Files
gt-oai a046481ad9 Wire up cloud reqs in exec, app-server (#10241)
We're fetching cloud requirements in TUI in
https://github.com/openai/codex/pull/10167.

This adds the same fetching in exec and app-server binaries also.
2026-01-30 23:53:41 +00:00
..

codex-exec-server

This crate contains the code for two executables:

  • codex-exec-mcp-server is an MCP server that provides a tool named shell that runs a shell command inside a sandboxed instance of Bash. Every resulting execve(2) call made within Bash is intercepted and run via the executable defined by the BASH_EXEC_WRAPPER environment variable within the Bash process. In practice, BASH_EXEC_WRAPPER is set to codex-execve-wrapper.
  • codex-execve-wrapper is the executable that takes the arguments to the execve(2) call and "escalates" it to the MCP server via a shared file descriptor (specified by the CODEX_ESCALATE_SOCKET environment variable) for consideration. Based on the Codex .rules, the MCP server replies with one of:
    • Run: codex-execve-wrapper should invoke execve(2) on itself to run the original command within Bash
    • Escalate: forward the file descriptors of the current process to the MCP server so the command can be run faithfully outside the sandbox. Because the MCP server will have the original FDs for stdout and stderr, it can write those directly. When the process completes, the MCP server forwards the exit code to codex-execve-wrapper so that it exits in a consistent manner.
    • Deny: the MCP server has declared the proposed command to be "forbidden," so codex-execve-wrapper will print an error to stderr and exit with 1.

Patched Bash

We carry a small patch to execute_cmd.c (see patches/bash-exec-wrapper.patch) that adds support for BASH_EXEC_WRAPPER. The original commit message is “add support for BASH_EXEC_WRAPPER” and the patch applies cleanly to a8a1c2fac029404d3f42cd39f5a20f24b6e4fe4b from https://github.com/bminor/bash. To rebuild manually:

git clone https://github.com/bminor/bash
git checkout a8a1c2fac029404d3f42cd39f5a20f24b6e4fe4b
git apply /path/to/patches/bash-exec-wrapper.patch
./configure --without-bash-malloc
make -j"$(nproc)"

Release workflow

.github/workflows/shell-tool-mcp.yml builds the Rust binaries, compiles the patched Bash variants, assembles the vendor/ tree, and creates codex-shell-tool-mcp-npm-<version>.tgz for inclusion in the Rust GitHub Release. When the version is a stable or alpha tag, the workflow also publishes the tarball to npm using OIDC. The workflow is invoked from rust-release.yml so the package ships alongside other Codex artifacts.