refactor: voice recordings on okio paths; host ports for the note composer

- RecordingResult/AnonymizedResult move to commons with okio Path files
  (commons now exposes okio as api); VoiceAnonymizationController moves to
  commonsUI and re-voices through AccountViewModelHost.anonymizeVoice.
- mediaUriOfFile expect/actual replaces Uri.fromFile in the voice uploads.
- AccountViewModelHost gains scheduledPostStore and createWritingAssistant;
  ShortNotePostViewModel no longer reads Amethyst.instance, Context, UUID or
  System time. AMETHYST_CLIENT_TAG_NAME moves to commons.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S7FuNBSKiyVecARSoE4B9P

amethyst/src/main/java/com/vitorpamplona/amethyst/model/accountsCache/AccountCacheState.kt

@@ -32,6 +32,7 @@ import com.vitorpamplona.amethyst.commons.marmot.EncryptedMarmotMessageStore
 import com.vitorpamplona.amethyst.commons.marmot.EncryptedMlsGroupStateStore
 import com.vitorpamplona.amethyst.commons.marmot.EncryptedPublishObligationStore
 import com.vitorpamplona.amethyst.commons.marmot.InMemoryMlsGroupStateStore
+import com.vitorpamplona.amethyst.commons.model.AMETHYST_CLIENT_TAG_NAME
 import com.vitorpamplona.amethyst.commons.model.Account
 import com.vitorpamplona.amethyst.commons.model.AccountSettings
 import com.vitorpamplona.amethyst.commons.model.GeohashIdentityStore
@@ -419,7 +420,7 @@ class AccountCacheState(
     }
 
     companion object {
-        const val CLIENT_TAG_NAME = "Amethyst"
+        const val CLIENT_TAG_NAME = AMETHYST_CLIENT_TAG_NAME
     }
 }
 

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/actions/uploads/RecordAudio.kt

@@ -36,6 +36,7 @@ import androidx.compose.ui.platform.LocalContext
 import com.google.accompanist.permissions.ExperimentalPermissionsApi
 import com.google.accompanist.permissions.isGranted
 import com.google.accompanist.permissions.rememberPermissionState
+import com.vitorpamplona.amethyst.commons.audio.RecordingResult
 import com.vitorpamplona.amethyst.commons.resources.Res
 import com.vitorpamplona.amethyst.commons.resources.record_a_message_description
 import com.vitorpamplona.amethyst.commons.ui.components.ToggleableBox

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/actions/uploads/RecordVoiceButton.kt

@@ -39,6 +39,7 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.unit.dp
 import com.vitorpamplona.amethyst.commons.audio.ExpandingCirclesAnimation
 import com.vitorpamplona.amethyst.commons.audio.FloatingRecordingIndicator
+import com.vitorpamplona.amethyst.commons.audio.RecordingResult
 import com.vitorpamplona.amethyst.commons.icons.symbols.Icon
 import com.vitorpamplona.amethyst.commons.icons.symbols.MaterialSymbols
 import com.vitorpamplona.amethyst.commons.resources.Res

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/actions/uploads/VoiceAnonymizer.kt

@@ -25,6 +25,7 @@ import android.media.MediaCodecInfo
 import android.media.MediaExtractor
 import android.media.MediaFormat
 import android.media.MediaMuxer
+import com.vitorpamplona.amethyst.commons.audio.AnonymizedResult
 import com.vitorpamplona.amethyst.commons.audio.PitchShifter
 import com.vitorpamplona.amethyst.commons.audio.VoicePreset
 import com.vitorpamplona.quartz.utils.Log
@@ -33,24 +34,12 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.currentCoroutineContext
 import kotlinx.coroutines.isActive
 import kotlinx.coroutines.withContext
+import okio.Path.Companion.toOkioPath
 import java.io.File
 import java.nio.ByteBuffer
 import java.nio.ByteOrder
 import kotlin.math.abs
 
-/**
- * Result of voice anonymization processing.
- *
- * @property file The output audio file (AAC in MP4 container)
- * @property waveform Amplitude data for waveform visualization (one value per second)
- * @property duration Audio duration in seconds
- */
-data class AnonymizedResult(
-    val file: File,
-    val waveform: List<Float>,
-    val duration: Int,
-)
-
 /**
  * Processes audio files to alter voice characteristics for privacy.
  *
@@ -109,7 +98,7 @@ class VoiceAnonymizer {
                 }
 
                 onProgress(1f)
-                Result.success(AnonymizedResult(outputFile, waveform, duration))
+                Result.success(AnonymizedResult(outputFile.toOkioPath(), waveform, duration))
             } catch (e: CancellationException) {
                 // Let cancellation propagate so structured concurrency works (e.g. the
                 // upload screen being dismissed cancels this job).

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/actions/uploads/VoiceMessagePreview.kt

@@ -48,6 +48,7 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Brush
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.unit.dp
+import com.vitorpamplona.amethyst.commons.audio.RecordingResult
 import com.vitorpamplona.amethyst.commons.icons.symbols.Icon
 import com.vitorpamplona.amethyst.commons.icons.symbols.MaterialSymbols
 import com.vitorpamplona.amethyst.commons.resources.Res
@@ -64,12 +65,12 @@ import com.vitorpamplona.quartz.nipA0VoiceMessages.AudioMeta
 import com.vitorpamplona.quartz.utils.Log
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.isActive
-import java.io.File
+import okio.Path
 
 @Composable
 fun VoiceMessagePreview(
     voiceMetadata: AudioMeta,
-    localFile: File? = null,
+    localFile: Path? = null,
     onRemove: () -> Unit,
     onReRecord: ((RecordingResult) -> Unit)? = null,
     isUploading: Boolean = false,
@@ -263,7 +264,7 @@ private fun ReRecordButton(
 @Composable
 private fun ManageMediaPlayer(
     voiceMetadata: AudioMeta,
-    localFile: File?,
+    localFile: Path?,
     onCompletion: () -> Unit,
     onPlayerChanged: (MediaPlayer?) -> Unit,
     onRelease: () -> Unit,
@@ -371,12 +372,12 @@ private fun handleWaveformScrub(
 
 private fun createMediaPlayer(
     url: String,
-    localFile: File?,
+    localFile: Path?,
 ): MediaPlayer? =
     try {
         MediaPlayer().apply {
-            if (localFile != null && localFile.exists()) {
-                setDataSource(localFile.absolutePath)
+            if (localFile != null && localFile.toFile().exists()) {
+                setDataSource(localFile.toString())
             } else {
                 setDataSource(url)
             }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/actions/uploads/VoiceMessageRecorder.kt

@@ -24,6 +24,7 @@ import android.content.Context
 import android.media.MediaRecorder
 import android.os.Build
 import androidx.media3.common.MimeTypes
+import com.vitorpamplona.amethyst.commons.audio.RecordingResult
 import com.vitorpamplona.quartz.utils.Log
 import com.vitorpamplona.quartz.utils.RandomInstance
 import com.vitorpamplona.quartz.utils.TimeUtils
@@ -35,15 +36,9 @@ import kotlinx.coroutines.cancel
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.isActive
 import kotlinx.coroutines.launch
+import okio.Path.Companion.toOkioPath
 import java.io.File
 
-class RecordingResult(
-    val file: File,
-    val mimeType: String,
-    val amplitudes: List<Float>,
-    val duration: Int,
-)
-
 @Suppress("DEPRECATION")
 class VoiceMessageRecorder {
     @Volatile
@@ -145,7 +140,7 @@ class VoiceMessageRecorder {
 
         return if (duration >= 1 && file != null) {
             RecordingResult(
-                file,
+                file.toOkioPath(),
                 MimeTypes.AUDIO_AAC,
                 amplitudesCopy,
                 duration,

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/ReactionsRow.kt

@@ -756,7 +756,7 @@ fun ReplyViaVoiceReaction(
             nav.nav {
                 Route.VoiceReply(
                     replyToNoteId = baseNote.idHex,
-                    recordingFilePath = audio.file.absolutePath,
+                    recordingFilePath = audio.file.toString(),
                     mimeType = audio.mimeType,
                     duration = audio.duration,
                     amplitudes = Json.encodeToString(audio.amplitudes),

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/AndroidAccountViewModelHost.kt

@@ -25,7 +25,11 @@ import androidx.core.content.ContextCompat
 import com.vitorpamplona.amethyst.AccountInfo
 import com.vitorpamplona.amethyst.AppModules
 import com.vitorpamplona.amethyst.LocalPreferences
+import com.vitorpamplona.amethyst.commons.audio.AnonymizedResult
+import com.vitorpamplona.amethyst.commons.audio.VoicePreset
 import com.vitorpamplona.amethyst.commons.model.location.DeviceLocation
+import com.vitorpamplona.amethyst.commons.scheduledposts.ScheduledPostStore
+import com.vitorpamplona.amethyst.commons.service.ai.WritingAssistant
 import com.vitorpamplona.amethyst.commons.service.lnurl.LnurlHttpTransport
 import com.vitorpamplona.amethyst.commons.service.lnurl.OkHttpLnurlTransport
 import com.vitorpamplona.amethyst.commons.service.pow.PoWJobFailure
@@ -33,8 +37,10 @@ import com.vitorpamplona.amethyst.commons.service.uploads.MediaUploader
 import com.vitorpamplona.amethyst.commons.tor.MoneyOpRelayRouting
 import com.vitorpamplona.amethyst.commons.tor.TorRelayEvaluation
 import com.vitorpamplona.amethyst.commons.viewmodels.AccountViewModelHost
+import com.vitorpamplona.amethyst.service.ai.WritingAssistantFactory
 import com.vitorpamplona.amethyst.service.notifications.NotificationUtils.dismissNotificationForEvent
 import com.vitorpamplona.amethyst.service.uploads.AndroidMediaUploader
+import com.vitorpamplona.amethyst.ui.actions.uploads.VoiceAnonymizer
 import com.vitorpamplona.amethyst.ui.note.payViaIntent
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.toHexKey
@@ -49,6 +55,7 @@ import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.onStart
+import okio.Path
 
 /** [AccountViewModelHost] over the app's [AppModules]. Lazy services are read on first use. */
 class AndroidAccountViewModelHost(
@@ -77,6 +84,16 @@ class AndroidAccountViewModelHost(
 
     override val deviceLocation: DeviceLocation get() = modules.locationManager
 
+    override val scheduledPostStore: ScheduledPostStore get() = modules.scheduledPostStore
+
+    override suspend fun anonymizeVoice(
+        input: Path,
+        presetName: String,
+    ): Result<AnonymizedResult> = VoiceAnonymizer().anonymize(input.toFile(), VoicePreset.valueOf(presetName))
+
+    // Built on the application context: the assistant outlives any one Activity inside the ViewModel.
+    override fun createWritingAssistant(): WritingAssistant = WritingAssistantFactory.create(modules.appContext)
+
     override val savedAccounts: Flow<Set<HexKey>> =
         LocalPreferences
             .accountsFlow()

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/cordnGroup/CordnComposer.kt

@@ -42,6 +42,7 @@ import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.unit.dp
+import com.vitorpamplona.amethyst.commons.audio.RecordingResult
 import com.vitorpamplona.amethyst.commons.chats.ui.ThinSendButton
 import com.vitorpamplona.amethyst.commons.model.cordnGroups.CordnGroupChatroom
 import com.vitorpamplona.amethyst.commons.model.nip30CustomEmojis.EmojiPackState
@@ -65,7 +66,6 @@ import com.vitorpamplona.amethyst.commons.ui.theme.EditFieldTrailingIconModifier
 import com.vitorpamplona.amethyst.commons.ui.theme.SuggestionListDefaultHeightChat
 import com.vitorpamplona.amethyst.commons.ui.theme.placeholderText
 import com.vitorpamplona.amethyst.commons.viewmodels.AccountViewModel
-import com.vitorpamplona.amethyst.ui.actions.uploads.RecordingResult
 import com.vitorpamplona.amethyst.ui.actions.uploads.VoiceMessagePreview
 import com.vitorpamplona.quartz.nipA0VoiceMessages.AudioMeta
 

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/cordnGroup/CordnGroupChatScreen.kt

@@ -68,6 +68,7 @@ import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.unit.dp
 import androidx.core.content.ContextCompat
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.vitorpamplona.amethyst.commons.audio.RecordingResult
 import com.vitorpamplona.amethyst.commons.audio.WaveformData
 import com.vitorpamplona.amethyst.commons.chats.ui.AutoScrollToNewest
 import com.vitorpamplona.amethyst.commons.cordn.CordnGroupManager
@@ -121,7 +122,6 @@ import com.vitorpamplona.amethyst.commons.ui.theme.placeholderText
 import com.vitorpamplona.amethyst.commons.viewmodels.AccountViewModel
 import com.vitorpamplona.amethyst.model.cordn.CordnMediaService
 import com.vitorpamplona.amethyst.service.uploads.MetadataStripper
-import com.vitorpamplona.amethyst.ui.actions.uploads.RecordingResult
 import com.vitorpamplona.amethyst.ui.actions.uploads.VoiceMessageRecorder
 import com.vitorpamplona.amethyst.ui.note.types.RenderAudioWaveformPlayer
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.utils.ChatFileUploadDialog
@@ -219,7 +219,7 @@ private fun CordnGroupChat(
             // it after sending. A note recorded and then abandoned — the screen closed,
             // the room switched — never reached that, so it stayed on disk: an
             // unencrypted copy of a message that was never even sent.
-            pendingVoice?.file?.delete()
+            pendingVoice?.file?.toFile()?.delete()
         }
     }
     var attachError by remember { mutableStateOf<String?>(null) }
@@ -595,11 +595,11 @@ private fun CordnGroupChat(
                 onVoiceNote = { recording ->
                     // Re-recording replaces what was there; the old file is a temp
                     // file this screen owns, so it goes now rather than being leaked.
-                    pendingVoice?.file?.delete()
+                    pendingVoice?.file?.toFile()?.delete()
                     pendingVoice = recording
                 },
                 onRemoveVoice = {
-                    pendingVoice?.file?.delete()
+                    pendingVoice?.file?.toFile()?.delete()
                     pendingVoice = null
                 },
                 attaching = attaching,
@@ -1311,7 +1311,7 @@ private suspend fun sendVoiceNote(
             ?: throw CordnAttachmentException(loadStringRes(Res.string.cordn_send_no_session))
 
     try {
-        val bytes = withContext(Dispatchers.IO) { recording.file.readBytes() }
+        val bytes = withContext(Dispatchers.IO) { recording.file.toFile().readBytes() }
         val tag =
             CordnMediaService(accountViewModel.account)
                 .upload(
@@ -1331,7 +1331,7 @@ private suspend fun sendVoiceNote(
         // invisible to the person who sent it.
         room.add(session.manager.send(room.gid, content = caption.trim(), tags = arrayOf(tag)))
     } finally {
-        withContext(Dispatchers.IO) { recording.file.delete() }
+        withContext(Dispatchers.IO) { recording.file.toFile().delete() }
     }
 }
 

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/home/ShortNotePostScreen.kt

@@ -63,7 +63,6 @@ import androidx.compose.ui.Alignment.Companion.CenterVertically
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.hapticfeedback.HapticFeedbackType
-import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.platform.LocalHapticFeedback
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.tooling.preview.Preview
@@ -192,7 +191,6 @@ fun ShortNotePostScreen(
     postViewModel.init(accountViewModel)
     postViewModel.setGroupThread(groupThreadId, groupThreadRelayUrl)
 
-    val context = LocalContext.current
     val mediaResolver = rememberSharedMediaResolver()
 
     val proposeAiImprovements by
@@ -201,8 +199,7 @@ fun ShortNotePostScreen(
 
     LaunchedEffect(proposeAiImprovements) {
         if (proposeAiImprovements == BooleanType.ALWAYS) {
-            // The assistant outlives this Activity inside the ViewModel, so it must not hold it.
-            postViewModel.initWritingAssistant(context.applicationContext)
+            postViewModel.initWritingAssistant()
         }
     }
 

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/home/ShortNotePostViewModel.kt

@@ -20,7 +20,6 @@
  */
 package com.vitorpamplona.amethyst.ui.screen.loggedIn.home
 
-import android.content.Context
 import androidx.compose.foundation.text.input.TextFieldState
 import androidx.compose.foundation.text.input.clearText
 import androidx.compose.foundation.text.input.setTextAndPlaceCursorAtEnd
@@ -33,8 +32,10 @@ import androidx.compose.runtime.setValue
 import androidx.compose.runtime.snapshots.SnapshotStateMap
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
-import com.vitorpamplona.amethyst.Amethyst
+import com.vitorpamplona.amethyst.commons.audio.RecordingResult
+import com.vitorpamplona.amethyst.commons.audio.VoiceAnonymizationController
 import com.vitorpamplona.amethyst.commons.audio.VoicePreset
+import com.vitorpamplona.amethyst.commons.model.AMETHYST_CLIENT_TAG_NAME
 import com.vitorpamplona.amethyst.commons.model.Account
 import com.vitorpamplona.amethyst.commons.model.AddressableNote
 import com.vitorpamplona.amethyst.commons.model.BooleanType
@@ -77,6 +78,7 @@ import com.vitorpamplona.amethyst.commons.service.uploads.SelectedMedia
 import com.vitorpamplona.amethyst.commons.service.uploads.SelectedMediaProcessing
 import com.vitorpamplona.amethyst.commons.service.uploads.UploadOrchestrator
 import com.vitorpamplona.amethyst.commons.service.uploads.UploadingState
+import com.vitorpamplona.amethyst.commons.service.uploads.mediaUriOfFile
 import com.vitorpamplona.amethyst.commons.ui.loadStringRes
 import com.vitorpamplona.amethyst.commons.ui.note.creators.messagefield.IMessageField
 import com.vitorpamplona.amethyst.commons.ui.note.creators.notify.IAudience
@@ -89,11 +91,8 @@ import com.vitorpamplona.amethyst.commons.ui.text.onUiThread
 import com.vitorpamplona.amethyst.commons.ui.text.replaceCurrentWord
 import com.vitorpamplona.amethyst.commons.ui.text.setTextAndPlaceCursorAtBeginning
 import com.vitorpamplona.amethyst.commons.ui.uploads.errorResource
+import com.vitorpamplona.amethyst.commons.util.platformFileSystem
 import com.vitorpamplona.amethyst.commons.viewmodels.AccountViewModel
-import com.vitorpamplona.amethyst.model.accountsCache.AccountCacheState
-import com.vitorpamplona.amethyst.service.ai.WritingAssistantFactory
-import com.vitorpamplona.amethyst.ui.actions.uploads.RecordingResult
-import com.vitorpamplona.amethyst.ui.actions.uploads.VoiceAnonymizationController
 import com.vitorpamplona.amethyst.ui.note.creators.location.ILocationGrabber
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.privateDM.send.IMetaAttachments
 import com.vitorpamplona.quartz.experimental.nip95.data.FileStorageEvent
@@ -188,7 +187,9 @@ import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.collectLatest
 import kotlinx.coroutines.launch
-import java.util.UUID
+import okio.Path
+import kotlin.uuid.ExperimentalUuidApi
+import kotlin.uuid.Uuid
 
 enum class UserSuggestionAnchor {
     MAIN_MESSAGE,
@@ -287,7 +288,7 @@ open class ShortNotePostViewModel :
 
     // Voice Messages
     var voiceRecording by mutableStateOf<RecordingResult?>(null)
-    var voiceLocalFile by mutableStateOf<java.io.File?>(null)
+    var voiceLocalFile by mutableStateOf<Path?>(null)
     var isUploadingVoice by mutableStateOf(false)
     var voiceMetadata by mutableStateOf<AudioMeta?>(null)
     var voiceSelectedServer by mutableStateOf<ServerName?>(null)
@@ -305,9 +306,10 @@ open class ShortNotePostViewModel :
                     error,
                 )
             },
+            anonymize = { file, preset -> accountViewModel.host.anonymizeVoice(file, preset.name) },
         )
 
-    val activeFile: java.io.File?
+    val activeFile: Path?
         get() = voiceAnonymization.activeFile(voiceLocalFile)
 
     val activeWaveform: List<Float>?
@@ -478,9 +480,9 @@ open class ShortNotePostViewModel :
         accountViewModel.settings.uiSettingsFlow.automaticallyProposeAiImprovements.value ==
             BooleanType.ALWAYS
 
-    fun initWritingAssistant(context: Context) {
+    fun initWritingAssistant() {
         if (writingAssistant != null) return
-        writingAssistant = WritingAssistantFactory.create(context)
+        writingAssistant = accountViewModel.host.createWritingAssistant() ?: return
         refreshAiStatus()
     }
 
@@ -1260,21 +1262,23 @@ open class ShortNotePostViewModel :
      * Runs on the mining queue's scope when PoW is on, so it must not touch
      * viewModelScope.
      */
+    @OptIn(ExperimentalUuidApi::class)
     private suspend fun storeScheduledPost(
         template: EventTemplate<out Event>,
         extraNotesToBroadcast: List<Event>,
         publishAtSec: Long,
     ) {
         val (event, relays, extras) = accountViewModel.account.createPostEvent(template, extraNotesToBroadcast)
-        Amethyst.instance.scheduledPostStore.add(
+        val store = accountViewModel.host.scheduledPostStore ?: return
+        store.add(
             ScheduledPost(
-                id = UUID.randomUUID().toString(),
+                id = Uuid.random().toString(),
                 accountPubkey = event.pubKey,
                 signedEventJson = event.toJson(),
                 relayUrls = relays.map { it.url },
                 extraEventsJson = extras.map { it.toJson() },
                 publishAtSec = publishAtSec,
-                createdAtSec = System.currentTimeMillis() / 1000,
+                createdAtSec = TimeUtils.now(),
             ),
         )
     }
@@ -1570,7 +1574,7 @@ open class ShortNotePostViewModel :
         val replyingToEvent = originalNote?.event ?: return false
         return replyingToEvent is TextNoteEvent &&
             replyingToEvent.isNewThread() &&
-            replyingToEvent.isClient(AccountCacheState.CLIENT_TAG_NAME)
+            replyingToEvent.isClient(AMETHYST_CLIENT_TAG_NAME)
     }
 
     fun upload(
@@ -1916,14 +1920,13 @@ open class ShortNotePostViewModel :
         voiceOrchestrator = null
     }
 
-    private fun deleteVoiceLocalFile(toDelete: java.io.File? = voiceLocalFile) {
+    private fun deleteVoiceLocalFile(toDelete: Path? = voiceLocalFile) {
         toDelete?.let { file ->
             try {
-                if (file.delete()) {
-                    Log.d("ShortNotePostViewModel") { "Deleted voice file: ${file.absolutePath}" }
-                }
+                platformFileSystem.delete(file, mustExist = false)
+                Log.d("ShortNotePostViewModel") { "Deleted voice file: $file" }
             } catch (e: Exception) {
-                Log.w("ShortNotePostViewModel", "Failed to delete voice file: ${file.absolutePath}", e)
+                Log.w("ShortNotePostViewModel", "Failed to delete voice file: $file", e)
             }
         }
     }
@@ -1942,7 +1945,7 @@ open class ShortNotePostViewModel :
         isUploadingVoice = true
 
         try {
-            val uri = android.net.Uri.fromFile(fileToUpload)
+            val uri = mediaUriOfFile(fileToUpload)
             val orchestrator = UploadOrchestrator()
             voiceOrchestrator = orchestrator
 

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/home/VoiceReplyViewModel.kt

@@ -27,6 +27,8 @@ import androidx.compose.runtime.setValue
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import com.vitorpamplona.amethyst.Amethyst
+import com.vitorpamplona.amethyst.commons.audio.RecordingResult
+import com.vitorpamplona.amethyst.commons.audio.VoiceAnonymizationController
 import com.vitorpamplona.amethyst.commons.audio.VoicePreset
 import com.vitorpamplona.amethyst.commons.model.Note
 import com.vitorpamplona.amethyst.commons.model.cache.LocalCache
@@ -41,11 +43,10 @@ import com.vitorpamplona.amethyst.commons.service.pow.PoWReplay
 import com.vitorpamplona.amethyst.commons.service.uploads.CompressorQuality
 import com.vitorpamplona.amethyst.commons.service.uploads.UploadOrchestrator
 import com.vitorpamplona.amethyst.commons.service.uploads.UploadingState
+import com.vitorpamplona.amethyst.commons.service.uploads.mediaUriOfFile
 import com.vitorpamplona.amethyst.commons.ui.loadStringRes
-import com.vitorpamplona.amethyst.commons.util.deleteOrWarn
+import com.vitorpamplona.amethyst.commons.util.platformFileSystem
 import com.vitorpamplona.amethyst.commons.viewmodels.AccountViewModel
-import com.vitorpamplona.amethyst.ui.actions.uploads.RecordingResult
-import com.vitorpamplona.amethyst.ui.actions.uploads.VoiceAnonymizationController
 import com.vitorpamplona.quartz.nip01Core.tags.people.toPTag
 import com.vitorpamplona.quartz.nip10Notes.TextNoteEvent
 import com.vitorpamplona.quartz.nip10Notes.tags.markedETags
@@ -61,7 +62,8 @@ import kotlinx.coroutines.Job
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import kotlinx.serialization.json.Json
-import java.io.File
+import okio.Path
+import okio.Path.Companion.toPath
 
 @Stable
 class VoiceReplyViewModel : ViewModel() {
@@ -70,7 +72,7 @@ class VoiceReplyViewModel : ViewModel() {
     var replyToNote: Note? by mutableStateOf(null)
 
     var voiceRecording: RecordingResult? by mutableStateOf(null)
-    var voiceLocalFile: File? by mutableStateOf(null)
+    var voiceLocalFile: Path? by mutableStateOf(null)
     var voiceMetadata: AudioMeta? by mutableStateOf(null)
     var voiceSelectedServer: ServerName? by mutableStateOf(null)
     var voiceOrchestrator: UploadOrchestrator? by mutableStateOf(null)
@@ -89,9 +91,10 @@ class VoiceReplyViewModel : ViewModel() {
                     )
                 }
             },
+            anonymize = { file, preset -> accountViewModel.host.anonymizeVoice(file, preset.name) },
         )
 
-    val activeFile: File?
+    val activeFile: Path?
         get() = voiceAnonymization.activeFile(voiceLocalFile)
 
     val activeWaveform: List<Float>?
@@ -126,7 +129,7 @@ class VoiceReplyViewModel : ViewModel() {
                 emptyList()
             }
 
-        val file = File(recordingFilePath)
+        val file = recordingFilePath.toPath()
         voiceLocalFile = file
         voiceRecording =
             RecordingResult(
@@ -164,11 +167,10 @@ class VoiceReplyViewModel : ViewModel() {
     private fun deleteVoiceLocalFile() {
         voiceLocalFile?.let { file ->
             try {
-                if (file.deleteOrWarn("VoiceReplyViewModel", "voice file")) {
-                    Log.d("VoiceReplyViewModel") { "Voice file removed or already gone: ${file.absolutePath}" }
-                }
+                platformFileSystem.delete(file, mustExist = false)
+                Log.d("VoiceReplyViewModel") { "Voice file removed or already gone: $file" }
             } catch (e: Exception) {
-                Log.w("VoiceReplyViewModel", "Failed to delete voice file: ${file.absolutePath}", e)
+                Log.w("VoiceReplyViewModel", "Failed to delete voice file: $file", e)
             }
         }
     }
@@ -195,7 +197,7 @@ class VoiceReplyViewModel : ViewModel() {
                 try {
                     val result =
                         withContext(Dispatchers.IO) {
-                            val uri = android.net.Uri.fromFile(fileToUpload)
+                            val uri = mediaUriOfFile(fileToUpload)
                             orchestrator.upload(
                                 uri = uri,
                                 mimeType = recording.mimeType,

commons/build.gradle.kts

@@ -87,8 +87,9 @@ kotlin {
                 // the ForwardingFileSystem the apps wrap Coil's disk cache in. It
                 // used to arrive transitively through Coil; with Coil in
                 // :commonsUI the Apple targets lost it (JVM still saw it via
-                // OkHttp), so declare the dependency the file actually has.
-                implementation(libs.okio)
+                // OkHttp), so declare the dependency the file actually has. `api`
+                // because voice recordings cross module boundaries as okio Paths.
+                api(libs.okio)
 
                 // DataStore (KMP, Apache-2.0) — the preference storage layer.
                 // Publishes android/jvm/ios/linux/macos variants plus common

commons/src/androidMain/kotlin/com/vitorpamplona/amethyst/commons/service/uploads/MediaUri.android.kt

@@ -21,7 +21,10 @@
 package com.vitorpamplona.amethyst.commons.service.uploads
 
 import android.net.Uri
+import okio.Path
 
 actual typealias MediaUri = Uri
 
 actual fun MediaUri.lastPathSegmentOrNull(): String? = lastPathSegment
+
+actual fun mediaUriOfFile(path: Path): MediaUri = Uri.fromFile(path.toFile())

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/audio/VoiceRecording.kt

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.commons.audio
+
+import okio.Path
+
+/** A finished voice-message recording: the audio file, its type, and its waveform. */
+class RecordingResult(
+    val file: Path,
+    val mimeType: String,
+    val amplitudes: List<Float>,
+    val duration: Int,
+)
+
+/**
+ * A recording re-voiced for privacy.
+ *
+ * @property file The output audio file (AAC in MP4 container)
+ * @property waveform Amplitude data for waveform visualization (one value per second)
+ * @property duration Audio duration in seconds
+ */
+data class AnonymizedResult(
+    val file: Path,
+    val waveform: List<Float>,
+    val duration: Int,
+)

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/model/ClientTag.kt

@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.commons.model
+
+/** The name this app signs into NIP-89 `client` tags, and recognizes on events it wrote. */
+const val AMETHYST_CLIENT_TAG_NAME = "Amethyst"

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/service/uploads/MediaUri.kt

@@ -20,6 +20,8 @@
  */
 package com.vitorpamplona.amethyst.commons.service.uploads
 
+import okio.Path
+
 /**
  * A picked file's address as the platform hands it over: Android's `content://` [android.net.Uri]
  * (a typealias there, so app code keeps reading it as a `Uri`), a string-backed subclass
@@ -30,6 +32,9 @@ expect abstract class MediaUri {
     abstract override fun toString(): String
 }
 
+/** The address of a local file, such as a voice recording the app wrote itself. */
+expect fun mediaUriOfFile(path: Path): MediaUri
+
 /** The last path segment of this address, if it has one (on Android, `Uri.lastPathSegment`). */
 expect fun MediaUri.lastPathSegmentOrNull(): String?
 

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/viewmodels/AccountViewModelHost.kt

@@ -20,7 +20,10 @@
  */
 package com.vitorpamplona.amethyst.commons.viewmodels
 
+import com.vitorpamplona.amethyst.commons.audio.AnonymizedResult
 import com.vitorpamplona.amethyst.commons.model.location.DeviceLocation
+import com.vitorpamplona.amethyst.commons.scheduledposts.ScheduledPostStore
+import com.vitorpamplona.amethyst.commons.service.ai.WritingAssistant
 import com.vitorpamplona.amethyst.commons.service.lnurl.LnurlHttpTransport
 import com.vitorpamplona.amethyst.commons.service.pow.PoWJobFailure
 import com.vitorpamplona.amethyst.commons.service.uploads.MediaUploader
@@ -34,6 +37,7 @@ import com.vitorpamplona.quartz.nip01Core.relay.sockets.WebsocketBuilder
 import kotlinx.collections.immutable.PersistentMap
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.StateFlow
+import okio.Path
 
 /**
  * What the account's ViewModel needs from the process it runs in: app-wide services that outlive
@@ -74,6 +78,21 @@ interface AccountViewModelHost {
     /** The device's position as geohashes. */
     val deviceLocation: DeviceLocation get() = DeviceLocation.None
 
+    /** Posts signed now and published later by a background worker; null where scheduling is unsupported. */
+    val scheduledPostStore: ScheduledPostStore? get() = null
+
+    /**
+     * Re-voices the recording at [input] with the voice preset named [presetName], into a new file
+     * beside it.
+     */
+    suspend fun anonymizeVoice(
+        input: Path,
+        presetName: String,
+    ): Result<AnonymizedResult> = Result.failure(UnsupportedOperationException("Voice anonymization is not available on this platform"))
+
+    /** A new on-device writing assistant, or null where the platform has none. */
+    fun createWritingAssistant(): WritingAssistant? = null
+
     /** Public keys of every account saved on this device. */
     val savedAccounts: Flow<Set<HexKey>>
 

commons/src/iosMain/kotlin/com/vitorpamplona/amethyst/commons/service/uploads/MediaUri.ios.kt

@@ -20,6 +20,8 @@
  */
 package com.vitorpamplona.amethyst.commons.service.uploads
 
+import okio.Path
+
 actual abstract class MediaUri {
     actual abstract override fun toString(): String
 }
@@ -38,3 +40,5 @@ class StringMediaUri(
 }
 
 actual fun MediaUri.lastPathSegmentOrNull(): String? = lastPathSegmentOf(toString())
+
+actual fun mediaUriOfFile(path: Path): MediaUri = StringMediaUri(path.toString())

commons/src/jvmMain/kotlin/com/vitorpamplona/amethyst/commons/service/uploads/MediaUri.jvm.kt

@@ -20,6 +20,8 @@
  */
 package com.vitorpamplona.amethyst.commons.service.uploads
 
+import okio.Path
+
 actual abstract class MediaUri {
     actual abstract override fun toString(): String
 }
@@ -38,3 +40,5 @@ class StringMediaUri(
 }
 
 actual fun MediaUri.lastPathSegmentOrNull(): String? = lastPathSegmentOf(toString())
+
+actual fun mediaUriOfFile(path: Path): MediaUri = StringMediaUri(path.toString())

commonsUI/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/audio/VoiceAnonymizationController.kt

@@ -18,22 +18,24 @@
  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
-package com.vitorpamplona.amethyst.ui.actions.uploads
+package com.vitorpamplona.amethyst.commons.audio
 
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.setValue
-import com.vitorpamplona.amethyst.commons.audio.VoicePreset
+import com.vitorpamplona.amethyst.commons.util.platformFileSystem
 import com.vitorpamplona.quartz.utils.Log
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.launch
-import java.io.File
+import okio.Path
 
 class VoiceAnonymizationController(
     private val scope: CoroutineScope,
     private val logTag: String,
     private val onError: (Throwable) -> Unit,
+    /** Re-voices a recording with a preset; the platform's audio pipeline, reached through the host. */
+    private val anonymize: suspend (Path, VoicePreset) -> Result<AnonymizedResult>,
 ) {
     var selectedPreset: VoicePreset by mutableStateOf(VoicePreset.NONE)
         private set
@@ -44,7 +46,7 @@ class VoiceAnonymizationController(
 
     private var processingJob: Job? = null
 
-    fun activeFile(originalFile: File?): File? =
+    fun activeFile(originalFile: Path?): Path? =
         if (selectedPreset == VoicePreset.NONE) {
             originalFile
         } else {
@@ -60,7 +62,7 @@ class VoiceAnonymizationController(
 
     fun selectPreset(
         preset: VoicePreset,
-        originalFile: File?,
+        originalFile: Path?,
     ) {
         Log.d(logTag) { "selectPreset called with: ${preset.name}, pitchFactor: ${preset.pitchFactor}" }
         if (processingPreset != null || preset == selectedPreset) return
@@ -82,8 +84,7 @@ class VoiceAnonymizationController(
         processingJob =
             scope.launch {
                 try {
-                    val anonymizer = VoiceAnonymizer()
-                    val result = anonymizer.anonymize(file, preset)
+                    val result = anonymize(file, preset)
 
                     result
                         .onSuccess { anonymizedResult ->
@@ -109,15 +110,10 @@ class VoiceAnonymizationController(
     fun deleteDistortedFiles() {
         distortedFiles.values.forEach { result ->
             try {
-                if (result.file.exists()) {
-                    if (result.file.delete()) {
-                        Log.d(logTag) { "Deleted distorted file: ${result.file.absolutePath}" }
-                    } else {
-                        Log.w(logTag) { "Failed to delete distorted file: ${result.file.absolutePath}" }
-                    }
-                }
+                platformFileSystem.delete(result.file, mustExist = false)
+                Log.d(logTag) { "Deleted distorted file: ${result.file}" }
             } catch (e: Exception) {
-                Log.w(logTag, "Failed to delete distorted file: ${result.file.absolutePath}", e)
+                Log.w(logTag, "Failed to delete distorted file: ${result.file}", e)
             }
         }
         distortedFiles = emptyMap()