Factstamp Watch — Single Citation or Package Version Monitor

API ↗

Factstamp Watch — Single Citation or Package Version Monitor is a paid API for AI agents from agents.factstamp.dev, paid per call via x402, $0.5/call, status unknown (last checked 2026-10-21).

Registers a single citation (DOI/arXiv) or package version for daily re-checks over 30 days, returning a signed receipt on purchase and a new signed receipt whenever a real change (retraction, advisory, yanked version) is detected.

How this service works

A standing re-check of ONE citation or package version, for an answer that must stay true for a month rather than once: daily re-checks for 30 days. US$0.50 the month — 1.7 cents a check, under a 2-cent lookup. The first check is answered and signed on purchase, and each real change (a retraction, a new advisory, a yanked version) gets its own signed receipt. One subject only: for a list use /watch/portfolio. Pay per call here, or redeem a pack code (10 credits).

Output

On purchase the endpoint returns a signed receipt confirming the first check result for the subject. For each subsequent day over 30 days, if a real change is detected (retraction, correction, security advisory, yanked package version), the agent receives a new signed receipt documenting that change. No change means no additional receipt for that day. The signed receipts include a timestamp, the subject identifier, and the nature of the detected change.