Citation/source validation: legal articles, statutes, DOIs against authoritative registers.

Verify legal & academic citations against authoritative sources. 448 EUR-Lex verified articles (MiCA 149, DSGVO 99, DORA 64, AMLR 90, NIS2 46) + Semantic Scholar + OpenAlex + German codes (BGB, KWG). Detects fake citations like 'Art. 999 MiCA' or 'doi:10.9999/fake-paper'.