{"id":"sumlog.v1","title":"Verifiable counted total (Merkle-sum log)","unit":"USD, with a signed root","chain_set":"eip155:8453 (Base)","window":"all counted payments at the time of the head","definition":"Every counted payment (receipt read, after registration, not a routing hop: the set behind observed_pay_usd) is a leaf of a Merkle-sum tree in block order: leaf = SHA-256(0x00 || uint64be(amount_micro) || event_id|agent|to|amount_micro|block_epoch); node = SHA-256(0x01 || left || right || uint64be(left_sum) || uint64be(right_sum)), sum = left + right; RFC 6962 shape. The signed head carries the root, the total, and the root of a second tree whose leaves are each agent's own (root, sum, count), whose total must equal the first. A proof of one payment, or of one agent's record, recomputes the root and the total from the leaf up.","method":"afg-sumlog, daily at 04:10 UTC; Ed25519 signature over afg-sum-log:v1:<leaves>:<root>:<sum_micro>:<agent_root>:<agents>:<timestamp_ms> with the published key. The counted set is not strictly append-only (a routing-hop re-check hours later, a late-found old payment), so every head states how many of the previous head's leaves are unchanged in order, changed, removed and added, and every agent record states the same for that agent. Proofs: /api/sum-log?event= and ?agent=; the hash levels are also served as 256-node tiles.","excludes":["Payments whose receipt is not read yet, routing hops, and payments before registration (none of them is in the counted set)."],"does_not_assert":["That the chain facts behind a leaf are right: the log proves what we published, and each leaf names the receipt to re-derive it from.","Append-only across heads: the numbers in the head say what changed."],"source":"AFG-Pulse sum log","since":"2026-10-13","revisions":[],"body_sha256":"ab81505aae105685cd953bff365d29062f79a89379286f5ad58e7fe4110cf9fe","url":"https://agenticfinancegraph.com/def/sumlog.v1","ladder":"https://agenticfinancegraph.com/ai-agent-liveness-methodology-l0-l9-ladder","license":"https://creativecommons.org/licenses/by/4.0/","attribution":"Agentic Finance Graph — https://agenticfinancegraph.com"}