# QRCode.Pub

> Free QR code generator plus small pay-per-call web tools for AI agents: QR images, web page to Markdown, page metadata, 30-day file hosting. No account, no API key. Paid calls cost $0.005–$0.01 in USDC via HTTP 402 (x402 on Base or Solana, or MPP on Tempo); nothing is charged for a 4xx answer.

## Agent endpoints

- [Catalog with prices and input schemas](https://qrcode.pub/x402): also served at https://qrcode.pub/.well-known/x402
- [OpenAPI 3.1 discovery document](https://qrcode.pub/openapi.json): every endpoint, parameters and x-payment-info
- [Free QR code image](https://qrcode.pub/api/qr?data=hello): GET /api/qr?data=…&size=300&format=png|svg (rate-limited)
- [Paid QR code image, $0.005](https://qrcode.pub/x402/qr?data=hello): GET /x402/qr?data=…&size=&format=&ecc=&margin=&color=&bgcolor=
- [Web page to Markdown, $0.01](https://qrcode.pub/x402/extract?url=https://example.com): GET /x402/extract?url=… → title, Markdown, links
- [Web page metadata, $0.005](https://qrcode.pub/x402/meta?url=https://example.com): GET /x402/meta?url=… → OpenGraph, Twitter, icons, JSON-LD
- [Host a file for 30 days, $0.01](https://qrcode.pub/x402/store): POST /x402/store with raw bytes (image, PDF, text, JSON, …) → public URL https://qrcode.pub/f/{id}; DELETE /x402/store/{id} with the returned Bearer token

## Paying

- [x402](https://x402.org): send PAYMENT-SIGNATURE (USDC on Base eip155:8453 or Solana mainnet) in response to the 402; the receipt comes back in PAYMENT-RESPONSE
- [MPP](https://mpp.dev): the same 402 carries WWW-Authenticate: Payment challenges (tempo: USDC.e on Tempo chain 4217; evm: USDC on Base); answer with Authorization: Payment and read Payment-Receipt
- [Validate](https://qrcode.pub/qr-code-api#x402): `npx mppx validate https://qrcode.pub --endpoint GET:/x402/qr --query data=hi`

## MCP and skills

- [Remote MCP server](https://qrcode.pub/mcp): Streamable HTTP, tools qr_code (free), page_to_markdown, page_metadata, host_file; registry name pub.qrcode/tools
- [Stdio bridge](https://github.com/AgentiLoop/qrcode-pub-mcp): `npx -y github:AgentiLoop/qrcode-pub-mcp`
- [Agent Skills](https://qrcode.pub/.well-known/agent-skills/index.json): `npx skills add AgentiLoop/skills`

## Docs

- [API documentation](https://qrcode.pub/qr-code-api): human-readable reference for the free API, x402, MPP, MCP and skills
- [Terms](https://qrcode.pub/terms)
- [Privacy](https://qrcode.pub/privacy)