GPT-5.4 was released as a unified frontier model that brings together recent advances in reasoning, coding, and agentic workflows, explicitly incorporating the coding capabilities of GPT-5.3-Codex. It is positioned as the most capable and efficient option in its line for professional work, aimed at getting complex real tasks done accurately and with less back-and-forth. In ChatGPT, the Thinking variant surfaces an upfront plan of its reasoning so users can adjust direction while the response is still in progress, helping align the final output with the original intent without extra turns.

The same release introduces native, state-of-the-art computer-use capabilities in Codex and the API, letting agents operate software and carry out multi-step workflows across applications, spreadsheets, presentations, and documents. GPT-5.4 Thinking also improves deep web research on highly specific queries and maintains context more reliably during longer thinking passes, delivering higher-quality answers more quickly. Through an OpenAI-compatible endpoint, it can be wired into coding agents like OpenCode, Cursor, Codex, and Claude Code, making it a practical fit for teams that want a single model handling reasoning, code, research, and tool-driven task execution.