Codex CLI Version Tracker: Environment Variables, Models & Features#

Published on July 13, 2026

We analyze OpenAI's Codex CLI releases to document the environment variables, model IDs, and feature surface exposed by each build. Because Codex is open source, we pair binary analysis with the official changelog so every finding is grounded in what OpenAI actually shipped.

Tracking the other agents too? See the Claude Code Version Tracker for our release-by-release analysis of Anthropic's CLI.