DOI Retraction & Academic Citation Verification API
FactStamp (agents.factstamp.dev) verifies academic DOIs, arXiv identifiers, cited paper titles, and retraction status deterministically against Crossref, arXiv, and Retraction Watch—with no LLM in the verdict path. A recent University of Turku / Columbia audit of 21.6M references found fabricated-DOI rates climbing to 23.0 per 10,000 papers in Q1 2026, while the Charlotin AI Hallucination Cases database tracks over 1,260 legal filings with hallucinated citations. FactStamp's verify_citation tool returns verified, contradicted, or unknown with an offline-verifiable Ed25519 receipt for US$0.02 per call (or US$0.01/item in verify_bulk).
Verify a DOI or Citation (WebMCP-Enabled)
Citation Verification Comparison
| Tool | Title-to-DOI Match | Retraction Watch Check | Signed Audit Receipt |
|---|---|---|---|
FactStamp verify_citation |
Yes (deterministic string/record match) | Yes | Ed25519 JCS v2 receipt (US$0.02) |
| Raw Crossref REST API | Manual parsing required | Requires separate Retraction Watch lookup | Unsigned JSON |
Test an offline receipt at GET https://agents.factstamp.dev/receipt/selftest or integrate factstamp/watch-action on .bib files in CI.