JP-Verify Invoice Facts — one invoice's register, statutory-item, arithmetic and schedule facts (JSON)

Check ONE invoice from its facts (see InvoiceCheckRequest). What is checked: the issuer's 登録番号 against the NTA register — well-formed (REG-01), present (REG-02) and registered on the transaction date / period (REG-03, evaluated against every registration episode the NTA publishes for the number once the mirror's history table is complete — status_on_date.episode_scope says which); the statutory items of 消費税法57条の4 as presence checks (ITEM-01..06); the printed rates (RATE-01..03); arithmetic on the document's own figures (ARITH-01..05 — per-rate tax within one-yen rounding, sums, totals); plus the published transitional-deduction schedule tier for the evaluation date with its source URLs, and the register/document-name comparison (name_match, never a verdict). Every rule carries a status (pass / fail / unknown / not_applicable), a detail and a source id; rule_set_version names the rule set (catalog: GET /v1/invoice/rules).

NOT tax advice: register facts, document checks and the published schedule only; no determination of any deduction, credit or entitlement — the buyer's consumption-tax treatment is for the taxpayer and their 税理士. No buyer-side input is accepted.

Free refusal (400, nothing charged) for request-level defects only: not an object, missing or malformed issue_date, both transaction_date and transaction_period, a bad document_type / category / amount_basis / currency, more than 10 tax_lines, a non-numeric amount (negative amounts are accepted on every document type and reported as document.amount_sign), return_date on a document type other than return_invoice (適格返還請求書 — declared by the caller, never inferred), an over-long name, a supplier_t_number that is not number-shaped (longer than 32 characters) or a string that cannot be UTF-8 encoded. A missing or malformed 登録番号 is a document finding and is metered — reported as a finding WITHOUT its text (document.supplier_t_number is null, document.supplier_t_number_state says malformed). Metered 1 unit per document on every tier. "sign": true returns an Ed25519-signed record with a sibling compact jws (Growth / Reseller keys; other tiers get signed_record: null and a note). Opt-in Idempotency-Key request header: a retry with the same key + body replays the first response (Idempotent-Replayed: true) instead of being re-metered. Names and amounts are consumed in memory only — never stored, logged or echoed; the digest carries no name.