QR code

Returns JSON with a QR code for your text or URL as SVG markup and an SVG data URL, with error correction level and border options, generated by the uqr library.

Use this when you need a qr code generator for a URL, text, Wi-Fi or payment link as an SVG image.

Do not use for reading or decoding an existing QR code, logos, colored codes or PNG output.

Price: 0.004 USDC per call (x402, eip155:8453). Typical response time: 500 ms (p95).

Call it over HTTP (x402)

POST https://x402-gateway.blackwoodstate8.workers.dev/v1/qr-code. A request without payment gets 402 Payment Required with the PAYMENT-REQUIRED header; any x402 client signs an EIP-3009 authorization and retries with PAYMENT-SIGNATURE (or X-PAYMENT). Invalid input is answered with 400 and not charged.

curl -i -X POST https://x402-gateway.blackwoodstate8.workers.dev/v1/qr-code -H 'content-type: application/json' -d '{"text":"https://x402-gateway.blackwoodstate8.workers.dev","ecc":"M"}'
Pay to0xbD2cf002490E99124156baee307FBd5FDF5e57A7
Asset0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 (USDC)
Amount4000 atomic units (0.004 USDC)
Authorization window60 s

Call it over MCP

Streamable HTTP at https://x402-gateway.blackwoodstate8.workers.dev/mcp, tool blackwood_qrcode_generate. Payment goes in _meta["x402/payment"]; without it the tool returns the payment requirements.

Input

FieldTypeMeaning
textstringText or URL to encode, e.g. https://example.com (up to 2000 characters)
ecc (optional)stringError correction level: L 7%, M 15% (default), Q 25%, H 30%
border (optional)integerQuiet zone around the code, in modules (default 2)
pixelSize (optional)integerSVG units per module (default 10)

Example:

{
  "text": "https://x402-gateway.blackwoodstate8.workers.dev",
  "ecc": "M"
}

Output

Real example:

{
  "svg": "<svg xmlns=\"http://www.w3.org/2000/svg\" viewBox=\"0 0 370 370\"><r...(10900 characters)",
  "dataUrl": "data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcm...(14562 characters)",
  "version": 4,
  "modules": 37,
  "ecc": "M",
  "bytes": 10900
}
JSON Schema
{
  "type": "object",
  "properties": {
    "svg": {
      "type": "string"
    },
    "dataUrl": {
      "type": "string"
    },
    "version": {
      "type": "number"
    },
    "modules": {
      "type": "number"
    },
    "ecc": {
      "type": "string"
    },
    "bytes": {
      "type": "number"
    }
  },
  "required": [
    "svg",
    "dataUrl",
    "version",
    "modules",
    "ecc",
    "bytes"
  ],
  "additionalProperties": false
}

More

Free schema and example: GET https://x402-gateway.blackwoodstate8.workers.dev/v1/qr-code. OpenAPI 3.1 · llms.txt · All services