6506765168
## Why
Managed filesystem `deny_read` requirements are administrator-enforced
restrictions on specific paths. Once those requirements are active,
Codex should not drop them just because an execution path would
otherwise leave the sandbox.
Before this change, an explicit escalation, a prefix-rule allow, a
sandbox-denial retry, or an app-server legacy sandbox override could
rebuild the runtime policy without those managed read-deny entries and
expose a path the administrator had marked unreadable.
This is narrower than general sandbox-mode constraints. If an enterprise
only sets `allowed_sandbox_modes`, a trusted `prefix_rule(..., decision
= "allow")` can still run its matching command unsandboxed; this PR only
preserves managed filesystem `deny_read` restrictions across those
paths.
## What Changed
- Mark filesystem policies built from managed `deny_read` requirements
so callers can tell when those deny entries must survive escalation.
- Preserve managed deny-read entries when runtime permission profiles
are rebuilt through protocol, app-server, or legacy sandbox-policy
compatibility paths.
- Keep managed deny-read attempts inside the selected sandbox on the
first attempt and after sandbox-denial retries.
- Preserve the same behavior in the zsh-fork escalation path, including
prefix-rule-driven escalation.
- Add a regression test showing the opposite case too: without managed
deny-read, a prefix-rule allow still chooses unsandboxed execution.
## Verification
Targeted automated verification:
```shell
cargo test -p codex-core shell_request_escalation_execution_is_explicit -- --nocapture
cargo test -p codex-core prefix_rule_uses_unsandboxed_execution_without_managed_deny_read -- --nocapture
cargo test -p codex-core prefix_rule_preserves_managed_deny_read_escalation -- --nocapture
cargo test -p codex-protocol permission_profile_round_trip_preserves_filesystem_policy_metadata -- --nocapture
cargo test -p codex-protocol preserving_deny_entries_keeps_unrestricted_policy_enforceable -- --nocapture
cargo test -p codex-app-server-protocol permission_profile_file_system_permissions_preserves_policy_metadata -- --nocapture
cargo check -p codex-app-server -p codex-tui
```
Smoke-test invocations:
```shell
# macOS exact deny + allowed control
codex exec --skip-git-repo-check -C "$ROOT" \
-c 'default_permissions="deny_read_smoke"' \
-c 'permissions.deny_read_smoke.filesystem={":minimal"="read",":project_roots"={"."="write","secrets"="none","future-secret"="none","**/*.env"="none"}}' \
'Run shell commands only. Print the contents of allowed.txt. Then test whether reading secrets/exact-secret.txt succeeds without printing that file if it does. End with exactly two lines: allowed=<contents> and exact_secret=<BLOCKED or READABLE>.'
# Linux exact deny + allowed control
codex exec --skip-git-repo-check -C "$ROOT" \
-c 'default_permissions="deny_read_smoke"' \
-c 'permissions.deny_read_smoke.filesystem={":minimal"="read",glob_scan_max_depth=3,":project_roots"={"."="write","secrets"="none","future-secret"="none","**/*.env"="none"}}' \
'Run shell commands only. Print the contents of allowed.txt. Then test whether reading secrets/exact-secret.txt succeeds without printing that file if it does. End with exactly two lines: allowed=<contents> and exact_secret=<BLOCKED or READABLE>.'
```
Observed manual smoke matrix:
| Case | macOS Seatbelt | Linux bubblewrap |
| --- | --- | --- |
| `cat allowed.txt` | Pass | Pass |
| `cat secrets/exact-secret.txt` | Blocked | Blocked |
| `cat envs/root.env` | Blocked | Blocked |
| `cat envs/nested/one.env` | Blocked | Blocked |
| `cat envs/nested/two.env` | Blocked | Blocked |
| `cat alias-to-secrets/exact-secret.txt` | Blocked | Blocked |
| Missing denied path | A file created after sandbox setup remained
unreadable | Creation was blocked by the reserved missing-path
placeholder, and the placeholder was cleaned up after exit |
| Real `codex exec` shell turn | Pass | Pass |
Notes:
- The Linux smoke run used the fallback glob walker because the devbox
did not have `rg` installed.
- The smoke matrix verifies the end-to-end filesystem behavior on macOS
and Linux; the escalation-specific behavior is covered by the focused
tests above.
---------
Co-authored-by: Codex <noreply@openai.com>
Co-authored-by: Charlie Marsh <charliemarsh@openai.com>
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
- 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. 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 [--log-denials] [COMMAND]...
# Linux
codex sandbox linux [COMMAND]...
# Windows
codex sandbox windows [COMMAND]...
# Legacy aliases
codex debug seatbelt [--log-denials] [COMMAND]...
codex debug landlock [COMMAND]...
To try a writable legacy sandbox mode with these commands, pass an explicit config override such
as -c 'sandbox_mode="workspace-write"'.
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 becomes 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.