{"uid":"cap_j9b06Xlm-306Tx7rXWPfn","slug":"web-evidence-api-quick-claim-verification-edd43f6a","name":"Web Evidence API – Quick Claim Verification","description":"Machine-discoverable services AI agents can call and purchase autonomously.","url":"https://api.aisoup.net/v1/claims/verify/quick?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":3,"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":"0.02","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_Mie9iSEs-jw3AeUgprErg","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 natural-language claim against web sources and returns a verdict, cited evidence, source snapshots, cryptographic hashes, and conflict detection.","exampleAgentPrompt":"Can you fact-check the claim 'The Base mainnet chain ID is 8453' using only authoritative sources, give me up to 3 citations, and flag any conflicting information you find?","exampleUseCases":[{"title":"News headline accuracy check","prompt":"I saw a headline saying 'The EU banned single-use plastics in 2021' — can you verify that claim using authoritative sources, show me the cited evidence, and let me know if any sources contradict each other?"},{"title":"Technical spec confirmation for a dev team","prompt":"Our docs say Ethereum's EIP-1559 introduced a base fee burn mechanism — can you verify that claim against official sources with at most 3 citations, and flag any conflicts?"},{"title":"Regulatory compliance fact-check","prompt":"We need to confirm whether GDPR fines can reach up to 4% of global annual turnover — please verify this claim using official sources only, within the EU jurisdiction, and include any conflicting interpretations you find."}],"resultDescription":"Returns a JSON object containing the verdict status (confirmed/refuted/uncertain), a natural-language conclusion, an array of evidence citations with URLs and excerpts, cryptographic snapshot hashes for provenance, detected conflicting sources, a list of atomic facts, observed timestamp, a unique verificationId, and any noted limitations of the verification.","failureModes":["Claim too vague or ambiguous — returns uncertain status with explanation","No sources found within freshnessHours window — returns insufficient evidence","Blocked or allowed domain filters eliminate all viable sources — returns empty evidence array","Claim exceeds 4000 character limit — returns validation error","Payment not completed (x402) — returns 402 Payment Required before processing","Source policy 'official_only' returns zero results for niche topics — falls back to limitations note"],"whenToPreferThis":"Choose this endpoint when you need a cited, machine-readable verdict on a specific factual claim — especially when source provenance, snapshot hashes, and conflict detection matter. Prefer it over general web search when you need structured evidence with a definitive conclusion rather than raw search results, and when auditability (via snapshots and verificationId) is important for downstream trust or compliance workflows.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-13T00:35:30.007Z","isFirstParty":false,"canonicalSlug":"web-evidence-api-quick-claim-verification-edd43f6a"}