x402check HTTP 402 Deep Audit: Coming Soon
Free x402 readiness checker

Is your endpoint ready for x402 agent payments?

Inspect any URL for HTTP 402 compliance, payment payload structure, accepted networks, and receiving addresses.

Tip: test the exact paid endpoint URL — x402 usually gates specific API routes, not the homepage.

Sample report Example
https://astra-x402-data.astratc.workers.dev/v1/coin?id=bitcoin
x402 Ready — Compliant HTTP 402 Endpoint
READY · HTTP 402 · 6/6 checks passed
  • Endpoint is reachablepass
  • Served over HTTPSpass
  • Asks for payment (HTTP 402)pass
  • Carries an x402 payment challengepass
  • Payment options are completepass
  • Networks are recognizedpass
schemeexact
networkbase
maxAmountRequired10000
asset0x833589fC…bdA02913
payTo0x1A7Dc267…57c9b865

Sample report shown for illustration — values from a real check of the public endpoint above. Run a check to inspect your own URL.

Probing endpoint for HTTP 402 payment requirements...
STATUS

How It Works

  1. 01. Enter an endpoint: Paste any public webpage or API URL you want to inspect.
  2. 02. Simulate an unauthenticated request: Our probe sends a standard HTTP request and captures the status headers and raw response body.
  3. 03. Review your readiness report: See which x402 fields pass validation, which networks and assets are advertised, and what needs fixing.

What We Check

Endpoint Reachability

Verifies that the target host resolves via DNS and responds within standard timeout limits.

HTTPS Transport

Confirms the endpoint is served over TLS (https://). Plain HTTP still gets checked, but unencrypted transport raises a security warning (warn) — payment details should not travel in the clear.

HTTP 402 Status Code

Checks whether the endpoint asks unauthenticated clients for payment: an explicit 402 Payment Required status code, or — in x402 v2 — a PAYMENT-REQUIRED response header.

Payment Requirements Envelope

Validates the x402 payment challenge against the schema, including x402Version and required fields — carried in the JSON response body in v1, or in the base64-encoded PAYMENT-REQUIRED header in v2.

Payment Options Completeness

Checks that every option in the accepts array is fully specified — scheme, network, amount, payTo, and asset all present — so an agent can actually pick one and pay.

Supported Networks

Identifies the network declared by each payment option — plain chain names in v1 (such as base) and CAIP-2 identifiers in v2 (such as eip155:8453). A network we do not recognize is flagged with a warning.

FAQ

What is the x402 protocol?

x402 is an open payment standard built around the native HTTP 402 Payment Required status code, enabling AI agents and automated clients to pay for API calls and web resources programmatically. Following Mastercard's October 20, 2026 announcement adding x402 support to Agent Pay, standardizing 402 responses allows endpoints to accept machine-to-machine payments seamlessly.

Is x402check free to use?

Yes, running single-URL readiness checks and inspecting parsed payment parameters is completely free. Deep-dive multi-endpoint audits, automated monitoring, and transaction simulation reports are coming soon.

Why does my URL return "Not Detected"?

A not_detected result means your server responded normally (typically with HTTP 200 OK, 401 Unauthorized, or 403 Forbidden) rather than 402 Payment Required (or a PAYMENT-REQUIRED response header). If your x402 middleware only triggers on specific API routes or requires certain request headers, make sure you test the exact gated endpoint URL.

Which blockchain networks and tokens are supported?

x402check displays whatever networks and token contracts your endpoint advertises in its accepts array — there is no hardcoded list. We recognize the standard plain chain names used in x402 v1 and the CAIP-2 network identifiers used in v2; a network string we do not recognize is flagged with a warning, but it does not fail the check on its own.