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Install SyncedStore and required dependencies:

npm install --save @syncedstore/core

# SyncedStore builds on top of yjs, install that too:
npm install --save yjs

Optional dependencies

Also install the following helper libraries to get started:

# For syncing over webrtc:
npm install --save y-webrtc

# If you use React, install the helper library:
npm install --save @syncedstore/react

y-webrtc is optional, but great during development. Later, you might want to use a different sync provider instead of y-webrtc.

Creating a store

Now, let's set up a store which contains and describes the data that should be synced across users and devices.

import { syncedStore, getYjsValue } from "@syncedstore/core";
import { WebrtcProvider } from "y-webrtc";

// (optional, define types for TypeScript)
type Vehicle = { color: string; brand: string };

// Create your SyncedStore store
export const store = syncedStore({ vehicles: [] as Vehicle[] });

// Get the Yjs document and sync automatically using y-webrtc
const doc = getYjsValue(store);
const webrtcProvider = new WebrtcProvider("my-document-id", doc);

You can now add objects to the store.vehicles array, and they will be synced automatically with other users. Even if you change properties (e.g.: store.vehicles[0].color = "red";), this will be synced with other users.

More about the main syncedStore method below, or continue to the interactive example.

syncedStore method

The function syncedStore creates a store and takes two parameters:

  • shape: an object that describes the data you want to keep in the store. Use the shape to define the names of objects, arrays, etc. you want to make collaborative and share across users.
  • doc (optional): a Y.Doc instance. This will be the backing yjs document that contains the data in the store. Defaults to creating a new Y.Doc.


Use the shape object to define the types ("shape") of the data you want to keep in the store. You can define as many properties as you like, and there are four different data types you can use; these are explained below.

const shape = {
exampleArrayData: [],
exampleObjectData: {},
exampleXMLData: "xml",
exampleTextData: "text",
const store = syncedStore(shape);


exampleArrayData in the code snippet above. Arrays must always be initialized as an empty array []. You'll now be able to operate on the array store.exampleArrayData like you're used to (e.g.: push, filter, etc), and changes will be synced across the users of your app.


exampleObjectData in the code snippet above. Objects must always be initialized as an empty object {}. Objects in SyncedStore resemble Maps or plain javascript objects. You'll be able to set and get properties like you're used to with regular Javascript plain objects (e.g. = "Monday";).

XML (advanced)

exampleXMLData in the code snippet above. store.exampleXMLData will now return a SyncedXml instance.

Text (advanced)

exampleTextData in the code snippet above. store.exampleTextData will now return a SyncedText instance, see Working with text.