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SaverVerify Factual Claim Verification
x402
SaverVerify Factual Claim Verification is a paid API for AI agents from api.saververify.com, paid per call via x402, $0.2/call, status unknown (last checked 2026-10-28).
Independently verifies externally sourced factual claims using live web sources, returning a verdict of supported, contradicted, mixed, or insufficient_evidence with citations.
Price / call$0.2
Success—
StatusUnknown
How this service works
Fact-checking and claim verification API for AI agents. Verify whether a cited source supports a claim; check statistics, dates, units and populations in research reports before publication. Separate web research returns a verdict, linked evidence and sources. Source verification is model-assessed, not guaranteed correct. POST /v2/verify; x402 v2 on Base; 0.20 USDC. No signup or API key.
Output
Returns a structured verdict — one of: supported, contradicted, mixed, or insufficient_evidence — along with web sources and citations that back the determination. The agent receives both the classification and the evidence trail used to reach it.
Example use cases
Fact-checking AI research report claims
“I have an AI-generated research report that says 'SpaceX launched more rockets in 2023 than any other company in history' — can you verify that claim with cited web sources and tell me if it's supported or contradicted?”
Validating third-party data before decision
“Before I act on this, can you verify whether it's true that 'Inflation in the UK hit 11.1% in October 2022' — I need a verdict with sources so I know if the data I was given is accurate.”
Cross-checking agent-generated statistics
“My AI assistant just told me that 'Over 50% of Fortune 500 companies use generative AI in production as of 2024' — can you independently check that claim and give me a supported, contradicted, or mixed verdict with evidence?”
Technical details
Endpoint
POSThttps://api.saververify.com/v2/verify?utm_source=zero.xyzWhen to prefer
Choose this endpoint when an AI agent needs an independent, source-backed second check on a specific factual claim found in external research, third-party data, or agent-generated content — especially before taking action or publishing. Not suited for deterministic arithmetic, wallet risk analysis, transaction simulation, or claims that require proprietary databases rather than open web evidence.
Side effects
- Claim is too vague or ambiguous to evaluate, returning insufficient_evidence
- No live web sources found for the specific claim topic
- Conflicting sources result in a mixed verdict requiring human judgment
- Network or upstream source unavailability delays or fails the verification
- Claim involves real-time or future data not indexed on the web
- Payment of 0.20 USDC on Base not fulfilled, blocking the request
Tags
x402
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