Files
llmx/codex-rs
vjain419 80b00a193e feat(gpt5): add model_verbosity for GPT‑5 via Responses API (#2108)
**Summary**
- Adds `model_verbosity` config (values: low, medium, high).
- Sends `text.verbosity` only for GPT‑5 family models via the Responses
API.
- Updates docs and adds serialization tests.

**Motivation**
- GPT‑5 introduces a verbosity control to steer output length/detail
without pro
mpt surgery.
- Exposing it as a config knob keeps prompts stable and makes behavior
explicit
and repeatable.

**Changes**
- Config:
  - Added `Verbosity` enum (low|medium|high).
- Added optional `model_verbosity` to `ConfigToml`, `Config`, and
`ConfigProfi
le`.
- Request wiring:
  - Extended `ResponsesApiRequest` with optional `text` object.
- Populates `text.verbosity` only when model family is `gpt-5`; omitted
otherw
ise.
- Tests:
- Verifies `text.verbosity` serializes when set and is omitted when not
set.
- Docs:
  - Added “GPT‑5 Verbosity” section in `codex-rs/README.md`.
  - Added `model_verbosity` section to `codex-rs/config.md`.

**Usage**
- In `~/.codex/config.toml`:
  - `model = "gpt-5"`
  - `model_verbosity = "low"` (or `"medium"` default, `"high"`)
- CLI override example:
  - `codex -c model="gpt-5" -c model_verbosity="high"`

**API Impact**
- Requests to GPT‑5 via Responses API include: `text: { verbosity:
"low|medium|h
igh" }` when configured.
- For legacy models or Chat Completions providers, `text` is omitted.

**Backward Compatibility**
- Default behavior unchanged when `model_verbosity` is not set (server
default “
medium”).

**Testing**
- Added unit tests for serialization/omission of `text.verbosity`.
- Ran `cargo fmt` and `cargo test --all-features` (all green).

**Docs**
- `README.md`: new “GPT‑5 Verbosity” note under Config with example.
- `config.md`: new `model_verbosity` section.

**Out of Scope**
- No changes to temperature/top_p or other GPT‑5 parameters.
- No changes to Chat Completions wiring.

**Risks / Notes**
- If OpenAI changes the wire shape for verbosity, we may need to update
`Respons
esApiRequest`.
- Behavior gated to `gpt-5` model family to avoid unexpected effects
elsewhere.

**Checklist**
- [x] Code gated to GPT‑5 family only
- [x] Docs updated (`README.md`, `config.md`)
- [x] Tests added and passing
- [x] Formatting applied

Release note: Add `model_verbosity` config to control GPT‑5 output verbosity via the Responses API (low|medium|high).
2025-08-22 09:12:10 -07:00
..
2025-07-30 18:37:00 -07:00
2025-08-19 13:22:02 -07:00
2025-08-20 07:26:14 +00:00
2025-08-22 08:24:13 -07:00
2025-08-18 13:08:53 -07:00

Codex CLI (Rust Implementation)

We provide Codex CLI as a standalone, native executable to ensure a zero-dependency install.

Installing Codex

Today, the easiest way to install Codex is via npm, though we plan to publish Codex to other package managers soon.

npm i -g @openai/codex@native
codex

You can also download a platform-specific release directly from our GitHub Releases.

What's new in the Rust CLI

While we are working to close the gap between the TypeScript and Rust implementations of Codex CLI, note that the Rust CLI has a number of features that the TypeScript CLI does not!

Config

Codex supports a rich set of configuration options. Note that the Rust CLI uses config.toml instead of config.json. See config.md for details.

Model Context Protocol Support

Codex CLI functions as an MCP client that can connect to MCP servers on startup. See the mcp_servers section in the configuration documentation for details.

It is still experimental, but you can also launch Codex as an MCP server by running codex mcp. Use the @modelcontextprotocol/inspector to try it out:

npx @modelcontextprotocol/inspector codex mcp

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.

codex exec to run Codex programmatially/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. Output is printed to the terminal directly. You can set the RUST_LOG environment variable to see more about what's going on.

Typing @ triggers a fuzzy-filename search over the workspace root. Use up/down to select among the results and Tab or Enter to replace the @ with the selected path. You can use Esc to cancel the search.

--cd/-C flag

Sometimes it is not convenient to cd to the directory you want Codex to use as the "working root" before running Codex. Fortunately, codex supports a --cd option so you can specify whatever folder you want. You can confirm that Codex is honoring --cd by double-checking the workdir it reports in the TUI at the start of a new session.

Shell completions

Generate shell completion scripts via:

codex completion bash
codex completion zsh
codex completion fish

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 debug seatbelt [--full-auto] [COMMAND]...

# Linux
codex debug landlock [--full-auto] [COMMAND]...

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".

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 to be 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.