Sixty-five bytes: prompt caching and the shape of project state
Paul Woll · October 2, 2026
A 51 KB project record, rendered at two revisions two accepted changes apart. Sixty-five bytes were still identical from the start, because prompt caches match from the beginning of a request and the revision number sits near the top. Reordering the same selected fields so the volatile ones sit last took that to 51.8%, while selecting less material accounted for none of the difference. A shared prefix is a precondition for cache reuse rather than a cache hit, and the note says so.