OpenAI has once again eliminated its standalone Codex model, folding its capabilities into the latest GPT-5.5 release. According to Romain Huet, OpenAI's Head of Developer Experience, there is no longer a separate Codex model for programming tasks as of GPT-5.4. The final standalone version, Codex 5.3, shipped in early February.
Huet explained that GPT-5.5 delivers significant improvements in agentic coding, where AI autonomously handles programming tasks, as well as enhanced computer use and overall performance. Additionally, GPT-5.5 uses fewer tokens than GPT-5.4 on equivalent Codex tasks, yielding better results with lower resource consumption. However, despite reduced token usage, API pricing has increased by approximately 20%.
This is not the first time OpenAI has discontinued Codex. The company originally launched Codex in 2021, shut it down in 2023 in favor of general-purpose models, and then revived it in May 2025 as Codex-1 based on the o3 model. That version was paired with the Codex AI agent software, which continues to be developed and remains a key focus for OpenAI alongside ChatGPT.