{"name":"citation-verify","description":"Citation verifier / fact-check against URL / does-this-source-support-this-claim / hallucination detector. Fetches a source URL (HTML stripped, 100KB cap), and asks Venice claude-sonnet-4-6 whether a given claim is supported, contradicted, or absent. Returns verdict, confidence (0-1), and the strongest evidence quote when available.","price":"$0.01","method":"POST","input_schema":{"properties":{"claim":{"type":"string","description":"The claim to verify."},"source_url":{"type":"string","description":"Public http(s) URL of the source to check against. Up to 100KB read."}},"required":["claim","source_url"]},"input_example":{"claim":"GPT-4 was released in March 2023","source_url":"https://en.wikipedia.org/wiki/GPT-4"},"output_example":{"claim":"GPT-4 was released in March 2023","source_url":"https://en.wikipedia.org/wiki/GPT-4","source_chars":38421,"source_bytes_total":78124,"truncated":false,"verdict":"supported","confidence":0.95,"evidence_quote":"GPT-4 was released on March 14, 2023.","model":"claude-sonnet-4-6","source":"venice + http"},"x402_payment_required":true,"x402_facilitator":"https://api.cdp.coinbase.com/platform/v2/x402"}