What changed between two frozen, immutable sovereign-reserve snapshots. Takes optional { from, to } snapshot dates (YYYY-MM-DD); defaults to the two newest. Returns { status, as_of, from, to, counts, added[], removed[], changed[], envelope[], disclaimer, cite }, where each changed row carries country_code, country_name, source_quality { from, to } and changes[] of { field, basis (reported | derived), from, to }. With fewer than two snapshots it returns status "insufficient_snapshots" and diff: null — not an empty diff. Example: {"from": "2026-09-04", "to": "2026-10-01"}. CoinGecko values carry attribution: "Powered by CoinGecko" and source_terms. Information, not financial advice. Every answer carries data_contract { source, as_of, status, corrections_url, license }. This server answers bounded questions, one question, one answer; for bulk, history, backfills and scheduled pulls use the CSVs and datapackage.json at https://coinbucha.com/data.