GPT-5.4 Thinking System Card capability update

AI Impact Summary

GPT-5.4 gains a Thinking System Card capability, signaling an updated or new reasoning module within the model. The description is empty, so exact behavior is unclear, but the change likely affects long-horizon planning and tool-use patterns. Teams should run controlled experiments to measure impacts on accuracy, latency, and edge-case handling, and update prompt templates to leverage the Thinking System Card effectively.