SCRIPTMASTERLABS — ClaimGate

PAID tool ($0.25 USDC via x402, Base). Fact-check a claim against live web sources: the claim is decomposed into sub-claims, sources are fetched live, Jev jurors judge per-source-family entailment with verbatim-quote evidence that must pass an anti-hallucination substring gate, and the verdict is coherence-gated (coherence = |sum(w*d)| / sum(w) over source families, weights 3/2/1 by source class) and sealed as a stored receipt. Send the x402 PAYMENT-SIGNATURE header on the /mcp request; without payment the call returns the canonical x402 challenge (HTTP 402, amount 250000 = $0.25 USDC, payTo of the canonical SML receiver). If the jury is not configured the call fails before any payment is requested, so nobody pays for a check that cannot run.

{
  "type": "object",
  "properties": {
    "claim": {
      "type": "string",
      "minLength": 10,
      "maxLength": 2000,
      "description": "The claim to fact-check, as a single statement or a short paragraph."
    },
    "sources": {
      "type": "array",
      "maxItems": 8,
      "items": {
        "type": "string",
        "maxLength": 2048
      },
      "description": "Optional public HTTPS source URLs to check against (max 8). When omitted or fewer than 2 are usable, ClaimGate searches the live web."
    },
    "sub_claims": {
      "type": "array",
      "maxItems": 4,
      "items": {
        "type": "string",
        "minLength": 8,
        "maxLength": 2000
      },
      "description": "Optional caller-provided decomposition of the claim into sub-claims (max 4). When omitted, the claim text is split into sentences."
    }
  },
  "required": [
    "claim"
  ],
  "additionalProperties": false
}

Free preview: decompose a claim into sub-claims, fetch the sources live (or search for them), classify each source and group sources into independent families, and show exactly what a paid fact_check_claim would check. No verdict, no jury calls, no payment.

{
  "type": "object",
  "properties": {
    "claim": {
      "type": "string",
      "minLength": 10,
      "maxLength": 2000,
      "description": "The claim to fact-check, as a single statement or a short paragraph."
    },
    "sources": {
      "type": "array",
      "maxItems": 8,
      "items": {
        "type": "string",
        "maxLength": 2048
      },
      "description": "Optional public HTTPS source URLs to check against (max 8). When omitted or fewer than 2 are usable, ClaimGate searches the live web."
    }
  },
  "required": [
    "claim"
  ],
  "additionalProperties": false
}

Check whether ClaimGate is live, whether the Jev jury is configured, which x402 facilitator is selected, how many receipts are stored, and the paid-check price.

{
  "type": "object",
  "properties": {},
  "additionalProperties": false
}

The full public ClaimGate methodology: coherence formula, source-class weights, verdict thresholds, the anti-hallucination verbatim-quote gate, family independence rules, and honest limits. calibrated:false — thresholds are stated, not fitted.

{
  "type": "object",
  "properties": {},
  "additionalProperties": false
}

Fetch a stored ClaimGate receipt by receipt_id (the sealed record of a paid fact check: sub-claims, sources, per-family verdicts with validated verbatim quotes, coherence, verdict, and payment).

{
  "type": "object",
  "properties": {
    "receipt_id": {
      "type": "string",
      "minLength": 4,
      "maxLength": 128,
      "description": "Receipt id returned by fact_check_claim, e.g. cg_..._........"
    }
  },
  "required": [
    "receipt_id"
  ],
  "additionalProperties": false
}