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Fact-Checker API (klymax402)
x402
Fact-Checker API (klymax402) is a paid API for AI agents from fact-checker.api.klymax402.com, paid per call via x402, $0.012/call, status unknown (last checked 2026-09-13).
Verifies a factual claim by searching for evidence online and returning sourced results
Price / call$0.012
Success—
StatusUnknown
How this service works
Fact-check a claim by searching for evidence online
Output
Returns a verification assessment of the submitted claim along with up to the requested number of online sources that provide evidence either supporting or contradicting the claim.
Example use cases
Example prompt
“Can you fact-check this claim for me: 'The Eiffel Tower is 330 meters tall' — and pull up to 8 sources so I can see the evidence?”
Technical details
Endpoint
GEThttps://fact-checker.api.klymax402.com/api/checkWhen to prefer
Use this endpoint when you need to verify a specific factual claim against real online evidence and want sourced results. Prefer this over general web search when you want a structured fact-check response rather than raw search results, and when the query is a concrete verifiable assertion rather than an open-ended question.
Side effects
- Claim string is empty or missing — likely returns 400 or validation error
- max_sources exceeds 10 — may be capped or return an error
- Claim is too ambiguous or unverifiable — may return low-confidence or no sources
- Network/search backend unavailable — may return 500 or timeout
- Claim is in a language other than English — may produce incomplete results
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| claim | string | The factual claim to verify (e.g., 'The Eiffel Tower is 330 meters tall') |
| max_sources | number | Maximum number of sources to return (default: 5, max: 10) |
Tags
x402
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