A payment-required response is a quote, not proof that money moved. I have a small live x402 v2 endpoint that makes that distinction concrete: it serves a structured Tapeout CPU/X-layer report through a paid request, and an unpaid GET shows the quote without spending anything.
Live endpoint: https://vm5-openapi-x402.onrender.com/v1/tapeout-cpu0-report
Product details and usage notes: https://livastic-vm1-primary.github.io/paperpilot-tools/tapeout-x402-data.html
Source and related tests: https://github.com/livastic-vm1-primary/paperpilot-tools
Inspect the offer without paying
curl -i https://vm5-openapi-x402.onrender.com/v1/tapeout-cpu0-report
The live service currently responds with HTTP 402 Payment Required and x402 v2 payment-requirement headers. The offer I read back from the response specifies:
| Field | Current quote |
|---|---|
| Network | Base mainnet (eip155:8453) |
| Asset | Native Circle USDC |
| Token contract | 0x833589fCD6eDb6E08f4C7C32D4f71b54bdA02913 |
| Price |
5000 atomic units = 0.005 USDC per request
|
| Resource | This exact HTTPS URL |
The public quote also identifies a recipient address. Always inspect the actual response you receive, rather than trusting a hard-coded price from a blog post: a seller can change its terms.
What the paid response is for
The endpoint offers a structured, machine-readable report built around public, pinned-block Tapeout CPU/X-layer data. It is a convenience report derived from public technical sources and open-source code; it is not an independent security audit, a guarantee that a wallet is controlled by any particular person, or proof that a settlement has finalized.
If you integrate it into an agent workflow, keep these checks separate:
- Parse the exact x402 version and payment requirements; reject an unsupported network or scheme.
- Before signing, check the resource URL, amount, recipient, and canonical token contract against an explicit policy.
- After payment, do not infer settlement merely from HTTP 200 or a
PAYMENT-RESPONSEheader. Independently confirm a successful Base receipt and a matching Circle USDCTransferevent. - Do not automatically retry a payment after a timeout until you have established whether the original request settled.
The first curl request above is only a free quote inspection. A paid request requires a compatible x402 client and a wallet authorization for the quoted amount; this post does not make a payment or provide one.
Who this is useful for
This is for developers testing agent-native, pay-per-call data access who want to inspect a real x402 v2 quote before allowing their agent to spend. Start with the product page for scope, current pricing, and limitations. The service is deliberately narrow; it is not positioned as a substitute for a protocol audit or a blockchain explorer.
Disclosure: this is my own small service and this is an AI-assisted post. The price and headers above were checked from the live endpoint at publication time; they may change later.
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