Single Instance

GitHub crates.io

API Reference

Ensure that a single instance of your tauri app is running at a time using the Single Instance Plugin.

Supported Platforms

This plugin requires a Rust version of at least 1.75

Platform	Level	Notes
windows
linux
macos
android
ios

Setup

Install the Single Instance plugin to get started.

Automatic

Use your project’s package manager to add the dependency:

npm

npm run tauri add single-instance

yarn

yarn run tauri add single-instance

pnpm

pnpm tauri add single-instance

bun

bun tauri add single-instance

cargo

cargo tauri add single-instance

Manual

1. Run the following command in the src-tauri folder to add the plugin to the project’s dependencies in Cargo.toml:

   cargo add tauri-plugin-single-instance --target 'cfg(any(target_os = "macos", windows, target_os = "linux"))'

2. Modify lib.rs to initialize the plugin:

   lib.rs

   #[cfg_attr(mobile, tauri::mobile_entry_point)]
   pub fn run() {
       tauri::Builder::default()
           .setup(|app| {
               #[cfg(desktop)]
               app.handle().plugin(tauri_plugin_single_instance::init(|app, args, cwd| {}));
               Ok(())
           })
           .run(tauri::generate_context!())
           .expect("error while running tauri application");
   }

Usage

The plugin is already installed and initialized, and it should be functioning correctly right away. Nevertheless, we can also enhance its functionality with the init() method.

The plugin init() method takes a closure that is invoked when a new app instance was started, but closed by the plugin. The closure has three arguments:

1. app: The AppHandle of the application.
2. args: The list of arguments, that was passed by the user to initiate this new instance.
3. cwd: The Current Working Directory denotes the directory from which the new application instance was launched.

So, the closure should look like below

.plugin(tauri_plugin_single_instance::init(|app, args, cwd| {
  // Write your code here...
}))

Focusing on New Instance

By default, when you initiate a new instance while the application is already running, no action is taken. To focus the window of the running instance when user tries to open a new instance, alter the callback closure as follows:

src-tauri/src/lib.rs

use tauri::{AppHandle, Manager};

pub fn run() {
    let mut builder = tauri::Builder::default();
    #[cfg(desktop)]
    {
        builder = builder.plugin(tauri_plugin_single_instance::init(|app, args, cwd| {
            let _ = app.get_webview_window("main")
                       .expect("no main window")
                       .set_focus();
        }));
    }

    builder
        .run(tauri::generate_context!())
        .expect("error while running tauri application");
}