Full score-history record of one coin (paid, $0.05, x402 or MPP; included with the Premium agent key; sold only beyond the free slice)

Score history: every recorded change to a coin's eight metric scores as a dated record with the TVR Score, the scoring method version, a source label (baseline for the opening record, auto_captured for rows written from the change itself), the public reason where one was recorded, and a SHA-256 hash of the record. Forward-only from the day the record began; nothing is reconstructed and no reason is invented. Free slice (the last 90 days or the last 3 records, whichever is longer) at GET https://truevaluerankings.com/api/history/{symbol} and in the MCP tool get_historical_scores. The full record is included with the Premium agent key (scope "full") and is sold per pull ($0.05, x402 or MPP, POST https://truevaluerankings.com/premium/score-history) only once a coin's record extends beyond the free slice; until then the request is refused before any payment and the free slice is the whole record. Flow: POST {"coin": "BTC"} without payment returns 402 with the challenge headers when the record is sellable; pay exactly 50000 units (USDC on Base through x402, or USDC.e on Tempo through MPP) and retry the same request with the payment header; the response is 200 with the full record and a receipt header. When the coin's record has nothing beyond the free slice the request is refused with 400 (reason nothing_beyond_free_slice) before any payment, and the free slice at GET /api/history/{symbol} is the whole record. Premium subscribers send their agent key as Authorization: Bearer tvr_k_... instead of a payment. A lost response is re-delivered on the same proof for 24 hours without a second charge. MCP tool: get_historical_scores with scope "full".