# Website Claim Checker

> Website Claim Checker is a paid API for AI agents from website-evidence-pack.blissful.chatgpt.site, paid per call via x402, $0.05/call, status unknown (last checked 2026-10-22).

Verifies whether a specific factual claim is supported by evidence found on a given website, returning a verdict and source-linked citations.

## Facts

- Endpoint: POST https://website-evidence-pack.blissful.chatgpt.site/api/x402/website-claim-check?utm_source=zero.xyz
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-22
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/website-claim-checker-91e88397
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_dfFGjm6nD9pJtyXEIa3m7

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 website-claim-checker-91e88397 -d '<json body>'
```

Example prompt: Can you check whether the claim 'This domain is for use in illustrative examples in documents' is actually supported on example.com — I need a verdict and the exact quote from the page as evidence.

## When to prefer this

Choose this endpoint when you need exact, source-linked evidence that a specific claim appears verbatim or near-verbatim on a public website — especially for compliance, due diligence, competitive intelligence, or ad-copy verification. Prefer it over general web search when you need a structured audit trail with direct quotes and page-level citations rather than snippets from a search engine.

## Known failure modes

- Claim not found on the site returns verdict 'unresolved' rather than 'unsupported'
- Paywalled or JavaScript-heavy pages may not be fully audited
- Redirects to unexpected domains result in resolved_url differing from requested_url
- Ambiguous or paraphrased claims may not match exact on-page text, yielding unresolved verdict
- Site blocking crawlers returns empty pages_audited and unresolved verdict

## How this service works

Focused x402 tools for website CRO audits, public company contacts, exact claim evidence checks, and source-linked research. From $0.02 USDC on Base.

## Output

Returns a JSON object containing a verdict ('supported', 'unsupported', or 'unresolved'), an array of citations each with an id, a quoted passage, the source URL, and the page section where the evidence was found, plus the list of pages audited, the resolved URL, the audit timestamp, any limitations, and the schema version.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "format": "uri",
   "maxLength": 2048,
   "description": "Absolute public HTTP(S) homepage URL."
  },
  "claim": {
   "type": "string",
   "maxLength": 500,
   "minLength": 3,
   "description": "Specific business claim to check against first-party website text."
  },
  "max_pages": {
   "type": "integer",
   "default": 4,
   "maximum": 4,
   "minimum": 1,
   "description": "Maximum public same-site HTML pages to inspect."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "claim": "This domain is for use in illustrative examples in documents.",
  "verdict": "supported",
  "citations": [
   {
    "id": "evidence-1",
    "claim": "Published purpose",
    "quote": "This domain is for use in illustrative examples in documents.",
    "source_url": "https://example.com/",
    "page_section": "Main content"
   }
  ],
  "audited_at": "2026-07-21T12:00:00.000Z",
  "limitations": [
   "Support requires an exact first-party quote; absence is unresolved."
  ],
  "resolved_url": "https://example.com/",
  "pages_audited": [
   "https://example.com/"
  ],
  "requested_url": "https://example.com/",
  "schema_version": "2026-07-24"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/website-claim-checker-91e88397/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from website-evidence-pack.blissful.chatgpt.site](https://www.zero.xyz/host/website-evidence-pack.blissful.chatgpt.site/llms.txt)