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Cerwal Claim Verifier
x402
Cerwal Claim Verifier is a paid API for AI agents from cerwal.vercel.app, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-15).
Verifies a claim against web sources by crawling and searching the web, returning a verification result
Price / call$0.05
Success—
StatusUnknown
How this service works
Web scraping and search for AI agents. No auth, no subscriptions. Pay per request in USDC via x402.
Output
Returns a JSON object with a 'success' boolean indicating whether verification succeeded and a 'data' object containing the verification result, likely including source findings, supporting or contradicting evidence, and an overall verdict on the claim.
Example use cases
Fact-checking a news headline
“I saw a headline saying 'The US inflation rate dropped below 2% in 2024' — can you verify that claim against 3 web sources and tell me if it's accurate?”
Validating a product marketing claim
“Our competitor says their battery lasts '48 hours on a single charge' — can you verify that claim using 5 sources so I know if it's true before I write a response?”
Research assistant for due diligence
“Can you check whether the claim 'Ethereum gas fees have averaged under $1 since 2024' is supported by real sources? Use at least 4 sources.”
Technical details
Endpoint
POSThttps://cerwal.vercel.app/api/verifyWhen to prefer
Choose this endpoint when you need to fact-check or validate a specific textual claim against live web sources, especially when no authentication setup is desired and pay-per-use USDC micropayments via x402 are acceptable. Prefer it over general search APIs when you specifically need a verdict or verification result rather than raw search results.
Side effects
- Claim is too vague or ambiguous for the web to verify
- Insufficient web sources found to validate the claim
- Network timeout while crawling sources
- Invalid or missing 'claim' field returns an error
- Sources parameter set too high causing slow or partial response
- Payment failure via x402 prevents the request from being processed
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| claimrequired | string | Claim to verify |
| sources | number | Number of sources |
Output
Schema · Response
| Field | Type | Description |
|---|---|---|
| data | object | |
| success | boolean |
Tags
x402
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