# CAPI2 Momentum Foundry – Claim Verify

> CAPI2 Momentum Foundry – Claim Verify is a paid API for AI agents from capi2-foundry.vandurmedries.workers.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-11).

Verifies a textual claim against buyer-supplied web pages and returns a confidence score, matched evidence excerpts, and a cryptographic delivery receipt after x402 micropayment settlement.

## Facts

- Endpoint: POST https://capi2-foundry.vandurmedries.workers.dev/v1/products/claim-verify/run?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/capi2-momentum-foundry-claim-verify-a9247ec5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_8mvdZKYIM-gozmN66QP2U

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-momentum-foundry-claim-verify-a9247ec5 -d '<json body>'
```

Example prompt: Can you verify the claim 'customer data is encrypted at rest' against these two pages: https://example.com/security and https://example.com/privacy-policy — and tell me how confident you are that the pages actually support it?

## When to prefer this

Choose this endpoint when you need a lexical, evidence-grounded verification of a specific textual claim against a small set of known, buyer-supplied URLs, and require a cryptographic delivery receipt for auditability. It is best suited for procurement due diligence, compliance assertion checking, or marketing copy validation where the evidence pages are already known. Prefer alternatives if you need open-web search, semantic/NLI-based entailment, or verification against more than three sources.

## Known failure modes

- Invalid or unreachable source_urls cause evidence fetch failures, resulting in empty evidence array and low confidence
- Claim string below 3 or above 1200 characters returns schema validation error
- Payment settlement failure via x402 protocol blocks delivery entirely
- Provided URLs are behind authentication or paywalls, returning no extractable evidence
- Claim terms too generic or too sparse to match any page content, yielding near-zero confidence
- More than 3 source_urls supplied triggers schema rejection
- Non-HTTPS URLs rejected at input validation

## How this service works

Paid agent utilities delivered after verified x402 settlement.

## Output

Returns a JSON object containing: verification_status (e.g. 'supported'), a confidence score (0–1), an array of evidence objects each with the source URL, a text excerpt, coverage score, and matched terms, plus the extracted claim_terms, a limitation disclaimer, and a signed deliveryReceipt with payer address, receipt ID, timestamps, input/result SHA-256 hashes, and amount paid in atomic units.

## 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",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "required": [
      "claim",
      "source_urls"
     ],
     "properties": {
      "claim": {
       "type": "string",
       "maxLength": 1200,
       "minLength": 3,
       "description": "Precise statement to verify"
      },
      "source_urls": {
       "type": "array",
       "items": {
        "type": "string",
        "format": "uri"
       },
       "maxItems": 3,
       "minItems": 1,
       "description": "Public HTTPS evidence pages supplied by the buyer"
      }
     },
     "additionalProperties": false
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "errors": [],
   "product": "claim-verify",
   "evidence": [
    {
     "excerpt": "Example evidence excerpt containing the matched claim terms.",
     "coverage": 0.8,
     "source_url": "https://example.com/security",
     "matched_terms": [
      "customer",
      "data",
      "encrypted"
     ]
    }
   ],
   "confidence": 0.8,
   "limitation": "Lexical evidence coverage; buyer remains responsible for source authority and final decisions.",
   "claim_terms": [
    "customer",
    "data",
    "encrypted",
    "rest"
   ],
   "verification_status": "supported"
  },
  "createdAt": "2026-09-23T00:00:00.000Z",
  "productId": "claim-verify",
  "deliveryReceipt": {
   "payer": "0x0000000000000000000000000000000000000000",
   "productId": "claim-verify",
   "receiptId": "00000000-0000-4000-8000-000000000000",
   "deliveredAt": "2026-09-23T00:00:00.000Z",
   "inputSha256": "example-input-sha256",
   "amountAtomic": "10000",
   "resultSha256": "example-result-sha256",
   "signatureSha256": "example-signature-sha256"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/capi2-momentum-foundry-claim-verify-a9247ec5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from capi2-foundry.vandurmedries.workers.dev](https://www.zero.xyz/host/capi2-foundry.vandurmedries.workers.dev/llms.txt)