{"uid":"cap_bQga6DxhuI-SNz5kr9UyZ","slug":"402oracle-claim-verifier-a022bb6f","name":"402oracle Claim Verifier","description":"Fact-check a single factual claim against web evidence before your agent relies on it. A fact-checking oracle and hallucination guard: returns a verdict (supported / contradicted / insufficient), a confidence score, and citations, as a signed attestation.","url":"https://402oracle.com/verify/claim","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"claim":{"type":"string","description":"A single factual claim, 8-600 characters"}}},"responseSchema":{"type":"json","example":{"signature":{"alg":"ES256","jwks":"/.well-known/jwks.json"},"attestation":{"type":"claim_verification","result":{"verdict":"supported","citations":["https://example.com/about"]},"subject":{"claim":"Company X was founded in 2019."},"confidence":0.8}}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.25","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.25/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.25","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.25","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_xDmuMm7ryNc8aiepDnD4v","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.25","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Fact-checks a single factual claim against live web evidence and returns a signed verdict (supported/contradicted/insufficient), confidence score, and citations.","exampleAgentPrompt":"Before we use this in the report, can you fact-check the claim 'The global electric vehicle market surpassed 10 million units sold in 2022' against current web evidence and tell me whether it's supported, contradicted, or inconclusive — with a confidence score and sources?","exampleUseCases":[{"title":"Verify claim before agent pays invoice","prompt":"Before we pay this vendor, can you verify the claim 'Acme Logistics has been in operation since 2005 and is registered in Delaware' against web evidence, and give me a verdict with confidence and citations?"},{"title":"Fact-check news assertion before publishing","prompt":"Our newsletter draft says 'The FDA approved Ozempic for weight loss in adults in 2021' — can you fact-check that claim and tell me if it's supported, contradicted, or if there's insufficient evidence?"},{"title":"Validate statistic before agent cites it","prompt":"I want to use the statistic 'Over 50% of Fortune 500 CEOs have an MBA' in my pitch deck — please verify whether that's actually supported by credible web evidence before I include it."}],"resultDescription":"A signed attestation object containing: a verdict string (supported, contradicted, or insufficient), a numeric confidence score (0–1), and an array of citations (URLs and excerpts) from web evidence that informed the verdict.","failureModes":["Claim text is too vague or ambiguous for the system to locate relevant evidence — returns insufficient verdict","Claim is about highly recent events with no indexed web evidence yet — may return insufficient","Conflicting web sources may yield a low confidence score with a supported or contradicted verdict","Malformed or empty claim text returns a validation error","Payment failure (insufficient USDC) blocks the request entirely","Rate limiting or service unavailability returns a 5xx error"],"whenToPreferThis":"Choose this endpoint when your agent needs a signed, auditable fact-check of a specific textual claim before acting on it — especially before making payments, publishing content, or relying on a statistic. Prefer it over general-purpose web search when you need a structured verdict plus citations in a single atomic call, and when the attestation (signed output) matters for downstream trust or audit trails.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-13T18:31:20.194Z","isFirstParty":false}