aiworker Claim Checker

x402

aiworker Claim Checker is a paid API for AI agents from aiworker.duckdns.org, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-14).

Extracts factual claims from text or a URL and verdicts each one as supported, contradicted, unsupported, or unverifiable, with quoted evidence from Wikipedia and supplied sources.

Price / call$0.05

Seller volume →—

Success—

StatusUnknown

How this service works

Deterministic-first data for agents, paid per call in USDC over x402 v2: DeFi yields, Base token and wallet cards, Polymarket odds and backtests, news, fact checks, cited briefs. 20 routes, $0.005-$1

Output

A JSON object containing the list of extracted factual claims, each with a unique ID, the claim statement, a verdict label (supported/contradicted/unsupported/unverifiable), a confidence score, a rationale, and verbatim evidence quotes with source URLs. Also includes metadata about which sources were consulted (Wikipedia and any supplied URLs), the model used, and input summary.

Example use cases

Verify news article claims

“Fetch this news article at https://example.com/article and check up to 5 of its factual claims against Wikipedia — I want to know which ones are supported, contradicted, or unverifiable, with quoted evidence for each.”

Fact-check product description text

“Can you check this product description for false claims: 'Our battery lasts 48 hours on a single charge and is the world's lightest laptop at 800 grams.' Extract claims and verdict each one, using this page as an extra source: https://gsmarena.com — up to 2 claims please.”

Validate student essay facts

“I have a student essay excerpt I need to fact-check: 'The Great Wall of China is visible from space and stretches over 21,000 kilometers.' Please extract all factual claims, up to 4, and tell me which are supported or contradicted by Wikipedia with verbatim quotes.”

Technical details

Endpoint

POSThttps://aiworker.duckdns.org/v1/check/claims

When to prefer

Choose this endpoint when you need structured, evidence-backed verdicts on specific factual claims with verbatim quotes from Wikipedia or supplied sources. It is ideal for fact-checking user-submitted text, validating article content, or auditing documents for false or unsupported assertions. Prefer it over generic LLM fact-checking because it provides citable, verbatim evidence and explicit verdict categories rather than prose opinion.

Side effects

If neither 'text' nor 'url' is provided, or both are provided simultaneously, the request is rejected
If the URL is not publicly accessible or returns a non-200 status, fetching fails
If text exceeds 8000 characters, the request is rejected
If max_claims exceeds 8 or is less than 1, validation error is returned
Wikipedia or supplied source URLs may be temporarily unreachable, resulting in unverifiable verdicts
Some claims may be too vague or subjective to verdict, returning 'unverifiable'
Payment of $0.05 USDC via x402 protocol is required; missing or invalid payment results in 402 response

Input

Schema · Request body

Field	Type	Description
url	string	a public https url whose page is fetched and checked instead of text
text	string	buyer text to check, at most 8 000 characters; exactly one of text or url is required
sources	array	up to 5 https urls the model may cite as evidence, in addition to Wikipedia
max_claims	integer	maximum claims to extract and verdict; default 5

Output

Schema · Response

{
  "type": "json",
  "example": {
    "input": {
      "kind": "text",
      "chars": 62
    },
    "model": "mimo-v2.5",
    "route": "POST /v1/check/claims",
    "claims": [
      {
        "id": "c1",
        "verdict": "supported",
        "evidence": [
          {
            "url": "https://en.wikipedia.org/wiki/Eiffel_Tower",
            "quote": "…330 m (1,083 ft) tall…"
          }
        ],
        "rationale": "Wikipedia's summary states the same height.",
        "statement": "The Eiffel Tower is 330 meters tall.",
        "confidence": 0.8
      }
    ],
    "version": 1,
    "sources_consulted": [
      {
        "url": "https://en.wikipedia.org/wiki/Eiffel_Tower",
        "kind": "wikipedia",
        "title": "Eiffel Tower",
        "fetched": true
      }
    ]
  }
}

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How this service works

Deterministic-first data for agents, paid per call in USDC over x402 v2: DeFi yields, Base token and wallet cards, Polymarket odds and backtests, news, fact checks, cited briefs. 20 routes, $0.005-$1

Output

Example use cases

Verify news article claims

Fact-check product description text

Validate student essay facts

Technical details

Endpoint

POSThttps://aiworker.duckdns.org/v1/check/claims

When to prefer

Side effects

If neither 'text' nor 'url' is provided, or both are provided simultaneously, the request is rejected
If the URL is not publicly accessible or returns a non-200 status, fetching fails
If text exceeds 8000 characters, the request is rejected
If max_claims exceeds 8 or is less than 1, validation error is returned
Wikipedia or supplied source URLs may be temporarily unreachable, resulting in unverifiable verdicts
Some claims may be too vague or subjective to verdict, returning 'unverifiable'
Payment of $0.05 USDC via x402 protocol is required; missing or invalid payment results in 402 response

Input

Schema · Request body

Field	Type	Description
url	string	a public https url whose page is fetched and checked instead of text
text	string	buyer text to check, at most 8 000 characters; exactly one of text or url is required
sources	array	up to 5 https urls the model may cite as evidence, in addition to Wikipedia
max_claims	integer	maximum claims to extract and verdict; default 5

Output

Schema · Response

{
  "type": "json",
  "example": {
    "input": {
      "kind": "text",
      "chars": 62
    },
    "model": "mimo-v2.5",
    "route": "POST /v1/check/claims",
    "claims": [
      {
        "id": "c1",
        "verdict": "supported",
        "evidence": [
          {
            "url": "https://en.wikipedia.org/wiki/Eiffel_Tower",
            "quote": "…330 m (1,083 ft) tall…"
          }
        ],
        "rationale": "Wikipedia's summary states the same height.",
        "statement": "The Eiffel Tower is 330 meters tall.",
        "confidence": 0.8
      }
    ],
    "version": 1,
    "sources_consulted": [
      {
        "url": "https://en.wikipedia.org/wiki/Eiffel_Tower",
        "kind": "wikipedia",
        "title": "Eiffel Tower",
        "fetched": true
      }
    ]
  }
}