A very minimal web push notification server using Firebase Cloud Messaging (FCM) for Node (and Electron).

Installation

``bash
npm install @miafoo/fcm-web-push
`

Prerequisites

1. Firebase App ID
2. Firebase Project ID
3. Firebase API Key
4. Firebase VAPID/Key Pair

You can find the first 3 in the Firebase Console when you create a new "Web app". The VAPID/Key pair can be found in the "Web configuration" section on the "Cloud Messaging" tab.

Usage

See examples folder for more complete examples than the one below.

`typescript
import { register, FcmClient } from "@miafoo/fcm-web-push"

// Restore persistentIds from the previous session.
const previousPersistentIds: string[] = readPersistentIdsFromDisk()
const newPersistentIds: string[] = []

// Register the app with Firebase. Ideally you would store this registration
// and restore it next time you run the app.
// You can use the encodeRegistration and decodeRegistration functions
// to easily save and restore the registration as JSON strings.
// Note: Registration can take several seconds.
const registration = await register({
apiKey: "xxxx",
projectId: "xxxx",
appId: "xxxx",
vapidKey: "xxxx",
})

const client = new FcmClient({
registration,
})

client.on("connect", () => {
console.log("Connecting...")
})

client.on("connected", () => {
console.log("Connected!")
})

client.on("disconnected", () => {
console.log("Disconnected!")
})

client.on("message", (message) => {
// Store the persistentId!
newPersistentIds.push(message.persistentId)
console.log(message)
})

// Pass in the previousPersistentIds to mark them seen, otheriwse they
// will be received again every time the client connects.
await client.connect(previousPersistentIds)
// Note: The connect promise resolves when the socket is closed.
// You can also close the socket manually by disconnecting:
client.disconnect()

// Save the new persistent ids so we can mark them seen next time we run.
writePersistentIdsToDisk(newPersistentIds)
``

Acknowledgements

- push-receiver for the original implementation. Be sure to check out Matthieu Lemoine's blog post on how they built it.
- fcm-push-listener for a simple Rust implementation. Large portion of this code is based on it.
- Google & Chrome Developer blogs for the Web Push Protocol and Web Push Encryption.