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Cited Brief DOI Checker
x402
Cited Brief DOI Checker is a paid API for AI agents from cited-brief.cited-brief.workers.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-14).
Validates DOIs, arXiv IDs, and doi.org links against Crossref to confirm existence, check for retractions, and verify cited titles match the real publication metadata.
Price / call$0.01
Success—
StatusUnknown
How this service works
Pay-per-call web research tools for AI agents, paid in USDC over x402.
Output
A JSON object containing a summary count of found, not_found, and retracted papers, plus per-DOI details including resolved URL, publication type, year, venue, publisher, author list, citation count, retraction status, title match score (0–1), and any notices about the paper.
Example use cases
Detecting hallucinated citations in AI output
“I used an AI to draft a literature review and I'm worried some of the citations might be made up. Can you check these five DOIs — 10.1016/j.cell.2020.01.001, 10.1038/s41586-021-03819-2, 10.1126/science.abe8654, 10.1073/pnas.2026316118, 10.1101/2022.05.10.491413 — and verify they actually exist and haven't been retracted?”
Title mismatch check before journal submission
“Before I submit my manuscript, can you verify that my reference titles match the real papers? Here are two DOIs with the titles I used: DOI 10.1038/nature12373 titled 'Nanometre-scale thermometry in a living cell', and DOI 10.1126/science.1171759 titled 'A Bacterium That Can Grow by Using Arsenic Instead of Phosphorus'. Let me know if the titles are correct.”
Retraction screening for systematic review
“I'm compiling a systematic review and need to make sure none of my key references have been retracted. Please check these DOIs: 10.1016/S0140-6736(97)11096-0, 10.1097/00007691-200312000-00002, and 10.1093/jnci/djt088, and flag any that are retracted or couldn't be found.”
Technical details
Endpoint
POSThttps://cited-brief.cited-brief.workers.dev/check-doi?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need to validate academic references at scale, particularly to catch hallucinated citations from LLMs, verify title accuracy, or screen for retracted papers. Prefer it over manual Crossref queries when checking batches of up to 10 DOIs at once with title comparison built in. Ideal for agents performing literature review quality assurance, manuscript preparation assistance, or fact-checking of AI-generated academic content.
Side effects
- DOI not found in Crossref — returned with found:false
- arXiv ID does not resolve to a valid paper
- Title mismatch detected — title_ok:false and title_match score below threshold
- Input array exceeds 10 items — rejected by schema validation
- Malformed DOI or URL that cannot be parsed
- Crossref API unavailable or rate-limited — upstream error returned
- Payment not completed via x402 — request blocked before processing
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| ids | array | DOIs (10.xxxx/...), doi.org links or arXiv ids |
| titles | array | Titles you cited, in the same order as ids, to compare with the real ones |
Output
Schema · Response
{
"type": "json",
"example": {
"found": 2,
"checked": 2,
"results": [
{
"doi": "10.1038/nature12373",
"url": "https://doi.org/10.1038/nature12373",
"kind": "doi",
"type": "journal-article",
"year": 2013,
"found": true,
"input": "10.1038/nature12373",
"title": "Nanometre-scale thermometry in a living cell",
"venue": "Nature",
"source": "crossref",
"authors": [
"G. Kucsko",
"P. C. Maurer"
],
"notices": [],
"cited_by": 1200,
"title_ok": true,
"published": "2013-08",
"publisher": "Springer Science and Business Media LLC",
"retracted": false,
"title_match": 1,
"author_count": 9
}
],
"not_found": 0,
"retracted": 0
}
}Tags
x402
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