prompt ineligible. Rollback also rebuilds terminal scrollback from the retained transcript cells so repeated cancellations and terminal resizes do not duplicate history. ## How to Test 1. Start the TUI with `cargo run -p codex-cli --bin codex`. 2. In a fresh thread, submit the first prompt and press `Esc` before Codex emits substantive output. Confirm that the prompt returns to the composer for editing and its submitted transcript row is removed. 3. Repeat with `Ctrl+C`, then repeat after at least one completed turn. Confirm the same behavior. 4. Submit a prompt, wait for assistant output or tool activity, then cancel. Confirm that the transcript remains intact and the prompt is not restored into the composer. 5. Cancel several output-free prompts and resize the terminal between attempts. Confirm that the startup banner, tip, and transcript history do not duplicate in scrollback. Targeted tests: - `just test -p codex-tui cancelled_turn_edit_restores_prompt` - `just test -p codex-tui output_free_interrupted_turn_requests_prompt_restore` - `just test -p codex-tui visible_output_prevents_cancelled_turn_prompt_restore` - `just test -p codex-tui thinking_status_keeps_cancelled_turn_prompt_restore_eligible` - `just test -p codex-tui patch_activity_prevents_cancelled_turn_prompt_restore` The full `just test -p codex-tui` run completed with `2746` passing tests and two unrelated existing guardian feature-flag failures. `just argument-comment-lint` remains blocked locally by the existing Bazel LLVM `compiler-rt` sanitizer-header glob failure; the touched Rust diff was manually audited for positional literal comments.
Codex CLI (Rust Implementation)
We provide Codex CLI as a standalone executable to ensure a zero-dependency install.
Installing Codex
Today, the easiest way to install Codex is via npm:
npm i -g @openai/codex
codex
You can also install via Homebrew (brew install --cask codex) or download a platform-specific release directly from our GitHub Releases.
Documentation quickstart
- First run with Codex? Start with
docs/getting-started.md(links to the walkthrough for prompts, keyboard shortcuts, and session management). - Want deeper control? See
docs/config.mdanddocs/install.md.
What's new in the Rust CLI
The Rust implementation is now the maintained Codex CLI and serves as the default experience. It includes a number of features that the legacy TypeScript CLI never supported.
Config
Codex supports a rich set of configuration options. Note that the Rust CLI uses config.toml instead of config.json. See docs/config.md for details.
Model Context Protocol Support
MCP client
Codex CLI functions as an MCP client that allows the Codex CLI and IDE extension to connect to MCP servers on startup. See the configuration documentation for details.
MCP server (experimental)
Codex can be launched as an MCP server by running codex mcp-server. This allows other MCP clients to use Codex as a tool for another agent.
Use the @modelcontextprotocol/inspector to try it out:
npx @modelcontextprotocol/inspector codex mcp-server
Use codex mcp to add/list/get/remove MCP server launchers defined in config.toml, and codex mcp-server to run the MCP server directly.
Notifications
You can enable notifications by configuring a script that is run whenever the agent finishes a turn. The notify documentation includes a detailed example that explains how to get desktop notifications via terminal-notifier on macOS. When Codex detects that it is running under WSL 2 inside Windows Terminal (WT_SESSION is set), the TUI automatically falls back to native Windows toast notifications so approval prompts and completed turns surface even though Windows Terminal does not implement OSC 9.
codex exec to run Codex programmatically/non-interactively
To run Codex non-interactively, run codex exec PROMPT (you can also pass the prompt via stdin) and Codex will work on your task until it decides that it is done and exits. If you provide both a prompt argument and piped stdin, Codex appends stdin as a <stdin> block after the prompt so patterns like echo "my output" | codex exec "Summarize this concisely" work naturally. Output is printed to the terminal directly. You can set the RUST_LOG environment variable to see more about what's going on.
Use codex exec --ephemeral ... to run without persisting session rollout files to disk.
Experimenting with the Codex Sandbox
To test to see what happens when a command is run under the sandbox provided by Codex, use the sandbox subcommand in Codex CLI:
# Uses the sandbox implementation for the current host OS:
# Seatbelt on macOS, the Linux sandbox on Linux, and Windows restricted token on Windows.
codex sandbox [COMMAND]...
# macOS-only diagnostic option
codex sandbox --log-denials [COMMAND]...
codex sandbox also accepts --profile NAME (-p NAME) to layer
$CODEX_HOME/NAME.config.toml onto the base user config for the sandboxed
command.
Selecting a sandbox policy via --sandbox
The Rust CLI exposes a dedicated --sandbox (-s) flag that lets you pick the sandbox policy without having to reach for the generic -c/--config option:
# Run Codex with the default, read-only sandbox
codex --sandbox read-only
# Allow the agent to write within the current workspace while still blocking network access
codex --sandbox workspace-write
# Danger! Disable sandboxing entirely (only do this if you are already running in a container or other isolated env)
codex --sandbox danger-full-access
In workspace-write, Codex also includes ~/.codex/memories in its writable roots so memory maintenance does not require an extra approval.
Code Organization
This folder is the root of a Cargo workspace. It contains quite a bit of experimental code, but here are the key crates:
core/contains the business logic for Codex. Ultimately, we hope this becomes a library crate that is generally useful for building other Rust/native applications that use Codex.exec/"headless" CLI for use in automation.tui/CLI that launches a fullscreen TUI built with Ratatui.cli/CLI multitool that provides the aforementioned CLIs via subcommands.
If you want to contribute or inspect behavior in detail, start by reading the module-level README.md files under each crate and run the project workspace from the top-level codex-rs directory so shared config, features, and build scripts stay aligned.