feat: expose wry permission handler API

[F0RLE]

Is your feature request related to a problem? Please describe.

Currently, Tauri applications (especially on Windows/WebView2) show native permission prompts for capabilities like Microphone and Camera. For kiosk applications or embedded systems where user interaction is limited, we need a way to automatically grant these permissions without prompting the user.

Describe the solution you'd like

Since wry has recently added a with_permission_handler API (supported in wry#1656), I would like to see this exposed in Tauri.

Ideally, we could configure a handler in WebviewWindowBuilder similar to how navigation_handler is exposed:

tauri::Builder::default()
  .setup(|app| {
    let window = tauri::WebviewWindowBuilder::new(app, "main", tauri::WebviewUrl::default())
      .permission_handler(|kind| {
        match kind {
           // Allow microphone access without prompt
           tauri::PermissionKind::Microphone => tauri::PermissionResponse::Allow,
           _ => tauri::PermissionResponse::Default,
        }
      })
      .build()?;
    Ok(())
  })

[Katze719]

I’m building a small desktop app (picture‑in‑picture for another monitor) and need screen capture via getDisplayMedia(). It works in the browser and in Electron apps like Discord, but in Tauri on Linux (Fedora + Hyprland/Wayland) the call fails: after I pick a screen in the system dialog I get “Screen sharing was cancelled or denied” (NotAllowedError). PipeWire and xdg-desktop-portal-hyprland are running and screen sharing works in other apps, so the blocker is that the Tauri/WebKit webview never grants the permission, there’s no way for the app to allow the display-capture request.

[F0RLE]

Hi! I'm actually working on this right now.

I am currently preparing a PR for tauri core to expose this API. Once merged, you will be able to handle permissions (like getDisplayMedia screenshare requests) directly in your Rust builder without native prompts failing.

[F0RLE]

Update: I've just submitted the PRs to fix this!

1. wry#1654 - Adds the DisplayCapture permission kind specifically for getDisplayMedia on Linux (WebKitGTK).
2. tauri#14865 - Exposes the API to Tauri today.

If you want to test it right now before it's merged, you can patch your Cargo.toml:

[patch.crates-io]
tauri = { git = "https://github.com/F0RLE/tauri", branch = "feat/permission-handler" }
tauri-runtime = { git = "https://github.com/F0RLE/tauri", branch = "feat/permission-handler" }
tauri-runtime-wry = { git = "https://github.com/F0RLE/tauri", branch = "feat/permission-handler" }
wry = { git = "https://github.com/F0RLE/wry", branch = "feat/permission-handler" }

Then simply handle the permission in your builder:

use tauri::webview::{PermissionKind, PermissionResponse};

tauri::Builder::default()
  .on_permission_request(|_webview, kind| {
    match kind {
      // specifically for getDisplayMedia on Linux
      PermissionKind::DisplayCapture => PermissionResponse::Allow,
      _ => PermissionResponse::Default,
    }
  })