Buyer-controlled · Base x402

x402 Compatibility Witness

Check a public x402 paid endpoint against known buyer-client contract requirements and buy a full remediation Witness only when ApexScout has a verified finding.

Free preflight · $0.25 only when a verified remediation match exists

Page load makes no target request and executes no payment. The Witness checks contract compatibility, not endpoint quality or commercial success.

Ready. One unpaid GET is made only after you submit.

What the free match checks

Contract

Canonical x402 challenge

HTTP 402, PAYMENT-REQUIRED decoding, header/body parity, version, scheme, network, amount, asset, redacted destination, and timeout.

Client

Buyer compatibility

Known AWAL, generic x402 fetch, Cloudflare Agents, and browser-wallet contract requirements without signing or paying.

Safety

One constrained request

HTTPS only, public DNS only, pinned address, no redirects, five-second timeout, 256 KiB limit, no credentials, cookies, body, or buyer headers.

Paid result

Verified remediation only

The paid route appears only when a finding maps to ApexScout-owned Reliability Ledger evidence. It never makes a second target request.

Public-safe sample

{
  "status": "issues_found",
  "matchId": "awal-latest.invalid-payment-required-response.7f22b81a",
  "compatible": false,
  "issuesFound": 2,
  "fullWitnessAvailable": true,
  "fullWitnessPriceUsd": "0.25",
  "paymentExecuted": false
}

Privacy boundary

Stored

Allowlisted contract findings
Redacted payment destination suffix
Content digest and short-lived match
Aggregate product counters

Never stored or exposed

Raw target body or logs
Full wallet addresses or payment signatures
Buyer identity, IP, session, or cookies
Private keys, API secrets, or authorization headers