OpenAI has announced the release of GPT-5.5, the latest upgrade to the company's family of models powering its ChatGPT and Codex apps. OpenAI describes GPT-5.5 as better at multi-step work, claiming it can plan, use tools, and verify its own output with less hand-holding. The model is said to offer gains in agentic coding, computer use, and early-stage scientific research. GPT-5.5 Thinking offers