OpenAI Folds Codex into GPT-5.5, Ends Dedicated Model
OpenAI has once again discontinued its dedicated coding model, Codex. The company merged it into the primary GPT-5.5 model. This follows a similar move with GPT-5.4, where the separate programming tool became part of the core system.
Romain Huet, OpenAI's Head of Developer Experience, confirmed the change. He stated there is no longer a distinct Codex line. GPT-5.3, released in early February, stands as the last standalone version of the model.
Advances in GPT-5.5 Capabilities
Huet highlighted key improvements in GPT-5.5. The model excels in agentic coding, where artificial intelligence manages programming tasks independently. It also offers enhanced computer use and superior results on everyday tasks.
On Codex-specific tasks, GPT-5.5 consumes fewer tokens compared to GPT-5.4. This leads to improved outcomes while using fewer resources. OpenAI, founded in 2015 as a research organization focused on safe artificial general intelligence, has built its reputation on the GPT series. Models like GPT-3 and GPT-4 powered tools such as ChatGPT, launched in late 2022, which popularized conversational AI for millions.
Codex originated as a code-focused model trained on vast programming data. It powered early versions of GitHub Copilot, a popular autocomplete tool for developers. OpenAI's shift toward unified models reflects a strategy to combine specialized skills into versatile systems.
Pricing Adjustments
Despite lower token usage, API costs for GPT-5.5 rise by about 20 percent. Developers will notice higher expenses even after accounting for efficiency gains. Huet shared these details via a post on X, formerly Twitter.
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OpenAI continues to prioritize developer tools. The API supports integrations for building applications, from chatbots to code generators.
Codex's Rocky History
This marks the second time OpenAI has phased out Codex. In 2023, the company deprecated the original model to emphasize general-purpose language systems. General models proved capable enough for coding, reducing the need for a niche variant.
Codex returned in May 2025 as Codex-1. This version drew from the o3 base model and included the Codex AI agent software. That agent tool remains under active development. It serves as a major focus for OpenAI, running parallel to enhancements in ChatGPT.
OpenAI's model roadmap has evolved quickly. Releases like GPT-5.3 and GPT-5.4 built toward broader capabilities. GPT-5.5 consolidates these efforts, blending coding prowess with general intelligence.
Romain Huet plays a central role in these updates. As Head of Developer Experience, he guides API improvements and communicates changes to builders worldwide.
The integration simplifies OpenAI's offerings. Developers access top coding features through one model, streamlining workflows.