MCP server · operational

QRCode.Pub tools

Generate QR code images (free) and, pay-per-call via x402 (USDC on Base or Solana, no API key): web page to Markdown, page metadata (OpenGraph/JSON-LD), host a file at a public URL for 30 days.

Stateless Streamable HTTP MCP server at POST https://qrcode.pub/mcp (also listed in the official MCP registry as pub.qrcode/tools). Tools: qr_code (free; returns an MCP image block plus a permanent https://qrcode.pub/api/qr URL), page_to_markdown ($0.01; title, description, clean Markdown, links; deterministic, no model call), page_metadata ($0.005; title, canonical URL, language, OpenGraph/Twitter tags, icons, JSON-LD), host_file ($0.01; up to 5 MB png/jpeg/webp/gif/pdf/json/txt/md/csv, served at https://qrcode.pub/f/<id> for 30 days with a delete token). Paid tools use x402 v2: call without the payment argument to receive the 402 payment requirements in structuredContent.paymentRequired, sign an exact-scheme USDC payment (eip155:8453 or solana mainnet, PayAI facilitator), retry with payment=<base64 PAYMENT-SIGNATURE>. Failed requests (4xx) are never charged. Same tools are available as plain HTTP at https://qrcode.pub/x402/* (OpenAPI: https://qrcode.pub/openapi.json).

endpoint: https://qrcode.pub/mcp
auth: none
try it: tested example call
curl -s -X POST https://qrcode.pub/mcp -H 'content-type: application/json' -H 'accept: application/json, text/event-stream' -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"qr_code","arguments":{"text":"https://example.com","format":"svg"}}}'
capabilities: generate-qr-code · convert-page-to-markdown · extract-page-links · extract-page-metadata · extract-opengraph-tags · extract-json-ld · host-file · upload-file · pay-per-call-x402
tags: qr-code · web-scraping · file-hosting · x402 · payments
pricing: qr_code free; page_metadata $0.005, page_to_markdown $0.01, host_file $0.01 per call via x402 (USDC)
i/o: application/json (JSON-RPC 2.0, Streamable HTTP) → application/json (MCP content blocks; image/png or image/svg+xml for QR codes)
docs: https://qrcode.pub/qr-code-api#mcp
machine-readable: /api/public/registry/qrcode-pub-tools-mcp

Get a key in one call

No account, no email, no dashboard

100 calls/day anonymous · 1,000/day with this free key · 50,000/day on Agent Pro. The key is returned instantly in the response — send it as the x-api-key header on any /api/public/* request.

tested example call

curl -s -X POST https://agentnexus.app/api/public/keys \
  -H 'content-type: application/json' \
  -d '{"agent":"my-agent","purpose":"tool discovery"}'

Use it from your agent

Point any MCP-capable agent (Claude, Cursor, your own) at the no-auth endpoint — it can then find QRCode.Pub tools and the rest of the registry on its own:

tested example call

claude mcp add --transport http agent-nexus https://agentnexus.app/api/public/mcp

Agents can discover QRCode.Pub tools through the Agent Nexus MCP server, /llms.txt or the discovery API.