3 services carry this tag in their source record. Tags come from the provider, not from us — a tag is a claim about what the service does, not proof that it does it well.
Citation lookup and reference list for a paper. Given a DOI, arXiv id, OpenAlex id, or PMID, returns its references (the works it cites) and its cited-by list (recent works that cite it), plus full metadata and citation...
Breached password check: is this password in known data breaches, and how often? Send only the SHA-1 hash (never the password); just the first 5 characters reach Have I Been Pwned (k-anonymity). Up to 50 hashes per call.
Citation graph of a paper: the works it references (outgoing) and the works that cite it (incoming), each as normalized records, plus the Semantic Scholar influential-citation count. Give a doi, arxiv, pmid, openalex_id...