Y-Sweet: a realtime CRDT-based document store, backed by object storage

Y-Sweet is an open-source document store and realtime sync backend, built on top of the Yjs CRDT library.

Features

• Persists document data to S3-compatible storage, like Figma.
• Scales horizontally with a session backend model.
• Deploys as a native Linux process.
• Provides document-level access control via client tokens.
• Written in Rust with a focus on stability and performance.

Y-Sweet stack

The Y-Sweet server can be used by any Yjs app, or you can use our opinionated stack to integrate Yjs and Y-Sweet into a Next.js app.

• create-y-sweet-app, a command line tool to quickly create a Y-Sweet app.
• @y-sweet/sdk, a TypeScript library for interacting with y-sweet-server from your application backend.
• @y-sweet/client, a TypeScript library for syncing documents from a client to a Y-Sweet server.
• @y-sweet/react, a library of React hooks for connecting to a Y-Sweet server and manipulating Yjs docs.
• A debugger for exploring Yjs document and presence state.

Y-Sweet is MIT-licensed, and was created by Jamsocket.

Getting started

The easiest way to start a Y-Sweet project is with the create-y-sweet-app command line tool:

npx create-y-sweet-app@latest

For more information, check out our documentation.

Docs

• API docs
  • TypeScript client
  • React hooks
  • Document management SDK
• Y-Sweet on Jamsocket (managed service) docs
• Self Hosting and Running Locally

Examples

Explore our collaborative examples to help you get started.

All examples are open source and live in this repository, within /examples.

Usage

Check the vanilla js example for more details.

On the client

import * as Y from 'yjs';
import { createYjsProvider } from '@y-sweet/client';

// Create the Yjs doc and link it to the Y-Sweet server:
const doc = new Y.Doc();
const docId = 'my-doc-id';
createYjsProvider(doc, docId, '/api/my-auth-endpoint');

// Now use the doc like a normal Yjs doc!
let mySharedMap = doc.getMap('thing');
mySharedMap.set("foo", 123);

// Update your UI based on `mySharedMap` changes like this, for example:
mySharedMap.observe((event) => {
  event.keysChanged.forEach((key) => {
    // do whatever you want based on the detected change:
    yourUpdateFunction(key, mySharedMap.get(key));
  });
});

On the server

import { DocumentManager } from '@y-sweet/sdk';

// Pass in a CONNECTION_STRING, which you can get from a Y-Sweet service in the Jamsocket dashboard or from running npx y-sweet@latest serve locally
const manager = new DocumentManager(CONNECTION_STRING);

// create an endpoint that auths your user and returns a Y-Sweet client token
export async function POST(request) {
  // in a production app, you'd want to authenticate the user
  // and make sure they have access to the given doc
  const body = await request.json();
  const docId = body.docId;
  const clientToken = await manager.getOrCreateDocAndToken(docId);
  return Response.json(clientToken);
}

Running the Y-Sweet server locally

If you have npm, the fastest way to run a local server is with npx:

npx y-sweet@latest serve

This will download the Y-Sweet server if you do not already have it, and run it.

By default, y-sweet serve does not write data to disk. You can specify a directory to persist data to, like this:

npx y-sweet@latest serve /path/to/data

If the directory starts with s3://, Y-Sweet will treat it as an S3-compatible bucket path. In this case, Y-Sweet will pick up your local AWS credentials from the environment. If you do not have AWS credentials set up, you can set them up with aws configure.

Packages

Server

Package Manager	Name	Version	Path
npm	y-sweet		js-pkg/server
crates.io	y-sweet		crates/y-sweet
crates.io	y-sweet-core		crates/y-sweet-core

Client

Package Manager	Name	Version	Path
npm	@y-sweet/sdk		js-pkg/sdk
npm	@y-sweet/client		js-pkg/client
npm	@y-sweet/react		js-pkg/react
pypi	y-sweet-sdk		python/y_sweet_sdk

Hosted Y-Sweet on Jamsocket

You can run Y-Sweet on your own server, or you can run it on Jamsocket. Jamsocket is purpose-built to scale up sync backends like Y-Sweet, and allows you to bring your own storage.

You can try it out for free today by following our quickstart guide.