Files
codex/codex-rs/README.md
efrazer-oai 9d1bf002c6 Significantly improve standalone installer (#17022)
## Summary

This PR significantly improves the standalone installer experience.

The main changes are:

1. We now install the codex binary and other dependencies in a
subdirectory under CODEX_HOME.
(`CODEX_HOME/packages/standalone/releases/...`)

2. We replace the `codex.js` launcher that npm/bun rely on with logic in
the Rust binary that automatically resolves its dependencies (like
ripgrep)

## Motivation

A few design constraints pushed this work.

1. Currently, the entrypoint to codex is through `codex.js`, which
forces a node dependency to kick off our rust app. We want to move away
from this so that the entrypoint to codex does not rely on node or
external package managers.
2. Right now, the native script adds codex and its dependencies directly
to user PATH. Given that codex is likely to add more binary dependencies
than ripgrep, we want a solution which does not add arbitrary binaries
to user PATH -- the only one we want to add is the `codex` command
itself.
3. We want upgrades to be atomic. We do not want scenarios where
interrupting an upgrade command can move codex into undefined state (for
example, having a new codex binary but an old ripgrep binary). This was
~possible with the old script.
4. Currently, the Rust binary uses heuristics to determine which
installer created it. These heuristics are flaky and are tied to the
`codex.js` launcher. We need a more stable/deterministic way to
determine how the binary was installed for standalone.
5. We do not want conflicting codex installations on PATH. For example,
the user installing via npm, then installing via brew, then installing
via standalone would make it unclear which version of codex is being
launched and make it tough for us to determine the right upgrade
command.

## Design

### Standalone package layout

Standalone installs now live under `CODEX_HOME/packages/standalone`:

```text
$CODEX_HOME/
  packages/
    standalone/
      current -> releases/0.111.0-x86_64-unknown-linux-musl
      releases/
        0.111.0-x86_64-unknown-linux-musl/
          codex
          codex-resources/
            rg
```

where `standalone/current` is a symlink to a release directory.

On Windows, the release directory has the same shape, with `.exe` names
and Windows helpers in `codex-resources`:

```text
%CODEX_HOME%\
  packages\
    standalone\
      current -> releases\0.111.0-x86_64-pc-windows-msvc
      releases\
        0.111.0-x86_64-pc-windows-msvc\
          codex.exe
          codex-resources\
            rg.exe
            codex-command-runner.exe
            codex-windows-sandbox-setup.exe
```

This gives us:
- atomic upgrades because we can fully stage a release before switching
`standalone/current`
- a stable way for the binary to recognize a standalone install from its
canonical `current_exe()` path under CODEX_HOME
- a clean place for binary dependencies like `rg`, Windows sandbox
helpers, and, in the future, our custom `zsh` etc

### Command location

On Unix, we add a symlink at `~/.local/bin/codex` which points directly
to the `$CODEX_HOME/packages/standalone/current/codex` binary. This
becomes the main entrypoint for the CLI.

On Windows, we store the link at
`%LOCALAPPDATA%\Programs\OpenAI\Codex\bin`.

### PATH persistence

This is a tricky part of the PR, as there's no ~super reliable way to
ensure that we end up on PATH without significant tradeoffs.

Most Unix variants will have `~/.local/bin` on PATH already, which means
we *should* be fine simply registering the command there in most cases.
However, there are cases where this is not the case. In these cases, we
directly edit the profile depending on the shell we're in.

- macOS zsh: `~/.zprofile`
- macOS bash: `~/.bash_profile`
- Linux zsh: `~/.zshrc`
- Linux bash: `~/.bashrc`
- fallback: `~/.profile`

On Windows, we update the User `Path` environment variable directly and
we don't need to worry about shell profiles.

### Standalone runtime detection

This PR adds a new shared crate, `codex-install-context`, which computes
install ownership once per process and caches it in a `OnceLock`.

That context includes:
- install manager (`Standalone`, `Npm`, `Bun`, `Brew`, `Other`)
- the managed standalone release directory, when applicable
- the managed standalone `codex-resources` directory, when present
- the resolved `rg_command`

The standalone path is detected by canonicalizing `current_exe()`,
canonicalizing CODEX_HOME via `find_codex_home()`, and checking whether
the binary is running from under
`$CODEX_HOME/packages/standalone/releases`.

We intentionally do not use a release metadata file. The binary path is
the source of truth.

### Dependency resolution

For standalone installs, `grep_files` now resolves bundled `rg` from
`codex-resources` next to the Codex binary.

For npm/bun/brew/other installs, `grep_files` falls back to resolving
`rg` from PATH.

For Windows standalone installs, Windows sandbox helpers are still found
as direct siblings when present. If they are not direct siblings, the
lookup also checks the sibling `codex-resources` directory.

### TUI update path

The TUI now has `UpdateAction::StandaloneUnix` and
`UpdateAction::StandaloneWindows`, which rerun the standalone install
commands.

Unix update command:

```sh
sh -c "curl -fsSL https://chatgpt.com/codex/install.sh | sh"
```

Windows update command:

```powershell
powershell -c "irm https://chatgpt.com/codex/install.ps1|iex"
```

The Windows updater runs PowerShell directly. We do this because `cmd
/C` would parse the `|iex` as a cmd pipeline instead of passing it to
PowerShell.

## Additional installer behavior

- standalone installs now warn about conflicting npm/bun/brew-managed
`codex` installs and offer to uninstall them
- same-version reruns do not redownload the release if it is already
staged locally

## Testing

Installer smoke tests run:
- macOS: fresh install into isolated `HOME` and `CODEX_HOME` with
`scripts/install/install.sh --release latest`
- macOS: reran the installer against the same isolated install to verify
the same-version/update path and PATH block idempotence
- macOS: verified the installed `codex --version` and bundled
`codex-resources/rg --version`
- Windows: parsed `scripts/install/install.ps1` with PowerShell via
`[scriptblock]::Create(...)`
- Windows: verified the standalone update action builds a direct
PowerShell command and does not route the `irm ...|iex` command through
`cmd /C`

---------

Co-authored-by: Codex <noreply@openai.com>
2026-04-15 14:44:01 -07:00

5.3 KiB

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

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, 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". 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 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.

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.