GPT-6 API Developer Guide: 7 Steps to Prepare Before It Ships
GPT-6 is not Spud. Spud shipped as GPT-5.5 on April 23, 2026 — a significant but differently-named model. The real GPT-6 is the next-generation system in OpenAI’s pipeline, and Polymarket traders give it 84% odds of releasing by December 31, 2026. Here is exactly what to change in your codebase now so that GPT-6 is a one-config-line upgrade, not a week-long rewrite. What Is GPT-6 (Spud)? Understanding the Naming Confusion GPT-6 (sometimes called “Spud” by developers) refers to the next major OpenAI model after GPT-5.5 — but the Spud codename has caused significant confusion in the developer community. The model internally codenamed “Spud” actually shipped on April 23, 2026 as GPT-5.5, not GPT-6. This naming slip caused many developers to believe GPT-6 was already live. It is not. GPT-5.5 achieved an Intelligence Index score of 60 on Artificial Analysis, topping all 153 reasoning models on the leaderboard at launch. Its API pricing is $5 per 1M input tokens and $30 per 1M output tokens — exactly double GPT-5.4. The real GPT-6 is the next-next model: it is expected to deliver a 40% performance improvement over current models in coding, reasoning, and agentic tasks, and to feature a 2 million token context window (double GPT-5.5’s 1M limit). For developers, the practical takeaway is straightforward: any code that hardcodes "gpt-5.5" or references Spud directly will need to change when GPT-6 lands. Start abstracting now. ...