git clone https://github.com/MaxFabian25/codex-force-gpt-5.4-xhigh-defaults.git
cd codex-force-gpt-5.4-xhigh-defaults/codex-rs && cargo run --bin codex

Codex CLI is a maintained fork of the OpenAI Codex CLI that runs locally on your computer.

If you want Codex in your code editor (VS Code, Cursor, Windsurf), install in your IDE.
If you want the desktop app experience, run codex app or visit the Codex App page.
If you are looking for the cloud-based agent from OpenAI, Codex Web, go to chatgpt.com/codex.

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Fork defaults

This fork tracks upstream stable rust-v0.111.0 and hard-overrides the default model stack to gpt-5.4 with reasoning xhigh, verbosity high, and reasoning summaries detailed.

Distribution model

This repository publishes fork-specific GitHub releases for tagged fork states. It does not publish a separate npm package or Homebrew cask.

Installing @openai/codex, brew install --cask codex, or downloading upstream OpenAI releases gives you the upstream CLI and upstream defaults, not this fork.

Use this fork when you want the maintained gpt-5.4 default override, the fork-specific release notes, or the exact source state behind the published fork tags.

Quickstart

Building and running this fork

Clone the fork and run the Rust CLI directly from source:

git clone https://github.com/MaxFabian25/codex-force-gpt-5.4-xhigh-defaults.git
cd codex-force-gpt-5.4-xhigh-defaults/codex-rs
cargo run --bin codex

That path keeps the fork separate from any upstream npm/Homebrew install you already use.

If you want the latest tagged fork state, use the GitHub Releases. Releases currently provide release notes plus GitHub's generated source archives; source-build remains the supported way to run the forked CLI.

For full system requirements and local build helpers, see Installing & building.

Using Codex with your ChatGPT plan

Run codex and select Sign in with ChatGPT. We recommend signing into your ChatGPT account to use Codex as part of your Plus, Pro, Team, Edu, or Enterprise plan. Learn more about what's included in your ChatGPT plan.

You can also use Codex with an API key, but this requires additional setup.

Docs

• Codex Documentation
• Contributing
• Installing & building
• Open source fund

This repository is licensed under the Apache-2.0 License.