Opper
OpenAI announced GPT-5.4 on March 5, 2026, releasing it simultaneously in ChatGPT as "GPT-5.4 Thinking," in the API, and in Codex. Alongside it, OpenAI launched GPT-5.4 Pro in ChatGPT and the API for users who want maximum performance on complex tasks, making it a distinct higher-end variant of the same frontier model According to the OpenAI announcement, GPT-5.4 ships with up to 1 million tokens of context, native state-of-the-art computer-use capabilities that let agents operate applications and carry out workflows across long horizons, and a new tool search feature for efficiently navigating large tool ecosystems. OpenAI also sta