{"uid":"cap_IDDTo2DuU_nB864zlaCVD","slug":"web-evidence-api-deep-claim-verification-4a5e961d","name":"Web Evidence API – Deep Claim Verification","description":"Machine-discoverable services AI agents can call and purchase autonomously.","url":"https://api.aisoup.net/v1/claims/verify/deep?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"asOf":{"type":["string","null"],"format":"date","description":"Optional date at which the claim should be evaluated."},"claim":{"type":"string","maxLength":4000,"minLength":3,"description":"The factual claim to verify."},"language":{"type":"string","description":"Preferred response language or auto."},"maxSources":{"type":"integer","maximum":15,"minimum":1,"description":"Maximum number of evidence sources to return."},"jurisdiction":{"type":["string","null"],"description":"Optional country, state, or legal jurisdiction."},"sourcePolicy":{"enum":["official_only","authoritative","open_web"],"description":"Policy controlling which kinds of web sources may be used."},"allowedDomains":{"type":"array","items":{"type":"string"},"description":"Optional hostname allowlist without schemes or paths."},"blockedDomains":{"type":"array","items":{"type":"string"},"description":"Optional hostname blocklist without schemes or paths."},"freshnessHours":{"type":["integer","null"],"maximum":8760,"minimum":1,"description":"Maximum preferred source age in hours."},"minimumSources":{"type":"integer","maximum":10,"minimum":1,"description":"Minimum number of evidence sources requested."},"includeConflicts":{"type":"boolean","description":"Whether to search for and report conflicting evidence."}}},"responseSchema":{"type":"json","example":{"claim":"The Base mainnet chain ID is 8453.","status":"confirmed","evidence":[],"conflicts":[],"snapshots":[],"conclusion":"Authoritative sources confirm that Base mainnet uses chain ID 8453.","observedAt":"2026-01-01T00:00:00Z","provenance":{},"atomicFacts":[],"limitations":[],"verificationId":"cv_example","providerSources":[]}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.12","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":"$0.12/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.12","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.12","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_AqehCoa0bh5BGefR9twAg","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.12","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Verifies a natural-language claim against web sources, returning a verdict with cited evidence, source snapshots, content hashes, and conflict analysis.","exampleAgentPrompt":"Can you verify the claim 'The Base mainnet chain ID is 8453' using only authoritative sources, return at least 2 sources, and include any conflicting evidence you find?","exampleUseCases":[{"title":"Fact-checking a news headline","prompt":"Can you verify the claim 'The WHO declared mpox a global health emergency in 2024' using authoritative sources only, with at least 3 references, and flag any conflicting accounts?"},{"title":"Validating a regulatory compliance fact","prompt":"I need to verify the claim 'GDPR fines can reach up to 4% of global annual turnover' — please check it against official EU sources only, as of today, and tell me if there are any conflicts."},{"title":"Confirming a crypto technical specification","prompt":"Please fact-check the statement 'Ethereum's proof-of-stake transition happened in September 2022' using open web sources, give me up to 5 citations, and include any snapshots or hashes for the evidence."}],"resultDescription":"Returns a JSON object with a verdict status (e.g. confirmed, disputed, unverified), a plain-language conclusion, an array of evidence citations with source URLs and metadata, an array of conflicting sources if found, content snapshots and hashes for provenance, a list of atomic facts extracted, observed timestamp, a unique verification ID, and any limitations of the analysis.","failureModes":["Claim too vague or ambiguous to evaluate — returns unverified with explanation","No sources found meeting freshness or domain policy constraints — returns insufficient_sources error","Claim exceeds 4000 character limit — returns validation error","freshnessHours window excludes all available evidence — returns empty evidence array","minimumSources threshold not met — may return partial result or failure flag","Payment not processed (x402) — returns 402 Payment Required before verification runs"],"whenToPreferThis":"Choose this endpoint when an agent needs cited, verifiable evidence for a specific claim rather than a simple web search or summarization. It is especially valuable when source provenance, content snapshots, and conflict detection matter — for example in journalism, compliance, research, or any agentic workflow where factual accountability is required. Prefer it over general search APIs when you need a structured verdict with hashes and citations rather than raw search results.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-12T18:38:26.220Z","isFirstParty":false,"canonicalSlug":"web-evidence-api-deep-claim-verification-4a5e961d"}