Channing CongerandGitHub
c6343e0649
### Purpose
While trying to build out CLI-Tools for the agent to use under skills we
have found that those tools sometimes need to invoke a user elicitation.
These elicitations are handled out of band of the codex app-server but
need to indicate to the exec manager that the command running is not
going to progress on the usual timeout horizon.
### Example
Model calls universal exec:
`$ download-credit-card-history --start-date 2026-01-19 --end-date
2026-02-19 > credit_history.jsonl`
download-cred-card-history might hit a hosted/preauthenticated service
to fetch data. That service might decide that the request requires an
end user approval the access to the personal data. It should be able to
signal to the running thread that the command in question is blocked on
user elicitation. In that case we want the exec to continue, but the
timeout to not expire on the tool call, essentially freezing time until
the user approves or rejects the command at which point the tool would
signal the app-server to decrement the outstanding elicitation count.
Now timeouts would proceed as normal.
### What's Added
- New v2 RPC methods:
- thread/increment_elicitation
- thread/decrement_elicitation
- Protocol updates in:
- codex-rs/app-server-protocol/src/protocol/common.rs
- codex-rs/app-server-protocol/src/protocol/v2.rs
- App-server handlers wired in:
- codex-rs/app-server/src/codex_message_processor.rs
### Behavior
- Counter starts at 0 per thread.
- increment atomically increases the counter.
- decrement atomically decreases the counter; decrement at 0 returns
invalid request.
- Transition rules:
- 0 -> 1: broadcast pause state, pausing all active stopwatches
immediately.
- \>0 -> >0: remain paused.
- 1 -> 0: broadcast unpause state, resuming stopwatches.
- Core thread/session logic:
- codex-rs/core/src/codex_thread.rs
- codex-rs/core/src/codex.rs
- codex-rs/core/src/mcp_connection_manager.rs
### Exec-server stopwatch integration
- Added centralized stopwatch tracking/controller:
- codex-rs/exec-server/src/posix/stopwatch_controller.rs
- Hooked pause/unpause broadcast handling + stopwatch registration:
- codex-rs/exec-server/src/posix/mcp.rs
- codex-rs/exec-server/src/posix/stopwatch.rs
- codex-rs/exec-server/src/posix.rs
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
- 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. 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.