How to check whether an x402 endpoint actually settles payment

Disclosure: We built YourAITools and its x402 endpoint checker.

A valid HTTP 402 response tells a buyer how to pay. It does not prove that the payment will settle or that the paid request will return useful data. Here is how to separate those checks.

1. Inspect the unpaid response

Open https://youraitools.co/verify-endpoint and paste your paid HTTPS route.

The free checker requests the endpoint without paying and reports its grade, payment versions, networks and price. No wallet or signup is required.

For a reproducible free example, I tested:

curl --get 'https://api.youraitools.co/x402fix/v1/preview' \
  --data-urlencode 'url=https://api.youraitools.co/toolfit/v1/lite'

That request returned HTTP 200 during this check. It inspects the target's unpaid response; it does not purchase the target API call.

2. Read the actual payment requirements

Check the scheme, network, asset, amount, pay-to address and resource, not just the grade.

The page also accepts a raw 402 JSON body or a base64 PAYMENT-REQUIRED header value. According to the page, that paste parser runs entirely in your browser.

If your browser cannot read the target response because of CORS, the server-side grade can still work. Use the raw response and paste parser to inspect the terms.

3. Separate settlement evidence from a good grade

The free checker cannot establish end-to-end settlement.

For that, look for evidence connecting the payment requirements, accepted payment, successful paid response and settlement transaction. Check that the transaction's network and details match the request being tested.

Our public example report is available at https://api.youraitools.co/x402fix/v1/settle-check. It records a successful paid request against our own endpoint and links its settlement transaction. It is an example report, not proof about your endpoint and not a purchase endpoint.

4. If needed, request a manually fulfilled check

The live verify-endpoint page offers a $19 verified settlement check. This is a manual service, not an instant automated checkout.

The published process is to email [e-mail] with your HTTPS endpoint and GET or POST method, pay in native USDC on Base or Solana using the instructions on the page, and email the transaction link.

The stated deliverable is a dated report covering the request, 402 response, settlement transaction and result. A failed check includes one free re-test within 30 days.

We did not purchase or perform a new settlement test for this tutorial.

What passing does not mean

Both checks are point-in-time technical checks, not endorsements. They do not establish data quality, ongoing uptime, security or business legitimacy, and they do not change YourAITools rankings.

Start with the free check: https://youraitools.co/verify-endpoint