{"uid":"cap_7OfaT52-7jlvGEjrWFOGn","slug":"claim-evaluator-518ea8fa","name":"Claim Evaluator","description":"Evaluate the likelihood of an LLM statement being true — with sources. Score 0–100, reasoning, and cited web sources. Pay per call via MPP.","url":"https://claim-evaluator.com/v1/evaluate","method":"POST","headers":{},"bodySchema":{"type":"object","required":["claim"],"properties":{"claim":{"type":"string","description":"Single factual claim to score. Prefer concrete, checkable statements over opinions or forecasts."}}},"responseSchema":{"type":"object","required":["likelihood","reasoning","sources"],"properties":{"sources":{"type":"array","items":{"type":"object","required":["name","url","stance","summary"],"properties":{"url":{"type":"string"},"name":{"type":"string"},"stance":{"enum":["confirm","deny","unclear"],"type":"string"},"summary":{"type":"string"}}},"maxItems":5,"minItems":3},"reasoning":{"type":"string","description":"2–3 sentence assessment"},"likelihood":{"type":"number","maximum":100,"minimum":0,"description":"0 = definitely false, 100 = definitely true"}}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.05","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":"$0.05/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.05","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.05","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_gc3gskRaDAy8N8R6J79Nl","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.05","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Scores the likelihood (0–100) that a factual claim is true, returning reasoning and cited web sources","exampleAgentPrompt":"Can you fact-check this claim for me and give it a truth score from 0 to 100 with sources: 'The Eiffel Tower is taller than the Empire State Building'?","exampleUseCases":[{"title":"Fact-checking AI-generated content","prompt":"I just got this answer from an AI: 'Aspirin was first synthesized in 1897 by Felix Hoffmann at Bayer.' Can you verify that claim, give it a likelihood score, and show me the sources that back it up or contradict it?"},{"title":"Verifying a news article statistic","prompt":"Someone shared an article claiming 'Global electric vehicle sales surpassed 10 million units in 2022.' Can you fact-check that and tell me how likely it is to be true, with sources?"},{"title":"Checking a debated historical claim","prompt":"My friend insists that 'Napoleon Bonaparte was unusually short for his time.' Can you score how likely that's actually true and pull some cited sources for me?"}],"resultDescription":"A JSON object containing: a `likelihood` score (0–100 integer, where 0 = definitely false and 100 = definitely true), a `reasoning` string (2–3 sentence assessment of the evidence), and a `sources` array of 3–5 web sources each with a name, URL, stance (confirm/deny/unclear), and a brief summary of what that source says about the claim.","failureModes":["Claim is too vague or opinion-based — endpoint performs best on concrete, checkable statements","No reliable sources found for very obscure or niche claims — may return sources with 'unclear' stance","LLM hallucination in reasoning if claim touches highly specialized domains","Rate limiting or payment failure if USDC balance is insufficient for the $0.05 per-call fee","Empty or malformed `claim` field returns a validation error"],"whenToPreferThis":"Choose this endpoint when you need a structured, sourced truth score for a specific factual claim — especially to validate LLM-generated statements, fact-check user assertions, or add citation-backed credibility scoring to a pipeline. It is purpose-built for single-claim evaluation with a numerical score and cited stances, making it ideal over general web search when you need structured verification output rather than raw search results.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T00:31:50.551Z","isFirstParty":false}