OpenAI Releases GPT-5.1-Codex-Max: AI Agent with Windows Support and Million-Token Context

OpenAI has launched a new version of its AI-powered coding agent, now branded as GPT-5.1-Codex-Max, introducing significant improvements to autonomous development capabilities.

Key Features:

• Windows Environment Support - This marks the first Codex model trained to operate natively in Windows development environments, expanding platform compatibility beyond Unix-based systems.

• Context Compaction Technology - The new compaction feature enables the model to compress and manage contexts spanning millions of tokens, dramatically extending its operational memory.

• Extended Autonomous Operation - The system is engineered to work continuously for over 24 hours on complex tasks without human intervention.

• End-to-End Development Workflow - GPT-5.1-Codex-Max autonomously executes testing procedures, identifies and resolves bugs, and iterates toward project completion.

The model is accessible through the Codex platform and supports cross-device testing, including mobile devices and web browsers.

Source: https://openai.com/codex/