Realtime

Realtime allows you to listen to any events on the server-side in realtime using the subscribe method.

Instead of requesting new data via HTTP, the subscription will receive new data every time it changes, any connected client receives that update within milliseconds via a WebSocket connection.

This lets you build an interactive and responsive user experience by providing information from all of Appwrite's services in realtime. The example below shows subscribing to realtime events for file uploads.

Web

import { Client } from "appwrite";

const client = new Client()
    .setEndpoint('https://[HOSTNAME_OR_IP]/v1')
    .setProject('[PROJECT_ID]');

// Subscribe to files channel
client.subscribe('files', response => {
    if(response.events.includes('buckets.*.files.*.create')) {
        // Log when a new file is uploaded
        console.log(response.payload);
    }
});

Flutter

import 'package:appwrite/appwrite.dart';

final client = Client()
    .setEndpoint('https://[HOSTNAME_OR_IP]/v1')
    .setProject('[PROJECT_ID]');

final realtime = Realtime(client);

// Subscribe to files channel
final subscription = realtime.subscribe(['files']);

subscription.stream.listen((response) {
    if(response.events.contains('buckets.*.files.*.create')) {
    // Log when a new file is uploaded
    print(response.payload);
    }
});

Android

import io.appwrite.Client
import io.appwrite.services.Realtime

val client = Client(context)
    .setEndpoint("https://[HOSTNAME_OR_IP]/v1")
    .setProject("[PROJECT_ID]")

val realtime = Realtime(client)

// Subscribe to files channel
let subscription = realtime.subscribe("files") {
    if(it.events.contains("buckets.*.files.*.create")) {
        // Log when a new file is uploaded
        print(it.payload.toString());
    }
}

Apple

import Appwrite
import AppwriteModels

let client = Client()
    .setEndpoint("https://[HOSTNAME_OR_IP]/v1")
    .setProject("[PROJECT_ID]")

let realtime = Realtime(client)

// Subscribe to files channel
let subscription = realtime.subscribe(channels: ["files"]) { response in
    if(message.events!.contains("buckets.*.files.*.create")) {
        // Log when a new file is uploaded
        print(String(describing: response))
    }
}

To subscribe to updates from different resources, you need to specify one or more channels. The channels offer a wide and powerful selection that will allow you to listen to all possible resources. This allows you to receive updates not only from the database, but from all the services that Appwrite offers.

If you subscribe to a channel, you will receive callbacks for a variety of events related to the channel. The events attribute in the callback can be used to filter and respond to specific events in a channel.

All possible events can be found here.

Permissions

All subscriptions are secured by the permissions system offered by Appwrite, meaning a user will only receive updates to resources they have permission to access.

Using Role.any() on read permissions will allow any client to receive updates.

Examples

The examples below will show you how you can use Realtime in various ways.

Subscribe to a Channel

In this example we are subscribing to all updates related to our account by using the account channel. This will be triggered by any update related to the authenticated user, like updating the user's name or e-mail address.

Web

import { Client } from "appwrite";

const client = new Client()
    .setEndpoint('https://[HOSTNAME_OR_IP]/v1')
    .setProject('[PROJECT_ID]');

client.subscribe('account', response => {
    // Callback will be executed on all account events.
    console.log(response);
});

Flutter

import 'package:appwrite/appwrite.dart';

final client = Client()
    .setEndpoint('https://[HOSTNAME_OR_IP]/v1')
    .setProject('[PROJECT_ID]');

final realtime = Realtime(client);

final subscription = realtime.subscribe(['account']);

subscription.stream.listen((response) {
    // Callback will be executed on all account events.
    print(response);
})

Android

import io.appwrite.Client
import io.appwrite.services.Realtime

val client = Client(context)
    .setEndpoint("https://[HOSTNAME_OR_IP]/v1")
    .setProject("[PROJECT_ID]")

val realtime = Realtime(client)

val subscription = realtime.subscribe("account") {
    // Callback will be executed on all account events.
    print(it.payload.toString())
}

Apple

import Appwrite
import AppwriteModels

let client = Client()
    .setEndpoint("https://[HOSTNAME_OR_IP]/v1")
    .setProject("[PROJECT_ID]")

let realtime = Realtime(client)

let subscription = realtime.subscribe(channel: "account", callback: { response in
    // Callback will be executed on all account events.
    print(String(describing: response))
})

Subscribe to Multiple Channels

You can also listen to multiple channels at once by passing an array of channels. This will trigger the callback for any events for all channels passed.

In this example we are listening to the document A and all files by subscribing to the databases.A.collections.A.documents.A and files channels.

Web

import { Client } from "appwrite";

const client = new Client()
    .setEndpoint('https://[HOSTNAME_OR_IP]/v1')
    .setProject('[PROJECT_ID]');

client.subscribe(['collections.A.documents.A', 'files'], response => {
    // Callback will be executed on changes for documents A and all files.
    console.log(response);
});

Flutter

import 'package:appwrite/appwrite.dart';

final client = Client()
    .setEndpoint('https://[HOSTNAME_OR_IP]/v1')
    .setProject('[PROJECT_ID]');

final realtime = Realtime(client);

final subscription = realtime.subscribe(['databases.A.collections.A.documents.A', 'files']);

subscription.stream.listen((response) {
    // Callback will be executed on changes for documents A and all files.
    print(response);
})

Android

import io.appwrite.Client
import io.appwrite.services.Realtime

val client = Client(context)
    .setEndpoint("https://[HOSTNAME_OR_IP]/v1")
    .setProject("[PROJECT_ID]")
val realtime = Realtime(client)

realtime.subscribe("databases.A.collections.A.documents.A", "files") {
    // Callback will be executed on changes for documents A and all files.
    print(it.toString())
}

Apple

import Appwrite
import AppwriteModels

let client = Client()
    .setEndpoint("https://[HOSTNAME_OR_IP]/v1")
    .setProject("[PROJECT_ID]")

let realtime = Realtime(client)

realtime.subscribe(channels: ["databases.A.collections.A.documents.A", "files"]) { response in
    // Callback will be executed on changes for documents A and all files.
    print(String(describing: response))
}

Unsubscribe

If you no longer want to receive updates from a subscription, you can unsubscribe so that your callbacks are no longer called. Leaving old subscriptions alive and resubscribing can result in duplicate subscriptions and cause race conditions.

Web

import { Client } from "appwrite";

const client = new Client()
    .setEndpoint('https://[HOSTNAME_OR_IP]/v1')
    .setProject('[PROJECT_ID]');

const unsubscribe = client.subscribe('files', response => {
    // Callback will be executed on changes for all files.
    console.log(response);
});

// Closes the subscription.
unsubscribe();

Flutter

import 'package:appwrite/appwrite.dart';

final client = Client()
    .setEndpoint('https://[HOSTNAME_OR_IP]/v1')
    .setProject('[PROJECT_ID]');

final realtime = Realtime(client);

final subscription = realtime.subscribe(['files']);

subscription.stream.listen((response) {
    // Callback will be executed on changes for all files.
    print(response);
})

// Closes the subscription.
subscription.close();

Android

import io.appwrite.Client
import io.appwrite.services.Realtime

val client = Client(context)
    .setEndpoint("https://[HOSTNAME_OR_IP]/v1")
    .setProject("[PROJECT_ID]")

val realtime = Realtime(client)

val subscription = realtime.subscribe("files") {
    // Callback will be executed on changes for all files.
    print(param.toString())
}

// Closes the subscription.
subscription.close()

Apple


let client = Client()
let realtime = Realtime(client)

let subscription = realtime.subscribe(channel: "files") { response in
    // Callback will be executed on changes for all files.
    print(response.toString())
}

// Closes the subscription.
subscription.close()

Payload

The payload from the subscription will contain following properties:

Name	Type	Description
events	string[]	The system events that triggered this update.
channels	string[]	An array of channels that can receive this message.
timestamp	integer	The UNIX timestamp from the server to ensure consistency across all client platforms and real-time technologies.
payload	object	Payload contains the data equal to the response model.

If you subscribe to the documents channel and a document the user is allowed to read is updated, you will receive an object containing information about the event and the updated document.

The response will look like this:

{
    "events": [
        "collections.user.documents.627a95c0785cc5c7fff2.delete",
        "collections.*.documents.*.delete",
        "collections.user.documents.*.delete",
        "collections.*.documents.627a95c0785cc5c7fff2.delete",
        "collections.user.documents.627a95c0785cc5c7fff2",
        "collections.*.documents.*",
        "collections.user.documents.*",
        "collections.*.documents.627a95c0785cc5c7fff2",
        "collections.user",
        "collections.*"
    ],
    "channels": [
        "documents",
        "collections.user.documents",
        "collections.user.documents.627a95c0785cc5c7fff2"
    ],
    "timestamp": 1653957271,
    "payload": {
        "field1": "lorem ipsum",
        "field2": [],
        "$permissions": [
            "read(\"user:627a958ded6424a98a9f\")",
            "read(\"user:627a958ded6424a98a9f\")"
        ],
        "$id": "627a95c0785cc5c7fff2",
        "$collection": "example-collection"
    }
}

Channels

A list of all channels available you can subscribe to:

Channel	Description
account	All account related events (session create, name update...)
databases.[ID].collections.[ID].documents	Any create/update/delete events to any document in a collection
documents	Any create/update/delete events to any document
databases.[ID].collections.[ID].documents.[ID]	Any update/delete events to a given document
files	Any create/update/delete events to any file
buckets.[ID].files.[ID]	Any update/delete events to a given file of the given bucket
buckets.[ID].files	Any update/delete events to any file of the given bucket
teams	Any create/update/delete events to a any team
teams.[ID]	Any update/delete events to a given team
memberships	Any create/update/delete events to a any membership
memberships.[ID]	Any update/delete events to a given membership
executions	Any update to executions
executions.[ID]	Any update to a given execution
functions.[ID]	Any execution event to a given function

Custom Endpoint

The SDK will guess the endpoint of the Realtime API when setting the endpoint of your Appwrite instance. If you are running Appwrite with a custom proxy and changed the route of the Realtime API, you can call the setEndpointRealtime method on the Client SDK and set your new endpoint value.

By default the endpoint is wss://[HOSTNAME_OR_IP]/v1/realtime.

Web

import { Client } from "appwrite";
const client = new Client();

client.setEndpointRealtime('[HOSTNAME_OR_IP]');

Flutter

final client = Client();
client.setEndpointRealtime('[HOSTNAME_OR_IP]');

Android

val client = Client(context)
client.setEndpointRealtime("[HOSTNAME_OR_IP]")

Apple

let client = Client()
client.setEndpointRealtime("[HOSTNAME_OR_IP]")

Known Limitations

Authentication with Existing Subscription

If you authenticate a user and have an already existing subscription, the subscription will not receive updates for the newly authenticated user. You would need to re-create the subscription so that it will work with the new user.

Rapid Subscriptions Changes

The SDK creates a single WebSocket connection for all subscribed channels. Each time a channel is added or unsubscribed - the SDK currently creates a completely new connection and terminates the old one. Therefore, subscriptions to channels should always be done in conjunction with state management so as not to be unnecessarily built up several times by multiple components' life cycles.

Server-Side?

We currently are not offering access to realtime with Server SDKs and an API key.