This adds our own `mcp-types` crate to our Cargo workspace. We vendor in
the
[`2025-03-26/schema.json`](05f2045136/schema/2025-03-26/schema.json)
from the MCP repo and introduce a `generate_mcp_types.py` script to
codegen the `lib.rs` from the JSON schema.
Test coverage is currently light, but I plan to refine things as we
start making use of this crate.
And yes, I am aware that
https://github.com/modelcontextprotocol/rust-sdk exists, though the
published https://crates.io/crates/rmcp appears to be a competing
effort. While things are up in the air, it seems better for us to
control our own version of this code.
Incidentally, Codex did a lot of the work for this PR. I told it to
never edit `lib.rs` directly and instead to update
`generate_mcp_types.py` and then re-run it to update `lib.rs`. It
followed these instructions and once things were working end-to-end, I
iteratively asked for changes to the tests until the API looked
reasonable (and the code worked). Codex was responsible for figuring out
what to do to `generate_mcp_types.py` to achieve the requested test/API
changes.
For now, keep things simple such that we never update the `version` in
the `Cargo.toml` for the workspace root on the `main` branch. Instead,
create a new branch for a release, push one commit that updates the
`version`, and then tag that branch to kick off a release.
To test, I ran this script and created this release job:
https://github.com/openai/codex/actions/runs/14762580641
The generated DotSlash file has URLs that refer to
`https://github.com/openai/codex/releases/`, so let's set
`prerelease:false` (but keep `draft:true` for now) so those URLs should
work.
Also updated `version` in Cargo workspace so I will kick off a build
once this lands.
@oai-ragona and I discussed it, and we feel the REPL crate has served
its purpose, so we're going to delete the code and future archaeologists
can find it in Git history.
Apparently I made two key mistakes in
https://github.com/openai/codex/pull/740 (fixed in this PR):
* I forgot to redefine `$dest` in the `Stage Linux-only artifacts` step
* I did not define the `if` check correctly in the `Stage Linux-only
artifacts` step
This fixes both of those issues and bumps the workspace version to
`0.0.2504292006` in preparation for another release attempt.
Originally, the `interactive` crate was going to be a placeholder for
building out a UX that was comparable to that of the existing TypeScript
CLI. Though after researching how Ratatui works, that seems difficult to
do because it is designed around the idea that it will redraw the full
screen buffer each time (and so any scrolling should be "internal" to
your Ratatui app) whereas the TypeScript CLI expects to render the full
history of the conversation every time(*) (which is why you can use your
terminal scrollbar to scroll it).
While it is possible to use Ratatui in a way that acts more like what
the TypeScript CLI is doing, it is awkward and seemingly results in
tedious code, so I think we should abandon that approach. As such, this
PR deletes the `interactive/` folder and the code that depended on it.
Further, since we added support for mousewheel scrolling in the TUI in
https://github.com/openai/codex/pull/641, it certainly feels much better
and the need for scroll support via the terminal scrollbar is greatly
diminished. This is now a more appropriate default UX for the
"multitool" CLI.
(*) Incidentally, I haven't verified this, but I think this results in
O(N^2) work in rendering, which seems potentially problematic for long
conversations.
In putting up https://github.com/openai/codex/pull/665, I discovered
that the `expanduser` crate does not compile on Windows. Looking into
it, we do not seem to need it because we were only using it with a value
that was passed in via a command-line flag, so the shell expands `~` for
us before we see it, anyway. (I changed the type in `Cli` from `String`
to `PathBuf`, to boot.)
If we do need this sort of functionality in the future,
https://docs.rs/shellexpand/latest/shellexpand/fn.tilde.html seems
promising.
As described in detail in `codex-rs/execpolicy/README.md` introduced in
this PR, `execpolicy` is a tool that lets you define a set of _patterns_
used to match [`execv(3)`](https://linux.die.net/man/3/execv)
invocations. When a pattern is matched, `execpolicy` returns the parsed
version in a structured form that is amenable to static analysis.
The primary use case is to define patterns match commands that should be
auto-approved by a tool such as Codex. This supports a richer pattern
matching mechanism that the sort of prefix-matching we have done to
date, e.g.:
5e40d9d221/codex-cli/src/approvals.ts (L333-L354)
Note we are still playing with the API and the `system_path` option in
particular still needs some work.
As stated in `codex-rs/README.md`:
Today, Codex CLI is written in TypeScript and requires Node.js 22+ to
run it. For a number of users, this runtime requirement inhibits
adoption: they would be better served by a standalone executable. As
maintainers, we want Codex to run efficiently in a wide range of
environments with minimal overhead. We also want to take advantage of
operating system-specific APIs to provide better sandboxing, where
possible.
To that end, we are moving forward with a Rust implementation of Codex
CLI contained in this folder, which has the following benefits:
- The CLI compiles to small, standalone, platform-specific binaries.
- Can make direct, native calls to
[seccomp](https://man7.org/linux/man-pages/man2/seccomp.2.html) and
[landlock](https://man7.org/linux/man-pages/man7/landlock.7.html) in
order to support sandboxing on Linux.
- No runtime garbage collection, resulting in lower memory consumption
and better, more predictable performance.
Currently, the Rust implementation is materially behind the TypeScript
implementation in functionality, so continue to use the TypeScript
implmentation for the time being. We will publish native executables via
GitHub Releases as soon as we feel the Rust version is usable.
