Checks citations at the source
Metis Check asks the body that issues an identifier whether it exists and what it points to, then tells you in plain words. WHAT IT CHECKS Scholarly: DOI, PubMed ID, arXiv id, ORCID iD, ROR ID, ISBN, OpenAlex ID. More
Example path get_report · Metis check skill
https://check-api.metisfoundry.com/mcp/check
2 in the ChatGPT listing