{
  "name": "Clearsigned Verify",
  "description": "Machine-callable claim verification with no stake in the outcome. Submit a claim (and optional evidence); receive an Ed25519-signed, evidence-bearing receipt with a calibrated verdict: SUPPORTED, REFUTED, or UNVERIFIABLE. Confidence values are measured realized rates from a published calibration curve (0.914, n=116), never model-asserted. Commit precision 0.976 on the serving stack; between 0.959 and 0.976 across five measured stacks. Every receipt and its on-chain settlement are hash-chained in a publicly auditable ledger.",
  "url": "https://verify.clearsigned.com",
  "provider": {
    "organization": "Clearsigned",
    "url": "https://clearsigned.com"
  },
  "version": "1.0.0",
  "documentationUrl": "https://clearsigned.com/llms.txt",
  "capabilities": {
    "streaming": false,
    "pushNotifications": false
  },
  "defaultInputModes": ["application/json"],
  "defaultOutputModes": ["application/json"],
  "skills": [
    {
      "id": "verify-claim-t1",
      "name": "Verify a claim (T1)",
      "description": "Adversarial verification of a factual claim: live evidence gathering for and against, per-source stance judgments, a refuter pass, and a fixed confidence formula mapped through a published calibration curve. $0.05 USDC per call via x402 (Base mainnet, scheme exact). Response takes 5-20s; use a client timeout of at least 60s. Abstains (UNVERIFIABLE) rather than guesses when evidence is thin.",
      "tags": ["verification", "fact-checking", "x402", "payments", "trust"],
      "examples": [
        "POST https://verify.clearsigned.com/verify/t1 with {\"claim\": \"The Eiffel Tower is located in Paris, France.\", \"evidence\": []}"
      ]
    }
  ],
  "payment": {
    "protocol": "x402",
    "version": 2,
    "network": "eip155:8453",
    "scheme": "exact",
    "price": "$0.05 USDC per verification"
  },
  "verification": {
    "receiptSignature": "ed25519, public key at https://verify.clearsigned.com/pubkey — pin it, never trust the key embedded in a receipt",
    "publicLedger": "https://verify.clearsigned.com/ledger/verify",
    "calibration": "curve version cited on every receipt; provenance in the repository"
  }
}