# ScriptMasterLabs Fact-Check API

> ScriptMasterLabs Fact-Check API is a paid API for AI agents from mcp-x402-discovery.onrender.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Verifies a textual claim against authoritative data sources across federal, SEC, drug, healthcare, grants, and financial domains

## Facts

- Endpoint: GET https://mcp-x402-discovery.onrender.com/x402/fact-check
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/scriptmasterlabs-fact-check-api-a0a8fe3b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_wVsRedn0LarNki6IGXY9X

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability scriptmasterlabs-fact-check-api-a0a8fe3b
```

Example prompt: Can you fact-check this claim for me: 'Pfizer received a federal grant of $2 billion in 2023 for COVID vaccine development' — route it under the grants domain if that helps.

## When to prefer this

Choose this endpoint when you need programmatic fact-checking grounded in specific authoritative datasets — particularly federal grants, SEC filings, HUD/Section 8 housing, clinical trials, drug approvals, or insider trading disclosures. It is well-suited for compliance and regulatory verification tasks where the claim can be routed to a known domain. Prefer alternatives for general web-based fact-checking, social media claim verification, or real-time news fact-checking outside these specialized domains.

## Known failure modes

- Missing required 'claim' parameter returns a 400 error
- Claim exceeds 300 character limit and is rejected
- Payment not provided returns HTTP 402 requiring USDC on Base or USDG on Robinhood Chain
- Domain hint does not match available enum values and returns validation error
- Claim falls outside indexed datasets and returns unverified with no source
- Service temporarily unavailable on Render infrastructure returning 503

## How this service works

Pay-per-call crypto, RWA, federal, SEC, Section 8/HUD housing, and compliance APIs via x402. Primary: USDC on Base (eip155:8453). Also accepts Global Dollar (USDG) on Robinhood Chain (eip155:4663) via sovereign X-PAYMENT-TX. Hyphen routes only (e.g. /x402/gas-tracker, /x402/pha-lookup, /x402/sec-8k). MARKETPLACE REVIEW: use free /x402/playground/* (no key, no payment). Production /x402/* returns 402 unless paid via x402 or X-Api-Market-Key / X-API-Key from seller dashboard.

## Output

Returns a structured fact-check result indicating whether the claim is supported, refuted, or unverified, along with the relevant data source, confidence level, and any supporting evidence or citations found in federal, SEC, drug, healthcare, or housing datasets.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "claim"
     ],
     "properties": {
      "claim": {
       "type": "string",
       "description": "The claim or statement to fact-check (required, max 300 chars)."
      },
      "domain": {
       "enum": [
        "grants",
        "contracts",
        "drug",
        "provider",
        "insider",
        "yields",
        "clinical",
        "general"
       ],
       "type": "string",
       "description": "Hint to route to the correct data source (optional — auto-detected)."
      }
     }
    }
   }
  },
  "output": {
   "properties": {
    "example": {}
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "example": {}
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/scriptmasterlabs-fact-check-api-a0a8fe3b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from mcp-x402-discovery.onrender.com](https://www.zero.xyz/host/mcp-x402-discovery.onrender.com/llms.txt)