## Why
After removing `exec-server`, the next step is to wire a new shell tool
to `codex-rs/shell-escalation` directly.
That is blocked while `codex-shell-escalation` depends on `codex-core`,
because the new integration would require `codex-core` to depend on
`codex-shell-escalation` and create a dependency cycle.
This change ports the reusable pieces from the earlier prep work, but
drops the old compatibility shim because `exec-server`/MCP support is
already gone.
## What Changed
### Decouple `shell-escalation` from `codex-core`
- Introduce a crate-local `SandboxState` in `shell-escalation`
- Introduce a `ShellCommandExecutor` trait so callers provide process
execution/sandbox integration
- Update `EscalateServer::exec(...)` and `run_escalate_server(...)` to
use the injected executor
- Remove the direct `codex_core::exec::process_exec_tool_call(...)` call
from `shell-escalation`
- Remove the `codex-core` dependency from `codex-shell-escalation`
### Restore reusable policy adapter exports
- Re-enable `unix::core_shell_escalation`
- Export `ShellActionProvider` and `ShellPolicyFactory` from
`shell-escalation`
- Keep the crate root API simple (no `legacy_api` compatibility layer)
### Port socket fixes from the earlier prep commit
- Use `socket2::Socket::pair_raw(...)` for AF_UNIX socketpairs and
restore `CLOEXEC` explicitly on both endpoints
- Keep `CLOEXEC` cleared only on the single datagram client FD that is
intentionally passed across `exec`
- Clean up `tokio::AsyncFd::try_io(...)` error handling in the socket
helpers
## Verification
- `cargo shear`
- `cargo clippy -p codex-shell-escalation --tests`
- `cargo test -p codex-shell-escalation`
## Why
We already plan to remove the shell-tool MCP path, and doing that
cleanup first makes the follow-on `shell-escalation` work much simpler.
This change removes the last remaining reason to keep
`codex-rs/exec-server` around by moving the `codex-execve-wrapper`
binary and shared shell test fixtures to the crates/tests that now own
that functionality.
## What Changed
### Delete `codex-rs/exec-server`
- Remove the `exec-server` crate, including the MCP server binary,
MCP-specific modules, and its test support/test suite
- Remove `exec-server` from the `codex-rs` workspace and update
`Cargo.lock`
### Move `codex-execve-wrapper` into `codex-rs/shell-escalation`
- Move the wrapper implementation into `shell-escalation`
(`src/unix/execve_wrapper.rs`)
- Add the `codex-execve-wrapper` binary entrypoint under
`shell-escalation/src/bin/`
- Update `shell-escalation` exports/module layout so the wrapper
entrypoint is hosted there
- Move the wrapper README content from `exec-server` to
`shell-escalation/README.md`
### Move shared shell test fixtures to `app-server`
- Move the DotSlash `bash`/`zsh` test fixtures from
`exec-server/tests/suite/` to `app-server/tests/suite/`
- Update `app-server` zsh-fork tests to reference the new fixture paths
### Keep `shell-tool-mcp` as a shell-assets package
- Update `.github/workflows/shell-tool-mcp.yml` packaging so the npm
artifact contains only patched Bash/Zsh payloads (no Rust binaries)
- Update `shell-tool-mcp/package.json`, `shell-tool-mcp/src/index.ts`,
and docs to reflect the shell-assets-only package shape
- `shell-tool-mcp-ci.yml` does not need changes because it is already
JS-only
## Verification
- `cargo shear`
- `cargo clippy -p codex-shell-escalation --tests`
- `just clippy`
## Why
Shell execution refactoring in `exec-server` had become split between
duplicated code paths, which blocked a clean introduction of the new
reusable shell escalation flow. This commit creates a dedicated
foundation crate so later shell tooling changes can share one
implementation.
## What changed
- Added the `codex-shell-escalation` crate and moved the core escalation
pieces (`mcp` protocol/socket/session flow, policy glue) that were
previously in `exec-server` into it.
- Normalized `exec-server` Unix structure under a dedicated `unix`
module layout and kept non-Unix builds narrow.
- Wired crate/build metadata so `shell-escalation` is a first-class
workspace dependency for follow-on integration work.
## Verification
- Built and linted the stack at this commit point with `just clippy`.
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/12556).
* #12584
* #12583
* __->__ #12556
Michael Bolin ·