spacetimedb

SpacetimeDB Module Library and SDK

Overview

This repository contains both the SpacetimeDB module library and the TypeScript SDK for SpacetimeDB. The SDK allows you to interact with the database server from a client and applies type information from your SpacetimeDB server module.

Installation

The SDK is an NPM package, thus you can use your package manager of choice like NPM or Yarn, for example:

npm add spacetimedb

You can use the package in the browser, using a bundler like vite/parcel/rsbuild, in server-side applications like NodeJS, Deno, Bun, NextJS, Remix, and in Cloudflare Workers.

NOTE: For usage in NodeJS 18-21, you need to install the undici package as a peer dependency: npm add spacetimedb undici. Node 22 and later are supported out of the box.

Usage

In order to connect to a database you have to generate module bindings for your database.

import { DbConnection, tables } from './module_bindings';

const connection = DbConnection.builder()
  .withUri('ws://localhost:3000')
  .withDatabaseName('MODULE_NAME')
  .onDisconnect(() => {
    console.log('disconnected');
  })
  .onConnectError(() => {
    console.log('client_error');
  })
  .onConnect((connection, identity, _token) => {
    console.log(
      'Connected to SpacetimeDB with identity:',
      identity.toHexString()
    );

    connection.subscriptionBuilder().subscribe(tables.player);
  })
  .withToken('TOKEN')
  .build();

If you need to disconnect the client:

connection.disconnect();

Typically, you will use the SDK with types generated from SpacetimeDB module. For example, given a table named Player you can subscribe to player updates like this:

connection.db.player.onInsert((ctx, player) => {
  console.log(player);
});

Given a reducer called CreatePlayer you can call it using a call method:

connection.reducers.createPlayer();

React Usage

This module also includes React hooks to subscribe to tables under the spacetimedb/react subpath. The React integration is fully compatible with React StrictMode and handles the double-mount behavior correctly (only one WebSocket connection is created).

In order to use SpacetimeDB React hooks in your project, first add a SpacetimeDBProvider at the top of your component hierarchy:

const connectionBuilder = DbConnection.builder()
  .withUri('ws://localhost:3000')
  .withDatabaseName('MODULE_NAME')
  .withLightMode(true)
  .onDisconnect(() => {
    console.log('disconnected');
  })
  .onConnectError(() => {
    console.log('client_error');
  })
  .onConnect((conn, identity, _token) => {
    console.log(
      'Connected to SpacetimeDB with identity:',
      identity.toHexString()
    );

    conn.subscriptionBuilder().subscribe(tables.player);
  })
  .withToken('TOKEN');

ReactDOM.createRoot(document.getElementById('root')!).render(
  <React.StrictMode>
    <SpacetimeDBProvider connectionBuilder={connectionBuilder}>
      <App />
    </SpacetimeDBProvider>
  </React.StrictMode>
);

One you add a SpacetimeDBProvider to your hierarchy, you can use SpacetimeDB React hooks in your render function:

function App() {
  const conn = useSpacetimeDB<DbConnection>();
  const { rows: messages } = useTable<DbConnection, Message>('message');

  ...
}

Developer notes

To run the tests, do:

pnpm build && pnpm test