Files
codex/codex-rs/core
Michael Bolin c7bcb90f9b package: include zsh fork in Codex package (#23756)
## Why

The package layout gives Codex a stable place for runtime helpers that
should travel with the entrypoint. `shell_zsh_fork` still required users
to configure `zsh_path` manually, even though we already publish
prebuilt zsh fork artifacts.

This PR builds on #24129 and uses the shared DotSlash artifact fetcher
to include the zsh fork in Codex packages when a matching target
artifact exists. Packaged Codex builds can then discover the bundled
fork automatically; the user/profile `zsh_path` override is removed so
the feature uses the package-managed artifact instead of a legacy path
knob.

## What Changed

- Added `scripts/codex_package/codex-zsh`, a checked-in DotSlash
manifest for the current macOS arm64 and Linux zsh fork artifacts.
- Taught `scripts/build_codex_package.py` to fetch the matching zsh fork
artifact and install it at `codex-resources/zsh/bin/zsh` when available
for the selected target.
- Added package layout validation for the optional bundled zsh resource.
- Added `InstallContext::bundled_zsh_path()` and
`InstallContext::bundled_zsh_bin_dir()` for package-layout resource
discovery.
- Threaded the packaged zsh path through config loading as the runtime
`zsh_path` for packaged installs, and removed the config/profile/CLI
override path.
- Kept the packaged default zsh override typed as `AbsolutePathBuf`
until the existing runtime `Config::zsh_path` boundary.
- Updated app-server zsh-fork integration tests to spawn
`codex-app-server` from a temporary package layout with
`codex-resources/zsh/bin/zsh`, matching the new packaged discovery path
instead of setting `zsh_path` in config.
- Switched package executable copying from metadata-preserving `copy2()`
to `copyfile()` plus explicit executable bits, which avoids macOS
file-flag failures when local smoke tests use system binaries as inputs.

## Testing

To verify that the `zsh` executable from the Codex package is picked up
correctly, first I ran:

```shell
./scripts/build_codex_package.py
```

which created:

```
/private/var/folders/vw/x2knqmks50sfhfpy27nftl900000gp/T/codex-package-pms94kdp/
```

so then I ran:

```
/private/var/folders/vw/x2knqmks50sfhfpy27nftl900000gp/T/codex-package-pms94kdp/bin/codex exec --enable shell_zsh_fork 'run `echo $0`'
```

which reported the following, as expected:

```
/private/var/folders/vw/x2knqmks50sfhfpy27nftl900000gp/T/codex-package-pms94kdp/codex-resources/zsh/bin/zsh
```



---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/23756).
* #23768
* __->__ #23756
2026-05-22 17:54:07 -07:00
..

codex-core

This crate implements the business logic for Codex. It is designed to be used by the various Codex UIs written in Rust.

Dependencies

Note that codex-core makes some assumptions about certain helper utilities being available in the environment. Currently, this support matrix is:

macOS

Expects /usr/bin/sandbox-exec to be present.

When using the workspace-write sandbox policy, the Seatbelt profile allows writes under the configured writable roots while keeping .git (directory or pointer file), the resolved gitdir: target, and .codex read-only.

Network access and filesystem read/write roots are controlled by SandboxPolicy. Seatbelt consumes the resolved policy and enforces it.

Seatbelt also keeps the legacy default preferences read access (user-preference-read) needed for cfprefs-backed macOS behavior.

Linux

Expects the binary containing codex-core to run the equivalent of codex sandbox when arg0 is codex-linux-sandbox. See the codex-arg0 crate for details.

Legacy SandboxPolicy / sandbox_mode configs are still supported on Linux. They can continue to use the legacy Landlock path when the split filesystem policy is sandbox-equivalent to the legacy model after cwd resolution. Split filesystem policies that need direct FileSystemSandboxPolicy enforcement, such as read-only or denied carveouts under a broader writable root, automatically route through bubblewrap. The legacy Landlock path is used only when the split filesystem policy round-trips through the legacy SandboxPolicy model without changing semantics. That includes overlapping cases like /repo = write, /repo/a = none, /repo/a/b = write, where the more specific writable child must reopen under a denied parent.

The Linux sandbox helper prefers the first bwrap found on PATH outside the current working directory whenever it is available. If bwrap is present but too old to support --argv0, the helper keeps using system bubblewrap and switches to a no---argv0 compatibility path for the inner re-exec. If bwrap is missing, it falls back to the bundled codex-resources/bwrap binary shipped with Codex and Codex surfaces a startup warning through its normal notification path instead of printing directly from the sandbox helper. Codex also surfaces a startup warning when bubblewrap cannot create user namespaces. WSL2 uses the normal Linux bubblewrap path. WSL1 is not supported for bubblewrap sandboxing because it cannot create the required user namespaces, so Codex rejects sandboxed shell commands that would enter the bubblewrap path before invoking bwrap.

Windows

Legacy SandboxPolicy / sandbox_mode configs are still supported on Windows. Legacy read-only and workspace-write policies imply full filesystem read access; exact readable roots are represented by split filesystem policies instead.

The elevated Windows sandbox also supports:

  • legacy ReadOnly and WorkspaceWrite behavior
  • split filesystem policies that need exact readable roots, exact writable roots, or extra read-only carveouts under writable roots
  • backend-managed system read roots required for basic execution, such as C:\Windows, C:\Program Files, C:\Program Files (x86), and C:\ProgramData, when a split filesystem policy requests platform defaults

The unelevated restricted-token backend still supports the legacy full-read Windows model for legacy ReadOnly and WorkspaceWrite behavior. It also supports a narrow split-filesystem subset: full-read split policies whose writable roots still match the legacy WorkspaceWrite root set, but add extra read-only carveouts under those writable roots.

New [permissions] / split filesystem policies remain supported on Windows only when they can be enforced directly by the selected Windows backend or round-trip through the legacy SandboxPolicy model without changing semantics. Policies that would require direct explicit unreadable carveouts (none) or reopened writable descendants under read-only carveouts still fail closed instead of running with weaker enforcement.

All Platforms

Expects the binary containing codex-core to simulate the virtual apply_patch CLI when arg1 is --codex-run-as-apply-patch. See the codex-arg0 crate for details.