## Summary - Add a testable DNS lookup helper for the local or private host precheck while preserving production `lookup_host` behavior. - Add deterministic coverage for DNS timeout, lookup error, private resolution, and public resolution decisions. - Keep BUGB 15982 guarded without relying on ambient DNS timing or resolver behavior. ## Why BUGB 15982 was fixed by failing closed on DNS lookup errors and timeouts. The existing regression covered lookup failure through real DNS, but did not deterministically exercise the timeout branch. This PR adds a small injection point so CI can cover that branch without standing up slow authoritative DNS. ## Validation - `cargo test -p codex-network-proxy host_resolves_to_non_public_ip -- --nocapture` - `cargo test -p codex-network-proxy host_blocked_rejects_allowlisted_hostname_when_dns_lookup_fails -- --nocapture` - `cargo test -p codex-network-proxy` - `just fmt` - `just fix -p codex-network-proxy` - `git diff --check` ## Tickets - BUGB 15982 - https://linear.app/openai/issue/BUGB-15982/codex-dns-timeout-fail-open-in-codex-network-proxy-bypasses - Bugcrowd: https://tracker.bugcrowd.com/openai/submissions/b2bf131d-db04-478f-85aa-cdd17ca8f604
npm i -g @openai/codex
or brew install --cask codex
Codex CLI is a coding agent from OpenAI 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.
Quickstart
Installing and running Codex CLI
Install globally with your preferred package manager:
# Install using npm
npm install -g @openai/codex
# Install using Homebrew
brew install --cask codex
Then simply run codex to get started.
You can also go to the latest GitHub Release and download the appropriate binary for your platform.
Each GitHub Release contains many executables, but in practice, you likely want one of these:
- macOS
- Apple Silicon/arm64:
codex-aarch64-apple-darwin.tar.gz - x86_64 (older Mac hardware):
codex-x86_64-apple-darwin.tar.gz
- Apple Silicon/arm64:
- Linux
- x86_64:
codex-x86_64-unknown-linux-musl.tar.gz - arm64:
codex-aarch64-unknown-linux-musl.tar.gz
- x86_64:
Each archive contains a single entry with the platform baked into the name (e.g., codex-x86_64-unknown-linux-musl), so you likely want to rename it to codex after extracting it.
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, Business, 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
This repository is licensed under the Apache-2.0 License.
