{"uid":"cap_YtpBi9TKjUdqsYxo3Zkmm","slug":"claim-verification-8383b564","name":"Claim Verification","description":"Check whether a source supports, contradicts, or gives insufficient information about a claim - a typed verdict with a real probability, not generated text. Try GET /verify/sample.","url":"https://x402.agentindex.world/verify?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","properties":{"claim":{"type":"string","description":"The factual claim to check."},"source":{"type":"string","description":"The source text to check the claim against."}}},"responseSchema":{"type":"json","example":{"verdict":"supported","confidence":1,"probability":1,"x402_receipt":{"upstream":"verification","latency_ms":390,"model_served":"jev","price_paid_usdc":0},"probabilities":{"supported":1,"contradicted":0,"not_enough_info":0}}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","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":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_-vK6sF1VZ7oFklP6PW8Pd","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Checks whether a given source text supports, contradicts, or gives insufficient information about a factual claim, returning a typed verdict with a probability score.","exampleAgentPrompt":"Check whether this passage — 'The Eiffel Tower was completed in 1889 and stands 330 meters tall' — supports or contradicts the claim 'The Eiffel Tower is taller than 300 meters', and give me a probability score.","exampleUseCases":[{"title":"Fact-checking news article claims","prompt":"I have a claim that 'Global CO2 emissions fell by 7% in 2020' and a paragraph from an IPCC report — can you tell me whether the report supports, contradicts, or is inconclusive about that claim, and how confident you are?"},{"title":"Research citation validation","prompt":"I wrote in my paper that 'mRNA vaccines do not alter human DNA' — can you check whether this abstract I have from a Nature journal article actually supports that claim, and give me a probability?"},{"title":"Legal document consistency check","prompt":"Our contract clause says 'delivery is guaranteed within 5 business days' — does this email thread from the supplier support or contradict that claim? I need a verdict and confidence score."}],"resultDescription":"A typed verdict indicating whether the source supports, contradicts, or gives insufficient information about the claim, paired with a real probability score (not free-form generated text).","failureModes":["Missing 'claim' or 'source' field returns a 400 validation error","Source text too short or uninformative may result in 'insufficient information' verdict with low confidence","Payment failure or missing x402 header returns a 402 Payment Required response","Very long source texts may be truncated or cause timeouts","Ambiguous or compound claims may yield uncertain probabilities near 0.5"],"whenToPreferThis":"Choose this endpoint when you need a structured, probabilistic verdict on whether a specific text passage supports or refutes a claim — not free-form summarization. It is ideal for fact-checking pipelines, RAG validation, citation auditing, or any workflow requiring a machine-readable true/false/inconclusive classification with a confidence score rather than a generated explanation.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-03T00:37:14.318Z","isFirstParty":false,"canonicalSlug":"claim-verification-8383b564"}