qrpaint

A QR code that is also a picture: a lighthouse at sunset, a café awning, your own photograph — with a scannable code painted into it. qrpaint is a thin forwarding client for the hosted QRX service. It serves nine tools locally and passes every call, unchanged, to the service, which paints the picture, checks that it still scans, and hands back a code with its own short link.

Because the painting happens on the hosted service, this package holds no rendering logic of its own. What it does hold is the contract: the exact tool list and schemas from the service's public server card, the session handshake each call travels over, and the rule that nothing is ever sent until an API key is present.

Configuration

• QRX_API_KEY (required for tool calls) — your QRX API key, sent to the hosted endpoint on every request as Authorization: Bearer <key>. Without it, the server still starts and lists its tools, but every call fails with QRX_API_KEY is not set and no request is made.

• QRX_MCP_URL (optional) — the hosted MCP endpoint. Defaults to https://qrx.codes/mcp.

Related MCP server: QR for Agent

Tools

• generate_qr_code — start a new art code from a prompt (what the picture should show) and a destination link, with an optional style from list_styles. Answers at once with the code's id while the picture is painted.

• generate_qr_code_from_image — weave a code into a picture you already have, passed once as an attached image file, a public imageUrl, or imageBase64, plus the destination.

• vary_qr_code — a new code based on an existing code's id, with a change to its picture ("make it night time"). The original is untouched and the new code opens the same destination.

• get_qr_code — a code's status, finished image and short link by id; wait (0–25 seconds, default 25) lets it hold for a code that is still being painted.

• list_qr_codes — your codes, newest first, paged with limit (1–100, default 20) and cursor.

• change_qr_code_destination — retarget an existing link code to a new destination; printed copies follow at once.

• get_account — the connected account's plan and how much of today's code allowance remains.

• get_profile — which QRX account is connected.

• list_styles — the looks you can pass as style to generate_qr_code.

A typical flow is generate_qr_code (or generate_qr_code_from_image), then get_qr_code with the returned id until its status is succeeded — usually under a minute. Codes count against your QRX allowance; get_account shows what is left.

How forwarding works

Each tool call opens a fresh session with the hosted endpoint: an initialize request (protocol version 2025-03-26), the returned session id carried into a notifications/initialized note, then the tools/call request with your arguments exactly as given. Responses arrive as plain JSON or as server-sent events; both are read. The remote result comes back as JSON text. A remote error surfaces with the remote message, a non-2xx reply fails with qrx error: HTTP <status>, and an unreachable endpoint fails with qrx unreachable. Calls are never retried — a retry could paint (and charge) a second code. The handshake is a reconstruction of the standard Streamable HTTP session flow; the endpoint, the Bearer auth and the missing-key behaviour are the original package's documented design.

There is no local argument validation beyond the missing-key rule: the schemas above are served verbatim for your MCP client to validate against, and the service itself is the authority on every call.

CLI

Each tool is a subcommand taking one JSON argument string:

export QRX_API_KEY="<your key>"
npx @reneturcios/qrpaint generate_qr_code '{"prompt":"a lighthouse on a cliff at sunset","destination":"https://example.com/menu"}'
npx @reneturcios/qrpaint get_qr_code '{"id":"abc123"}'
npx @reneturcios/qrpaint list_qr_codes '{"limit":10}'
npx @reneturcios/qrpaint vary_qr_code '{"id":"abc123","change":"make it night time"}'
npx @reneturcios/qrpaint change_qr_code_destination '{"id":"abc123","destination":"https://example.com/new-menu"}'
npx @reneturcios/qrpaint get_account '{}'
npx @reneturcios/qrpaint list_styles '{}'
npx @reneturcios/qrpaint --version

Output is the remote result as JSON text. Exit codes: 0 on success, 1 on an error result (including a missing-key, remote or upstream failure), 2 on a usage error.

MCP server

npx -y @reneturcios/qrpaint mcp

MCP client config (provide the key through the client's environment):

{
  "mcpServers": {
    "qrpaint": {
      "command": "npx",
      "args": ["-y", "@reneturcios/qrpaint", "mcp"],
      "env": {
        "QRX_API_KEY": "<your key>"
      }
    }
  }
}

Docker

docker run -i -e QRX_API_KEY="<your key>" ghcr.io/cloudcorprecords/qrpaint
docker run --rm -e QRX_API_KEY="<your key>" ghcr.io/cloudcorprecords/qrpaint list_styles '{}'

Development

npm install
npm run build   # tsc -> dist/
npm test        # tsx --test test/*.test.ts (fake fetch only, no network)
npm run dev     # run the CLI from source

License

MIT — Copyright (c) 2026 Rene Turcios