Camera permissions on mobile (Android)

[jgonera]

Hi,

I love the idea of Tauri and I decided I'd use it for my first mobile/cross-platform app. I'm using React for the UI and found react-webcam for capturing the camera stream. It worked out of the box on desktop but when I try to run my app on Android, I got no video stream at all. It occurred to me that the app on my phone never asked for camera permissions. I searched the docs, Github, and Discord for how to request those from the user but couldn't find anything. I did see the barcode-scanner plugin and thought I'd try to figure out how it works there. It turns out that installing barcode-scanner plugin by tauri add barcode-scanner already has the desired effect: my app asks for camera permissions as soon as it starts and react-webcam displays the video stream.

I started going through barcode-scanner's code and it looks like there are separate Kotlin and Swift requestPermissions functions. Am I missing a simpler way of requesting camera permissions or does it actually involve writing Kotlin and Swift code to support both Android and iOS? If that's the case, then I'm a bit surprised that there's no simpler camera plugin without all the barcode functionality that the barcode-scanner could depend on. Is there a reason for this?

[FabianLars]

I think just adding this line https://github.com/tauri-apps/plugins-workspace/blob/v2/plugins/barcode-scanner/android/src/main/AndroidManifest.xml#L5 in gen/android/... should be enough. At least according to my own messages i wrote a while back 🙃

[m1212e]

This does indeed work. The permission request is automatically triggered as soon as the web process requests a media device, e.g. like this:

const stream = await navigator.mediaDevices.getUserMedia({
      video: true,
      audio: false,
    });

Does anyone have info on what to do to also support this for ios?

[FabianLars]

https://github.com/tauri-apps/tauri/blob/dev/examples%2Fapi%2Fsrc-tauri%2FInfo.plist

[jgonera]

Thank you, I haven't gotten a chance to test on iOS yet, but it works on Android!

[m1212e]

I did test IOS today, at least in the simulator, it works!

[SleekGeek-254]

Fix: Camera & Microphone in Tauri v2 Android (getUserMedia / NotAllowedError / NotReadableError)

If you're building a Tauri v2 app that uses getUserMedia for camera and microphone access, you've likely hit one or more of these errors on Android while iOS and desktop work perfectly:

• NotAllowedError: Permission denied
• NotReadableError: Could not start audio source

This guide documents every fix needed and explains why Android requires them.

---

Why Android Is Different

Android WebView has a two-layer permission system that doesn't exist on iOS or desktop:

Layer	iOS	Desktop	Android
OS permission popup	✅ Auto-triggers	✅ Auto-triggers	✅ Auto-triggers
WebView must also grant	❌ Not needed	❌ Not needed	✅ Required
Audio focus must be acquired	❌ Not needed	❌ Not needed	✅ Required
The OS popup appearing does not mean the WebView will get access. Both layers must be satisfied independently.

---

Fix 1 — AndroidManifest.xml

Add the microphone feature declaration and audio settings permission. Without MODIFY_AUDIO_SETTINGS, Android's audio subsystem refuses to hand the microphone to the WebView even after the user grants permission — this is what causes NotReadableError.

<uses-permission android:name="android.permission.CAMERA"/>
<uses-permission android:name="android.permission.RECORD_AUDIO"/>

<!-- Required to acquire audio focus — without this you get NotReadableError -->
<uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS"/>

<uses-feature android:name="android.hardware.camera" android:required="true" />
<!-- required="false" so the app installs on devices without a mic -->
<uses-feature android:name="android.hardware.microphone" android:required="false" />

<application ...>
    <activity
        android:hardwareAccelerated="true"
        android:windowSoftInputMode="adjustResize"
        android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|smallestScreenSize|screenLayout|uiMode"
        android:launchMode="singleTask"
        android:name=".MainActivity"
        android:exported="true">
        ...
    </activity>
</application>

---

Fix 2 — MainActivity.kt

This is the most important fix. The original bare MainActivity lets the OS popup appear but the WebView layer silently denies access afterwards. You need to bridge the two layers.

The wrong approaches

Too bare — WebView layer never gets the grant:

// Original — OS popup fires but WebView still denies
class MainActivity : TauriActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        enableEdgeToEdge()
        super.onCreate(savedInstanceState)
    }
}

Blind grant — bypasses the OS dialog entirely:

// Fixes WebView but skips asking the user — bad for security
wv.webChromeClient = object : WebChromeClient() {
    override fun onPermissionRequest(request: PermissionRequest) {
        runOnUiThread { request.grant(request.resources) }
    }
}

The correct approach — bridge both layers

package com.justdare.app

import android.Manifest
import android.content.pm.PackageManager
import android.media.AudioManager
import android.os.Bundle
import android.webkit.PermissionRequest
import android.webkit.WebChromeClient
import android.webkit.WebView
import android.view.ViewGroup
import androidx.activity.enableEdgeToEdge
import androidx.activity.result.contract.ActivityResultContracts
import androidx.core.content.ContextCompat

class MainActivity : TauriActivity() {

    // Holds the pending WebView permission request while we wait for the OS dialog
    private var pendingWebViewPermission: PermissionRequest? = null

    // Launcher for requesting CAMERA + RECORD_AUDIO together
    private val requestPermissionsLauncher = registerForActivityResult(
        ActivityResultContracts.RequestMultiplePermissions()
    ) { grants ->
        val cameraGranted = grants[Manifest.permission.CAMERA] == true
        val audioGranted = grants[Manifest.permission.RECORD_AUDIO] == true

        pendingWebViewPermission?.let { request ->
            val toGrant = mutableListOf<String>()
            if (cameraGranted) toGrant.add(PermissionRequest.RESOURCE_VIDEO_CAPTURE)
            if (audioGranted) toGrant.add(PermissionRequest.RESOURCE_AUDIO_CAPTURE)

            if (toGrant.isNotEmpty()) {
                request.grant(toGrant.toTypedArray())
            } else {
                request.deny()
            }
            pendingWebViewPermission = null
        }
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        enableEdgeToEdge()
        super.onCreate(savedInstanceState)
        WebView.setWebContentsDebuggingEnabled(true)
        hookWebViewPermissions()
    }

    override fun onResume() {
        super.onResume()
        hookWebViewPermissions()
    }

    private fun hookWebViewPermissions() {
        window.decorView.post {
            findWebView(window.decorView.rootView)?.let { wv ->
                wv.settings.javaScriptEnabled = true
                wv.settings.mediaPlaybackRequiresUserGesture = false

                // Tell Android this WebView will use the mic for real-time capture
                val audioManager = getSystemService(AUDIO_SERVICE) as AudioManager
                audioManager.mode = AudioManager.MODE_IN_COMMUNICATION

                wv.webChromeClient = object : WebChromeClient() {
                    override fun onPermissionRequest(request: PermissionRequest) {
                        runOnUiThread {
                            val cameraGranted = ContextCompat.checkSelfPermission(
                                this@MainActivity, Manifest.permission.CAMERA
                            ) == PackageManager.PERMISSION_GRANTED

                            val audioGranted = ContextCompat.checkSelfPermission(
                                this@MainActivity, Manifest.permission.RECORD_AUDIO
                            ) == PackageManager.PERMISSION_GRANTED

                            if (cameraGranted && audioGranted) {
                                // Both already granted — forward immediately to WebView
                                request.grant(request.resources)
                            } else {
                                // Not yet granted — hold the request and show the OS dialog
                                pendingWebViewPermission = request
                                val toRequest = mutableListOf<String>()
                                if (!cameraGranted) toRequest.add(Manifest.permission.CAMERA)
                                if (!audioGranted) toRequest.add(Manifest.permission.RECORD_AUDIO)
                                requestPermissionsLauncher.launch(toRequest.toTypedArray())
                            }
                        }
                    }
                }
            }
        }
    }

    private fun findWebView(view: android.view.View): WebView? {
        if (view is WebView) return view
        if (view is ViewGroup) {
            for (i in 0 until view.childCount) {
                findWebView(view.getChildAt(i))?.let { return it }
            }
        }
        return null
    }
}

How the bridge works

User taps camera button
        ↓
getUserMedia() called in JS
        ↓
Android fires onPermissionRequest on WebChromeClient
        ↓
     Already granted?
      /          \
    YES           NO
     |             |
Grant WebView    Save pending request
immediately      Show OS popup
                      |
              User taps Allow/Deny
                      |
              Grant/deny WebView
              based on user choice

pendingWebViewPermission suspends the WebView's permission request while the OS dialog is shown, then resolves it once the user responds. This is the bridge that was always missing.

---

Fix 3 — tauri.conf.json CSP

Tauri Android serves content from https://tauri.localhost. If this origin isn't in your CSP, Android's stricter WebView security can silently block media device access.

{
  "app": {
    "security": {
      "csp": "default-src 'self' https://tauri.localhost; img-src 'self' data: blob: https://tauri.localhost; media-src 'self' data: blob:; style-src 'self' 'unsafe-inline' https://fonts.googleapis.com; font-src 'self' https://fonts.gstatic.com data:; connect-src 'self' ipc: http://ipc.localhost https://ipc.localhost https://tauri.localhost"
    }
  }
}

---

Error Reference

Error	Cause	Fix
NotAllowedError: Permission denied	WebView layer not bridged to OS permission	Fix 2 — MainActivity.kt
NotReadableError: Could not start audio source	Android audio subsystem not acquired	Fix 1 (MODIFY_AUDIO_SETTINGS) + Fix 2 (AudioManager.MODE_IN_COMMUNICATION)
Permission popup never appears	request.grant() called unconditionally	Fix 2 — check OS permission before granting WebView
Works on iOS/desktop, broken on Android	WebView two-layer system not handled	All fixes above

---

Environment

Tested with:

• Tauri 2.10.3
• tauri-plugin-barcode-scanner 2
• Android minSdk 24, targetSdk 36
• Kotlin JVM target 1.8