e0c08cea4f
On a high-level, we try to design `config.toml` so that you don't have to "comment out a lot of stuff" when testing different options. Previously, defining a sandbox policy was somewhat at odds with this principle because you would define the policy as attributes of `[sandbox]` like so: ```toml [sandbox] mode = "workspace-write" writable_roots = [ "/tmp" ] ``` but if you wanted to temporarily change to a read-only sandbox, you might feel compelled to modify your file to be: ```toml [sandbox] mode = "read-only" # mode = "workspace-write" # writable_roots = [ "/tmp" ] ``` Technically, commenting out `writable_roots` would not be strictly necessary, as `mode = "read-only"` would ignore `writable_roots`, but it's still a reasonable thing to do to keep things tidy. Currently, the various values for `mode` do not support that many attributes, so this is not that hard to maintain, but one could imagine this becoming more complex in the future. In this PR, we change Codex CLI so that it no longer recognizes `[sandbox]`. Instead, it introduces a top-level option, `sandbox_mode`, and `[sandbox_workspace_write]` is used to further configure the sandbox when when `sandbox_mode = "workspace-write"` is used: ```toml sandbox_mode = "workspace-write" [sandbox_workspace_write] writable_roots = [ "/tmp" ] ``` This feels a bit more future-proof in that it is less tedious to configure different sandboxes: ```toml sandbox_mode = "workspace-write" [sandbox_read_only] # read-only options here... [sandbox_workspace_write] writable_roots = [ "/tmp" ] [sandbox_danger_full_access] # danger-full-access options here... ``` In this scheme, you never need to comment out the configuration for an individual sandbox type: you only need to redefine `sandbox_mode`. Relatedly, previous to this change, a user had to do `-c sandbox.mode=read-only` to change the mode on the command line. With this change, things are arguably a bit cleaner because the equivalent option is `-c sandbox_mode=read-only` (and now `-c sandbox_workspace_write=...` can be set separately). Though more importantly, we introduce the `-s/--sandbox` option to the CLI, which maps directly to `sandbox_mode` in `config.toml`, making config override behavior easier to reason about. Moreover, as you can see in the updates to the various Markdown files, it is much easier to explain how to configure sandboxing when things like `--sandbox read-only` can be used as an example. Relatedly, this cleanup also made it straightforward to add support for a `sandbox` option for Codex when used as an MCP server (see the changes to `mcp-server/src/codex_tool_config.rs`). Fixes https://github.com/openai/codex/issues/1248.
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, though we plan to publish Codex to other package managers soon.
npm i -g @openai/codex@native
codex
You can also download a platform-specific release directly from our GitHub Releases.
What's new in the Rust CLI
While we are working to close the gap between the TypeScript and Rust implementations of Codex CLI, note that the Rust CLI has a number of features that the TypeScript CLI does not!
Config
Codex supports a rich set of configuration options. Note that the Rust CLI uses config.toml instead of config.json. See config.md for details.
Model Context Protocol Support
Codex CLI functions as an MCP client that can connect to MCP servers on startup. See the mcp_servers section in the configuration documentation for details.
It is still experimental, but you can also launch Codex as an MCP server by running codex mcp. Use the @modelcontextprotocol/inspector to try it out:
npx @modelcontextprotocol/inspector codex mcp
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.
codex exec to run Codex programmatially/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.
Use @ for file search
Typing @ triggers a fuzzy-filename search over the workspace root. Use up/down to select among the results and Tab or Enter to replace the @ with the selected path. You can use Esc to cancel the search.
--cd/-C flag
Sometimes it is not convenient to cd to the directory you want Codex to use as the "working root" before running Codex. Fortunately, codex supports a --cd option so you can specify whatever folder you want. You can confirm that Codex is honoring --cd by double-checking the workdir it reports in the TUI at the start of a new session.
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 debug seatbelt [--full-auto] [COMMAND]...
# Linux
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.