The QR code API for codes that outlive the print run

Most searches for a QR code API are looking for something simpler than this, and sending you to the wrong tool would waste your afternoon. Here is the honest fork.

Create the code, print short_url, change the destination when the season changes, read the scans. That is the entire lifecycle, in every language we ship a client for.

export QRFLOW_KEY=qrf_live_...   # from Account › API keys

# 1. Who am I, what can this key do?
curl https://qrflow.codes/api/v1/me -H "Authorization: Bearer $QRFLOW_KEY"

# 2. Make a dynamic code. Print what comes back as short_url.
curl -X POST https://qrflow.codes/api/v1/codes \
  -H "Authorization: Bearer $QRFLOW_KEY" -H "Content-Type: application/json" \
  -d '{ "type": "url", "destination_data": { "url": "https://example.com/menu" }, "label": "Table tents" }'

# 3. The print-ready image (SVG, with your colors and frame).
curl "https://qrflow.codes/api/v1/codes/$CODE_ID/image.svg?size=1024" \
  -H "Authorization: Bearer $QRFLOW_KEY" -o menu.svg

# 4. Fall menu. The printed code keeps working.
curl -X PATCH https://qrflow.codes/api/v1/codes/$CODE_ID \
  -H "Authorization: Bearer $QRFLOW_KEY" -H "Content-Type: application/json" \
  -d '{ "destination_data": { "url": "https://example.com/menu-fall" } }'

# 5. How did it do?
curl "https://qrflow.codes/api/v1/codes/$CODE_ID/scans?group=day" -H "Authorization: Bearer $QRFLOW_KEY"

// npm install qrflow   (zero dependencies; ESM + CommonJS; full types)
import { QRFlow, QRFlowError } from "qrflow";

const qr = new QRFlow(process.env.QRFLOW_KEY!);

const { code } = await qr.createCode({
  type: "url",
  destination_data: { url: "https://example.com/menu" },
  label: "Table tents",
});
console.log(code.id, code.short_url);        // save both; print short_url

await qr.updateCode(code.id, { destination_data: { url: "https://example.com/menu-fall" } });

const stats = await qr.scans(code.id, { group: "day" });
console.log(stats.total, stats.rows);         // [{ key: "2026-09-21", scans: 18 }, ...]

try {
  await qr.updateCode(code.id, { slug: "menu" });
} catch (e) {
  if (e instanceof QRFlowError) console.log(e.status, e.code, e.message); // 400 no_domain: connect a domain first
}

# Download https://qrflow.codes/sdk/qrflow.py next to your code.
import os
from qrflow import QRFlow, QRFlowError

qr = QRFlow(os.environ["QRFLOW_KEY"])

code = qr.create_code(type="url", destination_data={"url": "https://example.com/menu"}, label="Table tents")["code"]
print(code["id"], code["short_url"])          # save both; print short_url

qr.update_code(code["id"], destination_data={"url": "https://example.com/menu-fall"})

stats = qr.scans(code["id"], group="day")
print(stats["total"], stats["rows"])

try:
    qr.update_code(code["id"], slug="menu")
except QRFlowError as e:
    print(e.status, e.code, e)                # 400 no_domain: connect a domain first

Twelve of them, plus webhooks. Bearer token, JSON in, JSON out, ordinary HTTP status codes. The full reference has request and response bodies for each, and there is an OpenAPI 3.1 document if you would rather generate a client.

Is there a free QR code API?

Not here, and it is worth being straight about it: our API is part of Business at $29 a month, because what it creates is a code we host and redirect for as long as it is printed. If all you need is an image of a string, you do not need an API at all. A library in your own code (qrcode on npm, qrcode in Python, or the same in any language) renders one offline, forever, for nothing.

What does the API do that a QR code library cannot?

A library draws a picture of whatever string you hand it, and that string is fixed the moment it is printed. This API creates a code whose destination lives on our side: you change where it points after it is on a thousand boxes, you see every scan by day, device and city, you print it on your own domain, and you get a webhook when something happens. If none of that matters, use the library.

Do I need an API key to use it from Claude or ChatGPT?

No, and this is the one part that is not Business-only. The MCP server at https://qrflow.codes/mcp authenticates with a normal sign-in, so an assistant can create and edit codes on any plan, including Free, within that plan's limits. API keys are the server-to-server route and stay on Business.

Where did Google's chart.googleapis.com QR endpoint go?

It is gone. The Image Charts endpoint was deprecated years ago and now answers 404 for QR requests (we checked in September 2026), and Google Charts, the JavaScript library that replaced it, does not draw QR codes at all. If you were using it for a plain image, a local library is the honest replacement. If the reason you wanted a hosted endpoint was that the destination might change, that is what this API is for.

What are the rate limits?

600 requests a minute per key. Past that you get a 429 with a Retry-After header, which the official clients respect. Ten keys and ten webhooks per account, 25,000 saved codes under fair use, and scan analytics in windows of up to 92 days.

Can I call it from the browser?

No, on purpose. The API refuses browser origins, because a key in front-end code is a key anyone can read and use to repoint your printed codes. Call it from your server, your worker or your build step, and keep the key in an environment variable.

Which languages are supported?

There is an official TypeScript client on npm (npm install qrflow, zero dependencies, ESM and CommonJS) and a single-file Python client. Everything else is plain REST over HTTPS with JSON, described by an OpenAPI 3.1 document you can point a generator at.

What happens to my codes if I stop paying?

Nothing is deleted. Keys and webhooks keep working for 30 days after you leave Business, then answer 402; codes already created keep redirecting, and the scan counter keeps running. Printed codes do not die because of a billing change.