On November 19–20, 2025 OpenAI released two related but distinct upgrades: GPT-5.1-Codex-Max, a new agentic coding model for Codex that emphasizes long-horizon coding, token efficiency, and “compaction” to sustain multi-window sessions; and GPT-5.1 Pro, an updated Pro-tier ChatGPT model tuned for clearer, more capable answers in complex, professional work. What is GPT-5.1-Codex-Max and what problem […]