ToolVet
77trust / 100

Generate

by Bulk QR Code Generator in Developer tools

x402 APIPassing, checked 4 h ago

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.

POST
https://qr-code-generator.underscoredone.com/generate
Price
$0.01
per call in USDC
Uptime
100%
last 30 days
Response time
303 ms
472 ms slowest 5%
Last check
Passed
4 h ago, next any minute now

Run a free test callHow to call it

Reliability

All checks passedSome failedAll failedNot checked

Status and outage history · Atom feed · Watch with other listings

How to call it

POST https://qr-code-generator.underscoredone.com/generate

Each call costs $0.01 in USDC on Base, paid with the request over x402.

Run a free test callOne unpaid request, the way an agent sends it. You see the payment challenge it gets back. Nothing is charged.

Example request

From the listing.

POST https://qr-code-generator.underscoredone.com/generate
content-type: application/json

{
  "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"
  ]
}

Parameters

ParameterTypeRequiredDescription
error_correctionstringNoHow much damage or dirt the QR code can survive and still scan correctly. Choose L (least tough, smallest code), M, Q, or H (most tough, slightly larger code). Defaults to H, which is best for printed labels or stickers.
sizeintegerNoHow wide (and tall — QR codes are square) the output image should be, measured in pixels. Must be between 100 and 1200. Defaults to 600 if you leave it out.
textsarrayYesThe list of things you want turned into QR codes — website addresses, phone numbers, plain text, WiFi credentials, anything you like. Each entry must be 700 characters or fewer. Empty entries are skipped. At least one real entry is required.

Example response

The provider's example. We can't check it without paying.

{
  "api_version": "1.0.0",
  "count": 2,
  "results": [
    {
      "qr_base64": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAlgAAAJYCAYAAAC+ZpjcAA...",
      "text": "https://example.com"
    },
    {
      "qr_base64": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAlgAAAJYCAYAAAC+ZpjcAA...",
      "text": "Phone: +1-800-555-0199"
    }
  ]
}

Call it from code

The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.01.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://qr-code-generator.underscoredone.com/generate' \
  -H 'content-type: application/json' \
  --data-raw '{"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"]}'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - -X POST 'https://qr-code-generator.underscoredone.com/generate' \
  -H 'content-type: application/json' \
  --data-raw '{"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"]}' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode
JavaScript: pay and call
// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.01 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.01" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.01 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fqr-code-generator.underscoredone.com%2Fgenerate&method=POST
const res = await pay("https://qr-code-generator.underscoredone.com/generate", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "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"
    ]
  }),
});
console.log(res.status, await res.text());
Python: pay and call
# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.01 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.01"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.post(
        "https://qr-code-generator.underscoredone.com/generate",
        json={
            "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",
            ],
        },
    )
    print(res.status_code, res.text)

Security scan

No findings

We scan names, descriptions and tool definitions for hidden instructions and other prompt-injection patterns.

Recent checks

WhenResultHTTPTimePrice
4 h agoPassed402297 ms$0.01
9 h agoPassed402265 ms$0.01
13 h agoPassed402316 ms$0.01
18 h agoPassed402370 ms$0.01
22 h agoPassed402226 ms$0.01
Show 10 older checks
27 h agoPassed402271 ms$0.01
31 h agoPassed402395 ms$0.01
35 h agoPassed402328 ms$0.01
39 h agoPassed402365 ms$0.01
44 h agoPassed402265 ms$0.01
2 days agoPassed402230 ms$0.01
2 days agoPassed402236 ms$0.01
2 days agoPassed402305 ms$0.01
3 days agoPassed402502 ms$0.01
3 days agoPassed402340 ms$0.01