core-agent-ide/codex-rs
Helmut Januschka 7daaabc795
fix: add tui.alternate_screen config and --no-alt-screen CLI flag for Zellij scrollback (#8555)
Fixes #2558

Codex uses alternate screen mode (CSI 1049) which, per xterm spec,
doesn't support scrollback. Zellij follows this strictly, so users can't
scroll back through output.

**Changes:**
- Add `tui.alternate_screen` config: `auto` (default), `always`, `never`
- Add `--no-alt-screen` CLI flag
- Auto-detect Zellij and skip alt screen (uses existing `ZELLIJ` env var
detection)

**Usage:**
```bash
# CLI flag
codex --no-alt-screen

# Or in config.toml
[tui]
alternate_screen = "never"
```

With default `auto` mode, Zellij users get working scrollback without
any config changes.

---------

Co-authored-by: Josh McKinney <joshka@openai.com>
2026-01-09 18:38:26 +00:00
..
.cargo chore(ci): add cargo audit workflow and policy (#7108) 2025-11-24 12:20:55 -08:00
.config fix flaky test: approval_matrix_covers_all_modes (#7028) 2025-11-20 14:37:42 -08:00
.github/workflows chore(ci): add cargo audit workflow and policy (#7108) 2025-11-24 12:20:55 -08:00
ansi-escape chore: add cargo-deny configuration (#7119) 2025-11-24 12:22:18 -08:00
app-server renaming: task to turn (#8963) 2026-01-09 17:31:17 +00:00
app-server-protocol feat: fork conversation/thread (#8866) 2026-01-08 12:54:20 -08:00
app-server-test-client renaming: task to turn (#8963) 2026-01-09 17:31:17 +00:00
apply-patch feat: introduce find_resource! macro that works with Cargo or Bazel (#8879) 2026-01-07 18:06:08 -08:00
arg0 chore: add cargo-deny configuration (#7119) 2025-11-24 12:22:18 -08:00
async-utils chore: add cargo-deny configuration (#7119) 2025-11-24 12:22:18 -08:00
backend-client Immutable CodexAuth (#8857) 2026-01-08 11:43:56 -08:00
chatgpt Immutable CodexAuth (#8857) 2026-01-08 11:43:56 -08:00
cli [device-auth] When headless environment is detected, show device login flow instead. (#8756) 2026-01-08 21:48:30 -08:00
cloud-tasks Immutable CodexAuth (#8857) 2026-01-08 11:43:56 -08:00
cloud-tasks-client cloud: status, diff, apply (#7614) 2025-12-05 21:39:23 +00:00
codex-api Add feature for optional request compression (#8767) 2026-01-07 13:21:40 -08:00
codex-backend-openapi-models chore: add cargo-deny configuration (#7119) 2025-11-24 12:22:18 -08:00
codex-client Add feature for optional request compression (#8767) 2026-01-07 13:21:40 -08:00
common feat: support allowed_sandbox_modes in requirements.toml (#8298) 2025-12-19 21:09:20 +00:00
core fix: add tui.alternate_screen config and --no-alt-screen CLI flag for Zellij scrollback (#8555) 2026-01-09 18:38:26 +00:00
debug-client chore: add small debug client (#8894) 2026-01-08 13:40:14 +00:00
docs renaming: task to turn (#8963) 2026-01-09 17:31:17 +00:00
exec renaming: task to turn (#8963) 2026-01-09 17:31:17 +00:00
exec-server fix: correct login shell mismatch in the accept_elicitation_for_prompt_rule() test (#8931) 2026-01-08 12:37:38 -08:00
execpolicy feat: add justification arg to prefix_rule() in *.rules (#8751) 2026-01-05 21:24:48 +00:00
execpolicy-legacy chore: add cargo-deny configuration (#7119) 2025-11-24 12:22:18 -08:00
feedback chore: unify conversation with thread name (#8830) 2026-01-07 17:04:53 +00:00
file-search feat: move file name derivation into codex-file-search (#8334) 2025-12-19 12:50:55 -08:00
keyring-store chore: add cargo-deny configuration (#7119) 2025-11-24 12:22:18 -08:00
linux-sandbox fix: introduce AbsolutePathBuf as part of sandbox config (#7856) 2025-12-12 15:25:22 -08:00
lmstudio make model optional in config (#7769) 2025-12-10 11:19:00 -08:00
login [device-auth] When headless environment is detected, show device login flow instead. (#8756) 2026-01-08 21:48:30 -08:00
mcp-server renaming: task to turn (#8963) 2026-01-09 17:31:17 +00:00
mcp-types Merge Modelfamily into modelinfo (#8763) 2026-01-07 10:35:09 -08:00
ollama make model optional in config (#7769) 2025-12-10 11:19:00 -08:00
otel chore: update metrics temporality (#8901) 2026-01-09 14:57:42 +00:00
process-hardening fix: pre-main hardening logic must tolerate non-UTF-8 env vars (#7749) 2025-12-08 16:00:24 -08:00
protocol fix: add tui.alternate_screen config and --no-alt-screen CLI flag for Zellij scrollback (#8555) 2026-01-09 18:38:26 +00:00
responses-api-proxy chore: add cargo-deny configuration (#7119) 2025-11-24 12:22:18 -08:00
rmcp-client Work around crash in system-configuration library (#8954) 2026-01-09 08:11:34 -07:00
scripts remove release script (#7885) 2025-12-11 13:40:48 -08:00
stdio-to-uds feat: introduce codex-utils-cargo-bin as an alternative to assert_cmd::Command (#8496) 2025-12-23 19:29:32 -08:00
tui fix: add tui.alternate_screen config and --no-alt-screen CLI flag for Zellij scrollback (#8555) 2026-01-09 18:38:26 +00:00
tui2 fix: add tui.alternate_screen config and --no-alt-screen CLI flag for Zellij scrollback (#8555) 2026-01-09 18:38:26 +00:00
utils fix: make the find_resource! macro responsible for the absolutize() call (#8884) 2026-01-07 23:03:43 -08:00
windows-sandbox-rs Elevated sandbox NUX (#8789) 2026-01-08 16:23:06 -08:00
.gitignore [MCP] Prefix MCP tools names with mcp__ (#5309) 2025-10-19 20:41:55 -04:00
Cargo.lock fix: remove existing process hardening from Codex CLI (#8951) 2026-01-08 21:19:34 -08:00
Cargo.toml fix: leverage codex_utils_cargo_bin() in codex-rs/core/tests/suite (#8887) 2026-01-08 14:56:16 +00:00
clippy.toml fix: switch rate limit reset handling to timestamps (#5304) 2025-10-17 17:39:37 -07:00
code Send text parameter for non-gpt-5 models (#4195) 2025-09-24 22:00:06 +00:00
config.md Fix link to MCP Servers config section (#5301) 2025-10-17 14:58:27 -07:00
default.nix fix: drop stale filedescriptor output hash for nix (#7865) 2025-12-11 10:43:50 -08:00
deny.toml fix: upgrade lru crate to 0.16.3 (#8845) 2026-01-07 10:11:27 -08:00
README.md chore: update outdated docs (#8701) 2026-01-03 02:19:52 -08:00
rust-toolchain.toml chore: upgrade to Rust 1.90 (#4124) 2025-09-24 08:32:00 -07:00
rustfmt.toml Update cargo to 2024 edition (#842) 2025-05-07 08:37:48 -07:00

Codex CLI (Rust Implementation)

We provide Codex CLI as a standalone, native 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

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. Output is printed to the terminal directly. You can set the RUST_LOG environment variable to see more about what's going on.

Experimenting with the Codex Sandbox

To test to see what happens when a command is run under the sandbox provided by Codex, we provide the following subcommands in Codex CLI:

# macOS
codex sandbox macos [--full-auto] [--log-denials] [COMMAND]...

# Linux
codex sandbox linux [--full-auto] [COMMAND]...

# Windows
codex sandbox windows [--full-auto] [COMMAND]...

# Legacy aliases
codex debug seatbelt [--full-auto] [--log-denials] [COMMAND]...
codex debug landlock [--full-auto] [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

The same setting can be persisted in ~/.codex/config.toml via the top-level sandbox_mode = "MODE" key, e.g. sandbox_mode = "workspace-write".

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 to be 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.