Collaborative editing

Introduction

Real-time collaboration, syncing between different devices and working offline used to be hard. We provide everything you need to keep everything in sync with the power of Y.js. The following guide helps you get started with collaborative editing in Tiptap. Don’t worry, a production-grade setup doesn’t require much code.

The video course

We are working on a video course which teaches everything you need to know about collaborative text editing with Tiptap. The first video is available for sponsors here:

Watch the video:
Make Tiptap collaborative (06:46)

In this video I’m adding the Collaboration extension to Tiptap to show you how you can add collaborative text editing capabilities to your editor. You’ll learn why the history handling differs for collaborative editors.

The content won’t sync over the wire yet, but we’ll cover that in an additional video.

Configure the editor

The underyling schema Tiptap uses is an excellent foundation to sync documents. With the Collaboration extension you can tell Tiptap to track changes to the document with Y.js.

Y.js is a conflict-free replicated data types implementation, or in other words: It’s really good in merging changes. And to achieve that, changes don’t even have to come in order. It’s totally fine to change a document while being offline and merge it with other changes when the device is online again.

Somehow, all clients need to interchange document modifications at some point. The most popular technologies to do that are WebRTC and WebSockets, so let’s have a closer look at those:

WebRTC

WebRTC uses a server only to connect clients with each other. The actual data is then flowing between the clients, without the server knowing anything about it and that’s great to take the first steps with collaborative editing.

First, install the dependencies:

npm install @tiptap/extension-collaboration yjs y-webrtc

Now, create a new Y document, and register it with Tiptap:

import { Editor } from '@tiptap/core'
import StarterKit from '@tiptap/starter-kit'
import Collaboration from '@tiptap/extension-collaboration'
import * as Y from 'yjs'
import { WebrtcProvider } from 'y-webrtc'

// A new Y document
const ydoc = new Y.Doc()
// Registered with a WebRTC provider
const provider = new WebrtcProvider('example-document', ydoc)

const editor = new Editor({
  extensions: [
    StarterKit.configure({
      // The Collaboration extension comes with its own history handling
      history: false,
    }),
    // Register the document with Tiptap
    Collaboration.configure({
      document: ydoc,
    }),
  ],
})

This should be enough to create a collaborative instance of Tiptap. Crazy, isn’t it? Try it out, and open the editor in two different browsers. Changes should be synced between different windows.

So how does this magic work? All clients need to connect with eachother, that’s the job of a provider. The WebRTC provider is the easiest way to get started with, as it uses a public server to connect clients directly with each other, but not to sync the actual changes. This has two downsides, though.

  1. Browsers refuse to connect with too many clients. With Y.js it’s enough if all clients are connected indirectly, but even that isn’t possible at some point. Or in other words, it doesn’t scale well for more than 100+ concurrent clients in the same document.
  2. It’s likely you want to involve a server to persist changes anyway. But the WebRTC signaling server (which connects all clients with eachother) doesn’t receive the changes and therefore doesn’t know what’s in the document.

Anyway, if you want to dive deeper, head over to the Y WebRTC repository on GitHub.

WebSocket (Recommended)

For most uses cases, a WebSocket provider is the recommended choice. It’s very flexible and can scale very well. To make it even easier, we are working on an official backend for Tiptap. The backend is still in early access (sponsors-only), but you can use the provider already.

For the client, the example is nearly the same, only the provider is different. First, let’s install the dependencies:

npm install @tiptap/extension-collaboration @hocuspocus/provider

And then register the WebSocket provider with Tiptap:

import { Editor } from '@tiptap/core'
import StarterKit from '@tiptap/starter-kit'
import Collaboration from '@tiptap/extension-collaboration'
import { HocuspocusProvider } from '@hocuspocus/provider'

// Set up the Hocuspocus WebSocket provider
const provider = new HocuspocusProvider({
  url: 'ws://127.0.0.1:1234',
  name: 'example-document',
})

const editor = new Editor({
  extensions: [
    StarterKit.configure({
      // The Collaboration extension comes with its own history handling
      history: false,
    }),
    // Register the document with Tiptap
    Collaboration.configure({
      document: provider.document,
    }),
  ],
})

This example doesn’t work out of the box. As you can see, it’s configured to talk to a WebSocket server which is available under ws://127.0.0.1:1234 (WebSocket protocol ws://, your local IP 127.0.0.1 and the port 1234). You need to set this up, too.

The WebSocket backend

To make the server part as easy as possible, we provide an opinionated server package, called Hocuspocus (currently available for sponsors and subscribers only). It’s a flexible Node.js package, that you can use to build your custom backend.

For the purpose of that guide, let’s just use the command-line interface which boots a minimal server literally in seconds:

npx @hocuspocus/cli --port 1234 --sqlite

This command downloads the Hocuspocus command-line interface, starts a server listening on port 1234 and stores changes in the memory (so it’s gone once you stop the command). The output should look like this:

Hocuspocus v1.0.0 running at:

> HTTP: http://127.0.0.1:1234
> WebSocket: ws://127.0.0.1:1234

Ready.

Try opening http://127.0.0.1:1234 in your browser. You should see a plain text OK if everything works fine.

Go back to your Tiptap editor and hit reload, it should now connect to the Hocuspocus WebSocket server and changes should sync with all other clients. Amazing, isn’t it?

Multiple network providers

You can even combine multiple providers. That’s not needed, but could keep clients connected, even if one connection - for example the WebSocket server - goes down for a while. Here is an example:

new WebrtcProvider('example-document', ydoc)
new HocuspocusProvider({
  url: 'ws://127.0.0.1:1234',
  name: 'example-document',
  document: ydoc,
})

Yes, that’s all.

Keep in mind that WebRTC needs a signaling server to connect clients. This signaling server doesn’t receive the synced data, but helps to let clients find each other. You can run your own signaling server, if you like. Otherwise it’s using a default URL baked into the package.

Show other cursors

To enable users to see the cursor and text selections of each other, add the CollaborationCursor extension.

import { Editor } from '@tiptap/core'
import StarterKit from '@tiptap/starter-kit'
import Collaboration from '@tiptap/extension-collaboration'
import CollaborationCursor from '@tiptap/extension-collaboration-cursor'
import { HocuspocusProvider } from '@hocuspocus/provider'

// Set up the Hocuspocus WebSocket provider
const provider = new HocuspocusProvider({
  url: 'ws://127.0.0.1:1234',
  name: 'example-document',
})

const editor = new Editor({
  extensions: [
    StarterKit.configure({
      // The Collaboration extension comes with its own history handling
      history: false,
    }),
    Collaboration.configure({
      document: provider.document,
    }),
    // Register the collaboration cursor extension
    CollaborationCursor.configure({
      provider: provider,
      user: {
        name: 'Cyndi Lauper',
        color: '#f783ac',
      },
    }),
  ],
})

As you can see, you can pass a name and color for every user. Look at the collaborative editing example, to see a more advanced example.

Offline support

Adding offline support to your collaborative editor is basically a one-liner, thanks to the fantastic Y IndexedDB adapter. Install it:

npm install y-indexeddb

And connect it with a Y document:

import { Editor } from '@tiptap/core'
import Collaboration from '@tiptap/extension-collaboration'
import * as Y from 'yjs'
import { IndexeddbPersistence } from 'y-indexeddb'

const ydoc = new Y.Doc()

// Store the Y document in the browser
new IndexeddbPersistence('example-document', ydoc)

const editor = new Editor({
  extensions: [
    // …
    Collaboration.configure({
      document: ydoc,
    }),
  ],
})

All changes will be stored in the browser then, even if you close the tab, go offline, or make changes while working offline. Next time you are online, the WebSocket provider will try to find a connection and eventually sync the changes.

Yes, it’s magic. As already mentioned, that is all based on the fantastic Y.js framework. And if you’re using it, or our integration, you should definitely sponsor Kevin Jahns on GitHub, he is the brain behind Y.js.

Our plug & play collaboration backend

Our collaborative editing backend handles the syncing, authorization, persistence and scaling. Let’s go through a few common use cases here!

Request early access

Our plug & play collaboration backend hocuspocus is still work in progress. If you want to give it a try, get early access.

The document name

The document name is 'example-document' in all examples here, but it could be any string. In a real-world app you’d probably add the name of your entity and the ID of the entity. Here is how that could look like:

const documentName = 'page.140'

In the backend, you can split the string to know the user is typing on a page with the ID 140 to manage authorization and such accordingly. New documents are created on the fly, no need to tell the backend about them, besides passing a string to the provider.

And if you would like to sync multiple fields with one Y.js document, just pass different fragment names to the collaboration extension:

// a Tiptap instance for the field
Collaboration.configure({
  document: ydoc,
  field: 'title',
})

// and another instance for the summary, both in the same Y.js document
Collaboration.configure({
  document: ydoc,
  field: 'summary',
})

If your setup is somehow more complex, for example with nested fragments, you can pass a raw Y.js fragment too. document and field will be ignored then.

// a raw Y.js fragment
Collaboration.configure({
  fragment: ydoc.getXmlFragment('custom'),
})

Authentication & Authorization

With the onAuthenticate hook you can check if a client is authenticated and authorized to view the current document. In a real world application this would probably be a request to an API, a database query or something else.

When throwing an error (or rejecting the returned Promise), the connection to the client will be terminated. If the client is authorized and authenticated you can also return contextual data which will be accessible in other hooks. But you don’t need to.

import { Server } from '@hocuspocus/server'

const server = Server.configure({
  async onAuthenticate({ token }) {
    // Example test if a user is authenticated
    if (token !== 'super-secret-token') {
      throw new Error('Not authorized!')
    }

    // You can set contextual data to use it in other hooks
    return {
      user: {
        id: 1234,
        name: 'John',
      },
    }
  },
})

server.listen()

Pitfalls

Schema updates

tiptap is very strict with the schema, that means, if you add something that’s not allowed according to the configured schema it’ll be thrown away. That can lead to a strange behaviour when multiple clients with different schemas share changes to a document.

Let’s say you added an editor to your app and the first people use it already. They have all a loaded instance of Tiptap with all default extensions, and therefor a schema that only allows those. But you want to add task lists in the next update, so you add the extension and deploy again.

A new user opens your app and has the updated schema (with task lists), while all others still have the old schema (without task lists). The new user checks out the newly added tasks lists and adds it to a document to show that feature to other users in that document. But then, it magically disappears right after she added it. What happened?

When one user adds a new node (or mark), that change will be synced to all other connected clients. The other connected clients apply those changes to the editor, and Tiptap, strict as it is, removes the newly added node, because it’s not allowed according to their (old) schema. Those changes will be synced to other connected clients and oops, it’s removed everywhere. To avoid this you have a few options:

  1. Never change the schema (not cool).
  2. Force clients to update when you deploy a new schema (tough).
  3. Keep track of the schema version and disable the editor for clients with an outdated schema (depends on your setup).

It’s on our list to provide features to make that easier. If you’ve got an idea how to improve that, share it with us!