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PowerSync SDK on NPM

The JavaScript part of the SDK is distributed via NPM

PowerSync SDK on crates.io

The Rust part of the SDK is available via crates.io

Source Code

Refer to packages/tauri in the powersync-js repo on GitHub

API Reference

Full API reference for the SDK

Example Projects

Gallery of example projects/demo apps built with Tauri and PowerSync

Changelog

Changelog for the SDK
This SDK is currently in a pre-alpha release.While the JavaScript parts are built with the stable @powersync/common package, database access and sync is implemented with our experimental Rust SDK.There are known limitations currently.

SDK Features

  • Real-time streaming of database changes: Changes made by one user are instantly streamed to all other users with access to that data. This keeps clients automatically in sync without manual polling or refresh logic.
  • Direct access to a local SQLite database: Data is stored locally, so apps can read and write instantly without network calls. This enables offline support and faster user interactions.
  • Asynchronous background execution: The SDK performs database operations in the background to avoid blocking the application’s main thread. This means that apps stay responsive, even during heavy data activity.
  • Query subscriptions for live updates: The SDK supports query subscriptions that automatically push real-time updates to client applications as data changes, keeping your UI reactive and up to date.
  • Automatic schema management: PowerSync syncs schemaless data and applies a client-defined schema using SQLite views. This architecture means that PowerSync SDKs can handle schema changes gracefully without requiring explicit migrations on the client-side.

Installation

Add the PowerSync Tauri NPM package to your project:
npm install @powersync/tauri-plugin
Like all trusted PowerSync packages, the Tauri plugin is only available through the @powersync/ scope on npm. The PowerSync Tauri plugin cannot be installed with the tauri add command.
Additionally, add the Tauri plugin crate to your Rust app (in the src-tauri directory):
cargo add tauri-plugin-powersync
In your lib.rs, ensure the plugin is loaded:
pub fn run() {
    tauri::Builder::default()
        .invoke_handler(tauri::generate_handler![connect])
+       .plugin(tauri_plugin_powersync::init())
        .run(tauri::generate_context!())
        .expect("error while running tauri application");
}
In src-tauri/capabilities/default.json, ensure powersync:default is listed under permissions to make PowerSync APIs available to JavaScript.

Getting Started

Prerequisites: To sync data between your client-side app and your backend source database, you must have completed the necessary setup for PowerSync, which includes connecting your source database to the PowerSync Service and deploying Sync Streams (or legacy Sync Rules) (steps 1-4 in the Setup Guide).

1. Define the Client-Side Schema

This refers to the for the managed SQLite database exposed by the PowerSync Client SDKs, that your app can read from and write to. The schema is applied when the database is instantiated (as we’ll show in the next step) — .
Generate schema automaticallyIn the PowerSync Dashboard, select your project and instance and click the Connect button in the top bar to generate the client-side schema in your preferred language. The schema will be generated based off your Sync Streams/Rules.Similar functionality exists in the CLI.Note: The generated schema will not include an id column, as the client SDK automatically creates an id column of type text. Consequently, it is not necessary to specify an id column in your schema. For additional information on IDs, refer to Client ID.
The types available are text, integer and real. These should map directly to the values produced by your Sync Streams (or legacy Sync Rules). If a value doesn’t match, it is cast automatically. For details on how backend source database types are mapped to the SQLite types, see Types.
The Tauri SDK inherits the same APIs from the JavaScript Web SDK via @powersync/common, with a few exceptions detailed below. See the Web SDK schema definition section for more advanced examples.
Example:
// AppSchema.ts
import { column, Schema, Table } from '@powersync/common';

const lists = new Table({
  created_at: column.text,
  name: column.text,
  owner_id: column.text
});

const todos = new Table(
  {
    list_id: column.text,
    created_at: column.text,
    completed_at: column.text,
    description: column.text,
    created_by: column.text,
    completed_by: column.text,
    completed: column.integer
  },
  { indexes: { list: ['list_id'] } }
);

export const AppSchema = new Schema({
  todos,
  lists
});

// For types
export type Database = (typeof AppSchema)['types'];
export type TodoRecord = Database['todos'];
// OR:
// export type Todo = RowType<typeof todos>;
export type ListRecord = Database['lists'];
Note: No need to declare a primary key id column, as PowerSync will automatically create this.

2. Instantiate the PowerSync Database

Next, you need to instantiate the PowerSync database. PowerSync streams changes from your backend source database into the client-side SQLite database, based on your Sync Streams (or legacy Sync Rules). In your client-side app, you can read from and write to the local SQLite database, whether the user is online or offline. Example:
import { PowerSyncTauriDatabase } from '@powersync/tauri-plugin';
import { appDataDir } from '@tauri-apps/api/path';

import { AppSchema } from './AppSchema';

export const db = new PowerSyncTauriDatabase({
  // The schema you defined in the previous step
  schema: AppSchema,
  database: {
    // Filename for the SQLite database.
    dbFilename: 'powersync.db',
    // An optional directory to store the database file in.
    dbLocationAsync: appDataDir,
  }
});
Finally, instruct PowerSync to sync data from your backend. For Tauri apps, the sync client must be driven from Rust code. To do that, add a new Tauri command to your Rust application:
use tauri_plugin_powersync::PowerSyncExt;

#[tauri::command]
async fn connect<R: Runtime>(
    app: AppHandle<R>,
    handle: usize,
) -> tauri_plugin_powersync::Result<()> {
    let ps = app.powersync();
    let database = ps.database_from_javascript_handle(handle)?;

    // MyBackendConnector is defined in the next step...
    let options = SyncOptions::new(MyRustConnector {
        db: database.clone(),
    });
    database.connect(options).await;

    Ok(())
}
Ensure the command is registered by including it in the invoke handler with tauri::generate_handler![connect]. You can then invoke that command from your JavaScript code to connect:
import { PowerSyncTauriDatabase } from '@powersync/tauri-plugin';
import { invoke } from '@tauri-apps/api/core';

async function connect(db: PowerSyncTauriDatabase) {
  await db.init();
  const handle = db.rustHandle;
  await invoke<void>('connect', { handle });
}

3. Integrate with your Backend

The PowerSync backend connector provides the connection between your application backend and the PowerSync client-side managed SQLite database. It is used to:
  1. Retrieve an auth token to connect to the PowerSync instance.
  2. Upload client-side writes to your backend API. Any writes that are made to the SQLite database are placed into an upload queue by the PowerSync Client SDK and automatically uploaded to your app backend (where you apply those changes to the backend source database) when the user is connected.
At the moment, backend connectors for the Tauri SDK must be implemented in Rust. This allows the connector to be used across multiple windows and even when no JavaScript is running.
Accordingly, the connector must implement two methods:
  1. fetch_credentials - This method will be automatically invoked by the PowerSync Client SDK every couple of minutes to obtain authentication credentials. See Authentication Setup for instructions on how the credentials should be generated.
  2. upload_data - This method will be automatically invoked by the PowerSync Client SDK whenever it needs to upload client-side writes to your app backend via your backend API. Therefore, in your implementation, you need to define how your backend API is called. See Writing Client Changes for considerations on the app backend implementation.
Example:
struct MyBackendConnector {
    db: PowerSyncDatabase,
}

#[async_trait]
impl BackendConnector for MyBackendConnector {
    async fn fetch_credentials(&self) -> Result<PowerSyncCredentials, PowerSyncError> {
        // implement fetchCredentials to obtain the necessary credentials to connect to your backend
        // See an example implementation in https://github.com/powersync-ja/powersync-native/blob/508193b0822b8dad1a534a16462e2fcd36a9ac68/examples/egui_todolist/src/database.rs#L119-L133

        Ok(PowerSyncCredentials {
            endpoint: "[Your PowerSync instance URL or self-hosted endpoint]".to_string(),
            // Use a development token (see Authentication Setup https://docs.powersync.com/configuration/auth/development-tokens) to get up and running quickly
            token: "An authentication token".to_string(),
        })
    }

    async fn upload_data(&self) -> Result<(), PowerSyncError> {
        // Implement uploadData to send local changes to your backend service
        // You can omit this method if you only want to sync data from the server to the client
        // See an example implementation under Usage Examples (sub-page)
        // See https://docs.powersync.com/handling-writes/writing-client-changes for considerations.
        let  mut local_writes = self.db.crud_transactions();
        while let Some(tx) = local_writes.try_next().await? {
            todo!("Inspect tx.crud for local writes that need to be uploaded to your backend");
            tx.complete().await?;
        }

        Ok(())
    }
}

Using PowerSync: CRUD functions

Once the PowerSync instance is configured you can start using the SQLite DB functions.
All CRUD examples from the JavaScript Web SDK apply: The Tauri SDK exposes the same JavaScript database API as the Web SDK. See the JavaScript Web SDK CRUD functions section for examples of get, getAll, watch, execute, writeTransaction, incremental watch updates, and differential results.
The most commonly used CRUD functions to interact with your SQLite data are:

Fetching a Single Item

The get method executes a read-only (SELECT) query and returns a single result. It throws an exception if no result is found. Use getOptional to return a single optional result (returns null if no result is found).
// Find a list item by ID
export const findList = async (id) => {
  const result = await db.get('SELECT * FROM lists WHERE id = ?', [id]);
  return result;
}

Querying Items (PowerSync.getAll)

The getAll method returns a set of rows from a table.
// Get all list IDs
export const getLists = async () => {
  const results = await db.getAll('SELECT * FROM lists');
  return results;
}

Watching Queries (PowerSync.watch)

The watch method executes a read query whenever a change to a dependent table is made.
async function* pendingLists(): AsyncIterable<string[]> {
  for await (const result of db.watch(
    `SELECT * FROM lists WHERE state = ?`,
    ['pending']
  )) {
    yield result.rows?._array ?? [];
  }
} 
For advanced watch query features like incremental updates and differential results, see Live Queries / Watch Queries.

Mutations (PowerSync.execute, PowerSync.writeTransaction)

The execute method can be used for executing single SQLite write statements.
// Delete a list item by ID
export const deleteList = async (id) => {
  const result = await db.execute('DELETE FROM lists WHERE id = ?', [id]);
  return TodoList.fromRow(results);
}

// OR: using a transaction
const deleteList = async (id) => {
  await db.writeTransaction(async (tx) => {
    // Delete associated todos
    await tx.execute(`DELETE FROM ${TODOS_TABLE} WHERE list_id = ?`, [id]);
    // Delete list record
    await tx.execute(`DELETE FROM ${LISTS_TABLE} WHERE id = ?`, [id]);
  });
};
When using the default client-side JSON-based view system, writes are applied to a view, with triggers writing to the underlying table. Because of this, result.rowsAffected from db.execute() can be 0 even when an UPDATE or DELETE succeeds.When you need to confirm whether a mutation changed any rows, add a RETURNING clause and check the returned rows:
const result = await db.execute(
  'UPDATE tasks SET deleted_at = ? WHERE id = ? AND deleted_at IS NULL RETURNING id',
  [now, id]
);

const wasUpdated = (result.rows?.length ?? 0) > 0;
If you need direct table writes, use raw tables.

Configure Logging

The Rust SDK uses the log crate which can be enabled using the Tauri logging plugin.

Sharing a database with Rust code

A PowerSyncTauriDatabase instance can be shared with Rust code:
  1. Call and await .init() on the database to ensure the database has been opened.
  2. Use the .rustHandle getter, which returns a number representing the database instance.
  3. This handle can now be passed as an argument to one of your Tauri commands. In Rust SDK, you can use AppHandle::powersync() and PowerSync::database_from_javascript_handle to inspect the database from Rust. See the Rust SDK guide for more information.
Connection locks and table updates are automatically shared between Rust and JavaScript code.

Limitations

  • The Rust SDK, which is used to implement the Tauri plugin, has limited support for legacy Sync Rules: On SyncStatus, lastSyncedAt, hasSynced and priorityStatusEntries are not available. Use the status on individual Sync Streams through SyncStatus.forStream instead.
  • Connecting to the PowerSync Service is only possible from Rust. Calling connect() from JavaScript will throw.

Additional Usage Examples

For more usage examples including accessing connection status, monitoring sync progress, and waiting for initial sync, see the Usage Examples page.

ORM Support

See JavaScript ORM Support for details.

Troubleshooting

See Troubleshooting for pointers to debug common issues.