{"uid":"cap_RWgQbhR_ZkQhPb3okyBOx","slug":"agentindex-x402-fact-check-0190ddd2","name":"AgentIndex x402 Fact-Check","description":"Fact-check verdict written by Claude Haiku 5.5 (Anthropic) from real web sources: supported/contradicted/mixed/unverifiable, each source with its stance (supports/contradicts/neutral). Answer in a few seconds. Try GET /fact-check/sample. Independently monitored: lumierepaycheck.org/e?url=https://x402.agentindex.world/fact-check","url":"https://x402.agentindex.world/fact-check?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","properties":{"claim":{"type":"string","description":"The factual claim to check against live web sources."}}},"responseSchema":{"type":"json","example":{"claim":"The Eiffel Tower is taller than the Statue of Liberty.","sources":[{"url":"https://example.com/eiffel-tower-facts","title":"Eiffel Tower Facts","stance":"supports"}],"verdict":"supported","confidence":0.92}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.04","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":"$0.02/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_atuKJV7i87J6x9OhHTuuk","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.02","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Verifies a factual claim against live web sources and returns a verdict with supporting evidence and confidence score","exampleAgentPrompt":"Can you fact-check this claim for me: 'The Great Wall of China is visible from space' — I want to know if it's supported or refuted with real sources and how confident you are?","exampleUseCases":[{"title":"Verifying viral social media claims","prompt":"I saw a post saying 'Humans only use 10% of their brain' — can you check if that's actually true using live web sources and tell me what the verdict is?"},{"title":"Journalist source cross-checking","prompt":"Fact-check this for my article: 'Electric vehicles produce zero lifetime carbon emissions' — I need a verdict, a confidence score, and the URLs of sources that support or refute it."},{"title":"Debunking health misinformation","prompt":"Someone told me that 'Drinking eight glasses of water a day is scientifically proven' — can you verify that claim against current web sources and tell me if it's supported?"}],"resultDescription":"A JSON object containing the original claim, a verdict ('supported', 'refuted', or 'inconclusive'), a confidence score between 0 and 1, and a list of sources each with a URL, title, and stance ('supports' or 'refutes') drawn from live web retrieval.","failureModes":["Claim is ambiguous or too broad — may return low confidence or inconclusive verdict","Live web sources unavailable or unreachable — may result in error or reduced source count","Claim involves highly niche or recent events not yet indexed — may return inconclusive with few sources","Malformed or empty claim field — returns validation error","Payment failure via x402 protocol — returns 402 Payment Required"],"whenToPreferThis":"Choose this endpoint when you need a structured, sourced verdict on a specific factual claim backed by live web retrieval — especially when you need a machine-readable confidence score and stance-labeled citations. Prefer it over generic search when you need a binary or graded fact-check output rather than raw search results. Best suited for agents performing misinformation detection, research validation, or automated journalism workflows.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-28T00:30:35.122Z","isFirstParty":false,"canonicalSlug":"agentindex-x402-fact-check-0190ddd2"}