QR Codes That Never Expire

What it does

QR Codes That Never Expire turns ONE piece of text, ONE web link or ONE stamp id into a QR code you can print or place on a page, as SVG and PNG. The code is static: the text is in the pattern itself, so scanning it never goes through an LLPRO server, nothing can be switched off, there is nothing to renew and nobody counts the scans. A link code is refused if the link points at a private or local address or the host name does not exist; that is an address check, not a check for phishing or malware. A stamp code opens the Countersign verify page of that stamp, so a printed code can prove what it points to. Every answer is dated and signed with our key; anyone can check the signature at the stamp page. We keep no copy of your text. No model, no styling, no logos, no tracking, no short links.

Who it is for

Agents and people who need a code for a menu, a poster, a shelf label, a business card, a document or a stamp, and do not want it to stop working when a free trial or a subscription ends.

Price

Free, no sign-up, no expiry: 500 codes a day per address. Paid calls are not offered.

Limits

Up to 300 characters; at most 271 bytes at error level L, 213 at M, 151 at Q, 119 at H. Static: a printed code cannot be edited. The link check looks at the address once, when the code is made (public address, ports 80/443, the name resolves); it is not a phishing or malware check. Text that would call, message, join Wi-Fi, add a contact or run something is refused. A stamp code lasts as long as countersign.llpro.ai. The signed record holds a salted hash of the text (a short text can be guessed from it) and a link's host name. Test-scan every printed code.

How to get one

Ask your own agent: it sends the text or link and gets back the picture files and a signed note. A stamp code (cs_ id) prints a pattern that opens that stamp's public verify page.

For developers: try it

POST https://llpro.ai/mcp
{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"qr_code_make","arguments":{"url":"https://llpro.ai/","ec_level":"M","format":"both"}}}
-> svg and png_base64 of the code, modules, version, hashes of both files, a signed observation, receipt, stamp link. Also accepts {"text": "..."} or {"stamp_id": "cs_..."}.

For agents

Tool qr_code_make on https://llpro.ai/mcp and in the tools list. Signed answers are checked with the public key below (signer llpro1:lnxnhq5wgg2lp35qxpbmjoyvfm): an Ed25519 signature over the observation as canonical JSON (sorted keys, no spaces).

Public key (base64): dtsaUovptT+v5Yzjog937+7Jlj3wsr1hqX/kTurQG1s=

This tool exists to be found by agents that search MCP registries for a QR code generator (road: MCP registries, through the Campus gateway: MCP, Agent2Agent and REST). It gives one signed, checkable answer per call; keep the signed observation with your work so a person can see what was made and when. How a stamp is checked: https://llpro.ai/stamp

Next

• Connect your agent: Use this and the other LLPRO tools from your own agent.
• Get your agent: No agent yet? Get one that asks first.
• Hand the whole job to the Hub: A code is one part. Tell the Hub the job (a printed menu, a poster, a labelled shelf); it routes you to the right tools.

For agents: this page as Markdown · JSON · llms.txt · MCP endpoint llpro.ai/mcp · agent card