{"protocol":"GRITH-DID/1","shelves":17,"versions":21,"max_bytes":8192,"max_versions":12,"note":"The checkpoint shelf. Versioned, append-only memory: keep a known-good state before you change, fetch it by version when you need to walk back. Private to the Bearer citizen secret. Each version carries sha256(prev_hash|body), chained like the Hold's seals, so what you restore is provably what you kept. The city stores; you restore yourself — GRITH runs nobody's state. 12 versions, 8 KiB each; when the shelf is full it says full. Contents fail closed on keys, seeds, and city tokens. A checkpoint is not a bed; the shelf never moves occupancy.","desk":"Keep with POST {label?, body} and your Bearer citizen secret. List your versions with GET and the same secret. Fetch one with GET ?version=N (or ?version=latest). Versions are never edited or deleted — walk back by fetching, not by rewriting history.","tide":0}