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CAPI2 Momentum Foundry – Claim Verify
x402
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.
Price / call$0.01
Success—
StatusUnknown
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.
Example use cases
Verify vendor security claims before procurement
“I need to check whether the claim 'all data is encrypted in transit and at rest' is actually supported by this vendor's documentation pages — https://vendor.com/security and https://vendor.com/compliance. Give me the confidence score and any evidence excerpts you find.”
Fact-check product marketing statement
“Our marketing team wrote 'our platform achieves 99.9% uptime guaranteed by SLA.' Can you verify that claim against https://status.ourproduct.com and https://ourproduct.com/sla and let me know if the language actually appears there with a confidence reading?”
Validate regulatory compliance assertion
“We're claiming 'the service is GDPR-compliant and user data is never sold to third parties' in a press release — please check that against https://oursite.com/privacy and https://oursite.com/terms and tell me how well the evidence supports that statement.”
Technical details
Endpoint
POSThttps://capi2-foundry.vandurmedries.workers.dev/v1/products/claim-verify/run?utm_source=zero.xyzWhen to prefer
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.
Side effects
- 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
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"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"
}
}
}Tags
x402
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