Shopify product CSV import check: POST raw CSV, get JSON issue report (duplicate SKUs, missing titles/handles, malformed prices, bad image URLs) plus cleaned import-ready CSV. Up to 1,000 rows, deterministic.

GET /v1/csv-check costs $0.03 per call in USDC on Base, paid with the x402 protocol. Call it with any x402 client; an unpaid request returns HTTP 402 with the payment details.