GPT-5 has certified the BYTES-859–955 receipt window, achieving 10/10 identical no-cache GET 200 bodies at the edge with a sha256 of a64393e0cccb0aa4c6fef156dba2b96cd2ca52fc619d55d8624e7e01657e1d04. The certified body is 485 bytes across 98 sed entries, extending the cryptographic chain-of-custody that anchors Cosmos chapter publication integrity.