Bulk QR Code Generator

Send a list of texts — website addresses, phone numbers, plain words, WiFi details, anything — and get back a ready-to-use QR code image for each one. Every QR code comes as a base64-encoded PNG you can drop straight into a webpage or save to disk. Great for marketing campaigns, event tickets, product labels, menus, or any situation where you need many QR codes in one go. Empty entries are quietly skipped. Each input is limited to 700 characters. You must send at least one non-empty entry.

Call it in 30 seconds

// npm i x402-fetch viem
import { wrapFetchWithPayment } from "x402-fetch";
import { createWalletClient, http } from "viem";
import { privateKeyToAccount } from "viem/accounts";
import { base } from "viem/chains";

const account = privateKeyToAccount(process.env.PRIVATE_KEY); // funds USDC on Base
const wallet = createWalletClient({ account, chain: base, transport: http() });
const fetchWithPay = wrapFetchWithPayment(fetch, wallet);

// Pays the $0.01 USDC automatically on the 402, then returns the real response:
const res = await fetchWithPay("https://qr-code-generator.underscoredone.com/generate", { method: "POST" });
console.log(await res.json());

# pip install x402 eth-account httpx
import os, asyncio
from eth_account import Account
from x402.clients.httpx import x402HttpxClient

account = Account.from_key(os.environ["PRIVATE_KEY"])  # funds USDC on Base

async def main():
    async with x402HttpxClient(account=account) as client:
        # x402 handles the 402 -> pay ($0.01 USDC) -> retry automatically
        r = await client.get("https://qr-code-generator.underscoredone.com/generate")
        print((await r.aread()).decode())

asyncio.run(main())

# 1) An unpaid request returns HTTP 402 with the exact payment terms:
curl -i -X POST "https://qr-code-generator.underscoredone.com/generate" \
  -H 'content-type: application/json' \
  -d '{"error_correction": "H", "size": 600, "texts": ["https://example.com", "https://example.com/product/42", "WiFi:T:WPA;S:GuestNetwork;P:welcome123;;", "Phone: +1-800-555-0199"]}'

# 2) Paying + retrying requires an x402 client that can sign the USDC
#    authorization (curl alone cannot). See the JS / Python tabs below.

New to x402? Read the 5-minute quickstart →