Next.js

Install

npx simpledatalogs init

The command finds your Next.js app, adds the key to .env.local, writes instrumentation-client.ts, shows you the diff first, and sends a test event. Then install the package:

npm install simpledatalogs

Or by hand

# .env.local
NEXT_PUBLIC_SIMPLEDATALOGS_KEY=sdl_pub_…

// instrumentation-client.ts (next to app/, or in src/)
import { init } from 'simpledatalogs'

init({ key: process.env.NEXT_PUBLIC_SIMPLEDATALOGS_KEY, autocapture: true })

instrumentation-client runs in the browser before your app (Next.js 15.3 or later). On older versions, call init() once in a client component rendered by your root layout.

Send everything, or only what you choose

• Everything: autocapture: true, as above.
• Only your own events: leave autocapture out and call track():

import { init } from 'simpledatalogs'

export const sdl = init({ key: process.env.NEXT_PUBLIC_SIMPLEDATALOGS_KEY })

sdl.track('signup', { plan: 'pro' })

In the first minute

• session_start, then a page_view with path, title, referrer and any utm_* parameters.
• A page_view for every client-side navigation (<Link>, router.push, back and forward).
• Uncaught errors and unhandled promise rejections on the Logs tab, with their stack.

Autocapture defaults

Feature	autocapture: true
Page views (App and Pages Router navigation)	on
Sessions (session_id, 30 idle minutes)	on
Errors and unhandled rejections	on
Outbound link clicks	off (autocapture: { outboundLinks: true })
Do Not Track / Global Privacy Control	respected: nothing automatic is sent

No cookies: the session id lives in sessionStorage. Every option is in the JavaScript SDK reference.