Qr Generator API — Pay Per Call with USDC on Base

qr_generator API

Generate a QR code or barcode as an image (SVG or PNG). Symbologies: qrcode/qr, code128, code39, ean13, ean8, upca, upce, isbn10, isbn13, issn, itf, gs1-128, databar. Part of the x402 Gateway — $0.002 per call, settled in USDC on Base. No accounts, no API keys: agents pay per request via the x402 protocol.

How payment works

Send a POST to https://x402.freeq.one/tools/qr_generator without a payment header and the API replies 402 Payment Required with an x402 challenge (payTo address, USDC amount, Base network). A paying agent signs the USDC payment and retries with the PAYMENT-SIGNATURE header (base64 JSON payment payload) — settlement is verified on-chain in seconds and the API response returns with a PAYMENT-RESPONSE receipt header.

Example call

curl -X POST https://x402.freeq.one/tools/qr_generator \
  -H "Content-Type: application/json" \
  -d '{"format": "qrcode", "data": "https://x402.freeq.one"}'

Browse every pay-per-call API on the all APIs page, or inspect the machine-readable service card and OpenAPI spec.