# capi2 Claim Verify

> capi2 Claim Verify is a paid API for AI agents from capi2-claim-verify.onrender.com, paid per call via x402, $0.01/call, status down (last checked 2026-09-15).

Verifies a text claim against one or more public evidence URLs and returns a structured verdict with confidence score and supporting evidence.

## Facts

- Endpoint: POST https://capi2-claim-verify.onrender.com/v1/data-clause-check
- Price: $0.01/call
- Payment: x402
- Status: down
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/capi2-claim-verify-0c1fcfc9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_TpgrvmO9wKD8zJeia59uu

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 capi2-claim-verify-0c1fcfc9 -d '<json body>'
```

Example prompt: Can you verify the claim 'Acme Corp encrypts all customer data at rest and in transit' against their security page at https://acmecorp.com/security — I need to know if it's actually supported by what's on that page.

## When to prefer this

Choose this endpoint when an AI agent needs to programmatically verify whether a specific textual claim (security, compliance, commercial, or product) is supported by publicly accessible evidence at one or more URLs, especially in vendor due diligence, procurement, or trust-verification workflows. It is particularly well suited for agent pipelines that need structured, machine-readable verdicts with confidence scores rather than a freeform web search summary. Prefer it over general web search when you need a formal SUPPORTED/UNSUPPORTED verdict with evidence citations and caveats.

## Known failure modes

- Source URL is inaccessible, paywalled, or returns a non-200 response — result will reflect limited or no evidence
- Claim is too vague or ambiguous for the evidence extractor to match against source content
- Source page content does not contain language relevant to the claim, yielding low confidence or UNSUPPORTED verdict
- Claim text exceeds 1200 characters or is fewer than 3 characters — request rejected with validation error
- More than 3 source URLs provided — request rejected
- Payment failure via x402 micropayment protocol — call blocked before processing
- Rate limits or rendering host cold-start delays on onrender.com may cause timeouts

## How this service works

Agent-native evidence-backed claim verification with x402 micropayments on Base USDC.

## Output

Returns a JSON object containing a verdict label (e.g. SUPPORTED_BY_SUPPLIED_SOURCE, UNSUPPORTED, INCONCLUSIVE), a confidence score (0–1), an array of evidence snippets with text and per-snippet scores, an evidence summary string, the verification status, caveats about limitations, the timestamp of the check, a unique request ID, and the final URLs that were fetched and checked.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "claim": {
   "type": "string",
   "maxLength": 1200,
   "minLength": 3,
   "description": "Vendor, product, compliance, security, or commercial claim to verify."
  },
  "claim_id": {
   "type": "string",
   "maxLength": 200
  },
  "vendor_url": {
   "type": "string",
   "format": "uri",
   "description": "Public source URL containing evidence relevant to the claim."
  },
  "source_urls": {
   "type": "array",
   "items": {
    "type": "string",
    "format": "uri"
   },
   "maxItems": 3,
   "minItems": 1,
   "description": "Optional list of up to three public evidence URLs. These are checked together; vendor_url remains supported for backward compatibility.",
   "uniqueItems": true
  },
  "vendor_name": {
   "type": "string",
   "maxLength": 200
  },
  "request_type": {
   "type": "string",
   "maxLength": 120
  },
  "verification_type": {
   "type": "string",
   "maxLength": 120
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "claim": "Vendor states that customer data is encrypted at rest.",
  "caveats": [
   "Checks only the supplied public URL."
  ],
  "verdict": "SUPPORTED_BY_SUPPLIED_SOURCE",
  "evidence": [
   {
    "text": "Customer data is encrypted at rest.",
    "score": 0.9,
    "source_url": "https://example.com/security"
   }
  ],
  "protocol": "capi2.claim_verify/1.6.1",
  "checked_at": "2026-08-26T15:00:00Z",
  "confidence": 0.88,
  "request_id": "cv_018f5f8f0c2b4f7a",
  "vendor_url": "https://example.com/security",
  "source_results": [
   {
    "status": "checked",
    "final_url": "https://example.com/security",
    "requested_url": "https://example.com/security"
   }
  ],
  "sources_checked": 1,
  "evidence_summary": "Customer data is encrypted at rest.",
  "verification_result": "supported",
  "verification_status": "supported",
  "evidence_source_urls": [
   "https://example.com/security"
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/capi2-claim-verify-0c1fcfc9/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from capi2-claim-verify.onrender.com](https://www.zero.xyz/host/capi2-claim-verify.onrender.com/llms.txt)