Add Sumly to a v0 app

v0 builds Next.js apps with the App Router, so Sumly goes into app/layout.tsx as a Script tag. Ask in chat or edit the file in the Code tab, then publish.

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v0one line, every page

Visitors

app/layout.tsx

<html lang="en"> <body>{children}</body> <Script src="…/s.js" data-site="sl_…" /></html>

✓ Changes published First visit/ · from Google

Drawn with an example line.

Step by step

1
In Sumly, open Visitors and copy your project's key, the sl_… in its line.
2
In v0, open the Code tab and add the Script below to app/layout.tsx, then save. Or send the message below in chat.
3
Click Publish, then Publish changes. Open the live app and the visit shows on Visitors.

Next's Script passes data attributes through to the script it adds.

import Script from 'next/script';

export default function RootLayout({ children }: { children: React.ReactNode }) {
  return (
    <html lang="en">
      <body>{children}</body>
      <Script src="https://sumly.dev/s.js" data-site="sl_your_key" />
    </html>
  );
}

Or paste this into v0's chat, with your own key.

In app/layout.tsx, add next/script's Script with src="https://sumly.dev/s.js" and data-site="sl_your_key", once, inside <html> after <body>. Do not change anything else.

Or let your coding assistant do it

Paste this into Claude Code, Cursor or Codex in your project. It fits the code to how your project is built, asks you for the dashboard steps and leaves the keys to you.

See what it says

Set up v0 for Sumly in this project.

Sumly (https://sumly.dev) shows revenue next to the visits and app users it came from. The full guide is https://sumly.dev/install/v0; read it if anything below is unclear.

Steps:
1. In Sumly, open Visitors and copy your project's key, the `sl_…` in its line.
2. In v0, open the Code tab and add the `Script` into Sumly to `app/layout.tsx`, then save. Or send the message into Sumly in chat.
3. Click Publish, then Publish changes. Open the live app and the visit shows on Visitors.

app/layout.tsx: Next's Script passes data attributes through to the script it adds.
```
import Script from 'next/script';

export default function RootLayout({ children }: { children: React.ReactNode }) {
  return (
    <html lang="en">
      <body>{children}</body>
      <Script src="https://sumly.dev/s.js" data-site="sl_your_key" />
    </html>
  );
}
```

Message: Or paste this into v0's chat, with your own key.
```
In app/layout.tsx, add next/script's Script with src="https://sumly.dev/s.js" and data-site="sl_your_key", once, inside <html> after <body>. Do not change anything else.
```

Keep in mind: A project kept on GitHub publishes through a pull request that v0 opens and merges; the change is live once the production deployment finishes.

How to work:
- Look at how this project is built first, and fit the code to its framework and its way of doing things; the examples above are a starting point, not something to paste as is.
- Steps that happen in a dashboard (Sumly, or v0's own) are mine: tell me exactly what to click, then wait for me.
- Keys the code needs belong in environment variables, never in the code or the repository. Never ask me to paste a secret key into this chat; tell me which variable to set.
- Change only what this needs, show me the changes before you commit, and tell me how to check that it works.
- sl_your_key stands for the project's public key; it is on the Visitors page in Sumly. Ask me for it.

Consent

In the EU, the EEA, the UK and Switzerland the script sets no cookie until you call sumly.consent(true), usually from your cookie banner once the visitor agrees, and counts visits without one until then. To wait for consent everywhere, add data-consent="always" to the line. Or add data-cookieless: no Sumly cookie anywhere, so nothing to ask, but a returning visitor counts as new each day and a payment is only traced to a visit on the same day.

Checkout

Stripe Payment Links, pricing tables and buy buttons, Polar checkout links, Paddle buttons and Gumroad product links on your pages carry the visitor into checkout by themselves. For a checkout your own server creates, pass the sumly_vid cookie as metadata named sumly_visitor_id, or send the buyer back to a page with the script and ?session_id={CHECKOUT_SESSION_ID} (Stripe) or ?checkout_id={CHECKOUT_ID} (Polar).

Your own domain

On Starter and Growth, one DNS record serves the script from your own address, past ad blockers: under Visitors › Add tracking › Your own address, enter one such as signal.your-site.com and add the CNAME it shows. If your checkout or app is on another domain, add it under Projects and payments › Other domains: the line then carries data-domains and one person stays one visitor across them.

Clicks and sections

Clicks on links to other sites count by themselves. Mark a button with data-sumly-event="signup" to count its clicks, and a section with data-sumly-scroll="pricing" to count the page views that reached it, a goal such as reached pricing.