Tauri App with Embedded Actix Web Server – Localhost Not Reachable After Build

[Alirezaaraby]

Hi everyone,

I’m developing a Tauri application that includes a built-in Actix Web server. Everything works perfectly during development when I run the app using npm run tauri dev. However, after building the application, the Actix server no longer responds to requests — it seems like localhost is not reachable.

I suspect this might be related to permissions or security restrictions in the production build, but I'm not entirely sure. I've already configured the connect-src directive in the Content Security Policy and attempted to bind the server to 0.0.0.0, but the issue persists.

Has anyone encountered a similar problem or have suggestions on what might be causing this?

Thanks in advance!

[FabianLars]

Did you try a debug build via the --debug flag already? It creates an app (in target/debug/) that behaves like a prod build but with the console and devtools attached so you can check for errors easier.

[Alirezaaraby]

Thanks, it's a good idea i will try that

[dennyak47]

I change lib.rs in tauri2, it works for me

// lib.rs
use std::thread;
use actix_web::{web, App, HttpServer, Responder};

#[tauri::command]
fn greet(name: &str) -> String {
    format!("Hello, {}! You've been greeted from Rust!", name)
}

#[cfg_attr(mobile, tauri::mobile_entry_point)]
pub fn run() {
    thread::spawn(|| {
        actix_web::rt::System::new().block_on(async {
            start_actix_server().await;
        })
    });
    tauri::Builder::default()
        .plugin(tauri_plugin_opener::init())
        .invoke_handler(tauri::generate_handler![greet])
        .run(tauri::generate_context!())
        .expect("error while running tauri application");
}

async fn start_actix_server() {
    async fn hello() -> impl Responder {
        "Hello from Actix"
    }

    HttpServer::new(|| App::new().route("/", web::get().to(hello)))
        .bind(("127.0.0.1", 8080))
        .unwrap()
        .run()
        .await
        .unwrap();
}