NotifyKit

import {
	channel,
	createNotifyKit,
	memoryAdapter,
	notification,
} from "@notifykitjs/core"
import { resendProvider } from "@notifykitjs/resend"

const inbox = channel.inbox()
const email = channel.email()

export const commentMentioned = notification({
	id: "comment_mentioned",
	payload: { actorName: "string", postTitle: "string", postUrl: "string" },
	channels: [
		inbox({
			title: "{{actorName}} mentioned you",
			body: "In {{postTitle}}",
			actionUrl: "{{postUrl}}",
		}),
		email({
			subject: "{{actorName}} mentioned you in {{postTitle}}",
			body: "Open {{postUrl}} to reply.",
		}),
	],
})

export const notify = createNotifyKit({
	notifications: [commentMentioned] as const,
	database: memoryAdapter(),
	providers: {
		email: resendProvider({
			apiKey: process.env.RESEND_API_KEY!,
			from: "hi@example.com",
		}),
	},
})

Install

Start a new Next.js app with everything wired up, or add the core package to an app you already have. The core has no required dependencies: it ships an in-memory database and fake providers, so it runs before you have picked either.

npx create-notifykit-app my-app

npm install @notifykitjs/core

bun add @notifykitjs/core

pnpm add @notifykitjs/core

How It Works

Define a notification once: an id, the payload it needs, and a template for each channel it can go out on. Send it from anywhere on your server with notify.send(), naming a recipient and passing the payload. NotifyKit then delivers it: an inbox item written to your database, an email through your provider, a signed webhook, each one checked against the recipient’s preferences first.

await notify.send({
	recipientId: "user_123",
	notificationId: "comment_mentioned",
	payload: { actorName: "Rey", postTitle: "Launch Plan", postUrl: "/posts/42" },
})

One call, several places it can land:

On the client, @notifykitjs/react gives you useInbox(), usePreferences(), and a <NotificationBell />, talking to routes you mount with one line in Next.js.

The Pipeline

Every send() goes through the same stages, in this order. Each one you have not configured is a no-op, and the first one that stops a send is the one to look at when a message does not arrive.

notify.explain() runs the same stages without storing or sending anything and tells you what each channel would do. See Explain and dry run.

Your Database

Recipients, inbox items, preferences, delivery records, and the delivery timeline are stored through a database adapter. memoryAdapter() is built in for development and tests; @notifykitjs/drizzle stores everything in SQLite or Postgres tables that sit next to your own, so you can join against them, back them up, and migrate them like the rest of your schema.

Nothing leaves your infrastructure except the messages themselves, which go to the email, SMS, or webhook provider you configured. See Database adapters.

Compared

NotifyKit is a library, not a platform, and that is a trade-off rather than an upgrade:

Choose a managed platform such as Knock, Courier, SuprSend, or Novu Cloud when non-engineers need to edit workflows, or you want many channels and managed delivery out of the box. Why NotifyKit goes through the choice in more detail.

Packages

Only the core is required. Add the rest as you need them:

Status

Next Steps

• Quickstart: scaffold an app and send your first notification
• Defining notifications: payloads, templates, and categories
• Next.js and React: put an inbox and a preferences page in your app
• Explain and dry run: find out why a notification did not arrive
• API reference: every method on notify