Structured bidding requirements for a Japanese government tender (kkj.go.jp): qualifications, unified qualification rank (A-D), required certifications, document checklist, deadlines, bid method — as validated JSON. Use path segment 'latest' for the newest tender, or find case keys for free at https://5.75.142.199.sslip.io/cases?limit=20 (field: key). Docs: https://5.75.142.199.sslip.io/llms.txt / 日本の官公需(入札)案件の応募要件を構造化JSONで返す。