core-agent-ide/codex-rs
Michael Bolin 3ca0e7673b
feat: run zsh fork shell tool via shell-escalation (#12649)
## Why

This PR switches the `shell_command` zsh-fork path over to
`codex-shell-escalation` so the new shell tool can use the shared
exec-wrapper/escalation protocol instead of the `zsh_exec_bridge`
implementation that was introduced in
https://github.com/openai/codex/pull/12052. `zsh_exec_bridge` relied on
UNIX domain sockets, which is not as tamper-proof as the FD-based
approach in `codex-shell-escalation`.

## What Changed

- Added a Unix zsh-fork runtime adapter in `core`
(`core/src/tools/runtimes/shell/unix_escalation.rs`) that:
- runs zsh-fork commands through
`codex_shell_escalation::run_escalate_server`
  - bridges exec-policy / approval decisions into `ShellActionProvider`
- executes escalated commands via a `ShellCommandExecutor` that calls
`process_exec_tool_call`
- Updated `ShellRuntime` / `ShellCommandHandler` / tool spec wiring to
select a `shell_command` backend (`classic` vs `zsh-fork`) while leaving
the generic `shell` tool path unchanged.
- Removed the `zsh_exec_bridge`-based session service and deleted
`core/src/zsh_exec_bridge/mod.rs`.
- Moved exec-wrapper entrypoint dispatch to `arg0` by handling the
`codex-execve-wrapper` arg0 alias there, and removed the old
`codex_core::maybe_run_zsh_exec_wrapper_mode()` hooks from `cli` and
`app-server` mains.
- Added the needed `codex-shell-escalation` dependencies for `core` and
`arg0`.

## Tests

- `cargo test -p codex-core
shell_zsh_fork_prefers_shell_command_over_unified_exec`
- `cargo test -p codex-app-server turn_start_shell_zsh_fork --
--nocapture`
- verifies zsh-fork command execution and approval flows through the new
backend
- includes subcommand approve/decline coverage using the shared zsh
DotSlash fixture in `app-server/tests/suite/zsh`
- To test manually, I added the following to `~/.codex/config.toml`:

```toml
zsh_path = "/Users/mbolin/code/codex3/codex-rs/app-server/tests/suite/zsh"

[features]
shell_zsh_fork = true
```

Then I ran `just c` to run the dev build of Codex with these changes and
sent it the message:

```
run `echo $0`
```

And it replied with:

```
  echo $0 printed:

  /Users/mbolin/code/codex3/codex-rs/app-server/tests/suite/zsh

  In this tool context, $0 reflects the script path used to invoke the shell, not just zsh.
```

so the tool appears to be wired up correctly.

## Notes

- The zsh subcommand-decline integration test now uses `rm` under a
`WorkspaceWrite` sandbox. The previous `/usr/bin/true` scenario is
auto-allowed by the new `shell-escalation` policy path, which no longer
produces subcommand approval prompts.
2026-02-24 10:31:08 -08:00
..
.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 feat: add support for building with Bazel (#8875) 2026-01-09 11:09:43 -08:00
app-server feat: run zsh fork shell tool via shell-escalation (#12649) 2026-02-24 10:31:08 -08:00
app-server-protocol feat(core) Introduce Feature::RequestPermissions (#11871) 2026-02-24 09:48:57 -08:00
app-server-test-client Add skill approval event/response (#12633) 2026-02-23 22:28:58 -08:00
apply-patch fix: codex-arg0 no longer depends on codex-core (#12434) 2026-02-21 00:20:42 -08:00
arg0 feat: run zsh fork shell tool via shell-escalation (#12649) 2026-02-24 10:31:08 -08:00
async-utils feat: add support for building with Bazel (#8875) 2026-01-09 11:09:43 -08:00
backend-client feat: support multiple rate limits (#11260) 2026-02-10 20:09:31 -08:00
chatgpt [apps] Enforce simple logo url format. (#12374) 2026-02-20 22:05:55 +00:00
cli feat: run zsh fork shell tool via shell-escalation (#12649) 2026-02-24 10:31:08 -08:00
cloud-requirements Cache cloud requirements (#11305) 2026-02-11 14:06:41 +00:00
cloud-tasks feat: split codex-common into smaller utils crates (#11422) 2026-02-11 12:59:24 +00:00
cloud-tasks-client add codex cloud list (#9324) 2026-01-16 08:56:38 -08:00
codex-api Send warmup request (#11258) 2026-02-24 08:15:47 -08:00
codex-backend-openapi-models feat: support multiple rate limits (#11260) 2026-02-10 20:09:31 -08:00
codex-client Log headers in trace mode (#9214) 2026-01-14 18:38:12 +00:00
codex-experimental-api-macros feat: experimental flags (#10231) 2026-02-02 11:06:50 +00:00
config chore: move config diagnostics out of codex-core (#12427) 2026-02-20 23:19:29 -08:00
core feat: run zsh fork shell tool via shell-escalation (#12649) 2026-02-24 10:31:08 -08:00
debug-client Add cwd as an optional field to thread/list (#11651) 2026-02-13 02:05:04 +00:00
docs feat(core): plumb distinct approval ids for command approvals (#12051) 2026-02-18 01:55:57 +00:00
exec Add skill approval event/response (#12633) 2026-02-23 22:28:58 -08:00
execpolicy feat(core): persist network approvals in execpolicy (#12357) 2026-02-23 21:37:46 -08:00
execpolicy-legacy feat: add support for building with Bazel (#8875) 2026-01-09 11:09:43 -08:00
feedback Add ability to attach extra files to feedback (#12370) 2026-02-20 22:26:14 +00:00
file-search app-server: add fuzzy search sessions for streaming file search (#10268) 2026-02-12 10:49:44 -08:00
hooks Allow hooks to error (#11615) 2026-02-16 14:11:05 +00:00
keyring-store feat: add support for building with Bazel (#8875) 2026-01-09 11:09:43 -08:00
linux-sandbox feat(linux-sandbox): implement proxy-only egress via TCP-UDS-TCP bridge (#11293) 2026-02-21 18:16:34 +00:00
lmstudio chore(deps): bump tracing from 0.1.43 to 0.1.44 in /codex-rs (#9880) 2026-01-26 15:48:45 -08:00
login voice transcription (#3381) 2026-02-23 22:15:18 +00:00
mcp-server feat(core) Introduce Feature::RequestPermissions (#11871) 2026-02-24 09:48:57 -08:00
network-proxy feat(network-proxy): add MITM support and gate limited-mode CONNECT (#9859) 2026-02-24 18:15:15 +00:00
ollama chore: nuke chat/completions API (#10157) 2026-02-03 11:31:57 +00:00
otel Add MCP server context to otel tool_result logs (#12267) 2026-02-20 10:26:19 -05:00
process-hardening feat: add support for building with Bazel (#8875) 2026-01-09 11:09:43 -08:00
protocol feat(core) Introduce Feature::RequestPermissions (#11871) 2026-02-24 09:48:57 -08:00
responses-api-proxy Update pnpm versions to fix cve-2026-24842 (#12009) 2026-02-19 14:27:55 -08:00
rmcp-client Add configurable MCP OAuth callback URL for MCP login (#11382) 2026-02-19 13:32:10 -08:00
scripts Upgrade to rust 1.93 (#10080) 2026-01-28 17:46:18 +00:00
secrets Move sanitizer into codex-secrets (#12306) 2026-02-20 22:47:54 +00:00
shell-command fix(core) exec policy parsing 3 (#12485) 2026-02-22 06:26:13 +00:00
shell-escalation feat: run zsh fork shell tool via shell-escalation (#12649) 2026-02-24 10:31:08 -08:00
skills refactor(core): move embedded system skills into codex-skills crate (#12435) 2026-02-21 08:34:08 +00:00
state feat: do not enqueue phase 2 if not necessary (#12344) 2026-02-20 17:21:45 +00:00
stdio-to-uds feat: add support for building with Bazel (#8875) 2026-01-09 11:09:43 -08:00
tui feat: run zsh fork shell tool via shell-escalation (#12649) 2026-02-24 10:31:08 -08:00
utils feat: use process group to kill the PTY (#12688) 2026-02-24 16:55:23 +00:00
vendor build(linux-sandbox): always compile vendored bubblewrap on Linux; remove CODEX_BWRAP_ENABLE_FFI (#11498) 2026-02-11 21:30:41 -08:00
windows-sandbox-rs Protect workspace .agents directory in Windows sandbox (#11970) 2026-02-17 09:40:46 -08:00
.gitignore [MCP] Prefix MCP tools names with mcp__ (#5309) 2025-10-19 20:41:55 -04:00
BUILD.bazel Add feature-gated freeform js_repl core runtime (#10674) 2026-02-11 12:05:02 -08:00
Cargo.lock feat: run zsh fork shell tool via shell-escalation (#12649) 2026-02-24 10:31:08 -08:00
Cargo.toml feat: run zsh fork shell tool via shell-escalation (#12649) 2026-02-24 10:31:08 -08:00
clippy.toml fix: switch rate limit reset handling to timestamps (#5304) 2025-10-17 17:39:37 -07:00
config.md Fix link to MCP Servers config section (#5301) 2025-10-17 14:58:27 -07:00
default.nix fix(nix): include libcap dependency on linux builds (#12415) 2026-02-20 19:32:15 -08:00
deny.toml feat(tui): syntax highlighting via syntect with theme picker (#11447) 2026-02-21 20:26:58 -08:00
node-version.txt Add feature-gated freeform js_repl core runtime (#10674) 2026-02-11 12:05:02 -08:00
README.md Fix: update parallel tool call exec approval to approve on request id (#11162) 2026-02-10 09:38:00 -08:00
rust-toolchain.toml Revert "chore(deps): bump rust-toolchain from 1.93.0 to 1.93.1 in /co…dex-rs (#11886)" (#12035) 2026-02-17 12:29:03 -08:00
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. 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".

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.