connection - Next Js

The connection() function allows you to indicate rendering should wait for an incoming user request before continuing.

It's useful when a component doesn't use Request-time APIs like cookies or headers, but still needs to produce different output per request, such as Math.random() or new Date().

import { connection } from 'next/server'

export default async function Page() {
  await connection() // prerendering stops here
  // the following code only runs at request time
  const rand = Math.random()
  return <span>{rand}</span>
}

jsx

import { connection } from 'next/server'

export default async function Page() {
  await connection() // prerendering stops here
  // the following code only runs at request time
  const rand = Math.random()
  return <span>{rand}</span>
}

Examples

Synchronous database drivers

Queries from synchronous database drivers like better-sqlite3 complete during prerendering. If you are not already using Request-time APIs, call connection() before your query to exclude them from prerendering:

import { connection } from 'next/server'
import Database from 'better-sqlite3'

const db = new Database('app.db')

export async function getVisitorCount() {
  await connection()
  return db.prepare('SELECT value FROM counters WHERE name = ?').get('visitors')
}

import { connection } from 'next/server'
import Database from 'better-sqlite3'

const db = new Database('app.db')

export async function getVisitorCount() {
  await connection()
  return db.prepare('SELECT value FROM counters WHERE name = ?').get('visitors')
}

Now any component that calls getVisitorCount() will be excluded from prerendering, along with the rest of its output.

Reference

Type

jsx

function connection(): Promise<void>

Parameters

The function does not accept any parameters.

Returns

The function returns a void Promise. It is not meant to be consumed.

Good to know

connection replaces unstable_noStore to better align with the future of Next.js.
The function is only necessary when dynamic rendering is required and common Request-time APIs are not used.

Version History

Version	Changes
`v15.0.0`	`connection` stabilized.
`v15.0.0-RC`	`connection` introduced.