Hallucination check and research for AI agents. POST /v1/check fact-checks one claim live with four independent web-searching models (GPT, Gemini, Grok, Claude): verdict, agreement such as 4/4, confidence and sources, $0.25. POST /v1/ask returns dated research cards from KARP's multi-model research library, $0.03. Free POST /v1/coverage shows what's covered. USDC on Base or Solana; nothing is charged if a call fails.
| verified | Not yet: listing not claimed with domain proof. |
| trusted | Not yet: needs Live-Tested. |
/api/v1/call/x402.karp-agents-api[](https://agentropolis.io/listing/x402.karp-agents-api)