Files
codex/codex-rs
viyatb-oai c7b55cdc46 feat: add network proxy feature flag (#20147)
## Why

The permissions migration is making
`permissions.<profile>.network.enabled` the canonical sandbox network
bit, while proxy startup is a separate concern. Enabling network access
should not implicitly start the proxy, and users who are still on legacy
sandbox modes need a separate place to opt into proxy startup and
provide proxy-specific settings.

This follow-up to #19900 gives the network proxy its own feature surface
instead of overloading permission-profile network semantics.

## What changed

- Add an experimental `network_proxy` feature with a configurable
`[features.network_proxy]` table.
- Overlay `features.network_proxy` settings onto the configured proxy
state after permission-profile selection, so the proxy only starts when
the active `NetworkSandboxPolicy` already allows network access.
- Preserve `[experimental_network]` startup behavior independently of
the new feature flag.

## Behavior and examples

There are now three related knobs:

- `permissions.<profile>.network.enabled` controls whether the active
permission profile has network access at all.
- `features.network_proxy` enables proxy restrictions for an
already-network-enabled profile.
- Legacy `sandbox_mode` plus `[sandbox_workspace_write].network_access`
still control whether legacy `workspace-write` has network access at
all.

The rule is:

- network off + proxy flag on -> network stays off, proxy is a no-op
- network on + proxy flag off -> unrestricted direct network
- network on + proxy flag on -> network stays on, with proxy
restrictions applied

For permission profiles, the feature toggle adds proxy restrictions only
when network access is already enabled:

```toml
default_permissions = "workspace"

[permissions.workspace.filesystem]
":minimal" = "read"

[permissions.workspace.network]
enabled = true

[features]
network_proxy = true
```

If `network.enabled = false`, the same feature flag is a no-op: network
remains off and the proxy does not start.

For legacy sandbox config, `network_access` remains the master switch:

```toml
sandbox_mode = "workspace-write"

[sandbox_workspace_write]
network_access = true

[features]
network_proxy = true
```

That keeps legacy `workspace-write` network access on, but routes it
through the proxy policy. If `network_access = false`, the proxy feature
is a no-op and legacy `workspace-write` remains offline.

The same proxy opt-in can be supplied from the CLI:

```bash
codex -c 'features.network_proxy=true'
```

Additional proxy settings can be supplied when a table is needed:

```bash
codex \
  -c 'features.network_proxy.enabled=true' \
  -c 'features.network_proxy.enable_socks5=false'
```

The intended behavior matrix is:

| Config surface | Network setting | `features.network_proxy` | Direct
sandbox network | Proxy |
| --- | --- | --- | --- | --- |
| Permission profile | `network.enabled = false` | off | restricted |
off |
| Permission profile | `network.enabled = false` | on | restricted | off
|
| Permission profile | `network.enabled = true` | off | enabled | off |
| Permission profile | `network.enabled = true` | on | enabled | on |
| Legacy `workspace-write` | `network_access = false` | off | restricted
| off |
| Legacy `workspace-write` | `network_access = false` | on | restricted
| off |
| Legacy `workspace-write` | `network_access = true` | off | enabled |
off |
| Legacy `workspace-write` | `network_access = true` | on | enabled | on
|

`[experimental_network]` requirements remain separate from the user
feature toggle and still start the proxy on their own.

Relevant code:
-
[`features/src/feature_configs.rs`](https://github.com/openai/codex/blob/43785aff47/codex-rs/features/src/feature_configs.rs#L58-L117)
defines the feature-specific proxy config.
-
[`core/src/config/mod.rs`](https://github.com/openai/codex/blob/43785aff47/codex-rs/core/src/config/mod.rs#L1959-L1964)
reads the feature table, and [later applies it only when network access
is already
enabled](https://github.com/openai/codex/blob/43785aff47/codex-rs/core/src/config/mod.rs#L2448-L2458).

## Verification

Added focused coverage for:
- keeping the proxy off when `features.network_proxy` is enabled but
sandbox network access is disabled
- the full permission-profile and legacy `workspace-write` matrix above
- preserving `[experimental_network]` startup without the feature
- reusing profile-supplied proxy settings when the feature is enabled

Ran:
- `cargo test -p codex-features`
- `cargo test -p codex-core network_proxy_feature`
- `cargo test -p codex-core
experimental_network_requirements_enable_proxy_without_feature`
2026-05-11 14:12:00 -07:00
..
2026-05-01 18:15:38 +02:00
2026-05-11 19:45:08 +02:00
2026-05-01 18:15:38 +02:00

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 [--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.