# Research Paper Citation Verifier

> Research Paper Citation Verifier is a paid API for AI agents from research-papers.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-31).

Verifies a cited DOI exists, checks whether its registered title matches the claimed title, and reports retraction status

## Facts

- Endpoint: GET https://research-papers.x402tookit.com/citation-verify?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/research-paper-citation-verifier-c989f2d0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_03Zkgtv_54dLrM_BQjjLp

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 research-paper-citation-verifier-c989f2d0
```

Example prompt: Can you verify this citation for me — DOI 10.1038/nature12373, claimed title 'CRISPR-Cas9 for genome editing', published in 2013? I want to know if the DOI is real, whether the title matches, and if the paper has ever been retracted.

## When to prefer this

Use this endpoint when you need to verify the integrity of a specific academic citation — confirming the DOI resolves, the title is accurately cited, and the paper hasn't been retracted. Prefer this over a general DOI metadata lookup when citation accuracy and retraction status are both required in a single call. It is the right choice for automated bibliography auditing, academic integrity workflows, or fact-checking pipelines where suspicious citations need multi-dimensional validation.

## Known failure modes

- DOI not found in Crossref — returns null metadata and degraded verdict
- Title parameter omitted — title match check skipped, noted in notChecked array
- Network timeout reaching Crossref or Retraction Watch — degraded flag set to true
- Invalid DOI format — may return empty or error response
- Retraction Watch unavailable — retraction check skipped with degraded notice

## How this service works

Verify a citation: does the DOI exist, does its real title match the claimed title, and has it been retracted?

## Output

Returns a structured verdict with: whether the DOI exists, the registered title vs. claimed title and their similarity score, year consistency, retraction status (from Crossref and Retraction Watch), first author, journal name, a plain-language summary, a list of reasons behind the verdict, and metadata about which checks were performed or skipped.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "doi"
     ],
     "properties": {
      "doi": {
       "type": "string",
       "description": "The DOI being cited"
      },
      "year": {
       "type": "integer",
       "description": "The year claimed"
      },
      "title": {
       "type": "string",
       "description": "The title claimed for it (to check for mismatch)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "doi": {
       "type": [
        "null",
        "string"
       ]
      },
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "journal": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "sourceUrl": {
       "type": [
        "null",
        "string"
       ]
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "notChecked": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "thresholds": {
       "type": [
        "null",
        "object"
       ],
       "properties": {
        "mismatchBelow": {
         "type": [
          "null",
          "number"
         ]
        }
       }
      },
      "firstAuthor": {
       "type": [
        "null",
        "string"
       ]
      },
      "claimedTitle": {
       "type": [
        "null",
        "string"
       ]
  
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/research-paper-citation-verifier-c989f2d0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from research-papers.x402tookit.com](https://www.zero.xyz/host/research-papers.x402tookit.com/llms.txt)