# verify-citation

> verify-citation is a paid API for AI agents from goodsong.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Verifies whether a citation exists, checks if it has been retracted, and confirms that title/authors/year/journal metadata match the canonical academic record via Crossref and OpenAlex.

## Facts

- Endpoint: POST https://goodsong.dev/verify/citation
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/verify-citation-14d843f0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_uwPCaR1BCp-nVTJth4UyM

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability verify-citation-14d843f0 -d '<json body>'
```

Example prompt: Can you check whether this citation is real and not retracted? The paper is 'Attention Is All You Need' by Vaswani et al., published in 2017 in NeurIPS — the DOI is 10.48550/arXiv.1706.03762.

## When to prefer this

Use this endpoint when you need to validate academic citations for correctness and retraction status, especially before including references in a manuscript, literature review, or fact-checked document. Prefer this over manual lookup when you have structured citation fields (DOI, title, authors, year, journal) and need a programmatic, reliable answer. It is particularly valuable for catching hallucinated AI-generated citations or flagging retracted papers that could undermine research credibility.

## Known failure modes

- DOI not found in Crossref or OpenAlex — returns non-existence result
- Title/author search returns ambiguous multiple matches when no DOI is provided
- Retraction data may lag real-world retractions if not yet indexed in Crossref
- Metadata mismatch may occur for papers with variant title spellings or name formats
- Network timeout or upstream API unavailability from Crossref or OpenAlex

## How this service works

Verify a citation: does it exist, is it retracted, and do the given title/authors/year/journal match the canonical record? Checked against Crossref (retraction data included) with OpenAlex as a fallback when no DOI is given.

## Output

A structured response indicating whether the cited work exists in Crossref or OpenAlex, whether it has been retracted, and whether the supplied title, authors, year, and journal match the canonical bibliographic record. Discrepancies between provided metadata and the canonical record are flagged.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "doi": {
   "type": "string",
   "description": "The citation's DOI, if known."
  },
  "year": {
   "type": "integer",
   "description": "Publication year."
  },
  "title": {
   "type": "string",
   "description": "The work's title."
  },
  "authors": {
   "type": "array",
   "items": {
    "type": "string"
   },
   "description": "Author names, as e.g. ['Jane Doe', 'John Smith']."
  },
  "journal": {
   "type": "string",
   "description": "Journal or venue name."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/verify-citation-14d843f0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from goodsong.dev](https://www.zero.xyz/host/goodsong.dev/llms.txt)