{"name":"claim-corroborate","description":"Fact check a claim and see exactly who agrees and who disagrees. Composite: one call runs web-search + wikipedia-search + x-search + arxiv-search + citation-verify + sentiment in parallel, then re-verifies the top hits against their source pages and rolls up a corroboration count. Send a claim and get back a per-source stance (supports, contradicts, or unclear) with the snippet it was judged on, plus an overall corroboration score. Sources without a conclusive citation-verify read fall back to a keyword-overlap heuristic instead of guessing. Use it as a fact check API, claim verification tool, source cross-reference for research agents, or a misinformation screen before an agent repeats a claim downstream.","price":"$0.05","method":"POST","input_schema":{"properties":{"claim":{"type":"string","description":"The factual claim to check, e.g. 'the Great Wall of China is visible from space'. Max 500 chars."},"lang":{"type":"string","description":"Optional 2-8 character language code for the Wikipedia search leg, e.g. 'en' or 'es'. Default 'en'."},"max_sources":{"type":"number","description":"Max results pulled per corpus (web, Wikipedia, X, arXiv) before dedup. Default 5, range 1-10."}},"required":["claim"]},"input_example":{"claim":"the Great Wall of China is visible from space with the naked eye","max_sources":5},"output_example":{"claim":"the Great Wall of China is visible from space with the naked eye","corroboration":{"supporting":1,"contradicting":3,"unclear":1,"score":-0.4},"sources":[{"corpus":"web-search","title":"No, you can't see the Great Wall from space","url":"https://example.com/great-wall-myth","stance":"contradicts","snippet":"Astronauts have confirmed the wall is not visible to the naked eye from orbit.","method":"citation-verify"}],"sentiment":{"overall_sentiment":"neutral","overall_score":0.02},"composed_of":["web-search","wikipedia-search","x-search","arxiv-search","sentiment","citation-verify"],"components":[{"name":"web-search","ok":true,"ms":640},{"name":"citation-verify:0","ok":true,"ms":3200}],"degraded":false},"x402_payment_required":true,"x402_facilitator":"https://api.cdp.coinbase.com/platform/v2/x402"}