Merge pull request #4135 from vitorpamplona/claude/relaxed-hawking-7otkl6

NIP-71 video interop, and a renderer for every NIP-51 list kind

.claude/skills/searchable-events/references/searchable-kinds.md

@@ -138,6 +138,7 @@ Separator legend: **NL** = `joinToString("\n")`, **SP** = `joinToString(" ")`.
 | 39000 | GroupMetadataEvent | nip29RelayGroups/metadata | `listOfNotNull(name(), about())` NL |
 | 39089 | FollowListEvent | nip51Lists/followList | `listOfNotNull(title(), description())` NL |
 | 39092 | MediaStarterPackEvent | nip51Lists/mediaStarterPack | `listOfNotNull(title(), description())` NL |
+| 39307 | TextTrackEvent | nip71Video/textTrack | `content` (the WebVTT cue text) |
 | 39701 | WebBookmarkEvent | nipB0WebBookmarks | `listOfNotNull(title(), description())` NL |
 | 40002 | StreamMessageV2Event | buzz/stream | `content` |
 | 40100 | CanvasEvent | buzz/stream | `content` |

amethyst/src/main/java/com/vitorpamplona/amethyst/model/Account.kt

@@ -316,6 +316,7 @@ import com.vitorpamplona.quartz.nip72ModCommunities.rules.tags.PubkeyRuleTag
 import com.vitorpamplona.quartz.nip72ModCommunities.rules.tags.WotTag
 import com.vitorpamplona.quartz.nip85TrustedAssertions.list.tags.ServiceProviderTag
 import com.vitorpamplona.quartz.nip88Polls.poll.PollEvent
+import com.vitorpamplona.quartz.nip88Polls.poll.tags.PollType
 import com.vitorpamplona.quartz.nip88Polls.response.PollResponseEvent
 import com.vitorpamplona.quartz.nip89AppHandlers.clientTag.NostrSignerWithClientTag
 import com.vitorpamplona.quartz.nip89AppHandlers.clientTag.withoutClientTag
@@ -1209,6 +1210,12 @@ class Account(
         }
     }
 
+    suspend fun changeCaptionsEnabled(enabled: Boolean) {
+        if (settings.changeCaptionsEnabled(enabled)) {
+            sendNewAppSpecificData()
+        }
+    }
+
     suspend fun changeVideoPlayerButtonItems(items: List<VideoPlayerButtonItem>) {
         if (settings.changeVideoPlayerButtonItems(items)) {
             sendNewAppSpecificData()
@@ -2309,7 +2316,15 @@ class Account(
         val poll = cache.getOrCreateNote(event.id).toEventHint<PollEvent>()
 
         if (poll != null) {
-            val template = PollResponseEvent.build(poll, responses)
+            // The poll decides how its answers are counted, so it decides which builder applies:
+            // a single-choice answer is the first tag only, and sending several would record
+            // whichever one the reader saw first.
+            val template =
+                when (event.pollType()) {
+                    PollType.SINGLE_CHOICE ->
+                        responses.firstOrNull()?.let { PollResponseEvent.buildSingleChoice(poll, it) } ?: return
+                    PollType.MULTI_CHOICE -> PollResponseEvent.buildMultipleChoice(poll, responses)
+                }
 
             val signedEvent = signer.sign(template)
 

amethyst/src/main/java/com/vitorpamplona/amethyst/model/AccountSettings.kt

@@ -410,6 +410,15 @@ class AccountSettings(
         return false
     }
 
+    fun changeCaptionsEnabled(enabled: Boolean): Boolean {
+        if (syncedSettings.videoPlayer.captionsEnabled.value != enabled) {
+            syncedSettings.videoPlayer.captionsEnabled.tryEmit(enabled)
+            saveAccountSettings()
+            return true
+        }
+        return false
+    }
+
     fun changeAudioVisualizer(style: VisualizerStyle): Boolean {
         if (syncedSettings.media.audioVisualizer.value != style) {
             syncedSettings.media.audioVisualizer.tryEmit(style)

amethyst/src/main/java/com/vitorpamplona/amethyst/model/AccountSyncedSettings.kt

@@ -70,6 +70,7 @@ class AccountSyncedSettings(
     val videoPlayer =
         AccountVideoPlayerPreferences(
             MutableStateFlow(mergeWithDefaultVideoPlayerButtons(internalSettings.videoPlayer.buttonItems).toImmutableList()),
+            MutableStateFlow(internalSettings.videoPlayer.captionsEnabled),
         )
     val media =
         AccountMediaPreferences(
@@ -118,7 +119,7 @@ class AccountSyncedSettings(
                     security.sendKind0EventsToLocalRelay.value,
                     security.addClientTag.value,
                 ),
-            videoPlayer = AccountVideoPlayerPreferencesInternal(videoPlayer.buttonItems.value),
+            videoPlayer = AccountVideoPlayerPreferencesInternal(videoPlayer.buttonItems.value, videoPlayer.captionsEnabled.value),
             media = AccountMediaPreferencesInternal(media.audioVisualizer.value.name),
             chats =
                 AccountChatPreferencesInternal(
@@ -208,6 +209,10 @@ class AccountSyncedSettings(
             videoPlayer.buttonItems.tryEmit(newVideoPlayerButtonItems)
         }
 
+        if (videoPlayer.captionsEnabled.value != syncedSettingsInternal.videoPlayer.captionsEnabled) {
+            videoPlayer.captionsEnabled.tryEmit(syncedSettingsInternal.videoPlayer.captionsEnabled)
+        }
+
         val newAudioVisualizer = VisualizerStyle.fromName(syncedSettingsInternal.media.audioVisualizer)
         if (media.audioVisualizer.value != newAudioVisualizer) {
             media.audioVisualizer.tryEmit(newAudioVisualizer)
@@ -254,6 +259,7 @@ class AccountReactionPreferences(
 @Stable
 class AccountVideoPlayerPreferences(
     var buttonItems: MutableStateFlow<ImmutableList<VideoPlayerButtonItem>>,
+    val captionsEnabled: MutableStateFlow<Boolean>,
 )
 
 @Stable

amethyst/src/main/java/com/vitorpamplona/amethyst/model/AccountSyncedSettingsInternal.kt

@@ -107,6 +107,7 @@ enum class VideoPlayerAction {
     Download,
     PictureInPicture,
     Cast,
+    Captions,
 }
 
 @Serializable
@@ -127,6 +128,7 @@ val DefaultVideoPlayerButtonItems =
         VideoPlayerButtonItem(VideoPlayerAction.Mute, VideoButtonLocation.TopBar),
         VideoPlayerButtonItem(VideoPlayerAction.Quality, VideoButtonLocation.TopBar),
         VideoPlayerButtonItem(VideoPlayerAction.Cast, VideoButtonLocation.TopBar),
+        VideoPlayerButtonItem(VideoPlayerAction.Captions, VideoButtonLocation.TopBar),
         VideoPlayerButtonItem(VideoPlayerAction.Share, VideoButtonLocation.OverflowMenu),
         VideoPlayerButtonItem(VideoPlayerAction.Download, VideoButtonLocation.OverflowMenu),
         VideoPlayerButtonItem(VideoPlayerAction.PictureInPicture, VideoButtonLocation.OverflowMenu),
@@ -184,6 +186,10 @@ class AccountNavigationPreferencesInternal(
 @Serializable
 class AccountVideoPlayerPreferencesInternal(
     var buttonItems: List<VideoPlayerButtonItem> = DefaultVideoPlayerButtonItems,
+    // Feed videos autoplay muted, so captions are what make them legible — on by default, and
+    // remembered once the viewer says otherwise. Defaulted rather than required so a blob written
+    // by a client that predates the field still decodes.
+    var captionsEnabled: Boolean = true,
 )
 
 @Serializable

amethyst/src/main/java/com/vitorpamplona/amethyst/service/playback/composable/GetVideoController.kt

@@ -70,6 +70,16 @@ fun GetVideoController(
     // warm-pool fast path keeps position and buffered data intact.
     val keepAlive = remember { mutableStateOf(true) }
 
+    // Captions can resolve *after* playback starts: a `text-track` tag naming a kind-39307
+    // coordinate is only turned into a SubtitleConfiguration once that event arrives, which
+    // rebuilds `mediaItem` with the same videoUri and a different subtitle list. The mediaId is
+    // the video URI either way, so the warm-pool fast path below would read "already loaded" and
+    // the new tracks would never reach the player. A MediaController doesn't carry the item's
+    // `localConfiguration` across the service IPC, so the subtitles can't be read back off the
+    // controller to compare — we remember what we last pushed instead. Deliberately keyless so it
+    // survives the keyed remember below being rebuilt by the very change it has to detect.
+    val lastAppliedCaptions = remember { mutableStateOf<Int?>(null) }
+
     val controllerState by remember(mediaItem, keepAlive.value) {
         if (keepAlive.value) {
             PlaybackServiceClient
@@ -118,6 +128,7 @@ fun GetVideoController(
                     // We still re-prepare if the player ended up IDLE somehow (e.g. it was demoted
                     // to cold and resurfaced, or hit an error before we attached).
                     val targetMediaId = mediaItem.item.mediaId
+                    val captionsFingerprint = mediaItem.src.captions.hashCode()
                     val needsLoad = state.controller.currentMediaItem?.mediaId != targetMediaId
                     if (needsLoad) {
                         // Cold load: a fresh decoder/codec instance gets allocated here. If a
@@ -127,6 +138,20 @@ fun GetVideoController(
                         Log.d("PlaybackService") { "Cold load (setMediaItem+prepare) for $targetMediaId" }
                         state.controller.setMediaItem(mediaItem.item)
                         state.controller.prepare()
+                        lastAppliedCaptions.value = captionsFingerprint
+                    } else if (lastAppliedCaptions.value != null && lastAppliedCaptions.value != captionsFingerprint) {
+                        // Same video, new caption set, and this composable is the one that loaded
+                        // it: re-set the item so the side-loaded subtitle sources get merged in.
+                        // Restarting from the current position keeps the rebuffer down to whatever
+                        // the cache can't serve. The `!= null` guard is what keeps a warm player
+                        // that arrived already carrying someone else's item from being re-prepared
+                        // on a fingerprint we never pushed — that's the rebuffer the pool exists
+                        // to avoid, and its captions are whatever that mount applied.
+                        val resumeAt = state.controller.currentPosition
+                        Log.d("PlaybackService") { "Captions changed for $targetMediaId - re-applying at $resumeAt" }
+                        state.controller.setMediaItem(mediaItem.item, resumeAt)
+                        state.controller.prepare()
+                        lastAppliedCaptions.value = captionsFingerprint
                     } else if (state.controller.playbackState == Player.STATE_IDLE) {
                         Log.d("PlaybackService") { "Warm controller in STATE_IDLE — re-preparing" }
                         state.controller.prepare()

amethyst/src/main/java/com/vitorpamplona/amethyst/service/playback/composable/RenderVideoPlayer.kt

@@ -51,6 +51,7 @@ import com.vitorpamplona.amethyst.service.playback.composable.controls.Fullscree
 import com.vitorpamplona.amethyst.service.playback.composable.controls.LogVideoQualitySelection
 import com.vitorpamplona.amethyst.service.playback.composable.controls.METERED_MAX_SHORT_SIDE_PX
 import com.vitorpamplona.amethyst.service.playback.composable.controls.RenderAnimatedBottomInfo
+import com.vitorpamplona.amethyst.service.playback.composable.controls.RenderCaptions
 import com.vitorpamplona.amethyst.service.playback.composable.controls.RenderCenterButtons
 import com.vitorpamplona.amethyst.service.playback.composable.controls.RenderTopButtons
 import com.vitorpamplona.amethyst.service.playback.composable.controls.TopGradientOverlay
@@ -217,6 +218,15 @@ fun RenderVideoPlayer(
             shutter = {},
         )
 
+        // Above the picture but below the controls, so the transport bar and the bottom gradient
+        // draw over the cues rather than the other way around.
+        if (mediaItem.src.captions.isNotEmpty()) {
+            RenderCaptions(
+                controllerState = controllerState,
+                modifier = Modifier.align(Alignment.BottomCenter),
+            )
+        }
+
         RenderPlaybackError(
             controllerState = controllerState,
             videoUri = mediaItem.src.videoUri,

amethyst/src/main/java/com/vitorpamplona/amethyst/service/playback/composable/VideoView.kt

@@ -37,6 +37,7 @@ import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.layout.ContentScale
+import com.vitorpamplona.amethyst.commons.model.nip71Video.CaptionTrack
 import com.vitorpamplona.amethyst.model.MediaAspectRatioCache
 import com.vitorpamplona.amethyst.ui.components.DisplayBlurHash
 import com.vitorpamplona.amethyst.ui.components.ImageUrlWithDownloadButton
@@ -46,6 +47,8 @@ import com.vitorpamplona.amethyst.ui.theme.Size75dp
 import com.vitorpamplona.amethyst.ui.theme.imageModifier
 import com.vitorpamplona.amethyst.ui.theme.videoGalleryModifier
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.DimensionTag
+import kotlinx.collections.immutable.ImmutableList
+import kotlinx.collections.immutable.persistentListOf
 
 @Immutable
 class WaveformData(
@@ -73,6 +76,7 @@ fun VideoView(
     thumbhash: String? = null,
     isLiveStream: Boolean = false,
     hash: String? = null,
+    captions: ImmutableList<CaptionTrack> = persistentListOf(),
 ) {
     val borderModifier =
         if (roundedCorner) {
@@ -83,7 +87,7 @@ fun VideoView(
             Modifier
         }
 
-    VideoView(videoUri, mimeType, title, thumb, borderModifier, contentScale, waveform, artworkUri, authorName, dimensions, blurhash, nostrUriCallback, onDialog, alwaysShowVideo, accountViewModel = accountViewModel, thumbhash = thumbhash, isLiveStream = isLiveStream, hash = hash)
+    VideoView(videoUri, mimeType, title, thumb, borderModifier, contentScale, waveform, artworkUri, authorName, dimensions, blurhash, nostrUriCallback, onDialog, alwaysShowVideo, accountViewModel = accountViewModel, thumbhash = thumbhash, isLiveStream = isLiveStream, hash = hash, captions = captions)
 }
 
 @Composable
@@ -107,6 +111,7 @@ fun VideoView(
     accountViewModel: AccountViewModel,
     thumbhash: String? = null,
     hash: String? = null,
+    captions: ImmutableList<CaptionTrack> = persistentListOf(),
 ) {
     val initialAutoStart = if (alwaysShowVideo) true else accountViewModel.settings.startVideoPlayback()
     // Reset the manual-show toggle when the video URI changes so a recycled feed slot
@@ -180,6 +185,7 @@ fun VideoView(
                     dim = dimensions,
                     hash = hash,
                     thumbhash = thumbhash,
+                    captions = captions,
                     accountViewModel = accountViewModel,
                     showControls = showControls,
                 )
@@ -236,6 +242,7 @@ fun VideoView(
                     dim = dimensions,
                     hash = hash,
                     thumbhash = thumbhash,
+                    captions = captions,
                     accountViewModel = accountViewModel,
                     showControls = showControls,
                 )

amethyst/src/main/java/com/vitorpamplona/amethyst/service/playback/composable/VideoViewInner.kt

@@ -26,10 +26,13 @@ import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.layout.ContentScale
+import com.vitorpamplona.amethyst.commons.model.nip71Video.CaptionTrack
 import com.vitorpamplona.amethyst.service.playback.composable.mainVideo.VideoPlayerActiveMutex
 import com.vitorpamplona.amethyst.service.playback.composable.mediaitem.GetMediaItem
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.DimensionTag
+import kotlinx.collections.immutable.ImmutableList
+import kotlinx.collections.immutable.persistentListOf
 
 val DEFAULT_MUTED_SETTING = mutableStateOf(true)
 
@@ -57,6 +60,7 @@ fun VideoViewInner(
     dim: DimensionTag? = null,
     hash: String? = null,
     thumbhash: String? = null,
+    captions: ImmutableList<CaptionTrack> = persistentListOf(),
     accountViewModel: AccountViewModel,
 ) {
     // keeps a copy of the value to avoid recompositions here when the DEFAULT value changes
@@ -83,6 +87,7 @@ fun VideoViewInner(
         dim = dim,
         hash = hash,
         thumbhash = thumbhash,
+        captions = captions,
     ) { mediaItem ->
         GetVideoController(
             mediaItem = mediaItem,

amethyst/src/main/java/com/vitorpamplona/amethyst/service/playback/composable/controls/CaptionLanguageControls.kt

@@ -0,0 +1,157 @@
+/*
+ * 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.service.playback.composable.controls
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.material3.ButtonDefaults
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.window.Popup
+import androidx.compose.ui.window.PopupProperties
+import androidx.media3.common.C
+import androidx.media3.common.Player
+import androidx.media3.common.TrackSelectionOverride
+import androidx.media3.common.Tracks
+import androidx.media3.common.util.UnstableApi
+import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.ui.stringRes
+import kotlinx.collections.immutable.ImmutableList
+import kotlinx.collections.immutable.toImmutableList
+import java.util.Locale
+
+/**
+ * The text tracks a player has, in the order the media declared them.
+ *
+ * A NIP-71 video can carry a `text-track` per language, so "captions" is not one thing to switch
+ * on — it is a list to choose from. Groups the player reports as unsupported are dropped: offering
+ * a language the decoder will refuse is worse than not offering it.
+ */
+@OptIn(UnstableApi::class)
+internal fun getTextTrackChoices(tracks: Tracks): ImmutableList<CaptionChoice> {
+    val choices = mutableListOf<CaptionChoice>()
+    tracks.groups
+        .filter { it.type == C.TRACK_TYPE_TEXT }
+        .forEach { group ->
+            for (i in 0 until group.length) {
+                if (!group.isTrackSupported(i)) continue
+                val format = group.getTrackFormat(i)
+                choices.add(
+                    CaptionChoice(
+                        group = group,
+                        trackIndex = i,
+                        language = format.language,
+                        label = format.label,
+                        isSelected = group.isTrackSelected(i),
+                    ),
+                )
+            }
+        }
+    return choices.toImmutableList()
+}
+
+internal data class CaptionChoice(
+    val group: Tracks.Group,
+    val trackIndex: Int,
+    val language: String?,
+    val label: String?,
+    val isSelected: Boolean,
+) {
+    /**
+     * What to print for this track.
+     *
+     * The publisher's own label wins when there is one. Otherwise the language code is expanded
+     * into the reader's locale — "en" is not a word to most people, "English" is — and only a
+     * track that names neither falls back to a generic term.
+     */
+    fun displayName(fallback: String): String =
+        label?.takeIf { it.isNotBlank() }
+            ?: language?.takeIf { it.isNotBlank() }?.let { Locale.forLanguageTag(it).displayLanguage.ifBlank { it } }
+            ?: fallback
+}
+
+@OptIn(UnstableApi::class)
+internal fun selectTextTrack(
+    player: Player,
+    choice: CaptionChoice,
+) {
+    player.trackSelectionParameters =
+        player.trackSelectionParameters
+            .buildUpon()
+            // Clearing the type disable as well: picking a language is a request to see captions,
+            // so it has to undo an earlier "off" rather than silently select a track nothing draws.
+            .setTrackTypeDisabled(C.TRACK_TYPE_TEXT, false)
+            .setOverrideForType(TrackSelectionOverride(choice.group.mediaTrackGroup, choice.trackIndex))
+            .build()
+}
+
+/**
+ * The language menu, shown in place of a plain on/off toggle when a video offers more than one
+ * caption track.
+ */
+@Composable
+internal fun CaptionLanguagePopup(
+    choices: ImmutableList<CaptionChoice>,
+    captionsEnabled: Boolean,
+    onSelectOff: () -> Unit,
+    onSelectTrack: (CaptionChoice) -> Unit,
+    onDismiss: () -> Unit,
+) {
+    Popup(
+        alignment = Alignment.BottomCenter,
+        onDismissRequest = onDismiss,
+        properties = PopupProperties(focusable = true),
+    ) {
+        val baseColors = ButtonDefaults.textButtonColors()
+        val contentColor = MaterialTheme.colorScheme.onBackground
+        val colors = remember(baseColors, contentColor) { baseColors.copy(contentColor = contentColor) }
+        val unnamed = stringRes(R.string.captions_unnamed_track)
+
+        Column(
+            modifier = Modifier.background(MaterialTheme.colorScheme.background),
+            verticalArrangement = Arrangement.Center,
+            horizontalAlignment = Alignment.CenterHorizontally,
+        ) {
+            TextButton(colors = colors, onClick = onSelectOff) {
+                Text(
+                    stringRes(R.string.captions_off),
+                    fontWeight = if (!captionsEnabled) FontWeight(1000) else FontWeight(400),
+                )
+            }
+
+            choices.forEach { choice ->
+                TextButton(colors = colors, onClick = { onSelectTrack(choice) }) {
+                    Text(
+                        choice.displayName(unnamed),
+                        fontWeight = if (captionsEnabled && choice.isSelected) FontWeight(1000) else FontWeight(400),
+                    )
+                }
+            }
+        }
+    }
+}

amethyst/src/main/java/com/vitorpamplona/amethyst/service/playback/composable/controls/OverflowMenu.kt

@@ -79,6 +79,9 @@ fun OverflowMenuButtonPreview() {
                 onCastClick = {},
                 castIcon = MaterialSymbols.Cast,
                 castContentDescription = "",
+                onCaptionsClick = {},
+                captionsIcon = MaterialSymbols.ClosedCaption,
+                captionsContentDescription = "",
             )
         }
     }
@@ -98,6 +101,9 @@ fun AnimatedOverflowMenuButton(
     onCastClick: () -> Unit,
     castIcon: MaterialSymbol,
     castContentDescription: String,
+    onCaptionsClick: () -> Unit,
+    captionsIcon: MaterialSymbol,
+    captionsContentDescription: String,
     modifier: Modifier = Modifier,
 ) {
     AnimatedVisibility(
@@ -118,6 +124,9 @@ fun AnimatedOverflowMenuButton(
             onCastClick = onCastClick,
             castIcon = castIcon,
             castContentDescription = castContentDescription,
+            onCaptionsClick = onCaptionsClick,
+            captionsIcon = captionsIcon,
+            captionsContentDescription = captionsContentDescription,
         )
     }
 }
@@ -135,6 +144,9 @@ fun OverflowMenuButton(
     onCastClick: () -> Unit,
     castIcon: MaterialSymbol,
     castContentDescription: String,
+    onCaptionsClick: () -> Unit,
+    captionsIcon: MaterialSymbol,
+    captionsContentDescription: String,
 ) {
     val menuExpanded = remember { mutableStateOf(false) }
 
@@ -239,6 +251,16 @@ fun OverflowMenuButton(
                                 onCastClick()
                             }
                         }
+
+                        VideoPlayerAction.Captions -> {
+                            M3ActionRow(
+                                icon = captionsIcon,
+                                text = captionsContentDescription,
+                            ) {
+                                menuExpanded.value = false
+                                onCaptionsClick()
+                            }
+                        }
                     }
                 }
             }

amethyst/src/main/java/com/vitorpamplona/amethyst/service/playback/composable/controls/RenderCaptions.kt

@@ -0,0 +1,103 @@
+/*
+ * 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.service.playback.composable.controls
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.unit.dp
+import androidx.media3.common.Player
+import androidx.media3.common.text.CueGroup
+import com.vitorpamplona.amethyst.service.playback.composable.MediaControllerState
+
+/**
+ * Draws the cues of the currently selected text track over the player.
+ *
+ * media3's Compose UI has no subtitle view — that lives in the View-based `PlayerView`, which this
+ * app does not use — so the cues are collected from the player and laid out here. Only the cue
+ * text is honoured: a WebVTT region/position would need the player's video rect, and every
+ * NIP-71 caption seen in the wild is plain bottom-centred dialogue.
+ *
+ * Nothing renders when no text track is selected, so this composable costs one listener on videos
+ * without captions.
+ */
+@Composable
+fun RenderCaptions(
+    controllerState: MediaControllerState,
+    modifier: Modifier = Modifier,
+) {
+    val player = controllerState.controller
+    var lines by remember(player) { mutableStateOf<List<String>>(emptyList()) }
+
+    DisposableEffect(player) {
+        lines =
+            player.currentCues.cues
+                .mapNotNull { it.text?.toString() }
+                .filter { it.isNotBlank() }
+
+        val listener =
+            object : Player.Listener {
+                override fun onCues(cueGroup: CueGroup) {
+                    lines = cueGroup.cues.mapNotNull { it.text?.toString() }.filter { it.isNotBlank() }
+                }
+            }
+        player.addListener(listener)
+        onDispose { player.removeListener(listener) }
+    }
+
+    if (lines.isEmpty()) return
+
+    Column(
+        modifier = modifier.padding(horizontal = 12.dp, vertical = 8.dp),
+        horizontalAlignment = Alignment.CenterHorizontally,
+        verticalArrangement = Arrangement.spacedBy(2.dp),
+    ) {
+        lines.forEach { line ->
+            Text(
+                text = line,
+                color = Color.White,
+                textAlign = TextAlign.Center,
+                style = MaterialTheme.typography.bodyMedium,
+                // A scrim behind the glyphs rather than a full-width bar: captions sit over the
+                // picture, and a translucent box only where there is text keeps the frame visible.
+                modifier =
+                    Modifier
+                        .background(CaptionScrim, MaterialTheme.shapes.extraSmall)
+                        .padding(horizontal = 6.dp, vertical = 2.dp),
+            )
+        }
+    }
+}
+
+private val CaptionScrim = Color.Black.copy(alpha = 0.6f)

amethyst/src/main/java/com/vitorpamplona/amethyst/service/playback/composable/controls/RenderTopButtons.kt

@@ -46,6 +46,7 @@ import androidx.compose.ui.draw.clip
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import androidx.media3.common.C
 import androidx.media3.common.Player
 import androidx.media3.common.Tracks
 import com.google.accompanist.permissions.ExperimentalPermissionsApi
@@ -98,6 +99,8 @@ fun RenderTopButtonsPreview() {
                 onPictureInPictureClick = {},
                 onZoomClick = {},
                 onOverflowQualityClick = {},
+                captionsEnabled = true,
+                onCaptionsClick = {},
                 modifier = Modifier,
                 accountViewModel = mockAccountViewModel(),
             )
@@ -143,6 +146,43 @@ fun RenderTopButtons(
     val videoGroup = getVideoTrackGroup(tracks)
     val hasMultipleQualities = videoGroup != null && videoGroup.length > 1
 
+    // Captions are side-loaded from the event's `text-track` tags (MediaItemCache flags the first
+    // one default). The account setting is the source of truth, not the player: a player comes
+    // out of the warm pool carrying whatever track selection the previous video left on it, so
+    // reading the preference off the instance would make the button's state depend on which
+    // player this video happened to be handed.
+    val captionsEnabled by accountViewModel.captionsEnabledFlow().collectAsStateWithLifecycle()
+
+    // Push the preference onto whichever player is attached, and re-push when either changes.
+    // Disabling the whole track type rather than deselecting one group: the type-level switch
+    // survives the player later picking a different track.
+    LaunchedEffect(player, captionsEnabled) {
+        val alreadyDisabled = player.trackSelectionParameters.disabledTrackTypes.contains(C.TRACK_TYPE_TEXT)
+        if (alreadyDisabled == captionsEnabled) {
+            player.trackSelectionParameters =
+                player.trackSelectionParameters
+                    .buildUpon()
+                    .setTrackTypeDisabled(C.TRACK_TYPE_TEXT, !captionsEnabled)
+                    .build()
+        }
+    }
+
+    // A video with one track has nothing to choose between, so the button stays a toggle. Only a
+    // multi-language video opens a menu — paying a popup for a single "English" row would be a
+    // worse answer to the same tap.
+    val captionChoices = remember(tracks) { getTextTrackChoices(tracks) }
+    val captionsPopupOpen = remember { mutableStateOf(false) }
+    val onCaptionsClick =
+        remember(captionsEnabled, captionChoices) {
+            {
+                if (captionChoices.size > 1) {
+                    captionsPopupOpen.value = true
+                } else {
+                    accountViewModel.setCaptionsEnabled(!captionsEnabled)
+                }
+            }
+        }
+
     val overflowQualityOpen = remember { mutableStateOf(false) }
 
     // Pause local playback while this video is casting so audio doesn't
@@ -210,10 +250,31 @@ fun RenderTopButtons(
                 }
             },
         onOverflowQualityClick = { overflowQualityOpen.value = true },
+        captionsEnabled = captionsEnabled,
+        onCaptionsClick = onCaptionsClick,
         modifier = modifier,
         accountViewModel = accountViewModel,
     )
 
+    if (captionsPopupOpen.value) {
+        CaptionLanguagePopup(
+            choices = captionChoices,
+            captionsEnabled = captionsEnabled,
+            onSelectOff = {
+                accountViewModel.setCaptionsEnabled(false)
+                captionsPopupOpen.value = false
+            },
+            onSelectTrack = { choice ->
+                // The override goes straight onto the player (it is per-video), while the
+                // preference is what persists the fact that captions are wanted at all.
+                selectTextTrack(player, choice)
+                accountViewModel.setCaptionsEnabled(true)
+                captionsPopupOpen.value = false
+            },
+            onDismiss = { captionsPopupOpen.value = false },
+        )
+    }
+
     if (overflowQualityOpen.value && videoGroup != null) {
         VideoQualityPopup(
             player = player,
@@ -237,10 +298,15 @@ fun RenderTopButtons(
     onPictureInPictureClick: () -> Unit,
     onZoomClick: (() -> Unit)?,
     onOverflowQualityClick: () -> Unit,
+    captionsEnabled: Boolean,
+    onCaptionsClick: () -> Unit,
     modifier: Modifier,
     accountViewModel: AccountViewModel,
 ) {
     val buttonItems by accountViewModel.videoPlayerButtonItemsFlow().collectAsStateWithLifecycle()
+    val captionsIcon = if (captionsEnabled) MaterialSymbols.ClosedCaption else MaterialSymbols.ClosedCaptionDisabled
+    val captionsContentDescription =
+        stringRes(if (captionsEnabled) R.string.captions_turn_off else R.string.captions_turn_on)
     val shareDialogVisible = remember { mutableStateOf(false) }
     val castDialogVisible = remember { mutableStateOf(false) }
     val castSessionState by Amethyst.instance.castRegistry.sessionState
@@ -297,21 +363,28 @@ fun RenderTopButtons(
             VideoPlayerAction.Cast -> {
                 BuildConfig.IS_CASTING_AVAILABLE && mediaData.videoUri.startsWith("http", ignoreCase = true)
             }
+
+            // A video with no `text-track` has nothing to toggle, so the button stays out of the
+            // row entirely rather than sitting there inert.
+            VideoPlayerAction.Captions -> {
+                mediaData.captions.isNotEmpty()
+            }
         }
 
     val canFullscreen = onZoomClick != null
+    val hasCaptions = mediaData.captions.isNotEmpty()
     // ImmutableList so Compose can treat the action lists as stable parameters when they're
     // passed through to AnimatedOverflowMenuButton — a plain List is unstable and forces the
     // overflow tree to recompose whenever any unrelated parent state ticks.
     val topBarActions =
-        remember(buttonItems, canFullscreen, hasMultipleQualities, isLive, pipSupported) {
+        remember(buttonItems, canFullscreen, hasMultipleQualities, isLive, pipSupported, hasCaptions) {
             buttonItems
                 .filter { it.location == VideoButtonLocation.TopBar && isAvailable(it.action) }
                 .map { it.action }
                 .toImmutableList()
         }
     val overflowActions =
-        remember(buttonItems, canFullscreen, hasMultipleQualities, isLive, pipSupported) {
+        remember(buttonItems, canFullscreen, hasMultipleQualities, isLive, pipSupported, hasCaptions) {
             buttonItems
                 .filter { it.location == VideoButtonLocation.OverflowMenu && isAvailable(it.action) }
                 .map { it.action }
@@ -377,6 +450,15 @@ fun RenderTopButtons(
                         onClick = onCastButtonClick,
                     )
                 }
+
+                VideoPlayerAction.Captions -> {
+                    AnimatedTopBarIconButton(
+                        controllerVisible = controllerVisible,
+                        symbol = captionsIcon,
+                        contentDescription = captionsContentDescription,
+                        onClick = onCaptionsClick,
+                    )
+                }
             }
         }
 
@@ -394,6 +476,9 @@ fun RenderTopButtons(
                 onCastClick = onCastButtonClick,
                 castIcon = castIcon,
                 castContentDescription = castContentDescription,
+                onCaptionsClick = onCaptionsClick,
+                captionsIcon = captionsIcon,
+                captionsContentDescription = captionsContentDescription,
             )
         }
 

amethyst/src/main/java/com/vitorpamplona/amethyst/service/playback/composable/mediaitem/GetMediaItem.kt

@@ -21,11 +21,16 @@
 package com.vitorpamplona.amethyst.service.playback.composable.mediaitem
 
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.SideEffect
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import com.vitorpamplona.amethyst.commons.model.nip71Video.CaptionTrack
 import com.vitorpamplona.amethyst.commons.ui.state.produceCachedState
 import com.vitorpamplona.amethyst.service.playback.composable.WaveformData
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.DimensionTag
+import kotlinx.collections.immutable.ImmutableList
+import kotlinx.collections.immutable.persistentListOf
 
 val mediaItemCache = MediaItemCache()
 
@@ -46,10 +51,21 @@ fun GetMediaItem(
     dim: DimensionTag? = null,
     hash: String? = null,
     thumbhash: String? = null,
+    captions: ImmutableList<CaptionTrack> = persistentListOf(),
     inner: @Composable (LoadedMediaItem) -> Unit,
 ) {
     val data =
-        remember(videoUri) {
+        // Captions join the key. They resolve asynchronously — a `text-track` that names a
+        // kind-39307 coordinate has to reach LocalCache first — so keying on the URI alone would
+        // lock in the caption-less item built on the first frame. The list only ever goes empty ->
+        // resolved, so this rebuilds at most once.
+        //
+        // What that rebuild reaches depends on when it lands. A feed video is mounted long before
+        // it is scrolled into view and played, so the item carrying the tracks is the one the
+        // controller loads. For a video already playing, GetVideoController's warm-path check sees
+        // the same mediaId and deliberately does not re-set the item, so the late tracks wait for
+        // the next mount rather than restarting playback under the viewer.
+        remember(videoUri, captions) {
             MediaItemData(
                 videoUri = videoUri,
                 authorName = authorName,
@@ -66,6 +82,7 @@ fun GetMediaItem(
                 dim = dim,
                 hash = hash,
                 thumbhash = thumbhash,
+                captions = captions,
             )
         }
 
@@ -79,7 +96,19 @@ fun GetMediaItem(
 ) {
     val mediaItem by produceCachedState(cache = mediaItemCache, key = data)
 
-    mediaItem?.let {
+    // produceCachedState re-remembers on a new key and starts at null while the replacement is
+    // built off-thread. Rendering that null would drop the whole player subtree for a frame and
+    // rebuild it — a visible blink — and for the one case that changes the key mid-playback
+    // (captions resolving after the first frame) the warm-pool check then declines to re-set an
+    // item carrying the same mediaId, so the blink would buy nothing. Keep drawing the item we
+    // already have until its replacement exists.
+    val previous = remember { mutableStateOf<LoadedMediaItem?>(null) }
+    val current = mediaItem
+    if (current != null && previous.value !== current) {
+        SideEffect { previous.value = current }
+    }
+
+    (current ?: previous.value)?.let {
         inner(it)
     }
 }

amethyst/src/main/java/com/vitorpamplona/amethyst/service/playback/composable/mediaitem/MediaItemCache.kt

@@ -22,9 +22,11 @@ package com.vitorpamplona.amethyst.service.playback.composable.mediaitem
 
 import android.os.Bundle
 import androidx.core.net.toUri
+import androidx.media3.common.C
 import androidx.media3.common.MediaItem
 import androidx.media3.common.MediaMetadata
 import androidx.media3.common.MimeTypes
+import com.vitorpamplona.amethyst.commons.model.nip71Video.CaptionTrack
 import com.vitorpamplona.amethyst.commons.ui.state.GenericBaseCache
 import com.vitorpamplona.quartz.utils.Log
 import kotlinx.coroutines.Dispatchers
@@ -61,6 +63,25 @@ class MediaItemCache : GenericBaseCache<MediaItemData, LoadedMediaItem>(20) {
             return null
         }
 
+        // A side-loaded track needs its media type declared: a NIP-71 `text-track` says nothing
+        // about the format, and a blossom-hosted one is `https://host/<sha256>` with no extension
+        // for ExoPlayer to infer from either. A track flagged default is the one ExoPlayer
+        // selects without being asked.
+        internal fun CaptionTrack.toSubtitleConfiguration(isDefault: Boolean = false): MediaItem.SubtitleConfiguration =
+            MediaItem.SubtitleConfiguration
+                .Builder(url.toUri())
+                .setMimeType(mimeType)
+                .setLanguage(language)
+                .setLabel(label())
+                .setSelectionFlags(if (isDefault) C.SELECTION_FLAG_DEFAULT else 0)
+                .build()
+
+        private fun CaptionTrack.label(): String? =
+            when {
+                language != null && type != null -> "$language \u00B7 $type"
+                else -> language ?: type
+            }
+
         // Restrict `.m3u8` matching to the path component so a query param or
         // fragment that happens to mention .m3u8 (e.g. `?ref=a.m3u8`) on an
         // MP4 URI doesn't misroute to HlsMediaSource.
@@ -83,7 +104,15 @@ class MediaItemCache : GenericBaseCache<MediaItemData, LoadedMediaItem>(20) {
                     .setMediaId(key.videoUri)
                     .setUri(key.videoUri)
                     .apply { normalizedMime?.let { setMimeType(it) } }
-                    .setMediaMetadata(
+                    .setSubtitleConfigurations(
+                        // Flagging the first track default is what decides WHICH track plays
+                        // once text is enabled. WHETHER it is enabled is the account's
+                        // captionsEnabled preference, which RenderTopButtons pushes onto the
+                        // player as a track-type switch — the two are independent.
+                        key.captions.mapIndexed { index, track ->
+                            track.toSubtitleConfiguration(isDefault = index == 0)
+                        },
+                    ).setMediaMetadata(
                         MediaMetadata
                             .Builder()
                             .setArtist(key.authorName?.ifBlank { null })

amethyst/src/main/java/com/vitorpamplona/amethyst/service/playback/composable/mediaitem/MediaItemData.kt

@@ -22,8 +22,11 @@ package com.vitorpamplona.amethyst.service.playback.composable.mediaitem
 
 import androidx.compose.runtime.Immutable
 import androidx.media3.common.MediaItem
+import com.vitorpamplona.amethyst.commons.model.nip71Video.CaptionTrack
 import com.vitorpamplona.amethyst.service.playback.composable.WaveformData
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.DimensionTag
+import kotlinx.collections.immutable.ImmutableList
+import kotlinx.collections.immutable.persistentListOf
 
 @Immutable
 data class MediaItemData(
@@ -48,6 +51,9 @@ data class MediaItemData(
     val dim: DimensionTag? = null,
     val hash: String? = null,
     val thumbhash: String? = null,
+    // NIP-71 `text-track` captions to side-load. A data class is the cache key, so this has to be
+    // a value that compares by content — ImmutableList keeps that true and keeps the key @Stable.
+    val captions: ImmutableList<CaptionTrack> = persistentListOf(),
 )
 
 @Immutable

amethyst/src/main/java/com/vitorpamplona/amethyst/service/playback/playerPool/CustomMediaSourceFactory.kt

@@ -29,6 +29,8 @@ import androidx.media3.exoplayer.drm.DrmSessionManagerProvider
 import androidx.media3.exoplayer.hls.HlsMediaSource
 import androidx.media3.exoplayer.source.DefaultMediaSourceFactory
 import androidx.media3.exoplayer.source.MediaSource
+import androidx.media3.exoplayer.source.MergingMediaSource
+import androidx.media3.exoplayer.source.SingleSampleMediaSource
 import androidx.media3.exoplayer.upstream.LoadErrorHandlingPolicy
 import com.vitorpamplona.amethyst.service.playback.PLAYBACK_DIAG_TAG
 import com.vitorpamplona.amethyst.service.playback.composable.mediaitem.MediaItemCache
@@ -104,6 +106,7 @@ class CustomMediaSourceFactory(
     dataSourceFactory: DataSource.Factory,
 ) : MediaSource.Factory {
     private val cachingDataSource: DataSource.Factory = videoCache.get(dataSourceFactory)
+    private val plainDataSource: DataSource.Factory = dataSourceFactory
 
     private val cachingFactory: MediaSource.Factory =
         DefaultMediaSourceFactory(cachingDataSource)
@@ -119,9 +122,10 @@ class CustomMediaSourceFactory(
     //
     // The cost of bypassing it: HLS items skip what DefaultMediaSourceFactory wraps around the
     // source — side-loaded subtitleConfigurations (MergingMediaSource), clipping, ad insertion, and
-    // live target-offset defaults. None are reachable today (MediaItemCache sets none of them, and
-    // the live setters aren't on the MediaSource.Factory interface), but anything added later must
-    // be mirrored here.
+    // live target-offset defaults. Subtitles ARE reachable now (MediaItemCache side-loads NIP-71
+    // `text-track` captions), so createMediaSource below mirrors that wrap for the HLS path;
+    // clipping and ad insertion remain unused, and the live setters aren't on the
+    // MediaSource.Factory interface. Anything else added later must be mirrored here too.
     private val cachingHlsFactory: MediaSource.Factory = hlsFactory(cachingDataSource)
     private val nonCachingHlsFactory: MediaSource.Factory = hlsFactory(dataSourceFactory)
 
@@ -137,7 +141,13 @@ class CustomMediaSourceFactory(
         return this
     }
 
+    // Retained as well as forwarded: the subtitle sources in withSideLoadedSubtitles are built per
+    // call rather than living in allFactories, so this is the only way they can be given the same
+    // retry/backoff behaviour the player configured for everything else.
+    private var loadErrorHandlingPolicy: LoadErrorHandlingPolicy? = null
+
     override fun setLoadErrorHandlingPolicy(loadErrorHandlingPolicy: LoadErrorHandlingPolicy): MediaSource.Factory {
+        this.loadErrorHandlingPolicy = loadErrorHandlingPolicy
         allFactories.forEach { it.setLoadErrorHandlingPolicy(loadErrorHandlingPolicy) }
         return this
     }
@@ -161,7 +171,16 @@ class CustomMediaSourceFactory(
             } else {
                 if (bypassCache) nonCachingFactory else cachingFactory
             }
-        val source = factory.createMediaSource(mediaItem)
+        // DefaultMediaSourceFactory is what merges side-loaded subtitle tracks into the playback
+        // source. The explicit HLS factory above does not, so on that path a caption track would
+        // load into nothing; mirror the wrap here. Progressive items already got it from the
+        // Default factory, so they must NOT be wrapped again.
+        val source =
+            if (hls) {
+                withSideLoadedSubtitles(factory.createMediaSource(mediaItem), mediaItem, bypassCache)
+            } else {
+                factory.createMediaSource(mediaItem)
+            }
 
         // Logs the routing inputs directly rather than a re-derived label, so it can't drift from
         // shouldBypassCache.
@@ -172,6 +191,38 @@ class CustomMediaSourceFactory(
         return source
     }
 
+    /**
+     * Rebuilds what [DefaultMediaSourceFactory] does for `subtitleConfigurations`: each side-loaded
+     * track becomes its own single-sample source, merged alongside the video.
+     *
+     * Subtitle files are small, immutable documents, so they follow the video's cache decision —
+     * a track fetched beside a cached VOD playlist is worth keeping too, and one beside a live
+     * stream is not worth a cache entry for a stream that is never replayed.
+     */
+    private fun withSideLoadedSubtitles(
+        source: MediaSource,
+        mediaItem: MediaItem,
+        bypassCache: Boolean,
+    ): MediaSource {
+        val subtitles = mediaItem.localConfiguration?.subtitleConfigurations.orEmpty()
+        if (subtitles.isEmpty()) return source
+
+        val dataSource = if (bypassCache) plainDataSource else cachingDataSource
+        val sources =
+            Array(subtitles.size + 1) { index ->
+                if (index == 0) {
+                    source
+                } else {
+                    SingleSampleMediaSource
+                        .Factory(dataSource)
+                        .apply { loadErrorHandlingPolicy?.let { setLoadErrorHandlingPolicy(it) } }
+                        .createMediaSource(subtitles[index - 1], C.TIME_UNSET)
+                }
+            }
+
+        return MergingMediaSource(*sources)
+    }
+
     // Only the explicit event-kind flag (kind:30311 live activities). Returns false when the flag
     // is absent or false; the HLS URL check in createMediaSource covers everything else.
     private fun isFlaggedLive(mediaItem: MediaItem): Boolean {

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/components/ZoomableContentDialog.kt

@@ -523,6 +523,7 @@ private fun RenderImageOrVideo(
                         controllerVisible = controllerVisible,
                         hasBlurhash = content.blurhash != null,
                         isFullscreen = true,
+                        captions = content.captions,
                         accountViewModel = accountViewModel,
                     )
                 }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/components/ZoomableContentView.kt

@@ -277,6 +277,7 @@ fun ZoomableContentView(
                         thumbhash = content.thumbhash,
                         isLiveStream = content.isLiveStream,
                         hash = content.hash,
+                        captions = content.captions,
                     )
                 }
             }

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

@@ -221,6 +221,8 @@ import com.vitorpamplona.amethyst.ui.note.types.RenderTextModificationEvent
 import com.vitorpamplona.amethyst.ui.note.types.RenderThread
 import com.vitorpamplona.amethyst.ui.note.types.RenderTorrent
 import com.vitorpamplona.amethyst.ui.note.types.RenderTorrentComment
+import com.vitorpamplona.amethyst.ui.note.types.RenderVideoCollaboration
+import com.vitorpamplona.amethyst.ui.note.types.RenderVideoCurationSet
 import com.vitorpamplona.amethyst.ui.note.types.RenderVoiceTrack
 import com.vitorpamplona.amethyst.ui.note.types.RenderWikiContent
 import com.vitorpamplona.amethyst.ui.note.types.RenderWikiMergeAcceptance
@@ -229,6 +231,25 @@ import com.vitorpamplona.amethyst.ui.note.types.RenderWikiRedirect
 import com.vitorpamplona.amethyst.ui.note.types.RenderZapPoll
 import com.vitorpamplona.amethyst.ui.note.types.ReplyRenderType
 import com.vitorpamplona.amethyst.ui.note.types.VideoDisplay
+import com.vitorpamplona.amethyst.ui.note.types.lists.RenderAppCurationSet
+import com.vitorpamplona.amethyst.ui.note.types.lists.RenderArticleCurationSet
+import com.vitorpamplona.amethyst.ui.note.types.lists.RenderBookmarkList
+import com.vitorpamplona.amethyst.ui.note.types.lists.RenderFavoriteAlgoFeedsList
+import com.vitorpamplona.amethyst.ui.note.types.lists.RenderGeohashList
+import com.vitorpamplona.amethyst.ui.note.types.lists.RenderGitAuthorList
+import com.vitorpamplona.amethyst.ui.note.types.lists.RenderGitRepositoryList
+import com.vitorpamplona.amethyst.ui.note.types.lists.RenderGoodWikiAuthorList
+import com.vitorpamplona.amethyst.ui.note.types.lists.RenderGoodWikiRelayList
+import com.vitorpamplona.amethyst.ui.note.types.lists.RenderHashtagList
+import com.vitorpamplona.amethyst.ui.note.types.lists.RenderInterestSet
+import com.vitorpamplona.amethyst.ui.note.types.lists.RenderKindMuteSet
+import com.vitorpamplona.amethyst.ui.note.types.lists.RenderLabeledBookmarkList
+import com.vitorpamplona.amethyst.ui.note.types.lists.RenderMediaFollowList
+import com.vitorpamplona.amethyst.ui.note.types.lists.RenderMediaStarterPack
+import com.vitorpamplona.amethyst.ui.note.types.lists.RenderMuteList
+import com.vitorpamplona.amethyst.ui.note.types.lists.RenderOldBookmarkList
+import com.vitorpamplona.amethyst.ui.note.types.lists.RenderPictureCurationSet
+import com.vitorpamplona.amethyst.ui.note.types.lists.RenderSimpleGroupList
 import com.vitorpamplona.amethyst.ui.note.types.observeZapSender
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.feed.types.RenderChatClip
@@ -291,6 +312,7 @@ import com.vitorpamplona.quartz.experimental.ratings.EntityRatingEvent
 import com.vitorpamplona.quartz.experimental.ratings.RelayReviewEvent
 import com.vitorpamplona.quartz.experimental.roadstr.confirmation.RoadEventConfirmationEvent
 import com.vitorpamplona.quartz.experimental.roadstr.report.RoadEventReportEvent
+import com.vitorpamplona.quartz.experimental.videoCollaboration.VideoCollaborationEvent
 import com.vitorpamplona.quartz.experimental.zapPolls.ZapPollEvent
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.metadata.MetadataEvent
@@ -328,8 +350,26 @@ import com.vitorpamplona.quartz.nip43RelayMembers.list.RelayMembershipListEvent
 import com.vitorpamplona.quartz.nip43RelayMembers.removeMember.RelayRemoveMemberEvent
 import com.vitorpamplona.quartz.nip50Search.SearchRelayListEvent
 import com.vitorpamplona.quartz.nip51Lists.PinListEvent
+import com.vitorpamplona.quartz.nip51Lists.appCurationSet.AppCurationSetEvent
+import com.vitorpamplona.quartz.nip51Lists.articleCurationSet.ArticleCurationSetEvent
+import com.vitorpamplona.quartz.nip51Lists.bookmarkList.BookmarkListEvent
+import com.vitorpamplona.quartz.nip51Lists.bookmarkList.OldBookmarkListEvent
+import com.vitorpamplona.quartz.nip51Lists.favoriteAlgoFeedsList.FavoriteAlgoFeedsListEvent
 import com.vitorpamplona.quartz.nip51Lists.followList.FollowListEvent
+import com.vitorpamplona.quartz.nip51Lists.geohashList.GeohashListEvent
+import com.vitorpamplona.quartz.nip51Lists.gitAuthorList.GitAuthorListEvent
+import com.vitorpamplona.quartz.nip51Lists.gitRepositoryList.GitRepositoryListEvent
+import com.vitorpamplona.quartz.nip51Lists.goodWikiAuthorList.GoodWikiAuthorListEvent
+import com.vitorpamplona.quartz.nip51Lists.goodWikiRelayList.GoodWikiRelayListEvent
+import com.vitorpamplona.quartz.nip51Lists.hashtagList.HashtagListEvent
+import com.vitorpamplona.quartz.nip51Lists.interestSet.InterestSetEvent
+import com.vitorpamplona.quartz.nip51Lists.kindMuteSet.KindMuteSetEvent
+import com.vitorpamplona.quartz.nip51Lists.labeledBookmarkList.LabeledBookmarkListEvent
+import com.vitorpamplona.quartz.nip51Lists.mediaFollowList.MediaFollowListEvent
+import com.vitorpamplona.quartz.nip51Lists.mediaStarterPack.MediaStarterPackEvent
+import com.vitorpamplona.quartz.nip51Lists.muteList.MuteListEvent
 import com.vitorpamplona.quartz.nip51Lists.peopleList.PeopleListEvent
+import com.vitorpamplona.quartz.nip51Lists.pictureCurationSet.PictureCurationSetEvent
 import com.vitorpamplona.quartz.nip51Lists.relayLists.BlockedRelayListEvent
 import com.vitorpamplona.quartz.nip51Lists.relayLists.BroadcastRelayListEvent
 import com.vitorpamplona.quartz.nip51Lists.relayLists.IndexerRelayListEvent
@@ -338,6 +378,8 @@ import com.vitorpamplona.quartz.nip51Lists.relayLists.RelayFeedsListEvent
 import com.vitorpamplona.quartz.nip51Lists.relayLists.TrustedRelayListEvent
 import com.vitorpamplona.quartz.nip51Lists.relaySets.RelaySetEvent
 import com.vitorpamplona.quartz.nip51Lists.releaseArtifactSet.ReleaseArtifactSetEvent
+import com.vitorpamplona.quartz.nip51Lists.simpleGroupList.SimpleGroupListEvent
+import com.vitorpamplona.quartz.nip51Lists.videoCurationSet.VideoCurationSetEvent
 import com.vitorpamplona.quartz.nip52Calendar.appt.day.CalendarDateSlotEvent
 import com.vitorpamplona.quartz.nip52Calendar.appt.time.CalendarTimeSlotEvent
 import com.vitorpamplona.quartz.nip52Calendar.calendar.CalendarEvent
@@ -1579,6 +1621,14 @@ private fun RenderNoteRow(
             VideoDisplay(baseNote, makeItShort, canPreview, backgroundColor, ContentScale.FillWidth, accountViewModel, nav)
         }
 
+        is VideoCollaborationEvent -> {
+            RenderVideoCollaboration(baseNote, quotesLeft, backgroundColor, accountViewModel, nav)
+        }
+
+        is VideoCurationSetEvent -> {
+            RenderVideoCurationSet(baseNote, quotesLeft, backgroundColor, accountViewModel, nav)
+        }
+
         is PictureEvent -> {
             PictureDisplay(baseNote, true, ContentScale.FillWidth, PaddingValues(vertical = 5.dp), backgroundColor, accountViewModel, nav)
         }
@@ -1788,6 +1838,82 @@ private fun RenderNoteRow(
             )
         }
 
+        is MuteListEvent -> {
+            RenderMuteList(baseNote, quotesLeft, backgroundColor, accountViewModel, nav)
+        }
+
+        is BookmarkListEvent -> {
+            RenderBookmarkList(baseNote, quotesLeft, backgroundColor, accountViewModel, nav)
+        }
+
+        is OldBookmarkListEvent -> {
+            RenderOldBookmarkList(baseNote, quotesLeft, backgroundColor, accountViewModel, nav)
+        }
+
+        is LabeledBookmarkListEvent -> {
+            RenderLabeledBookmarkList(baseNote, quotesLeft, backgroundColor, accountViewModel, nav)
+        }
+
+        is ArticleCurationSetEvent -> {
+            RenderArticleCurationSet(baseNote, quotesLeft, backgroundColor, accountViewModel, nav)
+        }
+
+        is PictureCurationSetEvent -> {
+            RenderPictureCurationSet(baseNote, quotesLeft, backgroundColor, accountViewModel, nav)
+        }
+
+        is AppCurationSetEvent -> {
+            RenderAppCurationSet(baseNote, quotesLeft, backgroundColor, accountViewModel, nav)
+        }
+
+        is GitRepositoryListEvent -> {
+            RenderGitRepositoryList(baseNote, quotesLeft, backgroundColor, accountViewModel, nav)
+        }
+
+        is FavoriteAlgoFeedsListEvent -> {
+            RenderFavoriteAlgoFeedsList(baseNote, quotesLeft, backgroundColor, accountViewModel, nav)
+        }
+
+        is GitAuthorListEvent -> {
+            RenderGitAuthorList(baseNote, backgroundColor, accountViewModel, nav)
+        }
+
+        is MediaFollowListEvent -> {
+            RenderMediaFollowList(baseNote, backgroundColor, accountViewModel, nav)
+        }
+
+        is GoodWikiAuthorListEvent -> {
+            RenderGoodWikiAuthorList(baseNote, backgroundColor, accountViewModel, nav)
+        }
+
+        is KindMuteSetEvent -> {
+            RenderKindMuteSet(baseNote, backgroundColor, accountViewModel, nav)
+        }
+
+        is MediaStarterPackEvent -> {
+            RenderMediaStarterPack(baseNote, backgroundColor, accountViewModel, nav)
+        }
+
+        is HashtagListEvent -> {
+            RenderHashtagList(baseNote, backgroundColor, accountViewModel, nav)
+        }
+
+        is InterestSetEvent -> {
+            RenderInterestSet(baseNote, backgroundColor, accountViewModel, nav)
+        }
+
+        is GeohashListEvent -> {
+            RenderGeohashList(baseNote, backgroundColor, accountViewModel)
+        }
+
+        is SimpleGroupListEvent -> {
+            RenderSimpleGroupList(baseNote, backgroundColor, accountViewModel)
+        }
+
+        is GoodWikiRelayListEvent -> {
+            RenderGoodWikiRelayList(baseNote, backgroundColor, accountViewModel)
+        }
+
         else -> {
             RenderTextEvent(
                 baseNote,

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/types/RememberCaptionTracks.kt

@@ -0,0 +1,76 @@
+/*
+ * 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.ui.note.types
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.key
+import androidx.compose.runtime.remember
+import com.vitorpamplona.amethyst.commons.model.nip71Video.CaptionTrack
+import com.vitorpamplona.amethyst.commons.model.nip71Video.captionTracks
+import com.vitorpamplona.amethyst.commons.model.nip71Video.mergeCaptionTracks
+import com.vitorpamplona.amethyst.commons.model.nip71Video.toCaptionTrack
+import com.vitorpamplona.amethyst.service.relayClient.reqCommand.event.observeNoteEvent
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.quartz.nip71Video.VideoEvent
+import com.vitorpamplona.quartz.nip71Video.textTrack.TextTrackEvent
+import kotlinx.collections.immutable.ImmutableList
+import kotlinx.collections.immutable.persistentListOf
+import kotlinx.collections.immutable.toImmutableList
+
+/**
+ * Resolves the caption tracks a NIP-71 video advertises, fetching the addressable ones.
+ *
+ * A `text-track` that names a URL is usable immediately. One that names a
+ * `39307:<pubkey>:<d>` coordinate is not, so it gets an [observeNoteEvent] of its own — that both
+ * reads the event out of LocalCache and puts it on an EventFinder subscription, so a track the
+ * device has never seen is requested from relays and appears when it lands.
+ *
+ * The same track is routinely advertised both ways at once (divine.video publishes the Blossom URL
+ * and its wrapping event side by side), so the two are merged by URL: the player is handed one
+ * configuration per distinct file, never a duplicate pair it would offer twice in its track menu.
+ */
+@Composable
+fun rememberCaptionTracks(
+    videoEvent: VideoEvent,
+    accountViewModel: AccountViewModel,
+): ImmutableList<CaptionTrack> {
+    val refs = remember(videoEvent) { videoEvent.captionTracks() }
+
+    // No early return: the pending list changes size when a recycled feed slot switches videos,
+    // and `key` is what lets Compose add and drop those child subscriptions in place.
+    val resolved =
+        refs.pending.map { pending ->
+            key(pending.address.toValue()) {
+                val note = remember(pending.address) { accountViewModel.getOrCreateAddressableNote(pending.address) }
+                val trackEvent by observeNoteEvent<TextTrackEvent>(note, accountViewModel)
+                trackEvent?.toCaptionTrack(pending.tag)
+            }
+        }
+
+    return remember(refs, resolved) {
+        if (refs.direct.isEmpty() && resolved.all { it == null }) {
+            persistentListOf()
+        } else {
+            mergeCaptionTracks(refs.direct, resolved.filterNotNull()).toImmutableList()
+        }
+    }
+}

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/types/RenderVideoCollaboration.kt

@@ -0,0 +1,97 @@
+/*
+ * 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.ui.note.types
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.MutableState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.unit.dp
+import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.commons.model.Note
+import com.vitorpamplona.amethyst.ui.navigation.navs.INav
+import com.vitorpamplona.amethyst.ui.note.LoadAddressableNote
+import com.vitorpamplona.amethyst.ui.note.NoteCompose
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.amethyst.ui.stringRes
+import com.vitorpamplona.quartz.experimental.videoCollaboration.VideoCollaborationEvent
+
+/**
+ * A collaborator's acceptance (or refusal) of a credit, rendered on its own.
+ *
+ * The event carries no content — everything it says is in the video it points at — so the video is
+ * embedded and the event itself is reduced to one line of context above it: the role the
+ * collaborator was given, and whether they took it.
+ */
+@Composable
+fun RenderVideoCollaboration(
+    baseNote: Note,
+    quotesLeft: Int,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val noteEvent = baseNote.event as? VideoCollaborationEvent ?: return
+    val video = remember(noteEvent) { noteEvent.video() }
+
+    Column(
+        modifier = Modifier.fillMaxWidth(),
+        verticalArrangement = Arrangement.spacedBy(4.dp),
+    ) {
+        val headline =
+            if (noteEvent.isAccepted()) {
+                stringRes(R.string.video_collaboration_accepted_on)
+            } else {
+                stringRes(R.string.video_collaboration_declined_on)
+            }
+        val role = remember(noteEvent) { noteEvent.role() }
+
+        Text(
+            text = if (role != null) "$headline · $role" else headline,
+            style = MaterialTheme.typography.bodySmall,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+        )
+
+        // quotesLeft guards the recursion: the embedded video can itself credit other work, and
+        // NoteCompose is what decrements it on the way down.
+        if (video != null && quotesLeft > 0) {
+            LoadAddressableNote(video, accountViewModel) { videoNote ->
+                videoNote?.let {
+                    NoteCompose(
+                        baseNote = it,
+                        isQuotedNote = true,
+                        quotesLeft = quotesLeft - 1,
+                        parentBackgroundColor = backgroundColor,
+                        accountViewModel = accountViewModel,
+                        nav = nav,
+                    )
+                }
+            }
+        }
+    }
+}

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/types/RenderVideoCredits.kt

@@ -0,0 +1,248 @@
+/*
+ * 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.ui.note.types
+
+import androidx.compose.foundation.layout.ExperimentalLayoutApi
+import androidx.compose.foundation.layout.FlowRow
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.key
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.commons.icons.symbols.Icon
+import com.vitorpamplona.amethyst.commons.icons.symbols.MaterialSymbols
+import com.vitorpamplona.amethyst.commons.ui.components.ClickableTextColor
+import com.vitorpamplona.amethyst.ui.navigation.navs.INav
+import com.vitorpamplona.amethyst.ui.navigation.routes.Route
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.rooms.LoadUser
+import com.vitorpamplona.amethyst.ui.stringRes
+import com.vitorpamplona.amethyst.ui.theme.HalfTopPadding
+import com.vitorpamplona.amethyst.ui.theme.lessImportantLink
+import com.vitorpamplona.quartz.experimental.videoCollaboration.VideoCollaborationEvent
+import com.vitorpamplona.quartz.nip01Core.core.Address
+import com.vitorpamplona.quartz.nip01Core.core.AddressableEvent
+import com.vitorpamplona.quartz.nip01Core.relay.filters.Filter
+import com.vitorpamplona.quartz.nip71Video.VideoEvent
+import com.vitorpamplona.quartz.nip71Video.credits.CreditTarget
+import com.vitorpamplona.quartz.nip71Video.credits.VideoCredit
+
+/**
+ * The line of credits under a video: who it features, who inspired it, whose audio it reuses.
+ *
+ * Every entry is a link, because the credit is only worth printing if it takes you to the person
+ * or the work. A credited person who has published a [VideoCollaborationEvent] for this video gets
+ * a check beside their name — they are not merely tagged, they took the credit.
+ *
+ * A `p` tag marked `mention` is kept even though the description may name the same person: on
+ * divine.video the description writes a plain `@handle`, which no client can turn into a link, so
+ * the tag is the only thing that resolves to an actual profile. The cost is a chip that repeats a
+ * `nostr:` mention already rendered inline, which is redundancy rather than a wrong credit.
+ */
+@OptIn(ExperimentalLayoutApi::class)
+@Composable
+fun RenderVideoCredits(
+    videoEvent: VideoEvent,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val credits = remember(videoEvent) { videoEvent.credits() }
+    if (credits.isEmpty()) return
+
+    // Only an addressable video has a coordinate for a collaborator to answer, so only there can
+    // an acceptance be looked up at all.
+    val videoAddress = remember(videoEvent) { (videoEvent as? AddressableEvent)?.address() }
+
+    FlowRow(modifier = HalfTopPadding) {
+        credits.forEach { credit ->
+            key(credit.target) {
+                RenderVideoCredit(credit, videoAddress, accountViewModel, nav)
+            }
+        }
+    }
+}
+
+@Composable
+private fun RenderVideoCredit(
+    credit: VideoCredit,
+    videoAddress: Address?,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    when (val target = credit.target) {
+        is CreditTarget.Person ->
+            LoadUser(target.pubKey, accountViewModel) { user ->
+                // Until the profile arrives there is no name to print, and a hex key in the
+                // credits reads as noise rather than as a person.
+                user?.let {
+                    CreditRow(
+                        label = personLabel(credit.label),
+                        // toBestDisplayName() is read inside the row so a profile that lands later
+                        // still renames the credit.
+                        name = "@" + it.toBestDisplayName(),
+                        confirmed = {
+                            // Only a role-marked credit is an invite someone can accept, and each
+                            // lookup registers a cache observer per credit per rendered card.
+                            // Watching every `mention` and `inspired-by` too would spend one per
+                            // feed item on an event that cannot exist.
+                            if (credit.label.isCollaborationRole()) {
+                                AcceptedCollaboration(target.pubKey, videoAddress, accountViewModel)
+                            }
+                        },
+                        onClick = { nav.nav(Route.Profile(target.pubKey)) },
+                    )
+                }
+            }
+
+        is CreditTarget.Video ->
+            CreditRow(
+                label = workLabel(credit.label),
+                name = target.address.dTag.take(SHORT_REF_LENGTH),
+                onClick = {
+                    nav.nav(Route.Note(target.address.toTag()))
+                },
+            )
+
+        is CreditTarget.Event ->
+            CreditRow(
+                label = workLabel(credit.label),
+                name = target.eventId.take(SHORT_REF_LENGTH),
+                onClick = { nav.nav(Route.Note(target.eventId)) },
+            )
+    }
+}
+
+/**
+ * Draws a check when [pubKey] has published an accepted [VideoCollaborationEvent] for this video.
+ *
+ * The response is matched by what both shapes in the wild agree on — the `a` tag naming the video
+ * — rather than by the response's own coordinate. divine-mobile keys the event by the video
+ * coordinate (so `34238:<collaborator>:<video coordinate>` would resolve it) but divine-web writes
+ * a random `d`, and asking for a coordinate nobody can predict found nothing for the client that
+ * publishes most of these. The relay side is covered by the `a` engagement filter every rendered
+ * addressable note already opens (see PostsAndChatMessagesToAddresses), so this reads the cache
+ * and costs no subscription of its own.
+ *
+ * Newest-first, so a collaborator who accepted and later withdrew reads as withdrawn.
+ */
+@Composable
+private fun AcceptedCollaboration(
+    pubKey: String,
+    videoAddress: Address?,
+    accountViewModel: AccountViewModel,
+) {
+    if (videoAddress == null) return
+
+    val responseFlow =
+        remember(pubKey, videoAddress) {
+            accountViewModel.account.cache.observeLatestEvent<VideoCollaborationEvent>(
+                Filter(
+                    kinds = listOf(VideoCollaborationEvent.KIND),
+                    authors = listOf(pubKey),
+                    tags = mapOf("a" to listOf(videoAddress.toValue())),
+                    limit = 1,
+                ),
+            )
+        }
+
+    val response by responseFlow.collectAsStateWithLifecycle(null)
+
+    if (response?.isAccepted() == true) {
+        Icon(
+            symbol = MaterialSymbols.CheckCircle,
+            contentDescription = stringRes(R.string.video_credit_accepted),
+            modifier = Modifier.padding(start = 2.dp),
+            tint = MaterialTheme.colorScheme.lessImportantLink,
+        )
+    }
+}
+
+@Composable
+private fun CreditRow(
+    label: String,
+    name: String,
+    confirmed: @Composable () -> Unit = {},
+    onClick: () -> Unit,
+) {
+    Row(
+        modifier = Modifier.padding(end = 8.dp),
+        verticalAlignment = Alignment.CenterVertically,
+    ) {
+        if (label.isNotBlank()) {
+            Text(
+                text = "$label ",
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                maxLines = 1,
+            )
+        }
+        ClickableTextColor(
+            text = name,
+            style = MaterialTheme.typography.bodySmall,
+            maxLines = 1,
+            overflow = TextOverflow.Ellipsis,
+            linkColor = MaterialTheme.colorScheme.lessImportantLink,
+            onClick = onClick,
+        )
+        confirmed()
+    }
+}
+
+// A person tagged without a stated capacity is still in the video — that is what NIP-71's `p`
+// means — so the neutral credit, not a blank one, is the honest default.
+@Composable
+private fun personLabel(marker: String?): String =
+    when (marker) {
+        INSPIRED_BY_MARKER -> stringRes(R.string.video_credit_inspired_by)
+        MENTION_MARKER, null -> stringRes(R.string.video_credit_featuring)
+        // Anything else is a role the video's author typed ("Collaborator", "Director"): print it.
+        else -> marker
+    }
+
+// The same treatment for a credited work. Both reference kinds route through here so an `e` tag
+// and an `a` tag carrying the same marker read identically — the `e` path used to print the raw
+// protocol token, so a `mention` showed up in the UI as the literal word "mention".
+@Composable
+private fun workLabel(marker: String?): String =
+    when (marker) {
+        AUDIO_MARKER -> stringRes(R.string.video_credit_audio_from)
+        MENTION_MARKER, null -> stringRes(R.string.video_credit_references)
+        else -> marker
+    }
+
+/** True for a marker that names a role rather than describing a reference. */
+private fun String?.isCollaborationRole(): Boolean = this != null && this != MENTION_MARKER && this != INSPIRED_BY_MARKER && this != AUDIO_MARKER
+
+private const val INSPIRED_BY_MARKER = "inspired-by"
+private const val MENTION_MARKER = "mention"
+private const val AUDIO_MARKER = "audio"
+
+// Enough of a hex id or `d` tag to tell two references apart without wrapping the row.
+private const val SHORT_REF_LENGTH = 8

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/types/RenderVideoCurationSet.kt

@@ -0,0 +1,217 @@
+/*
+ * 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.ui.note.types
+
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.horizontalScroll
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.MutableState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.key
+import androidx.compose.runtime.produceState
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.res.pluralStringResource
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.commons.model.Note
+import com.vitorpamplona.amethyst.ui.components.DisplayBlurHash
+import com.vitorpamplona.amethyst.ui.components.LoadNote
+import com.vitorpamplona.amethyst.ui.components.MyAsyncImage
+import com.vitorpamplona.amethyst.ui.navigation.navs.INav
+import com.vitorpamplona.amethyst.ui.navigation.routes.Route
+import com.vitorpamplona.amethyst.ui.note.LoadAddressableNote
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.amethyst.ui.stringRes
+import com.vitorpamplona.amethyst.ui.theme.imageModifier
+import com.vitorpamplona.quartz.nip01Core.core.Address
+import com.vitorpamplona.quartz.nip51Lists.bookmarkList.tags.AddressBookmark
+import com.vitorpamplona.quartz.nip51Lists.bookmarkList.tags.BookmarkIdTag
+import com.vitorpamplona.quartz.nip51Lists.bookmarkList.tags.EventBookmark
+import com.vitorpamplona.quartz.nip51Lists.videoCurationSet.VideoCurationSetEvent
+import com.vitorpamplona.quartz.nip71Video.VideoEvent
+import com.vitorpamplona.quartz.utils.Log
+
+/**
+ * A NIP-51 kind-30005 video list: its name, what it is for, and a strip of its videos.
+ *
+ * Members may be public tags or NIP-51 private ones inside the encrypted content — divine.video
+ * puts every member there, so for anyone but the list's owner the strip is legitimately empty and
+ * the card says so rather than looking broken.
+ */
+@Composable
+fun RenderVideoCurationSet(
+    baseNote: Note,
+    quotesLeft: Int,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val noteEvent = baseNote.event as? VideoCurationSetEvent ?: return
+
+    val publicItems = remember(noteEvent) { noteEvent.publicItems() }
+
+    // Decryption needs the signer and only succeeds for the list's owner, so it runs off the
+    // composition and simply yields nothing for everyone else.
+    //
+    // Null means "we did not read the content": not the owner, or the decrypt failed. An empty
+    // list means we read it and it holds nothing. The two have to stay apart, because a list whose
+    // encrypted content decrypts to `[]` is an empty list, not a private one — divine.video
+    // publishes exactly that for a list a user created and never added to.
+    val privateItems by
+        produceState<List<BookmarkIdTag>?>(initialValue = null, noteEvent) {
+            if (noteEvent.pubKey != accountViewModel.account.signer.pubKey) return@produceState
+            value =
+                try {
+                    noteEvent.privateItems(accountViewModel.account.signer)
+                } catch (e: Exception) {
+                    if (e is kotlin.coroutines.cancellation.CancellationException) throw e
+                    Log.w("RenderVideoCurationSet", "Cannot decrypt private items of ${noteEvent.id}", e)
+                    null
+                }
+        }
+
+    val items = remember(publicItems, privateItems) { publicItems + (privateItems ?: emptyList()) }
+
+    Column(
+        modifier = Modifier.fillMaxWidth(),
+        verticalArrangement = Arrangement.spacedBy(4.dp),
+    ) {
+        (noteEvent.title() ?: noteEvent.dTag()).takeIf { it.isNotBlank() }?.let {
+            Text(
+                text = it,
+                fontWeight = FontWeight.Bold,
+                maxLines = 2,
+                overflow = TextOverflow.Ellipsis,
+            )
+        }
+
+        noteEvent.description()?.let {
+            Text(
+                text = it,
+                style = MaterialTheme.typography.bodyMedium,
+                maxLines = 3,
+                overflow = TextOverflow.Ellipsis,
+            )
+        }
+
+        // An empty strip has two very different causes. Encrypted content we could not read means
+        // the members may be there and private; content we did read, or no content at all, means
+        // the list is simply empty. Calling that "Private list" would be a lie — to its own author
+        // most of all, who just decrypted it and found nothing in it.
+        val membersAreHidden = items.isEmpty() && noteEvent.content.isNotBlank() && privateItems == null
+
+        Text(
+            text =
+                if (membersAreHidden) {
+                    stringRes(R.string.video_curation_set_private_items)
+                } else {
+                    pluralStringResource(R.plurals.video_curation_set_video_count, items.size, items.size)
+                },
+            style = MaterialTheme.typography.bodySmall,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+        )
+
+        if (items.isNotEmpty() && quotesLeft > 0) {
+            Row(
+                modifier = Modifier.fillMaxWidth().horizontalScroll(rememberScrollState()),
+                horizontalArrangement = Arrangement.spacedBy(6.dp),
+            ) {
+                items.take(MAX_POSTERS).forEach { item ->
+                    key(item.toTagIdOnly().joinToString(":")) {
+                        VideoListMemberPoster(item, accountViewModel, nav)
+                    }
+                }
+            }
+        }
+    }
+}
+
+/** One video in the strip: its poster, or its blurhash until that loads. */
+@Composable
+private fun VideoListMemberPoster(
+    item: BookmarkIdTag,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    when (item) {
+        is AddressBookmark ->
+            LoadAddressableNote(item.address, accountViewModel) { note ->
+                note?.let { VideoPoster(it, accountViewModel) { nav.nav(Route.Note(addressTag(item.address))) } }
+            }
+
+        is EventBookmark ->
+            LoadNote(item.eventId, accountViewModel) { note ->
+                note?.let { VideoPoster(it, accountViewModel) { nav.nav(Route.Note(item.eventId)) } }
+            }
+    }
+}
+
+@Composable
+private fun VideoPoster(
+    note: Note,
+    accountViewModel: AccountViewModel,
+    onClick: () -> Unit,
+) {
+    val videoEvent = note.event as? VideoEvent ?: return
+    // The poster, not the video: a strip of simultaneously-playing players is unusable, and every
+    // NIP-71 imeta that has a thumbnail carries it as `image`.
+    val imeta = remember(videoEvent) { videoEvent.imetaTags().firstOrNull { it.image.isNotEmpty() } ?: videoEvent.imetaTags().firstOrNull() }
+    val poster = imeta?.image?.firstOrNull()
+
+    val tileModifier = Modifier.width(POSTER_WIDTH).height(POSTER_HEIGHT).clickable(onClick = onClick)
+
+    if (poster == null) {
+        imeta?.blurhash?.let { DisplayBlurHash(it, videoEvent.title(), ContentScale.Crop, tileModifier) }
+        return
+    }
+
+    MyAsyncImage(
+        imageUrl = poster,
+        contentDescription = videoEvent.title(),
+        contentScale = ContentScale.Crop,
+        mainImageModifier = tileModifier,
+        loadedImageModifier = MaterialTheme.colorScheme.imageModifier,
+        accountViewModel = accountViewModel,
+        onLoadingBackground = { imeta.blurhash?.let { DisplayBlurHash(it, videoEvent.title(), ContentScale.Crop, tileModifier) } },
+        onError = null,
+    )
+}
+
+private fun addressTag(address: Address) = Address.assemble(address.kind, address.pubKeyHex, address.dTag)
+
+// Enough to show what kind of list this is without turning a feed card into a gallery.
+private const val MAX_POSTERS = 8
+private val POSTER_WIDTH = 96.dp
+private val POSTER_HEIGHT = 128.dp

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/types/Video.kt

@@ -86,9 +86,12 @@ fun VideoDisplay(
     val image = remember(imeta) { imeta.image.firstOrNull() }
     val isYouTube = remember(imeta) { imeta.url.contains("youtube.com") || imeta.url.contains("youtu.be") }
     val tags = remember(note) { note.event?.tags?.toImmutableListOfLists() ?: EmptyTagList }
+    val captions = rememberCaptionTracks(videoEvent, accountViewModel)
 
     val content: BaseMediaContent =
-        remember(note) {
+        // Keyed on the captions too: an addressable `text-track` resolves after the first frame,
+        // and the player only picks up a track that is in the MediaItemData it was handed.
+        remember(note, captions) {
             val description = videoEvent.content.ifBlank { null } ?: event.alt()
             // A NIP-71 event asserts its own type, so only an explicit image imeta diverts to the
             // viewer; an unclassifiable one still belongs in the player. See classifyMedia.
@@ -118,6 +121,7 @@ fun VideoDisplay(
                     mimeType = imeta.mimeType,
                     blurhash = imeta.blurhash,
                     thumbhash = imeta.thumbhash,
+                    captions = captions,
                 )
             }
         }
@@ -200,6 +204,11 @@ fun VideoDisplay(
                     }
                 }
             }
+
+            // Outside the summary block on purpose: divine.video shorts routinely credit a
+            // soundtrack or a collaborator while leaving the description empty, and those credits
+            // are the only attribution the reused work gets.
+            RenderVideoCredits(videoEvent, accountViewModel, nav)
         }
     }
 }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/types/lists/AddressLists.kt

@@ -0,0 +1,148 @@
+/*
+ * 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.ui.note.types.lists
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.MutableState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.key
+import androidx.compose.runtime.remember
+import androidx.compose.ui.graphics.Color
+import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.commons.model.Note
+import com.vitorpamplona.amethyst.ui.navigation.navs.INav
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.amethyst.ui.stringRes
+import com.vitorpamplona.quartz.nip51Lists.appCurationSet.AppCurationSetEvent
+import com.vitorpamplona.quartz.nip51Lists.favoriteAlgoFeedsList.FavoriteAlgoFeedsListEvent
+import com.vitorpamplona.quartz.nip51Lists.gitRepositoryList.GitRepositoryListEvent
+import com.vitorpamplona.quartz.nip51Lists.simpleGroupList.SimpleGroupListEvent
+
+/** NIP-51 kind 10018: the git repositories this user follows. */
+@Composable
+fun RenderGitRepositoryList(
+    baseNote: Note,
+    quotesLeft: Int,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val noteEvent = baseNote.event as? GitRepositoryListEvent ?: return
+
+    val public = remember(noteEvent) { noteEvent.publicRepositories() }
+    val private by loadPrivateItems(noteEvent, accountViewModel) { noteEvent.privateRepositories(it) }
+
+    ListCard(
+        title = stringRes(R.string.kind_git_repositories),
+        description = null,
+        items = rememberAllMembers(public, private),
+        hasUnreadablePrivateItems = noteEvent.hidesPrivateMembers(private),
+        backgroundColor = backgroundColor,
+    ) { repo ->
+        key(repo.address.toValue()) {
+            AddressMemberRow(repo.address, quotesLeft, backgroundColor, accountViewModel, nav)
+        }
+    }
+}
+
+/** NIP-51 kind 10090: the DVM content feeds this user keeps to hand. */
+@Composable
+fun RenderFavoriteAlgoFeedsList(
+    baseNote: Note,
+    quotesLeft: Int,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val noteEvent = baseNote.event as? FavoriteAlgoFeedsListEvent ?: return
+
+    val public = remember(noteEvent) { noteEvent.publicFavoriteAlgoFeeds() }
+    val private by loadPrivateItems(noteEvent, accountViewModel) { noteEvent.privateFavoriteAlgoFeeds(it) }
+
+    ListCard(
+        title = stringRes(R.string.kind_favorite_algo_feeds),
+        description = null,
+        items = rememberAllMembers(public, private),
+        hasUnreadablePrivateItems = noteEvent.hidesPrivateMembers(private),
+        backgroundColor = backgroundColor,
+    ) { feed ->
+        key(feed.address.toValue()) {
+            AddressMemberRow(feed.address, quotesLeft, backgroundColor, accountViewModel, nav)
+        }
+    }
+}
+
+/** NIP-51 kind 30267: "references to multiple software applications". */
+@Composable
+fun RenderAppCurationSet(
+    baseNote: Note,
+    quotesLeft: Int,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val noteEvent = baseNote.event as? AppCurationSetEvent ?: return
+
+    val apps = remember(noteEvent) { noteEvent.apps() }
+
+    ListCard(
+        title = listTitle(noteEvent.title(), noteEvent.dTag(), R.string.kind_app_curation_set),
+        description = noteEvent.description(),
+        items = apps,
+        // Not a PrivateTagArrayEvent: an app set has no encrypted half to be locked out of.
+        hasUnreadablePrivateItems = false,
+        backgroundColor = backgroundColor,
+    ) { app ->
+        key(app.address.toValue()) {
+            AddressMemberRow(app.address, quotesLeft, backgroundColor, accountViewModel, nav)
+        }
+    }
+}
+
+/**
+ * NIP-51 kind 10009: the simple groups this user belongs to.
+ *
+ * A group is named by an id on a relay rather than by a coordinate, so it gets its own row: the
+ * group's name when it carries one, and the relay that hosts it underneath.
+ */
+@Composable
+fun RenderSimpleGroupList(
+    baseNote: Note,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+) {
+    val noteEvent = baseNote.event as? SimpleGroupListEvent ?: return
+
+    val public = remember(noteEvent) { noteEvent.publicGroups() }
+    val private by loadPrivateItems(noteEvent, accountViewModel) { noteEvent.privateGroups(it) }
+
+    ListCard(
+        title = stringRes(R.string.kind_simple_groups),
+        description = null,
+        items = rememberAllMembers(public, private),
+        hasUnreadablePrivateItems = noteEvent.hidesPrivateMembers(private),
+        backgroundColor = backgroundColor,
+    ) { group ->
+        key(group.groupId + group.relayUrl) {
+            LabelMemberRow(group.name?.takeIf { it.isNotBlank() } ?: group.groupId)
+        }
+    }
+}

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/types/lists/BookmarkLists.kt

@@ -0,0 +1,206 @@
+/*
+ * 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.ui.note.types.lists
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.MutableState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.key
+import androidx.compose.runtime.remember
+import androidx.compose.ui.graphics.Color
+import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.commons.model.Note
+import com.vitorpamplona.amethyst.ui.navigation.navs.INav
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.quartz.nip51Lists.articleCurationSet.ArticleCurationSetEvent
+import com.vitorpamplona.quartz.nip51Lists.bookmarkList.BookmarkListEvent
+import com.vitorpamplona.quartz.nip51Lists.bookmarkList.OldBookmarkListEvent
+import com.vitorpamplona.quartz.nip51Lists.bookmarkList.tags.BookmarkIdTag
+import com.vitorpamplona.quartz.nip51Lists.labeledBookmarkList.LabeledBookmarkListEvent
+import com.vitorpamplona.quartz.nip51Lists.pictureCurationSet.PictureCurationSetEvent
+
+/** NIP-51 kind 10003: the user's bookmarks — notes, articles, hashtags and links. */
+@Composable
+fun RenderBookmarkList(
+    baseNote: Note,
+    quotesLeft: Int,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val noteEvent = baseNote.event as? BookmarkListEvent ?: return
+
+    val public = remember(noteEvent) { noteEvent.publicBookmarks() }
+    val private by loadPrivateItems(noteEvent, accountViewModel) { noteEvent.privateBookmarks(it) }
+
+    BookmarkCard(
+        title = listTitle(noteEvent.title(), null, R.string.kind_bookmark_list),
+        description = null,
+        public = public,
+        private = private,
+        hidesPrivate = noteEvent.hidesPrivateMembers(private),
+        quotesLeft = quotesLeft,
+        backgroundColor = backgroundColor,
+        accountViewModel = accountViewModel,
+        nav = nav,
+    )
+}
+
+/**
+ * NIP-51 kind 30001: the deprecated bookmark set. Still rendered, because the events are on relays
+ * whether or not the spec wants them to be.
+ */
+@Suppress("DEPRECATION")
+@Composable
+fun RenderOldBookmarkList(
+    baseNote: Note,
+    quotesLeft: Int,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val noteEvent = baseNote.event as? OldBookmarkListEvent ?: return
+
+    val public = remember(noteEvent) { noteEvent.publicBookmarks() }
+    val private by loadPrivateItems(noteEvent, accountViewModel) { noteEvent.privateBookmarks(it) }
+
+    BookmarkCard(
+        title = listTitle(noteEvent.title(), noteEvent.dTag(), R.string.kind_bookmark_list),
+        description = null,
+        public = public,
+        private = private,
+        hidesPrivate = noteEvent.hidesPrivateMembers(private),
+        quotesLeft = quotesLeft,
+        backgroundColor = backgroundColor,
+        accountViewModel = accountViewModel,
+        nav = nav,
+    )
+}
+
+/** NIP-51 kind 30003: "user-defined bookmarks categories, for when bookmarks must be in labeled separate groups". */
+@Composable
+fun RenderLabeledBookmarkList(
+    baseNote: Note,
+    quotesLeft: Int,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val noteEvent = baseNote.event as? LabeledBookmarkListEvent ?: return
+
+    val public = remember(noteEvent) { noteEvent.publicBookmarks() }
+    val private by loadPrivateItems(noteEvent, accountViewModel) { noteEvent.privateBookmarks(it) }
+
+    BookmarkCard(
+        title = listTitle(noteEvent.titleOrName(), noteEvent.dTag(), R.string.kind_bookmark_set),
+        description = noteEvent.description(),
+        public = public,
+        private = private,
+        hidesPrivate = noteEvent.hidesPrivateMembers(private),
+        quotesLeft = quotesLeft,
+        backgroundColor = backgroundColor,
+        accountViewModel = accountViewModel,
+        nav = nav,
+    )
+}
+
+/** NIP-51 kind 30004: "groups of articles picked by users as interesting". */
+@Composable
+fun RenderArticleCurationSet(
+    baseNote: Note,
+    quotesLeft: Int,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val noteEvent = baseNote.event as? ArticleCurationSetEvent ?: return
+
+    val public = remember(noteEvent) { noteEvent.publicItems() }
+    val private by loadPrivateItems(noteEvent, accountViewModel) { noteEvent.privateItems(it) }
+
+    BookmarkCard(
+        title = listTitle(noteEvent.title(), noteEvent.dTag(), R.string.kind_article_curation_set),
+        description = noteEvent.description(),
+        public = public,
+        private = private,
+        hidesPrivate = noteEvent.hidesPrivateMembers(private),
+        quotesLeft = quotesLeft,
+        backgroundColor = backgroundColor,
+        accountViewModel = accountViewModel,
+        nav = nav,
+    )
+}
+
+/** NIP-51 kind 30006: "groups of pictures picked by users as interesting". */
+@Composable
+fun RenderPictureCurationSet(
+    baseNote: Note,
+    quotesLeft: Int,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val noteEvent = baseNote.event as? PictureCurationSetEvent ?: return
+
+    val public = remember(noteEvent) { noteEvent.publicItems() }
+    val private by loadPrivateItems(noteEvent, accountViewModel) { noteEvent.privateItems(it) }
+
+    BookmarkCard(
+        title = listTitle(noteEvent.title(), noteEvent.dTag(), R.string.kind_picture_curation_set),
+        description = noteEvent.description(),
+        public = public,
+        private = private,
+        hidesPrivate = noteEvent.hidesPrivateMembers(private),
+        quotesLeft = quotesLeft,
+        backgroundColor = backgroundColor,
+        accountViewModel = accountViewModel,
+        nav = nav,
+    )
+}
+
+/**
+ * The five bookmark-shaped kinds differ only in where their name comes from; what they hold is the
+ * same `e`/`a` reference, so the body they draw is the same one.
+ */
+@Composable
+private fun BookmarkCard(
+    title: String,
+    description: String?,
+    public: List<BookmarkIdTag>,
+    private: List<BookmarkIdTag>?,
+    hidesPrivate: Boolean,
+    quotesLeft: Int,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    ListCard(
+        title = title,
+        description = description,
+        items = rememberAllMembers(public, private),
+        hasUnreadablePrivateItems = hidesPrivate,
+        backgroundColor = backgroundColor,
+    ) { item ->
+        key(item.toTagIdOnly().joinToString(":")) {
+            BookmarkMemberRow(item, quotesLeft, backgroundColor, accountViewModel, nav)
+        }
+    }
+}

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/types/lists/GoodWikiRelayList.kt

@@ -0,0 +1,57 @@
+/*
+ * 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.ui.note.types.lists
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.MutableState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.key
+import androidx.compose.runtime.remember
+import androidx.compose.ui.graphics.Color
+import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.commons.model.Note
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.amethyst.ui.stringRes
+import com.vitorpamplona.quartz.nip01Core.relay.normalizer.displayUrl
+import com.vitorpamplona.quartz.nip51Lists.goodWikiRelayList.GoodWikiRelayListEvent
+
+/** NIP-51 kind 10102: the relays this user trusts for wiki articles. */
+@Composable
+fun RenderGoodWikiRelayList(
+    baseNote: Note,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+) {
+    val noteEvent = baseNote.event as? GoodWikiRelayListEvent ?: return
+
+    val public = remember(noteEvent) { noteEvent.publicRelays() }
+    val private by loadPrivateItems(noteEvent, accountViewModel) { noteEvent.privateRelays(it) }
+
+    ListCard(
+        title = stringRes(R.string.kind_good_wiki_relays),
+        description = null,
+        items = rememberAllMembers(public, private),
+        hasUnreadablePrivateItems = noteEvent.hidesPrivateMembers(private),
+        backgroundColor = backgroundColor,
+    ) { relay ->
+        key(relay.url) { LabelMemberRow(relay.displayUrl()) }
+    }
+}

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/types/lists/ListCard.kt

@@ -0,0 +1,185 @@
+/*
+ * 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.ui.note.types.lists
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.MutableState
+import androidx.compose.runtime.State
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.produceState
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.saveable.rememberSaveable
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.ui.components.ShowMoreButton
+import com.vitorpamplona.amethyst.ui.note.getGradient
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.amethyst.ui.stringRes
+import com.vitorpamplona.quartz.nip01Core.core.Event
+import com.vitorpamplona.quartz.nip01Core.signers.NostrSigner
+import com.vitorpamplona.quartz.utils.Log
+
+/** How many members a list card shows before it asks to be expanded. Matches DisplayPeopleList. */
+private const val COLLAPSED_MEMBERS = 3
+
+/**
+ * The shared shape of every NIP-51 list card: a name, an optional description, the members, and —
+ * when the viewer is not the list's author — an honest line about the ones they cannot see.
+ *
+ * Each list kind supplies its own title, its own member type and its own row, because a mute list
+ * of pubkeys and a bookmark list of notes are not the same thing and should not pretend to be.
+ * What they share is this frame.
+ */
+@Composable
+fun <T> ListCard(
+    title: String,
+    description: String?,
+    items: List<T>,
+    /** True when the event carries private members this viewer has no key for. */
+    hasUnreadablePrivateItems: Boolean,
+    backgroundColor: MutableState<Color>,
+    itemContent: @Composable (T) -> Unit,
+) {
+    var expanded by rememberSaveable { mutableStateOf(false) }
+    val shown = if (expanded) items else items.take(COLLAPSED_MEMBERS)
+
+    Text(
+        text = title,
+        fontWeight = FontWeight.Bold,
+        maxLines = 1,
+        overflow = TextOverflow.Ellipsis,
+        modifier = Modifier.fillMaxWidth().padding(5.dp),
+        textAlign = TextAlign.Center,
+    )
+
+    description?.takeIf { it.isNotBlank() }?.let {
+        Text(
+            text = it,
+            maxLines = 3,
+            overflow = TextOverflow.Ellipsis,
+            modifier = Modifier.fillMaxWidth().padding(horizontal = 5.dp),
+            textAlign = TextAlign.Center,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+        )
+    }
+
+    // Only when there is nothing else to show. A card with visible members already reads as a list,
+    // and most lists keep something private, so saying so on every one of them is noise. The line
+    // exists for the case that would otherwise be a title and blank space — an all-private list,
+    // which is what divine.video publishes — so that it reads as closed rather than as broken.
+    if (hasUnreadablePrivateItems && items.isEmpty()) {
+        Text(
+            text = stringRes(R.string.nip51_list_has_private_members),
+            style = MaterialTheme.typography.bodySmall,
+            modifier = Modifier.fillMaxWidth().padding(horizontal = 5.dp, vertical = 2.dp),
+            textAlign = TextAlign.Center,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+        )
+    }
+
+    Box {
+        Column(modifier = Modifier.fillMaxWidth().padding(top = 5.dp)) {
+            shown.forEach { itemContent(it) }
+        }
+
+        if (items.size > COLLAPSED_MEMBERS && !expanded) {
+            Row(
+                verticalAlignment = Alignment.CenterVertically,
+                horizontalArrangement = Arrangement.Center,
+                modifier =
+                    Modifier
+                        .align(Alignment.BottomCenter)
+                        .fillMaxWidth()
+                        .background(getGradient(backgroundColor)),
+            ) {
+                ShowMoreButton { expanded = true }
+            }
+        }
+    }
+}
+
+/**
+ * Decrypts a list's private members, and keeps "could not read them" apart from "there are none".
+ *
+ * `null` means we never got the plaintext — the viewer is not the author, or the decrypt failed.
+ * An empty list means we read the content and it holds nothing, which is an empty list and must
+ * not be labelled private: its author can see straight into it.
+ */
+@Composable
+fun <T> loadPrivateItems(
+    noteEvent: Event,
+    accountViewModel: AccountViewModel,
+    load: suspend (NostrSigner) -> List<T>?,
+): State<List<T>?> =
+    produceState<List<T>?>(initialValue = null, noteEvent) {
+        if (noteEvent.pubKey != accountViewModel.account.signer.pubKey) return@produceState
+        value =
+            try {
+                load(accountViewModel.account.signer)
+            } catch (e: Exception) {
+                if (e is kotlin.coroutines.cancellation.CancellationException) throw e
+                Log.w("NIP51ListCard", "Cannot decrypt private members of ${noteEvent.id}", e)
+                null
+            }
+    }
+
+/**
+ * True when this event is withholding members from the viewer.
+ *
+ * Both halves matter: an empty `content` is a list with no private members at all, and a non-null
+ * [privateItems] means we already read them, so neither is hidden.
+ */
+fun Event.hidesPrivateMembers(privateItems: List<*>?): Boolean = content.isNotEmpty() && privateItems == null
+
+/** A list's own name if it has one, else the `d` tag it is addressed by, else the kind's name. */
+@Composable
+fun listTitle(
+    explicitTitle: String?,
+    dTag: String?,
+    fallback: Int,
+): String =
+    explicitTitle?.takeIf { it.isNotBlank() }
+        ?: dTag?.takeIf { it.isNotBlank() }
+        ?: stringRes(fallback)
+
+/** Remembers the concatenation of a list's public and (once decrypted) private members. */
+@Composable
+fun <T> rememberAllMembers(
+    public: List<T>,
+    private: List<T>?,
+): List<T> = remember(public, private) { if (private == null) public else public + private }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/types/lists/ListItemRows.kt

@@ -0,0 +1,163 @@
+/*
+ * 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.ui.note.types.lists
+
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.HorizontalDivider
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.MutableState
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import com.vitorpamplona.amethyst.ui.components.LoadNote
+import com.vitorpamplona.amethyst.ui.navigation.navs.INav
+import com.vitorpamplona.amethyst.ui.navigation.routes.Route
+import com.vitorpamplona.amethyst.ui.note.LoadAddressableNote
+import com.vitorpamplona.amethyst.ui.note.NoteCompose
+import com.vitorpamplona.amethyst.ui.note.UserCompose
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.rooms.LoadUser
+import com.vitorpamplona.amethyst.ui.theme.DividerThickness
+import com.vitorpamplona.quartz.nip01Core.core.Address
+import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip51Lists.bookmarkList.tags.AddressBookmark
+import com.vitorpamplona.quartz.nip51Lists.bookmarkList.tags.BookmarkIdTag
+import com.vitorpamplona.quartz.nip51Lists.bookmarkList.tags.EventBookmark
+
+/**
+ * A member that is a person. Loaded lazily and skipped until the profile arrives, because a bare
+ * hex key in a list of people reads as noise rather than as a member.
+ */
+@Composable
+fun UserMemberRow(
+    pubKey: HexKey,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    LoadUser(pubKey, accountViewModel) { user ->
+        user?.let {
+            Column(modifier = Modifier.fillMaxWidth()) {
+                UserCompose(it, accountViewModel = accountViewModel, nav = nav)
+                HorizontalDivider(thickness = DividerThickness)
+            }
+        }
+    }
+}
+
+/**
+ * A member that is a note or an addressable event — a bookmark, a curated article, a repository.
+ *
+ * [quotesLeft] guards the recursion: a bookmarked note can itself quote things, and NoteCompose
+ * decrements it on the way down.
+ */
+@Composable
+fun BookmarkMemberRow(
+    item: BookmarkIdTag,
+    quotesLeft: Int,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    if (quotesLeft <= 0) return
+
+    when (item) {
+        is AddressBookmark -> AddressMemberRow(item.address, quotesLeft, backgroundColor, accountViewModel, nav)
+
+        is EventBookmark ->
+            LoadNote(item.eventId, accountViewModel) { note ->
+                note?.let {
+                    NoteCompose(
+                        baseNote = it,
+                        isQuotedNote = true,
+                        quotesLeft = quotesLeft - 1,
+                        parentBackgroundColor = backgroundColor,
+                        accountViewModel = accountViewModel,
+                        nav = nav,
+                    )
+                }
+            }
+    }
+}
+
+/** A member named by coordinate: an article, a repository, an app, a DVM feed. */
+@Composable
+fun AddressMemberRow(
+    address: Address,
+    quotesLeft: Int,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    if (quotesLeft <= 0) return
+
+    LoadAddressableNote(address, accountViewModel) { note ->
+        note?.let {
+            NoteCompose(
+                baseNote = it,
+                isQuotedNote = true,
+                quotesLeft = quotesLeft - 1,
+                parentBackgroundColor = backgroundColor,
+                accountViewModel = accountViewModel,
+                nav = nav,
+            )
+        }
+    }
+}
+
+/**
+ * A member that is just a word: a hashtag, a geohash, a muted word.
+ *
+ * [onClick] is optional because only some of these lead anywhere — a hashtag opens its feed, a
+ * muted word opens nothing.
+ */
+@Composable
+fun LabelMemberRow(
+    label: String,
+    onClick: (() -> Unit)? = null,
+) {
+    Column(modifier = Modifier.fillMaxWidth()) {
+        Text(
+            text = label,
+            style = MaterialTheme.typography.bodyLarge,
+            maxLines = 1,
+            overflow = TextOverflow.Ellipsis,
+            modifier =
+                Modifier
+                    .fillMaxWidth()
+                    .then(if (onClick != null) Modifier.clickable(onClick = onClick) else Modifier)
+                    .padding(horizontal = 10.dp, vertical = 6.dp),
+        )
+        HorizontalDivider(thickness = DividerThickness)
+    }
+}
+
+/** A hashtag member, which opens its feed. */
+@Composable
+fun HashtagMemberRow(
+    hashtag: String,
+    nav: INav,
+) = LabelMemberRow("#$hashtag") { nav.nav(Route.Hashtag(hashtag)) }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/types/lists/MuteList.kt

@@ -0,0 +1,109 @@
+/*
+ * 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.ui.note.types.lists
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.MutableState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.key
+import androidx.compose.runtime.remember
+import androidx.compose.ui.graphics.Color
+import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.commons.model.Note
+import com.vitorpamplona.amethyst.ui.components.LoadNote
+import com.vitorpamplona.amethyst.ui.navigation.navs.INav
+import com.vitorpamplona.amethyst.ui.note.NoteCompose
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.amethyst.ui.stringRes
+import com.vitorpamplona.quartz.nip51Lists.muteList.MuteListEvent
+import com.vitorpamplona.quartz.nip51Lists.muteList.tags.EventTag
+import com.vitorpamplona.quartz.nip51Lists.muteList.tags.HashtagTag
+import com.vitorpamplona.quartz.nip51Lists.muteList.tags.UserTag
+import com.vitorpamplona.quartz.nip51Lists.muteList.tags.WordTag
+
+/**
+ * NIP-51 kind 10000: the mute list.
+ *
+ * The only list whose members are of four different kinds at once — people, hashtags, words and
+ * threads — so it is the one kind that cannot borrow another card's body. Each member is drawn as
+ * what it actually is: a profile row for a person, a hashtag that opens its feed, a word as
+ * itself, and a muted thread as the note it silences.
+ *
+ * Most mute lists are mostly private, and for anyone but their author this renders as a title and
+ * an honest line saying so — which is the entire point, given that it used to render as the
+ * NIP-44 ciphertext.
+ */
+@Composable
+fun RenderMuteList(
+    baseNote: Note,
+    quotesLeft: Int,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val noteEvent = baseNote.event as? MuteListEvent ?: return
+
+    val public = remember(noteEvent) { noteEvent.publicMutes() }
+    val private by loadPrivateItems(noteEvent, accountViewModel) { noteEvent.privateMutes(it) }
+
+    ListCard(
+        title = stringRes(R.string.kind_mute_list),
+        description = null,
+        items = rememberAllMembers(public, private),
+        hasUnreadablePrivateItems = noteEvent.hidesPrivateMembers(private),
+        backgroundColor = backgroundColor,
+    ) { mute ->
+        when (mute) {
+            is UserTag -> key(mute.pubKey) { UserMemberRow(mute.pubKey, accountViewModel, nav) }
+            is HashtagTag -> key(mute.hashtag) { HashtagMemberRow(mute.hashtag, nav) }
+            is WordTag -> key(mute.word) { LabelMemberRow(mute.word) }
+            is EventTag ->
+                key(mute.eventId) {
+                    MutedThreadRow(mute.eventId, quotesLeft, backgroundColor, accountViewModel, nav)
+                }
+        }
+    }
+}
+
+/** A muted conversation, shown as the note it silences. */
+@Composable
+private fun MutedThreadRow(
+    eventId: String,
+    quotesLeft: Int,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    if (quotesLeft <= 0) return
+
+    LoadNote(eventId, accountViewModel) { note ->
+        note?.let {
+            NoteCompose(
+                baseNote = it,
+                isQuotedNote = true,
+                quotesLeft = quotesLeft - 1,
+                parentBackgroundColor = backgroundColor,
+                accountViewModel = accountViewModel,
+                nav = nav,
+            )
+        }
+    }
+}

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/types/lists/TagLists.kt

@@ -0,0 +1,118 @@
+/*
+ * 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.ui.note.types.lists
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.MutableState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.key
+import androidx.compose.runtime.remember
+import androidx.compose.ui.graphics.Color
+import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.commons.model.Note
+import com.vitorpamplona.amethyst.ui.navigation.navs.INav
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.amethyst.ui.stringRes
+import com.vitorpamplona.quartz.nip01Core.tags.hashtags.HashtagTag
+import com.vitorpamplona.quartz.nip51Lists.geohashList.GeohashListEvent
+import com.vitorpamplona.quartz.nip51Lists.hashtagList.HashtagListEvent
+import com.vitorpamplona.quartz.nip51Lists.interestSet.InterestSetEvent
+
+/** NIP-51 kind 10015: the hashtags this user follows. */
+@Composable
+fun RenderHashtagList(
+    baseNote: Note,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val noteEvent = baseNote.event as? HashtagListEvent ?: return
+
+    val public = remember(noteEvent) { noteEvent.publicHashtags() }
+    // HashtagListEvent exposes no private accessor of its own, but it is a PrivateTagArrayEvent
+    // like the rest, so its private half is read the same way InterestSetEvent reads its own.
+    val private by loadPrivateItems(noteEvent, accountViewModel) { signer ->
+        noteEvent.privateTags(signer)?.mapNotNull(HashtagTag::parse)
+    }
+
+    ListCard(
+        title = stringRes(R.string.kind_hashtag_follows),
+        description = null,
+        items = rememberAllMembers(public, private),
+        hasUnreadablePrivateItems = noteEvent.hidesPrivateMembers(private),
+        backgroundColor = backgroundColor,
+    ) { tag ->
+        key(tag) { HashtagMemberRow(tag, nav) }
+    }
+}
+
+/** NIP-51 kind 30015: "interest topics represented by a bunch of hashtags". */
+@Composable
+fun RenderInterestSet(
+    baseNote: Note,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val noteEvent = baseNote.event as? InterestSetEvent ?: return
+
+    val public = remember(noteEvent) { noteEvent.publicHashtags() }
+    val private by loadPrivateItems(noteEvent, accountViewModel) { noteEvent.privateHashtags(it) }
+
+    ListCard(
+        title = listTitle(noteEvent.title(), noteEvent.dTag(), R.string.kind_interest_set),
+        description = noteEvent.description(),
+        items = rememberAllMembers(public, private),
+        hasUnreadablePrivateItems = noteEvent.hidesPrivateMembers(private),
+        backgroundColor = backgroundColor,
+    ) { tag ->
+        key(tag) { HashtagMemberRow(tag, nav) }
+    }
+}
+
+/**
+ * NIP-51 kind 10081: the places this user follows.
+ *
+ * A geohash is not a hashtag — it is a location, and it gets no `#`. Shown verbatim because a
+ * geohash is what the list stores; turning it into a place name would need a geocoder we don't
+ * have on this path.
+ */
+@Composable
+fun RenderGeohashList(
+    baseNote: Note,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+) {
+    val noteEvent = baseNote.event as? GeohashListEvent ?: return
+
+    val public = remember(noteEvent) { noteEvent.publicGeohashes() }
+    val private by loadPrivateItems(noteEvent, accountViewModel) { noteEvent.decryptPrivateGeohashes(it) }
+
+    ListCard(
+        title = stringRes(R.string.kind_geohash_follows),
+        description = null,
+        items = rememberAllMembers(public, private),
+        hasUnreadablePrivateItems = noteEvent.hidesPrivateMembers(private),
+        backgroundColor = backgroundColor,
+    ) { geohash ->
+        key(geohash) { LabelMemberRow(geohash) }
+    }
+}

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/types/lists/UserLists.kt

@@ -0,0 +1,166 @@
+/*
+ * 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.ui.note.types.lists
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.MutableState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.key
+import androidx.compose.runtime.remember
+import androidx.compose.ui.graphics.Color
+import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.commons.model.Note
+import com.vitorpamplona.amethyst.ui.navigation.navs.INav
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.amethyst.ui.stringRes
+import com.vitorpamplona.quartz.nip51Lists.gitAuthorList.GitAuthorListEvent
+import com.vitorpamplona.quartz.nip51Lists.goodWikiAuthorList.GoodWikiAuthorListEvent
+import com.vitorpamplona.quartz.nip51Lists.kindMuteSet.KindMuteSetEvent
+import com.vitorpamplona.quartz.nip51Lists.mediaFollowList.MediaFollowListEvent
+import com.vitorpamplona.quartz.nip51Lists.mediaStarterPack.MediaStarterPackEvent
+
+/** NIP-51 kind 10017: the git authors whose patches this user wants to see. */
+@Composable
+fun RenderGitAuthorList(
+    baseNote: Note,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val noteEvent = baseNote.event as? GitAuthorListEvent ?: return
+
+    val public = remember(noteEvent) { noteEvent.publicAuthors() }
+    val private by loadPrivateItems(noteEvent, accountViewModel) { noteEvent.privateAuthors(it) }
+
+    ListCard(
+        title = stringRes(R.string.kind_git_authors),
+        description = null,
+        items = rememberAllMembers(public, private),
+        hasUnreadablePrivateItems = noteEvent.hidesPrivateMembers(private),
+        backgroundColor = backgroundColor,
+    ) { author ->
+        key(author.pubKey) { UserMemberRow(author.pubKey, accountViewModel, nav) }
+    }
+}
+
+/** NIP-51 kind 10020: the people whose media this user follows. */
+@Composable
+fun RenderMediaFollowList(
+    baseNote: Note,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val noteEvent = baseNote.event as? MediaFollowListEvent ?: return
+
+    val public = remember(noteEvent) { noteEvent.publicFollows() }
+    val private by loadPrivateItems(noteEvent, accountViewModel) { noteEvent.privateFollows(it) }
+
+    ListCard(
+        title = stringRes(R.string.kind_media_follows),
+        description = null,
+        items = rememberAllMembers(public, private),
+        hasUnreadablePrivateItems = noteEvent.hidesPrivateMembers(private),
+        backgroundColor = backgroundColor,
+    ) { follow ->
+        key(follow.pubKey) { UserMemberRow(follow.pubKey, accountViewModel, nav) }
+    }
+}
+
+/** NIP-51 kind 10101: the authors whose wiki articles this user trusts. */
+@Composable
+fun RenderGoodWikiAuthorList(
+    baseNote: Note,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val noteEvent = baseNote.event as? GoodWikiAuthorListEvent ?: return
+
+    val public = remember(noteEvent) { noteEvent.publicAuthors() }
+    val private by loadPrivateItems(noteEvent, accountViewModel) { noteEvent.privateAuthors(it) }
+
+    ListCard(
+        title = stringRes(R.string.kind_good_wiki_authors),
+        description = null,
+        items = rememberAllMembers(public, private),
+        hasUnreadablePrivateItems = noteEvent.hidesPrivateMembers(private),
+        backgroundColor = backgroundColor,
+    ) { author ->
+        key(author.pubKey) { UserMemberRow(author.pubKey, accountViewModel, nav) }
+    }
+}
+
+/**
+ * NIP-51 kind 30007: people muted for one kind only.
+ *
+ * "`d` tag MUST be the kind string" — so the `d` tag is not a name here, it is the kind being
+ * muted, and printing it as a title the way other sets do would be wrong.
+ */
+@Composable
+fun RenderKindMuteSet(
+    baseNote: Note,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val noteEvent = baseNote.event as? KindMuteSetEvent ?: return
+
+    val public = remember(noteEvent) { noteEvent.publicMutedUsers() }
+    val private by loadPrivateItems(noteEvent, accountViewModel) { noteEvent.privateMutedUsers(it) }
+    val mutedKind = remember(noteEvent) { noteEvent.dTag() }
+
+    ListCard(
+        title = stringRes(R.string.kind_mute_set_for_kind, mutedKind),
+        description = null,
+        items = rememberAllMembers(public, private),
+        hasUnreadablePrivateItems = noteEvent.hidesPrivateMembers(private),
+        backgroundColor = backgroundColor,
+    ) { muted ->
+        key(muted.pubKey) { UserMemberRow(muted.pubKey, accountViewModel, nav) }
+    }
+}
+
+/**
+ * NIP-51 kind 39092: a media starter pack — "a named set of profiles to be shared around with the
+ * goal of being followed together". Public by construction: a pack exists to be handed out.
+ */
+@Composable
+fun RenderMediaStarterPack(
+    baseNote: Note,
+    backgroundColor: MutableState<Color>,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val noteEvent = baseNote.event as? MediaStarterPackEvent ?: return
+
+    val members = remember(noteEvent) { noteEvent.followIds() }
+
+    ListCard(
+        title = listTitle(noteEvent.title(), noteEvent.dTag(), R.string.kind_media_starter_pack),
+        description = noteEvent.description(),
+        items = members,
+        hasUnreadablePrivateItems = false,
+        backgroundColor = backgroundColor,
+    ) { pubKey ->
+        key(pubKey) { UserMemberRow(pubKey, accountViewModel, nav) }
+    }
+}

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

@@ -2012,6 +2012,12 @@ class AccountViewModel(
 
     fun videoPlayerButtonItemsFlow() = account.settings.syncedSettings.videoPlayer.buttonItems
 
+    fun captionsEnabledFlow() = account.settings.syncedSettings.videoPlayer.captionsEnabled
+
+    fun setCaptionsEnabled(enabled: Boolean) {
+        viewModelScope.launch { account.changeCaptionsEnabled(enabled) }
+    }
+
     fun changeVideoPlayerButtonItems(items: List<com.vitorpamplona.amethyst.model.VideoPlayerButtonItem>) =
         launchSigner {
             account.changeVideoPlayerButtonItems(items)

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/profile/gallery/dal/UserProfileGalleryFeedFilter.kt

@@ -34,6 +34,7 @@ import com.vitorpamplona.quartz.nip53LiveActivities.clip.LiveActivitiesClipEvent
 import com.vitorpamplona.quartz.nip68Picture.PictureEvent
 import com.vitorpamplona.quartz.nip71Video.AddressableVideoEvent
 import com.vitorpamplona.quartz.nip71Video.RegularVideoEvent
+import com.vitorpamplona.quartz.nip71Video.VideoHorizontalEvent
 import com.vitorpamplona.quartz.nip71Video.VideoVerticalEvent
 
 class UserProfileGalleryFeedFilter(
@@ -53,7 +54,10 @@ class UserProfileGalleryFeedFilter(
         val addressableNotes =
             LocalCache.addressables
                 .filter(
-                    listOf(VideoVerticalEvent.KIND, VideoVerticalEvent.KIND),
+                    // Both NIP-71 addressable kinds: acceptableEvent() takes any
+                    // AddressableVideoEvent, so listing 34236 twice silently kept every
+                    // 34235 (horizontal) video out of the gallery.
+                    listOf(VideoVerticalEvent.KIND, VideoHorizontalEvent.KIND),
                     user.pubkeyHex,
                 ) { _, it ->
                     acceptableEvent(it, params, user)

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

@@ -46,6 +46,7 @@ import com.vitorpamplona.quartz.experimental.nipsOnNostr.NipTextEvent
 import com.vitorpamplona.quartz.experimental.nns.NNSEvent
 import com.vitorpamplona.quartz.experimental.notifications.wake.WakeUpEvent
 import com.vitorpamplona.quartz.experimental.profileGallery.ProfileGalleryEntryEvent
+import com.vitorpamplona.quartz.experimental.videoCollaboration.VideoCollaborationEvent
 import com.vitorpamplona.quartz.experimental.zapPolls.ZapPollEvent
 import com.vitorpamplona.quartz.kinds.KindNames
 import com.vitorpamplona.quartz.nip01Core.metadata.MetadataEvent
@@ -106,6 +107,7 @@ import com.vitorpamplona.quartz.nip51Lists.relayLists.ProxyRelayListEvent
 import com.vitorpamplona.quartz.nip51Lists.relayLists.RelayFeedsListEvent
 import com.vitorpamplona.quartz.nip51Lists.relayLists.TrustedRelayListEvent
 import com.vitorpamplona.quartz.nip51Lists.relaySets.RelaySetEvent
+import com.vitorpamplona.quartz.nip51Lists.videoCurationSet.VideoCurationSetEvent
 import com.vitorpamplona.quartz.nip52Calendar.appt.day.CalendarDateSlotEvent
 import com.vitorpamplona.quartz.nip52Calendar.appt.time.CalendarTimeSlotEvent
 import com.vitorpamplona.quartz.nip52Calendar.calendar.CalendarEvent
@@ -144,6 +146,7 @@ import com.vitorpamplona.quartz.nip71Video.VideoHorizontalEvent
 import com.vitorpamplona.quartz.nip71Video.VideoNormalEvent
 import com.vitorpamplona.quartz.nip71Video.VideoShortEvent
 import com.vitorpamplona.quartz.nip71Video.VideoVerticalEvent
+import com.vitorpamplona.quartz.nip71Video.textTrack.TextTrackEvent
 import com.vitorpamplona.quartz.nip72ModCommunities.approval.CommunityPostApprovalEvent
 import com.vitorpamplona.quartz.nip72ModCommunities.definition.CommunityDefinitionEvent
 import com.vitorpamplona.quartz.nip72ModCommunities.follow.CommunityListEvent
@@ -325,6 +328,9 @@ fun kindDisplayName(kind: Int): Int =
         TorrentCommentEvent.KIND -> R.string.kind_torrent_comments
         TrustedRelayListEvent.KIND -> R.string.kind_trusted_relays
         TrustProviderListEvent.KIND -> R.string.kind_trusted_providers
+        VideoCurationSetEvent.KIND -> R.string.kind_video_list
+        VideoCollaborationEvent.KIND -> R.string.kind_video_collaboration
+        TextTrackEvent.KIND -> R.string.kind_video_subtitles
         VideoHorizontalEvent.KIND -> R.string.kind_video_repl
         VideoVerticalEvent.KIND -> R.string.kind_shorts_repl
         VideoNormalEvent.KIND -> R.string.kind_video

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

@@ -63,6 +63,8 @@ import com.vitorpamplona.amethyst.R
 import com.vitorpamplona.amethyst.commons.icons.symbols.Icon
 import com.vitorpamplona.amethyst.commons.icons.symbols.MaterialSymbols
 import com.vitorpamplona.amethyst.commons.resources.Res
+import com.vitorpamplona.amethyst.commons.resources.video_player_settings_action_captions
+import com.vitorpamplona.amethyst.commons.resources.video_player_settings_action_captions_description
 import com.vitorpamplona.amethyst.commons.resources.video_player_settings_action_cast
 import com.vitorpamplona.amethyst.commons.resources.video_player_settings_action_cast_description
 import com.vitorpamplona.amethyst.commons.resources.video_player_settings_action_download
@@ -359,6 +361,7 @@ fun videoPlayerActionName(action: VideoPlayerAction): String =
         VideoPlayerAction.Download -> stringRes(Res.string.video_player_settings_action_download)
         VideoPlayerAction.PictureInPicture -> stringRes(Res.string.video_player_settings_action_pip)
         VideoPlayerAction.Cast -> stringRes(Res.string.video_player_settings_action_cast)
+        VideoPlayerAction.Captions -> stringRes(Res.string.video_player_settings_action_captions)
     }
 
 @Composable
@@ -371,4 +374,5 @@ fun videoPlayerActionDescription(action: VideoPlayerAction): String =
         VideoPlayerAction.Download -> stringRes(Res.string.video_player_settings_action_download_description)
         VideoPlayerAction.PictureInPicture -> stringRes(Res.string.video_player_settings_action_pip_description)
         VideoPlayerAction.Cast -> stringRes(Res.string.video_player_settings_action_cast_description)
+        VideoPlayerAction.Captions -> stringRes(Res.string.video_player_settings_action_captions_description)
     }

amethyst/src/main/res/values/strings.xml

@@ -2794,4 +2794,39 @@
     <!-- My Fitness: the signed-in user's own training summary. Android resource because
          NavBarItemDef labels are R.string ids. -->
     <string name="my_fitness">My Fitness</string>
+    <string name="captions_off">Off</string>
+    <string name="captions_unnamed_track">Captions</string>
+    <string name="captions_turn_on">Turn on captions</string>
+    <string name="captions_turn_off">Turn off captions</string>
+    <string name="kind_video_list">Video List</string>
+    <string name="kind_video_collaboration">Video Collaboration</string>
+    <string name="kind_video_subtitles">Video Subtitles</string>
+    <!-- NIP-71 video credits: what a video says about the people and works it references. -->
+    <string name="video_credit_inspired_by">Inspired by</string>
+    <string name="video_credit_featuring">Featuring</string>
+    <string name="video_credit_references">References</string>
+    <string name="video_credit_audio_from">Audio from</string>
+    <string name="video_credit_accepted">Credit accepted</string>
+    <string name="video_collaboration_accepted_on">Accepted a collaboration credit</string>
+    <string name="video_collaboration_declined_on">Declined a collaboration credit</string>
+    <string name="video_curation_set_private_items">Private list</string>
+    <string name="nip51_list_has_private_members">This list has private members only its author can see</string>
+    <string name="kind_git_authors">Git authors</string>
+    <string name="kind_media_follows">Media follows</string>
+    <string name="kind_good_wiki_authors">Trusted wiki authors</string>
+    <string name="kind_good_wiki_relays">Trusted wiki relays</string>
+    <string name="kind_mute_set_for_kind">Muted for kind %1$s</string>
+    <string name="kind_media_starter_pack">Media starter pack</string>
+    <string name="kind_bookmark_set">Bookmark set</string>
+    <string name="kind_article_curation_set">Article list</string>
+    <string name="kind_picture_curation_set">Picture list</string>
+    <string name="kind_app_curation_set">App list</string>
+    <string name="kind_git_repositories">Git repositories</string>
+    <string name="kind_favorite_algo_feeds">Favorite feeds</string>
+    <string name="kind_interest_set">Interests</string>
+    <string name="kind_simple_groups">Groups</string>
+    <plurals name="video_curation_set_video_count">
+        <item quantity="one">%1$d video</item>
+        <item quantity="other">%1$d videos</item>
+    </plurals>
 </resources>

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/model/cache/EventCache.kt

@@ -182,6 +182,7 @@ import com.vitorpamplona.quartz.experimental.ratings.EntityRatingEvent
 import com.vitorpamplona.quartz.experimental.ratings.RelayReviewEvent
 import com.vitorpamplona.quartz.experimental.roadstr.confirmation.RoadEventConfirmationEvent
 import com.vitorpamplona.quartz.experimental.roadstr.report.RoadEventReportEvent
+import com.vitorpamplona.quartz.experimental.videoCollaboration.VideoCollaborationEvent
 import com.vitorpamplona.quartz.experimental.zapPolls.ZapPollEvent
 import com.vitorpamplona.quartz.marmot.mip00KeyPackages.KeyPackageEvent
 import com.vitorpamplona.quartz.marmot.mip00KeyPackages.KeyPackageRelayListEvent
@@ -299,6 +300,7 @@ import com.vitorpamplona.quartz.nip51Lists.relayLists.TrustedRelayListEvent
 import com.vitorpamplona.quartz.nip51Lists.relaySets.RelaySetEvent
 import com.vitorpamplona.quartz.nip51Lists.releaseArtifactSet.ReleaseArtifactSetEvent
 import com.vitorpamplona.quartz.nip51Lists.simpleGroupList.SimpleGroupListEvent
+import com.vitorpamplona.quartz.nip51Lists.videoCurationSet.VideoCurationSetEvent
 import com.vitorpamplona.quartz.nip52Calendar.appt.day.CalendarDateSlotEvent
 import com.vitorpamplona.quartz.nip52Calendar.appt.time.CalendarTimeSlotEvent
 import com.vitorpamplona.quartz.nip52Calendar.calendar.CalendarEvent
@@ -355,6 +357,7 @@ import com.vitorpamplona.quartz.nip71Video.VideoHorizontalEvent
 import com.vitorpamplona.quartz.nip71Video.VideoNormalEvent
 import com.vitorpamplona.quartz.nip71Video.VideoShortEvent
 import com.vitorpamplona.quartz.nip71Video.VideoVerticalEvent
+import com.vitorpamplona.quartz.nip71Video.textTrack.TextTrackEvent
 import com.vitorpamplona.quartz.nip72ModCommunities.approval.CommunityPostApprovalEvent
 import com.vitorpamplona.quartz.nip72ModCommunities.definition.CommunityDefinitionEvent
 import com.vitorpamplona.quartz.nip72ModCommunities.follow.CommunityListEvent
@@ -3888,6 +3891,9 @@ open class EventCache :
                 is TrustProviderListEvent,
                 is VideoHorizontalEvent,
                 is VideoVerticalEvent,
+                is TextTrackEvent,
+                is VideoCollaborationEvent,
+                is VideoCurationSetEvent,
                 is WebBookmarkEvent,
                 is ExerciseTemplateEvent,
                 is PublicationIndexEvent,

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/model/nip71Video/CaptionTracks.kt

@@ -0,0 +1,104 @@
+/*
+ * 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.nip71Video
+
+import androidx.compose.runtime.Immutable
+import com.vitorpamplona.quartz.nip01Core.core.Address
+import com.vitorpamplona.quartz.nip71Video.VideoEvent
+import com.vitorpamplona.quartz.nip71Video.tags.TextTrackTag
+import com.vitorpamplona.quartz.nip71Video.textTrack.TextTrackEvent
+
+/**
+ * One timed-text track a player can side-load, resolved from a video's `text-track` tag.
+ *
+ * [url] is what the player fetches. NIP-71 never says what media type a track is served as, and a
+ * blossom-hosted one has no file extension either, so [mimeType] is always declared — WebVTT
+ * unless the referenced [TextTrackEvent] says otherwise.
+ */
+@Immutable
+data class CaptionTrack(
+    val url: String,
+    val mimeType: String = TextTrackEvent.DEFAULT_MIME_TYPE,
+    val language: String? = null,
+    // NIP-71 calls this the "type of supplementary information": captions, subtitles, chapters or
+    // metadata. Kept as published so a track picker can label and group by it.
+    val type: String? = null,
+)
+
+/**
+ * Splits a video's `text-track` tags into the ones a player can load on its own and the ones that
+ * first need a [TextTrackEvent] fetched.
+ *
+ * A `text-track` ref is either a URL (load it) or an addressable coordinate (resolve it). The same
+ * track is routinely published both ways — divine.video emits the Blossom URL and the
+ * `39307:<pubkey>:subtitles:<d>` coordinate side by side — so the two lists overlap by design and
+ * [mergeCaptionTracks] is what de-duplicates them once the events are in hand.
+ */
+fun VideoEvent.captionTracks(): ResolvedCaptionTracks {
+    val direct = mutableListOf<CaptionTrack>()
+    val pending = mutableListOf<PendingCaptionTrack>()
+
+    textTrack().forEach { tag ->
+        val address = Address.parse(tag.ref)
+        if (address != null) {
+            pending.add(PendingCaptionTrack(address, tag))
+        } else if (tag.ref.startsWith("http://", true) || tag.ref.startsWith("https://", true)) {
+            direct.add(CaptionTrack(url = tag.ref, language = tag.language, type = tag.type))
+        }
+        // Anything else — a bare event id, per NIP-71's own example — is not loadable as a file
+        // and has no address to resolve, so it is dropped rather than handed to the player as a
+        // URL it would fail to fetch.
+    }
+
+    return ResolvedCaptionTracks(direct, pending)
+}
+
+@Immutable
+data class ResolvedCaptionTracks(
+    val direct: List<CaptionTrack>,
+    val pending: List<PendingCaptionTrack>,
+)
+
+@Immutable
+data class PendingCaptionTrack(
+    val address: Address,
+    val tag: TextTrackTag,
+)
+
+/** The track a resolved [TextTrackEvent] contributes, or null when it hosts no fetchable file. */
+fun TextTrackEvent.toCaptionTrack(tag: TextTrackTag? = null): CaptionTrack? {
+    val url = url() ?: return null
+    return CaptionTrack(
+        url = url,
+        mimeType = mimeType() ?: TextTrackEvent.DEFAULT_MIME_TYPE,
+        // The event is the more specific source: it was written by whoever made the track, while
+        // the tag on the video is the video author's description of it.
+        language = language() ?: tag?.language,
+        type = tag?.type,
+    )
+}
+
+/**
+ * Collapses tracks that point at the same file. A video that advertises one track twice — once as
+ * a URL and once as the event that hosts it — would otherwise hand the player two identical
+ * subtitle configurations, and ExoPlayer shows both as selectable tracks.
+ */
+fun mergeCaptionTracks(vararg lists: List<CaptionTrack>): List<CaptionTrack> = lists.flatMap { it }.distinctBy { it.url }

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/model/nip71Video/VideoTrackSelection.kt

@@ -24,6 +24,7 @@ import com.vitorpamplona.amethyst.commons.richtext.MediaContentKind
 import com.vitorpamplona.amethyst.commons.richtext.RichTextParser
 import com.vitorpamplona.quartz.nip71Video.VideoEvent
 import com.vitorpamplona.quartz.nip71Video.VideoMeta
+import com.vitorpamplona.quartz.nip71Video.tags.HlsImetaTag
 
 /**
  * Picks the `imeta` entry a NIP-71 event's player should load.
@@ -58,7 +59,7 @@ import com.vitorpamplona.quartz.nip71Video.VideoMeta
  * keeps the placeholder and the layout intact when the master turns out to be the bare one.
  */
 fun VideoEvent.selectVideoTrack(): VideoMeta? {
-    val imetas = imetaTags()
+    val imetas = imetaTags().flatMap { it.withHlsVariant() }
     if (imetas.size <= 1) return imetas.firstOrNull()
 
     val candidates = imetas.filter { it.canBeTheVideo() }
@@ -81,6 +82,20 @@ fun VideoEvent.selectVideoTrack(): VideoMeta? {
     return selected.withLadderMetadataFrom(imetas)
 }
 
+// A publisher that keeps one imeta per video and hangs its adaptive manifest off the
+// non-standard `hls` property (divine.video does; see [HlsImetaTag]) describes a ladder NIP-71
+// would have written as a second imeta. Expand it into one, listed first so the HLS preference
+// below reaches it, and drop the fields that describe the progressive file specifically: `x` and
+// `size` are that blob's digest and byte count, and a manifest is neither.
+private fun VideoMeta.withHlsVariant(): List<VideoMeta> {
+    val manifest = hls?.takeIf { it.isNotBlank() && it != url } ?: return listOf(this)
+
+    return listOf(
+        copy(url = manifest, mimeType = HlsImetaTag.MIME_TYPE, hash = null, size = null, hls = null),
+        copy(hls = null),
+    )
+}
+
 // A NIP-71 event asserts it is a video, so an imeta is a candidate unless it says otherwise:
 // `audio/*` is a separate track under PR #2255, and `image/*` is a poster. Everything else —
 // including the HLS playlist MIMEs, which are neither `video/*` nor an image, and a bare URL with

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/model/privateChats/ChatPreview.kt

@@ -24,6 +24,8 @@ import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip04Dm.messages.PrivateDmEvent
 import com.vitorpamplona.quartz.nip37Drafts.DraftWrapEvent
+import com.vitorpamplona.quartz.nip51Lists.PrivateReplaceableTagArrayEvent
+import com.vitorpamplona.quartz.nip51Lists.PrivateTagArrayEvent
 import com.vitorpamplona.quartz.nip57Zaps.LnZapRequestEvent
 import com.vitorpamplona.quartz.nip59Giftwrap.seals.SealedRumorEvent
 import com.vitorpamplona.quartz.nip59Giftwrap.wraps.GiftWrapEvent
@@ -47,6 +49,12 @@ fun Event.hasEncryptedContent(): Boolean =
         is SealedRumorEvent -> true
         is GiftWrapEvent -> true
         is LnZapRequestEvent -> isPrivateZap()
+        // Every NIP-51 list keeps its private members as a NIP-44 payload in `content`. The two
+        // base classes cover all ~30 list kinds, present and future, which is the point: naming
+        // them one at a time is how kind 30005 came to print its own ciphertext on screen.
+        // A list with no private members carries an empty `content`, and the guard below skips it.
+        is PrivateTagArrayEvent -> content.isNotEmpty()
+        is PrivateReplaceableTagArrayEvent -> content.isNotEmpty()
         else -> false
     }
 

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/relayClient/event/watchers/FilterRepliesAndReactionsToAddresses.kt

@@ -25,6 +25,7 @@ import com.vitorpamplona.amethyst.commons.relayClient.subscriptions.ExplainedFil
 import com.vitorpamplona.amethyst.commons.relayClient.subscriptions.SubPurpose
 import com.vitorpamplona.amethyst.commons.relays.SincePerRelayMap
 import com.vitorpamplona.quartz.experimental.attestations.attestation.AttestationEvent
+import com.vitorpamplona.quartz.experimental.videoCollaboration.VideoCollaborationEvent
 import com.vitorpamplona.quartz.experimental.zapPolls.ZapPollEvent
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.relay.client.pool.RelayBasedFilter
@@ -67,6 +68,10 @@ val PostsAndChatMessagesToAddresses =
     listOf(
         CommunityPostApprovalEvent.KIND,
         LiveActivitiesChatMessageEvent.KIND,
+        // A collaborator's answer to being credited on a NIP-71 video. Only the `a` tag is
+        // common to both shapes in the wild — divine-web keys the event by a random `d`, so
+        // there is no coordinate to ask for and this `a` filter is the only way to see it.
+        VideoCollaborationEvent.KIND,
     )
 
 /**

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/relayClient/video/FeedBasis.kt

@@ -28,7 +28,30 @@ import com.vitorpamplona.quartz.nip71Video.VideoShortEvent
 import com.vitorpamplona.quartz.nip71Video.VideoVerticalEvent
 import com.vitorpamplona.quartz.nip94FileMetadata.FileHeaderEvent
 
-val SUPPORTED_VIDEO_FEED_MIME_TYPES = listOf("image/jpeg", "image/gif", "image/png", "image/webp", "video/mp4", "video/mpeg", "video/webm", "audio/aac", "audio/mpeg", "audio/webm", "audio/wav", "image/avif")
+// The media types the video/shorts feeds will admit. HLS playlists are in here because a
+// blossom-hosted manifest is `https://host/<sha256>` with no extension at all, so the MIME is the
+// only thing SupportedContent can match on — without them an adaptive-only video is dropped from
+// the feed entirely. All four spellings appear in the wild; RichTextParser.isHlsMimeType and
+// MediaItemCache.toExoPlayerMimeType recognise the same set.
+val SUPPORTED_VIDEO_FEED_MIME_TYPES =
+    listOf(
+        "image/jpeg",
+        "image/gif",
+        "image/png",
+        "image/webp",
+        "image/avif",
+        "video/mp4",
+        "video/mpeg",
+        "video/webm",
+        "audio/aac",
+        "audio/mpeg",
+        "audio/webm",
+        "audio/wav",
+        "application/vnd.apple.mpegurl",
+        "application/x-mpegurl",
+        "audio/x-mpegurl",
+        "audio/mpegurl",
+    )
 val SUPPORTED_VIDEO_FEED_MIME_TYPES_SET = SUPPORTED_VIDEO_FEED_MIME_TYPES.toSet()
 
 val PictureAndVideoKinds =

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/richtext/MediaContentModels.kt

@@ -21,7 +21,10 @@
 package com.vitorpamplona.amethyst.commons.richtext
 
 import androidx.compose.runtime.Immutable
+import com.vitorpamplona.amethyst.commons.model.nip71Video.CaptionTrack
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.DimensionTag
+import kotlinx.collections.immutable.ImmutableList
+import kotlinx.collections.immutable.persistentListOf
 
 // URL-based media content models (KMP). The locally-cached variants
 // (MediaPreloadedContent, MediaLocalImage, MediaLocalVideo) live in
@@ -115,6 +118,8 @@ open class MediaUrlVideo(
     thumbhash: String? = null,
     val isLiveStream: Boolean = false,
     authorPubKey: String? = null,
+    // NIP-71 `text-track` captions resolved for this video, for the player to side-load.
+    val captions: ImmutableList<CaptionTrack> = persistentListOf(),
 ) : MediaUrlContent(url, description, hash, dim, blurhash, uri, mimeType, thumbhash, authorPubKey)
 
 @Immutable

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/search/RenderableKinds.kt

@@ -49,6 +49,7 @@ import com.vitorpamplona.quartz.nip51Lists.bookmarkList.BookmarkListEvent
 import com.vitorpamplona.quartz.nip51Lists.bookmarkList.OldBookmarkListEvent
 import com.vitorpamplona.quartz.nip51Lists.followList.FollowListEvent
 import com.vitorpamplona.quartz.nip51Lists.peopleList.PeopleListEvent
+import com.vitorpamplona.quartz.nip51Lists.videoCurationSet.VideoCurationSetEvent
 import com.vitorpamplona.quartz.nip52Calendar.appt.day.CalendarDateSlotEvent
 import com.vitorpamplona.quartz.nip52Calendar.appt.time.CalendarTimeSlotEvent
 import com.vitorpamplona.quartz.nip52Calendar.calendar.CalendarEvent
@@ -176,6 +177,10 @@ object RenderableKinds {
             VideoShortEvent.KIND,
             VideoHorizontalEvent.KIND,
             VideoVerticalEvent.KIND,
+            // A video list has a card of its own, so by the rule the omission list states — in
+            // ALL when Amethyst can render it — it belongs in the window. Its title and
+            // description are what Quartz indexes, which is exactly what a reader would search.
+            VideoCurationSetEvent.KIND,
             AudioHeaderEvent.KIND,
             AudioTrackEvent.KIND,
             MusicTrackEvent.KIND,

commons/src/commonTest/kotlin/com/vitorpamplona/amethyst/commons/model/privateChats/ChatPreviewTest.kt

@@ -22,6 +22,8 @@ package com.vitorpamplona.amethyst.commons.model.privateChats
 
 import com.vitorpamplona.quartz.nip04Dm.messages.PrivateDmEvent
 import com.vitorpamplona.quartz.nip17Dm.messages.ChatMessageEvent
+import com.vitorpamplona.quartz.nip51Lists.muteList.MuteListEvent
+import com.vitorpamplona.quartz.nip51Lists.videoCurationSet.VideoCurationSetEvent
 import kotlin.test.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertFalse
@@ -69,6 +71,50 @@ class ChatPreviewTest {
         assertFalse(nip17Rumor().hasEncryptedContent())
     }
 
+    // A NIP-51 list keeps its private members as a NIP-44 payload in `content`. This is the real
+    // wire content of a divine.video kind-30005 video list, which used to render on screen as the
+    // base64 blob it is.
+    private val nip44ListContent =
+        "AqQxhO1d0DzuJQtkWdshs3Fvi/1OXp2sYl9rDAykMBOvD06Tg0DLP69/i03iA1SD/RHVp+TEUoG8k+0FUkr7fiEcSyWx9k37o5URbcGsESdMK9d5vAFm9Yjp5tatUuZa2gJG"
+
+    private fun videoList(content: String = nip44ListContent) =
+        VideoCurationSetEvent(
+            id = "vl".padEnd(64, '0'),
+            pubKey = other,
+            createdAt = 1_000,
+            tags = arrayOf(arrayOf("d", "my_vine_list"), arrayOf("title", "My List")),
+            content = content,
+            sig = someSig,
+        )
+
+    private fun muteList(content: String = nip44ListContent) =
+        MuteListEvent(
+            id = "ml".padEnd(64, '0'),
+            pubKey = other,
+            createdAt = 1_000,
+            tags = arrayOf(arrayOf("p", stranger)),
+            content = content,
+            sig = someSig,
+        )
+
+    @Test
+    fun anAddressableListWithPrivateMembersCarriesCiphertext() {
+        assertTrue(videoList().hasEncryptedContent())
+    }
+
+    @Test
+    fun aStandardListWithPrivateMembersCarriesCiphertext() {
+        assertTrue(muteList().hasEncryptedContent())
+    }
+
+    @Test
+    fun anAllPublicListHasNothingToHide() {
+        // No private members means no payload, and an empty string is not ciphertext — saying it
+        // was would hide a perfectly readable list behind a "private" label.
+        assertFalse(videoList(content = "").hasEncryptedContent())
+        assertFalse(muteList(content = "").hasEncryptedContent())
+    }
+
     // ---- chatPreviewOf -------------------------------------------------------
 
     @Test

commons/src/commonTest/kotlin/com/vitorpamplona/amethyst/commons/search/KindRegistryTest.kt

@@ -147,7 +147,7 @@ class KindRegistryTest {
         assertEquals(
             // 7516 is a found log: read inside a cache's thread, where `kind:geocache` already
             // leads, rather than looked up on its own.
-            listOf(24, 54, 1018, 1111, 1337, 1808, 7516, 10001, 10003, 30000, 30001, 30053, 30296, 30297, 30817, 31337),
+            listOf(24, 54, 1018, 1111, 1337, 1808, 7516, 10001, 10003, 30000, 30001, 30005, 30053, 30296, 30297, 30817, 31337),
             RenderableKinds.ALL.filter { KindRegistry.nameFor(it) == null }.sorted(),
         )
     }

commons/src/commonTest/kotlin/com/vitorpamplona/amethyst/commons/search/RenderableKindsTest.kt

@@ -87,6 +87,10 @@ class RenderableKindsTest {
                 1163,
                 32176,
                 39092,
+                // subtitle tracks: their cue text is indexed so a store can find what was said in
+                // a video, but the track has no card of its own — a hit here would be a wall of
+                // WebVTT rather than the video it belongs to.
+                39307,
                 // git: the repo itself is searchable, its patch/issue/status traffic is not
                 818,
                 1617,
@@ -142,7 +146,6 @@ class RenderableKindsTest {
                 30002,
                 30003,
                 30004,
-                30005,
                 30006,
                 30015,
                 30267,

commons/src/jvmTest/kotlin/com/vitorpamplona/amethyst/commons/model/nip71Video/DivineVideoInteropTest.kt

@@ -0,0 +1,375 @@
+/*
+ * 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.nip71Video
+
+import com.vitorpamplona.amethyst.commons.relayClient.video.SUPPORTED_VIDEO_FEED_MIME_TYPES_SET
+import com.vitorpamplona.amethyst.commons.richtext.MediaContentKind
+import com.vitorpamplona.amethyst.commons.richtext.RichTextParser
+import com.vitorpamplona.quartz.experimental.videoCollaboration.VideoCollaborationEvent
+import com.vitorpamplona.quartz.nip01Core.core.AddressableEvent
+import com.vitorpamplona.quartz.nip01Core.core.Event
+import com.vitorpamplona.quartz.nip01Core.relay.filters.Filter
+import com.vitorpamplona.quartz.nip18Reposts.GenericRepostEvent
+import com.vitorpamplona.quartz.nip22Comments.CommentEvent
+import com.vitorpamplona.quartz.nip25Reactions.ReactionEvent
+import com.vitorpamplona.quartz.nip51Lists.videoCurationSet.VideoCurationSetEvent
+import com.vitorpamplona.quartz.nip71Video.VideoVerticalEvent
+import com.vitorpamplona.quartz.nip71Video.credits.CreditTarget
+import com.vitorpamplona.quartz.nip71Video.credits.VideoCredit
+import com.vitorpamplona.quartz.nip71Video.textTrack.TextTrackEvent
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertNotNull
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/**
+ * Interop guard for divine.video (<https://github.com/divinevideo>), the biggest publisher of
+ * NIP-71 kind-34236 short videos on the network. Every fixture below is a real event pulled from
+ * `wss://relay.divine.video` — only the oversized `proofmode`/`device_attestation`/
+ * `identity_binding` blobs were stripped, which is why the signatures are not re-verified here.
+ *
+ * Divine's events exercise two shapes Amethyst used to get wrong and can silently regress on:
+ *
+ *  1. **Extension-less media URLs.** Videos live on Blossom, so the URL is
+ *     `https://media.divine.video/<sha256>` with no `.mp4`. Only the `imeta` `m` field says it is
+ *     a video, so every extension-driven branch (feed admission, image-vs-player classification)
+ *     has to consult the declared MIME first.
+ *  2. **Dual pointers on every interaction.** Reactions, reposts and comments carry BOTH the
+ *     addressable coordinate (`a`/`A`) and the specific version's event id (`e`/`E`), so both
+ *     have to resolve or the counters land on a note nobody renders.
+ */
+class DivineVideoInteropTest {
+    private val video =
+        """{"id":"fa5a793b24edfe109f8d02ad6aa6cde77b0a923566f891df403049721b46e8d9","pubkey":"4d7dccc0a5116daa057348ef79c573873cddd9eff066fc6a5f3d37e8264afbeb","created_at":1789661586,"kind":34236,"tags":[["d","c855df3d07ba963e9097d5a151b0c14a0a3d494e4ff9b04a389bc0b5f5c16862"],["text-track","https://media.divine.video/283a420202b620a9a326598b85bfcf0e8cb4ab4d52b947c628d8c29a1313006b","wss://relay.divine.video","captions","en"],["text-track","39307:4d7dccc0a5116daa057348ef79c573873cddd9eff066fc6a5f3d37e8264afbeb:subtitles:c855df3d07ba963e9097d5a151b0c14a0a3d494e4ff9b04a389bc0b5f5c16862","wss://relay.divine.video","captions","en"],["imeta","url https://media.divine.video/c855df3d07ba963e9097d5a151b0c14a0a3d494e4ff9b04a389bc0b5f5c16862","m video/mp4","image https://media.divine.video/e1d22b85609cb105dff64b4a402f13982a942dc59aee67218e6e3652c8597d2d","dim 1080x1920","x c855df3d07ba963e9097d5a151b0c14a0a3d494e4ff9b04a389bc0b5f5c16862","size 6579464","blurhash TQHxc{D%X7_Nw{nio#RiRjaJX8oz"],["title","Xmas Already??"],["summary","In the words of Jack Skellington from The Nightmare Before Christmas, \"What's this?\" 😭"],["t","retail"],["published_at","1789661611"],["duration","6"],["alt","Xmas Already??"],["allow_audio_reuse","true"],["e","218af5fc90d66a16ce273f00a4e412a71443441c04c67d1e34ff99c654871d3d","wss://relay.divine.video","audio"],["c2pa_manifest_id","urn:c2pa:b1d12836-a60f-4398-a081-c8f047483ab4"],["verification","verified_mobile"],["client","Divine","31990:d95aa8fc0eff8e488952495b8064991d27fb96ed8652f12cdedc5a4e8b5ae540:divine-mobile","wss://relay.divine.video"]],"content":"In the words of Jack Skellington from The Nightmare Before Christmas, \"What's this?\" 😭","sig":"c32a6486480465d3c4c695d8eee52868eb9c5e085fe54827478f7e183fea0602e969fa82476053136ae766536ec9ed7f0d4c9d009c5fb6991a2099696c66fc33"}"""
+
+    private val videoWithCredits =
+        """{"id":"085e909ec9acecdc0833b56162d358f057539bd56a12dabb3c4a76eba13ab176","pubkey":"62e04946ab28d27866f9c29a2c1b88e5ddca31a87110208249fd88693bc406f1","created_at":1789666628,"kind":34236,"tags":[["d","1de7ec53cfc7db7f4e0490aa76ac26408bc9052d287cd5565b96881085929972"],["imeta","url https://media.divine.video/1de7ec53cfc7db7f4e0490aa76ac26408bc9052d287cd5565b96881085929972","m video/mp4"],["title","ShowHole"],["a","34236:0db19e8f1b13e03cd07379edd37a71f07b08a4fb5e7eac222ba1d2c823807075:f11e7f9e2f0e11e80056893152f1850897d4f9164515e567ce13e443b953e305","wss://relay.divine.video","mention"],["p","0db19e8f1b13e03cd07379edd37a71f07b08a4fb5e7eac222ba1d2c823807075","wss://relay.divine.video","inspired-by"],["e","6a8edc14380fdd347ae9c8861b008e4771b885bfb55f1899979bd7a9515b3221","wss://relay.divine.video","audio"],["client","Divine","31990:d95aa8fc0eff8e488952495b8064991d27fb96ed8652f12cdedc5a4e8b5ae540:divine-mobile","wss://relay.divine.video"]],"content":"","sig":""}"""
+
+    private val subtitleEvent =
+        """{"id":"5a1c96f3f24b18ee1a9dbb5be04b60e4d7bb8f5e2dd1f2a9e9cf9f5f14b0e1f1","pubkey":"4d7dccc0a5116daa057348ef79c573873cddd9eff066fc6a5f3d37e8264afbeb","created_at":1789661600,"kind":39307,"tags":[["d","subtitles:c855df3d07ba963e9097d5a151b0c14a0a3d494e4ff9b04a389bc0b5f5c16862"],["a","34236:4d7dccc0a5116daa057348ef79c573873cddd9eff066fc6a5f3d37e8264afbeb:c855df3d07ba963e9097d5a151b0c14a0a3d494e4ff9b04a389bc0b5f5c16862"],["url","https://media.divine.video/283a420202b620a9a326598b85bfcf0e8cb4ab4d52b947c628d8c29a1313006b"],["m","text/vtt"],["l","en"],["client","Divine","31990:d95aa8fc0eff8e488952495b8064991d27fb96ed8652f12cdedc5a4e8b5ae540:divine-mobile","wss://relay.divine.video"]],"content":"WEBVTT\n\n1\n00:00:00.000 --> 00:00:02.500\nWe just started putting out Christmas stuff\n\n","sig":""}"""
+
+    private val repost =
+        """{"id":"20a0663382290c769b1fbd5e6ad84593d1f848fa75689e4ee4d6263aad5c8760","pubkey":"f67d985c0bfbf87eaa33b056f1d38ad991a6aa625b138bddb2a838bdbac29f40","created_at":1789666347,"kind":16,"tags":[["k","34236"],["a","34236:5ab67f7d7fed4f781008c0ec0d26c8113f9fb46094a8346246c70c75e75db9fb:8de0dcf06982b86aca7189ae50a8c3fe8605917433044ad62c146b723b877025"],["p","5ab67f7d7fed4f781008c0ec0d26c8113f9fb46094a8346246c70c75e75db9fb"],["e","ab074d5a577635b9d34281b31ea32170d54b09cfb4cbfcc4ae6a28f52653fca1"],["client","Divine","31990:d95aa8fc0eff8e488952495b8064991d27fb96ed8652f12cdedc5a4e8b5ae540:divine-mobile","wss://relay.divine.video"]],"content":"","sig":"4513526b886a1d9e1fb12a181a48811dc8765afd901458959a674d3e9d234b761a5cd2551c75cbe4210543f30c5a74b16720281acf88e11e09a67b0b219e3d3d"}"""
+
+    private val reaction =
+        """{"id":"88847c819aa18d9294de9ebc1156d6200becdd2fadad6bc6a0248b24f22d3c42","pubkey":"34257350449d357c37e93eb8aef387ff1fee8879d794da664462346a4b540aa8","created_at":1789666900,"kind":7,"tags":[["e","a75d3c1a2fb824544ae51d3d20b1a8280aea9647d13f87c06418233883e80890"],["a","34236:03c49dd3d68fdd15fc0bc7dff669d652af313408bfd6dde10daf27b02f54eb50:a983212b6a82e0d6f6a41efc085ddd0176e1cd3ebd8dcb4cac16219db0a283ef"],["p","03c49dd3d68fdd15fc0bc7dff669d652af313408bfd6dde10daf27b02f54eb50"],["k","34236"],["client","Divine","31990:d95aa8fc0eff8e488952495b8064991d27fb96ed8652f12cdedc5a4e8b5ae540:divine-mobile","wss://relay.divine.video"]],"content":"+","sig":"99d515ef57cb8425e26b85051202e305fb6f1f4265ea38bb041da24044c8ac3e95339bdcae01400307afa26417fb056b6aad1a34e826c4e267df7b4dc6c29e94"}"""
+
+    private val comment =
+        """{"id":"dac3c50f5a3c22f185dc8587a2eae3357087aa0ccfd1f1230f8308d7a047515a","pubkey":"f67d985c0bfbf87eaa33b056f1d38ad991a6aa625b138bddb2a838bdbac29f40","created_at":1789666353,"kind":1111,"tags":[["E","ab074d5a577635b9d34281b31ea32170d54b09cfb4cbfcc4ae6a28f52653fca1","","5ab67f7d7fed4f781008c0ec0d26c8113f9fb46094a8346246c70c75e75db9fb"],["A","34236:5ab67f7d7fed4f781008c0ec0d26c8113f9fb46094a8346246c70c75e75db9fb:8de0dcf06982b86aca7189ae50a8c3fe8605917433044ad62c146b723b877025",""],["K","34236"],["P","5ab67f7d7fed4f781008c0ec0d26c8113f9fb46094a8346246c70c75e75db9fb"],["e","ab074d5a577635b9d34281b31ea32170d54b09cfb4cbfcc4ae6a28f52653fca1","","5ab67f7d7fed4f781008c0ec0d26c8113f9fb46094a8346246c70c75e75db9fb"],["a","34236:5ab67f7d7fed4f781008c0ec0d26c8113f9fb46094a8346246c70c75e75db9fb:8de0dcf06982b86aca7189ae50a8c3fe8605917433044ad62c146b723b877025",""],["k","34236"],["p","5ab67f7d7fed4f781008c0ec0d26c8113f9fb46094a8346246c70c75e75db9fb"],["client","Divine","31990:d95aa8fc0eff8e488952495b8064991d27fb96ed8652f12cdedc5a4e8b5ae540:divine-mobile","wss://relay.divine.video"]],"content":"⚫️","sig":"8fa4fcb27882b0622d48e21f1323e4b16c2df24f6a127c49bc30a6e277ef6069f5cfb7b13ddf9788ac18c4cde031091b1d39e349cedde812a6fc8fd517dc3d1f"}"""
+
+    private val videoList =
+        """{"id":"70118cbfdd6ed7a0b774d083eb7e788a04f39660ad1aecb01cc645902d06cb9f","pubkey":"34257350449d357c37e93eb8aef387ff1fee8879d794da664462346a4b540aa8","created_at":1789666571,"kind":30005,"tags":[["d","my_vine_list"],["title","My List"],["description","My favorite vines and videos"],["playorder","chronological"],["client","Divine","31990:d95aa8fc0eff8e488952495b8064991d27fb96ed8652f12cdedc5a4e8b5ae540:divine-mobile","wss://relay.divine.video"]],"content":"Ai9Jcq6da7mTNMTcnDh+I4ZUwQcX5///rkV6ouuE7ZqaBnRIgg+rCqul8ykw4KKj6O7wwTm3jzxmTD7ZeEjD7LplcaH8kYDPnzAJWriiLC6tJ1THmXwx0SYYNYrtLs+t1cBR","sig":"7db79697f4adf9ff8b6aba918e5760508fe96fd8227b600ba41edc84d4efbf5a37af15ed7980da5e6106b9a7241583e3e4dce473728f215a0d70b0b28dbf52b2"}"""
+
+    private val collabResponse =
+        """{"id":"70cd826d52989fbfd6a12f7e62e4f9aa3c01c902c1bdeec61955d0271920a248","pubkey":"ddfdea0a598ec89f1383ca83b71993540c99ea5a3734b4d5aab23719ea6bde80","created_at":1789653321,"kind":34238,"tags":[["d","34236:32d84a21bb7702c538d5ddd3f9086e86e8b73e5d5cb2e67861eaca36708597e6:d67650d7e97d50a35f491ef24f463b4b408026b5b08c0bc9dbc8359cf4b8aa05"],["a","34236:32d84a21bb7702c538d5ddd3f9086e86e8b73e5d5cb2e67861eaca36708597e6:d67650d7e97d50a35f491ef24f463b4b408026b5b08c0bc9dbc8359cf4b8aa05","wss://relay.divine.video","root"],["p","32d84a21bb7702c538d5ddd3f9086e86e8b73e5d5cb2e67861eaca36708597e6"],["role","Collaborator"],["status","accepted"],["client","Divine","31990:d95aa8fc0eff8e488952495b8064991d27fb96ed8652f12cdedc5a4e8b5ae540:divine-mobile","wss://relay.divine.video"]],"content":"","sig":"65e476c6023de6e443810e630450e6f2c3bca0201a970adcb89f18788dc9bf2ab8e5431a68ff716d411aaa05caa83288549efed8814750c2a23cec62c69bab18"}"""
+
+    @Test
+    fun aShortVideoIsAnAddressableVerticalVideo() {
+        val event = Event.fromJson(video)
+
+        assertTrue(event is VideoVerticalEvent)
+        // The address must come from the `d` tag: an `a` tag elsewhere on the network points at
+        // `34236:<pubkey>:<d>`, and a class on the wrong base would split the cache in two.
+        assertEquals(
+            "34236:4d7dccc0a5116daa057348ef79c573873cddd9eff066fc6a5f3d37e8264afbeb:c855df3d07ba963e9097d5a151b0c14a0a3d494e4ff9b04a389bc0b5f5c16862",
+            (event as AddressableEvent).address().toValue(),
+        )
+        assertEquals("Xmas Already??", (event as VideoVerticalEvent).title())
+        assertEquals(6, event.duration())
+    }
+
+    @Test
+    fun theBlossomUrlIsPlayedAsAVideoDespiteHavingNoFileExtension() {
+        val track = (Event.fromJson(video) as VideoVerticalEvent).selectVideoTrack()
+
+        assertNotNull(track)
+        assertEquals("https://media.divine.video/c855df3d07ba963e9097d5a151b0c14a0a3d494e4ff9b04a389bc0b5f5c16862", track!!.url)
+        assertEquals("video/mp4", track.mimeType)
+        assertEquals("1080x1920", track.dimension.toString())
+        assertEquals(
+            "https://media.divine.video/e1d22b85609cb105dff64b4a402f13982a942dc59aee67218e6e3652c8597d2d",
+            track.image.firstOrNull(),
+        )
+
+        // VideoDisplay diverts to the image viewer only when classifyMedia says IMAGE. The URL has
+        // no extension at all, so the declared MIME is the only thing keeping this in the player.
+        assertEquals(MediaContentKind.VIDEO, RichTextParser.classifyMedia(track.url, track.mimeType))
+
+        // ...and the same MIME is what admits it into the Shorts/Video feeds, whose
+        // SupportedContent matcher would otherwise fall through to the extension list.
+        assertTrue(track.mimeType in SUPPORTED_VIDEO_FEED_MIME_TYPES_SET)
+    }
+
+    @Test
+    fun theAudioSourceETagIsNotAReplyPointer() {
+        // Divine marks the reused soundtrack as `["e", <id>, <relay>, "audio"]` on the video
+        // itself. LocalCache.computeReplyTo has no branch for video events, so this never turns
+        // the post into a reply — which would drop it out of the home feed and thread it under
+        // whatever video the audio came from.
+        val event = Event.fromJson(video) as VideoVerticalEvent
+        val audio = event.tags.first { it[0] == "e" }
+
+        assertEquals("218af5fc90d66a16ce273f00a4e412a71443441c04c67d1e34ff99c654871d3d", audio[1])
+        assertEquals("audio", audio[3])
+    }
+
+    @Test
+    fun captionsComeFromTheTextTrackTagsAndNotTheAudioPointer() {
+        // textTrack() used to run ETag::parse, so it returned the `e` tags instead — on this
+        // event, the reused-soundtrack pointer, which is not a caption track at all.
+        val tracks = (Event.fromJson(video) as VideoVerticalEvent).textTrack()
+
+        assertEquals(2, tracks.size)
+        // Divine publishes the same track twice: the WebVTT file on Blossom, and the addressable
+        // kind-39307 subtitle event that wraps it.
+        assertEquals("https://media.divine.video/283a420202b620a9a326598b85bfcf0e8cb4ab4d52b947c628d8c29a1313006b", tracks[0].ref)
+        assertEquals("39307:4d7dccc0a5116daa057348ef79c573873cddd9eff066fc6a5f3d37e8264afbeb:subtitles:c855df3d07ba963e9097d5a151b0c14a0a3d494e4ff9b04a389bc0b5f5c16862", tracks[1].ref)
+        tracks.forEach {
+            assertEquals("wss://relay.divine.video", it.relay)
+            assertEquals("captions", it.type)
+            assertEquals("en", it.language)
+        }
+        // No renderer consumes these yet — Amethyst plays divine.video shorts without captions.
+    }
+
+    @Test
+    fun theTwoFormsOfTheSameCaptionTrackCollapseIntoOne() {
+        val video = Event.fromJson(video) as VideoVerticalEvent
+        val refs = video.captionTracks()
+
+        // One `text-track` is directly loadable, the other has to be fetched first.
+        assertEquals(
+            listOf("https://media.divine.video/283a420202b620a9a326598b85bfcf0e8cb4ab4d52b947c628d8c29a1313006b"),
+            refs.direct.map { it.url },
+        )
+        assertEquals(1, refs.pending.size)
+        assertEquals(
+            TextTrackEvent.KIND,
+            refs.pending
+                .first()
+                .address.kind,
+        )
+        assertEquals(
+            "en",
+            refs.pending
+                .first()
+                .tag.language,
+        )
+
+        // The pending one resolves to the very same file, so the player gets one configuration,
+        // not two identical entries in its track menu.
+        val resolved = (Event.fromJson(subtitleEvent) as TextTrackEvent).toCaptionTrack(refs.pending.first().tag)
+        assertEquals("text/vtt", resolved?.mimeType)
+        assertEquals("en", resolved?.language)
+        assertEquals(1, mergeCaptionTracks(refs.direct, listOfNotNull(resolved)).size)
+    }
+
+    @Test
+    fun aRepostResolvesBothTheCoordinateAndTheVersionId() {
+        val event = Event.fromJson(repost)
+
+        assertTrue(event is GenericRepostEvent)
+        val boost = event as GenericRepostEvent
+        assertEquals(34236, boost.boostedKind())
+        assertEquals(
+            "34236:5ab67f7d7fed4f781008c0ec0d26c8113f9fb46094a8346246c70c75e75db9fb:8de0dcf06982b86aca7189ae50a8c3fe8605917433044ad62c146b723b877025",
+            boost.boostedAddress()?.toValue(),
+        )
+        assertEquals("ab074d5a577635b9d34281b31ea32170d54b09cfb4cbfcc4ae6a28f52653fca1", boost.boostedEventId())
+    }
+
+    @Test
+    fun aReactionResolvesBothTheCoordinateAndTheVersionId() {
+        val event = Event.fromJson(reaction)
+
+        assertTrue(event is ReactionEvent)
+        val like = event as ReactionEvent
+        assertEquals("+", like.content)
+        assertEquals(listOf("a75d3c1a2fb824544ae51d3d20b1a8280aea9647d13f87c06418233883e80890"), like.originalPost())
+        assertEquals(
+            listOf("34236:03c49dd3d68fdd15fc0bc7dff669d652af313408bfd6dde10daf27b02f54eb50:a983212b6a82e0d6f6a41efc085ddd0176e1cd3ebd8dcb4cac16219db0a283ef"),
+            like.linkedAddressIds(),
+        )
+    }
+
+    @Test
+    fun aTopLevelCommentRootsAtTheVideoCoordinate() {
+        val event = Event.fromJson(comment)
+
+        assertTrue(event is CommentEvent)
+        val reply = event as CommentEvent
+        val coordinate = "34236:5ab67f7d7fed4f781008c0ec0d26c8113f9fb46094a8346246c70c75e75db9fb:8de0dcf06982b86aca7189ae50a8c3fe8605917433044ad62c146b723b877025"
+
+        assertEquals(listOf(coordinate), reply.rootAddressIds())
+        assertEquals(listOf("ab074d5a577635b9d34281b31ea32170d54b09cfb4cbfcc4ae6a28f52653fca1"), reply.rootEventIds())
+        // A top-level comment repeats the root as its direct parent (lowercase a/e), so both the
+        // version note and the addressable note collect the reply. Note.addReply() dedupes, and
+        // consumeBaseReplaceable migrates the version's references onto the address.
+        assertEquals(listOf(coordinate), reply.replyAddressIds())
+    }
+
+    @Test
+    fun creditsReadTheMarkerWhicheverSlotItIsIn() {
+        // divine-mobile: ["p", <pubkey>, <relay>, "inspired-by"] and ["e", <id>, <relay>, "audio"].
+        val credits = (Event.fromJson(videoWithCredits) as VideoVerticalEvent).credits()
+
+        val person = credits.filterIsInstance<VideoCredit>().first { it.target is CreditTarget.Person }
+        assertEquals("0db19e8f1b13e03cd07379edd37a71f07b08a4fb5e7eac222ba1d2c823807075", (person.target as CreditTarget.Person).pubKey)
+        assertEquals("inspired-by", person.label)
+
+        val video = credits.first { it.target is CreditTarget.Video }
+        assertEquals("mention", video.label)
+        assertEquals(34236, (video.target as CreditTarget.Video).address.kind)
+
+        val audio = credits.first { it.target is CreditTarget.Event }
+        assertEquals("audio", audio.label)
+        assertEquals("6a8edc14380fdd347ae9c8861b008e4771b885bfb55f1899979bd7a9515b3221", (audio.target as CreditTarget.Event).eventId)
+    }
+
+    @Test
+    fun aRoleInTheRelaySlotIsReadAsTheLabelAndNotAsAHint() {
+        // divine-web's collaborator invite writes ["p", <pubkey>, "<role>"] — no relay hint at all,
+        // so the slot PTag reads for a hint holds the label instead.
+        val invite =
+            VideoVerticalEvent(
+                id = "a".repeat(64),
+                pubKey = "b".repeat(64),
+                createdAt = 1789666628,
+                tags = arrayOf(arrayOf("d", "vid"), arrayOf("p", "c".repeat(64), "Collaborator")),
+                content = "",
+                sig = "",
+            )
+
+        val credit = invite.credits().single()
+        assertEquals("Collaborator", credit.label)
+        assertEquals("c".repeat(64), (credit.target as CreditTarget.Person).pubKey)
+    }
+
+    @Test
+    fun aBareETagOnAVideoIsNotACredit() {
+        // No marker means nothing is being credited — printing "references <id>" for a stray
+        // threading tag would invent an attribution the publisher never made.
+        val stray =
+            VideoVerticalEvent(
+                id = "a".repeat(64),
+                pubKey = "b".repeat(64),
+                createdAt = 1789666628,
+                tags = arrayOf(arrayOf("d", "vid"), arrayOf("e", "d".repeat(64)), arrayOf("e", "e".repeat(64), "", "root")),
+                content = "",
+                sig = "",
+            )
+
+        assertTrue(stray.credits().isEmpty())
+    }
+
+    @Test
+    fun aCollaborationResponseNamesTheVideoItAccepts() {
+        val event = Event.fromJson(collabResponse)
+
+        assertTrue(event is VideoCollaborationEvent)
+        val response = event as VideoCollaborationEvent
+        assertEquals(
+            "34236:32d84a21bb7702c538d5ddd3f9086e86e8b73e5d5cb2e67861eaca36708597e6:d67650d7e97d50a35f491ef24f463b4b408026b5b08c0bc9dbc8359cf4b8aa05",
+            response.video()?.toValue(),
+        )
+        assertEquals("Collaborator", response.role())
+        assertTrue(response.isAccepted())
+        // divine-mobile happens to key this one by the video coordinate, but the `a` tag is what
+        // the lookup matches on — see [bothCollaborationShapesAreFoundByTheirATag].
+        assertEquals(response.video()?.toValue(), response.dTag())
+    }
+
+    @Test
+    fun bothCollaborationShapesAreFoundByTheirATag() {
+        // The `d` tag is the one thing the two publishers disagree on: divine-mobile writes the
+        // video coordinate, divine-web writes `crypto.randomUUID()`
+        // (divine-web/src/hooks/useApproveCollab.ts). Matching on `a` + author is what makes the
+        // credit's check mark appear for both — and is the same filter divine-web itself uses in
+        // useVideoCollaboratorStatus.ts.
+        val mobile = Event.fromJson(collabResponse) as VideoCollaborationEvent
+        val coord = mobile.video()!!.toValue()
+
+        val web =
+            VideoCollaborationEvent(
+                id = "a".repeat(64),
+                pubKey = mobile.pubKey,
+                createdAt = mobile.createdAt,
+                tags = arrayOf(arrayOf("a", coord), arrayOf("d", "0e1cbb2c-1b5a-4f1f-9f0e-2c6b2c8a9f11")),
+                content = "",
+                sig = "",
+            )
+
+        val byATag =
+            Filter(
+                kinds = listOf(VideoCollaborationEvent.KIND),
+                authors = listOf(mobile.pubKey),
+                tags = mapOf("a" to listOf(coord)),
+            )
+
+        assertTrue(byATag.match(mobile))
+        assertTrue(byATag.match(web))
+
+        // What the coordinate-addressed lookup used to do: it can only ever name one `d`, so the
+        // other publisher's answer was invisible however long you waited for it.
+        val byCoordinate =
+            Filter(
+                kinds = listOf(VideoCollaborationEvent.KIND),
+                authors = listOf(mobile.pubKey),
+                tags = mapOf("d" to listOf(coord)),
+            )
+
+        assertTrue(byCoordinate.match(mobile))
+        assertFalse(byCoordinate.match(web))
+    }
+
+    @Test
+    fun aResponseWithoutAStatusStillCounts() {
+        // divine-web publishes no `status` — it only emits the event on approval at all.
+        val webShape =
+            VideoCollaborationEvent(
+                id = "a".repeat(64),
+                pubKey = "b".repeat(64),
+                createdAt = 1789666628,
+                tags = arrayOf(arrayOf("a", "34236:${"c".repeat(64)}:vid"), arrayOf("d", "0e1cbb2c-1b5a-4f1f-9f0e-2c6b2c8a9f11")),
+                content = "",
+                sig = "",
+            )
+
+        assertTrue(webShape.isAccepted())
+        assertEquals("34236:${"c".repeat(64)}:vid", webShape.video()?.toValue())
+    }
+
+    @Test
+    fun aVideoListParsesButCarriesItsItemsEncrypted() {
+        val event = Event.fromJson(videoList)
+
+        assertTrue(event is VideoCurationSetEvent)
+        val list = event as VideoCurationSetEvent
+        assertEquals("my_vine_list", list.dTag())
+        assertEquals("My List", list.title())
+        assertEquals("My favorite vines and videos", list.description())
+        // Divine keeps every member in the NIP-51 encrypted `content`, so nothing is public and
+        // only the list's owner can decrypt the members; RenderVideoCurationSet says so rather
+        // than rendering an empty strip as though the list were broken.
+        assertTrue(list.publicItems().isEmpty())
+    }
+}

commons/src/jvmTest/kotlin/com/vitorpamplona/amethyst/commons/model/nip71Video/VideoTrackSelectionTest.kt

@@ -56,6 +56,42 @@ class VideoTrackSelectionTest {
         dimension = DimensionTag(width, height),
     )
 
+    @Test
+    fun anHlsPropertyOnTheImetaBecomesTheSelectedTrack() {
+        // divine.video's shape: one imeta for the progressive file, with the adaptive manifest
+        // hung off the non-standard `hls` key instead of a second imeta.
+        val progressive =
+            VideoMeta(
+                url = "https://media.divine.video/abc",
+                mimeType = "video/mp4",
+                dimension = DimensionTag(1080, 1920),
+                hash = "abc",
+                size = 6579464,
+                hls = "https://media.divine.video/abc/hls/master.m3u8",
+            )
+        val selected = event(progressive).selectVideoTrack()
+
+        assertEquals("https://media.divine.video/abc/hls/master.m3u8", selected?.url)
+        assertEquals(hls, selected?.mimeType)
+        // Shape metadata is the same footage, so it carries over...
+        assertEquals("1080x1920", selected?.dimension.toString())
+        // ...but `x` and `size` describe the mp4 blob, and a manifest is not that blob.
+        assertNull(selected?.hash)
+        assertNull(selected?.size)
+    }
+
+    @Test
+    fun aRedundantHlsPropertyDoesNotDuplicateTheTrack() {
+        val selfReferential =
+            VideoMeta(
+                url = "https://host/master.m3u8",
+                mimeType = hls,
+                hls = "https://host/master.m3u8",
+            )
+
+        assertEquals("https://host/master.m3u8", event(selfReferential).selectVideoTrack()?.url)
+    }
+
     @Test
     fun picksTheMasterWhenItIsListedFirst() {
         // Amethyst's own layout (HlsVideoEventBuilder): master first, dim = the top rung.

commonsUI/src/commonMain/composeResources/values/strings.xml

@@ -2213,6 +2213,8 @@
     <string name="video_player_settings_action_pip_description">Play the video in a floating window (hidden if unsupported)</string>
     <string name="video_player_settings_action_cast">Cast to Device</string>
     <string name="video_player_settings_action_cast_description">Send the video to a Chromecast receiver on your Wi-Fi (hidden for local files)</string>
+    <string name="video_player_settings_action_captions">Captions</string>
+    <string name="video_player_settings_action_captions_description">Turn subtitles on or off (hidden when the video has none)</string>
     <string name="audio_visualizer_settings_description">Choose the animation shown while audio notes play.</string>
     <string name="audio_visualizer_off">Off</string>
     <string name="audio_visualizer_bars">Spectrum Bars</string>

commonsUI/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/icons/symbols/MaterialSymbols.kt

@@ -67,6 +67,8 @@ object MaterialSymbols {
     val ChessKnight = MaterialSymbol("\uF25E")
     val Checklist = MaterialSymbol("\uE6B1")
     val ChevronRight = MaterialSymbol("\uE5CC")
+    val ClosedCaption = MaterialSymbol("\uE996")
+    val ClosedCaptionDisabled = MaterialSymbol("\uF1DC")
     val Circle = MaterialSymbol("\uEF4A")
     val Clear = MaterialSymbol("\uE5CD")
     val Close = MaterialSymbol("\uE5CD")

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/ui/NoteActions.kt

@@ -104,6 +104,7 @@ import com.vitorpamplona.quartz.nip47WalletConnect.Nip47WalletConnect
 import com.vitorpamplona.quartz.nip51Lists.bookmarkList.BookmarkListEvent
 import com.vitorpamplona.quartz.nip57Zaps.LnZapEvent
 import com.vitorpamplona.quartz.nip88Polls.poll.PollEvent
+import com.vitorpamplona.quartz.nip88Polls.poll.tags.PollType
 import com.vitorpamplona.quartz.nip88Polls.response.PollResponseEvent
 import kotlinx.coroutines.DelicateCoroutinesApi
 import kotlinx.coroutines.Dispatchers
@@ -1417,7 +1418,16 @@ suspend fun voteOnPoll(
 ) {
     if (responses.isEmpty()) return
     withContext(Dispatchers.IO) {
-        val template = PollResponseEvent.build(EventHintBundle(poll), responses)
+        // The poll decides how its answers are counted, so it decides which builder applies:
+        // a single-choice answer is the first tag only, and sending several would record
+        // whichever one the reader saw first.
+        val hint = EventHintBundle(poll)
+        val template =
+            when (poll.pollType()) {
+                PollType.SINGLE_CHOICE ->
+                    responses.firstOrNull()?.let { PollResponseEvent.buildSingleChoice(hint, it) } ?: return@withContext
+                PollType.MULTI_CHOICE -> PollResponseEvent.buildMultipleChoice(hint, responses)
+            }
         val signed = account.signer.sign(template)
         localCache.consume(signed, null, wasVerified = true)
         // Publish to the poll's OWN declared relays (NIP-88 `relay` tags) as well as our

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/experimental/videoCollaboration/VideoCollaborationEvent.kt

@@ -0,0 +1,112 @@
+/*
+ * 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.quartz.experimental.videoCollaboration
+
+import androidx.compose.runtime.Immutable
+import com.vitorpamplona.quartz.experimental.videoCollaboration.tags.RoleTag
+import com.vitorpamplona.quartz.experimental.videoCollaboration.tags.StatusTag
+import com.vitorpamplona.quartz.nip01Core.core.BaseAddressableEvent
+import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
+import com.vitorpamplona.quartz.nip01Core.hints.AddressHintProvider
+import com.vitorpamplona.quartz.nip01Core.hints.PubKeyHintProvider
+import com.vitorpamplona.quartz.nip01Core.signers.eventTemplate
+import com.vitorpamplona.quartz.nip01Core.tags.aTag.ATag
+import com.vitorpamplona.quartz.nip01Core.tags.dTag.dTag
+import com.vitorpamplona.quartz.nip01Core.tags.people.PTag
+import com.vitorpamplona.quartz.utils.TimeUtils
+
+/**
+ * A collaborator's answer to being credited on someone else's NIP-71 video.
+ *
+ * The invite is not an event of its own: the video's author adds the collaborator as a `p` tag on
+ * the video itself, and the collaborator answers with one of these, `a`-tagging the video. Only
+ * the collaborator can sign it, which is the point — it is what turns an unsolicited tag into a
+ * credit the tagged person actually stands behind.
+ *
+ * Two shapes exist in the wild and both are accepted here, because the `a` tag is the only field
+ * either guarantees:
+ *  - divine-web writes a random `d` with the coordinate in `a`;
+ *  - divine-mobile writes the coordinate itself as `d` (one response per video, replaceable) and
+ *    adds `p`, `role` and `status`.
+ *
+ * A response with no `status` is an acceptance: divine-web only publishes the event when the
+ * collaborator approves, so the event's existence *is* the answer. [isAccepted] reads it that way.
+ */
+@Immutable
+class VideoCollaborationEvent(
+    id: HexKey,
+    pubKey: HexKey,
+    createdAt: Long,
+    tags: Array<Array<String>>,
+    content: String,
+    sig: HexKey,
+) : BaseAddressableEvent(id, pubKey, createdAt, KIND, tags, content, sig),
+    AddressHintProvider,
+    PubKeyHintProvider {
+    override fun addressHints() = tags.mapNotNull(ATag::parseAsHint)
+
+    override fun linkedAddressIds() = tags.mapNotNull(ATag::parseAddressId)
+
+    override fun pubKeyHints() = tags.mapNotNull(PTag::parseAsHint)
+
+    override fun linkedPubKeys() = tags.mapNotNull(PTag::parseKey)
+
+    /** The video being collaborated on. */
+    fun video() = tags.firstNotNullOfOrNull(ATag::parseAddress)
+
+    /** The video's author, when the response names them. */
+    fun videoAuthor() = tags.firstNotNullOfOrNull(PTag::parseKey)
+
+    /** Free text, as the video's author typed it: "Collaborator", "Director", … */
+    fun role() = tags.firstNotNullOfOrNull(RoleTag::parse)
+
+    fun status() = tags.firstNotNullOfOrNull(StatusTag::parse)
+
+    /**
+     * True unless the collaborator explicitly said no. An absent `status` means yes — see the
+     * class docs: one of the two publishers only emits the event on approval.
+     */
+    fun isAccepted() = status()?.let { it == StatusTag.ACCEPTED } ?: true
+
+    companion object {
+        const val KIND = 34238
+
+        fun build(
+            video: ATag,
+            videoAuthor: HexKey? = null,
+            role: String? = null,
+            status: String = StatusTag.ACCEPTED,
+            // One response per video: keying on the coordinate makes a later answer replace the
+            // earlier one instead of leaving both on relays for readers to date-sort.
+            dTag: String = video.toTag(),
+            createdAt: Long = TimeUtils.now(),
+            initializer: TagArrayBuilder<VideoCollaborationEvent>.() -> Unit = {},
+        ) = eventTemplate(KIND, "", createdAt) {
+            dTag(dTag)
+            add(video.toATagArray())
+            videoAuthor?.let { add(PTag.assemble(it, null)) }
+            role?.let { add(RoleTag.assemble(it)) }
+            add(StatusTag.assemble(status))
+            initializer()
+        }
+    }
+}

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/experimental/videoCollaboration/tags/RoleTag.kt

@@ -0,0 +1,40 @@
+/*
+ * 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.quartz.experimental.videoCollaboration.tags
+
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
+/** What the collaborator is credited as, as free text the video's author typed. */
+class RoleTag {
+    companion object {
+        const val TAG_NAME = "role"
+
+        fun parse(tag: Array<String>): String? {
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
+            return tag[1]
+        }
+
+        fun assemble(role: String) = arrayOf(TAG_NAME, role)
+    }
+}

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/experimental/videoCollaboration/tags/StatusTag.kt

@@ -0,0 +1,43 @@
+/*
+ * 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.quartz.experimental.videoCollaboration.tags
+
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
+/** Whether the collaborator took the credit. Absent means accepted — see VideoCollaborationEvent. */
+class StatusTag {
+    companion object {
+        const val TAG_NAME = "status"
+
+        const val ACCEPTED = "accepted"
+        const val DECLINED = "declined"
+
+        fun parse(tag: Array<String>): String? {
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
+            return tag[1]
+        }
+
+        fun assemble(status: String) = arrayOf(TAG_NAME, status)
+    }
+}

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip50Search/SearchableKinds.kt

@@ -192,6 +192,7 @@ object SearchableKinds {
             39000, // GroupMetadataEvent
             39089, // FollowListEvent
             39092, // MediaStarterPackEvent
+            39307, // TextTrackEvent
             39701, // WebBookmarkEvent
             40002, // StreamMessageV2Event
             40100, // CanvasEvent

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip71Video/AddressableVideoEvent.kt

@@ -23,7 +23,6 @@ package com.vitorpamplona.quartz.nip71Video
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.BaseAddressableEvent
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
-import com.vitorpamplona.quartz.nip01Core.tags.events.ETag
 import com.vitorpamplona.quartz.nip01Core.tags.hashtags.hashtags
 import com.vitorpamplona.quartz.nip01Core.tags.people.PTag
 import com.vitorpamplona.quartz.nip01Core.tags.publishedAt.PublishedAtProvider
@@ -32,8 +31,10 @@ import com.vitorpamplona.quartz.nip23LongContent.tags.PublishedAtTag
 import com.vitorpamplona.quartz.nip23LongContent.tags.TitleTag
 import com.vitorpamplona.quartz.nip50Search.IndexableFieldVisitor
 import com.vitorpamplona.quartz.nip50Search.SearchableEvent
+import com.vitorpamplona.quartz.nip71Video.credits.VideoCredits
 import com.vitorpamplona.quartz.nip71Video.tags.DurationTag
 import com.vitorpamplona.quartz.nip71Video.tags.SegmentTag
+import com.vitorpamplona.quartz.nip71Video.tags.TextTrackTag
 import com.vitorpamplona.quartz.nip92IMeta.imetas
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashSha256Tag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MimeTypeTag
@@ -82,7 +83,11 @@ abstract class AddressableVideoEvent(
 
     override fun duration() = tags.firstNotNullOfOrNull(DurationTag::parse)
 
-    override fun textTrack() = tags.mapNotNull(ETag::parse)
+    // `text-track`, not `e`: reading ETag here returned the event's unrelated `e` tags
+    // (on a divine.video short, its "audio" source pointer) and never a caption track.
+    override fun textTrack() = tags.mapNotNull(TextTrackTag::parse)
+
+    override fun credits() = VideoCredits.parse(tags)
 
     override fun segments() = tags.mapNotNull(SegmentTag::parse)
 

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip71Video/IMetaTagBuilderExt.kt

@@ -25,6 +25,7 @@ import com.vitorpamplona.quartz.nip31Alts.AltTag
 import com.vitorpamplona.quartz.nip36SensitiveContent.ContentWarningTag
 import com.vitorpamplona.quartz.nip71Video.tags.BitrateTag
 import com.vitorpamplona.quartz.nip71Video.tags.DurationTag
+import com.vitorpamplona.quartz.nip71Video.tags.HlsImetaTag
 import com.vitorpamplona.quartz.nip71Video.tags.LanguageImetaTag
 import com.vitorpamplona.quartz.nip92IMeta.IMetaTagBuilder
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.BlurhashTag
@@ -78,6 +79,8 @@ fun IMetaTagBuilder.fallback(fallback: HexKey) = add(FallbackTag.TAG_NAME, fallb
 
 fun IMetaTagBuilder.service(service: HexKey) = add(ServiceTag.TAG_NAME, service)
 
+fun IMetaTagBuilder.hls(manifestUrl: String) = add(HlsImetaTag.TAG_NAME, manifestUrl)
+
 fun IMetaTagBuilder.bitrate(bitsPerSecond: Int) = add(BitrateTag.TAG_NAME, bitsPerSecond.toString())
 
 fun IMetaTagBuilder.duration(seconds: Double) = add(DurationTag.TAG_NAME, seconds.toString())

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip71Video/IMetaTagExt.kt

@@ -24,6 +24,7 @@ import com.vitorpamplona.quartz.nip31Alts.AltTag
 import com.vitorpamplona.quartz.nip36SensitiveContent.ContentWarningTag
 import com.vitorpamplona.quartz.nip71Video.tags.BitrateTag
 import com.vitorpamplona.quartz.nip71Video.tags.DurationTag
+import com.vitorpamplona.quartz.nip71Video.tags.HlsImetaTag
 import com.vitorpamplona.quartz.nip71Video.tags.LanguageImetaTag
 import com.vitorpamplona.quartz.nip92IMeta.IMetaTag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.BlurhashTag
@@ -77,6 +78,8 @@ fun IMetaTag.fallback() = properties.get(FallbackTag.TAG_NAME)
 
 fun IMetaTag.service() = properties.get(ServiceTag.TAG_NAME)
 
+fun IMetaTag.hls() = properties.get(HlsImetaTag.TAG_NAME)
+
 fun IMetaTag.bitrate(): Int? = properties.get(BitrateTag.TAG_NAME)?.firstOrNull()?.toIntOrNull()
 
 fun IMetaTag.duration(): Double? = properties.get(DurationTag.TAG_NAME)?.firstOrNull()?.toDoubleOrNull()

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip71Video/RegularVideoEvent.kt

@@ -23,7 +23,6 @@ package com.vitorpamplona.quartz.nip71Video
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
-import com.vitorpamplona.quartz.nip01Core.tags.events.ETag
 import com.vitorpamplona.quartz.nip01Core.tags.hashtags.hashtags
 import com.vitorpamplona.quartz.nip01Core.tags.people.PTag
 import com.vitorpamplona.quartz.nip01Core.tags.publishedAt.PublishedAtProvider
@@ -32,8 +31,10 @@ import com.vitorpamplona.quartz.nip23LongContent.tags.PublishedAtTag
 import com.vitorpamplona.quartz.nip23LongContent.tags.TitleTag
 import com.vitorpamplona.quartz.nip50Search.IndexableFieldVisitor
 import com.vitorpamplona.quartz.nip50Search.SearchableEvent
+import com.vitorpamplona.quartz.nip71Video.credits.VideoCredits
 import com.vitorpamplona.quartz.nip71Video.tags.DurationTag
 import com.vitorpamplona.quartz.nip71Video.tags.SegmentTag
+import com.vitorpamplona.quartz.nip71Video.tags.TextTrackTag
 import com.vitorpamplona.quartz.nip92IMeta.imetas
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.HashSha256Tag
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.MimeTypeTag
@@ -71,7 +72,11 @@ abstract class RegularVideoEvent(
 
     override fun duration() = tags.firstNotNullOfOrNull(DurationTag::parse)
 
-    override fun textTrack() = tags.mapNotNull(ETag::parse)
+    // `text-track`, not `e`: reading ETag here returned the event's unrelated `e` tags
+    // (on a divine.video short, its "audio" source pointer) and never a caption track.
+    override fun textTrack() = tags.mapNotNull(TextTrackTag::parse)
+
+    override fun credits() = VideoCredits.parse(tags)
 
     override fun segments() = tags.mapNotNull(SegmentTag::parse)
 

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip71Video/VideoEvent.kt

@@ -22,9 +22,10 @@ package com.vitorpamplona.quartz.nip71Video
 
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.IEvent
-import com.vitorpamplona.quartz.nip01Core.tags.events.ETag
 import com.vitorpamplona.quartz.nip01Core.tags.people.PTag
+import com.vitorpamplona.quartz.nip71Video.credits.VideoCredit
 import com.vitorpamplona.quartz.nip71Video.tags.SegmentTag
+import com.vitorpamplona.quartz.nip71Video.tags.TextTrackTag
 
 @Immutable
 interface VideoEvent : IEvent {
@@ -34,12 +35,18 @@ interface VideoEvent : IEvent {
 
     fun duration(): Int?
 
-    fun textTrack(): List<ETag>
+    fun textTrack(): List<TextTrackTag>
 
     fun segments(): List<SegmentTag>
 
     fun participants(): List<PTag>
 
+    /**
+     * Everyone and everything this video credits, with the word the publisher used for each.
+     * See [com.vitorpamplona.quartz.nip71Video.credits.VideoCredits].
+     */
+    fun credits(): List<VideoCredit>
+
     fun hashtags(): List<String>
 
     fun mimeType(): String?

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip71Video/VideoMeta.kt

@@ -34,6 +34,9 @@ data class VideoMeta(
     val hash: String? = null,
     val size: Int? = null,
     val service: String? = null,
+    // Non-standard `hls` property (divine.video): the adaptive manifest for the same
+    // footage this entry's `url` serves progressively. See [HlsImetaTag].
+    val hls: String? = null,
     val fallback: List<String> = emptyList(),
     val image: List<String> = emptyList(),
     val thumbhash: String? = null,
@@ -60,6 +63,7 @@ data class VideoMeta(
                 blurhash?.let { blurhash(it) }
                 thumbhash?.let { thumbhash(it) }
                 service?.let { service(it) }
+                hls?.let { hls(it) }
                 fallback.forEach { fallback(it) }
                 image.forEach { image(it) }
                 bitrate?.let { bitrate(it) }
@@ -80,6 +84,7 @@ data class VideoMeta(
                 hash = iMeta.hash()?.firstOrNull(),
                 size = iMeta.size()?.firstOrNull()?.toIntOrNull(),
                 service = iMeta.service()?.firstOrNull(),
+                hls = iMeta.hls()?.firstOrNull(),
                 fallback = iMeta.fallback() ?: emptyList(),
                 image = iMeta.image() ?: emptyList(),
                 thumbhash = iMeta.thumbhash()?.firstOrNull(),

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip71Video/credits/VideoCredits.kt

@@ -0,0 +1,133 @@
+/*
+ * 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.quartz.nip71Video.credits
+
+import androidx.compose.runtime.Immutable
+import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.core.TagArray
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.nip01Core.relay.normalizer.NormalizedRelayUrl
+import com.vitorpamplona.quartz.nip01Core.relay.normalizer.RelayUrlNormalizer
+import com.vitorpamplona.quartz.nip01Core.tags.aTag.ATag
+import com.vitorpamplona.quartz.nip01Core.tags.events.ETag
+import com.vitorpamplona.quartz.nip01Core.tags.people.PTag
+
+/**
+ * Who and what a video credits, beyond its author.
+ *
+ * NIP-71 only defines `p` as "a participant in the video". Everything richer is convention:
+ * divine.video labels each reference with what it is for — a person who inspired the piece, the
+ * video whose audio was reused, a collaborator who accepted a credit — and puts that word in the
+ * tag's marker slot. Reading the marker is what separates "featuring @x" from a bare mention.
+ */
+@Immutable
+data class VideoCredit(
+    val target: CreditTarget,
+    /**
+     * The marker as published: `inspired-by`, `mention`, `audio`, or a role like `Collaborator`.
+     * Null when the tag names a participant without saying in what capacity.
+     */
+    val label: String?,
+)
+
+@Immutable
+sealed interface CreditTarget {
+    @Immutable
+    data class Person(
+        val pubKey: HexKey,
+        val relay: NormalizedRelayUrl? = null,
+    ) : CreditTarget
+
+    @Immutable
+    data class Video(
+        val address: ATag,
+    ) : CreditTarget
+
+    @Immutable
+    data class Event(
+        val eventId: HexKey,
+        val relay: NormalizedRelayUrl? = null,
+    ) : CreditTarget
+}
+
+object VideoCredits {
+    // NIP-10's own markers on an `e`/`a` tag describe threading, not authorship. A video is never
+    // a reply, so any of these is either a stray or something other than a credit — reading them
+    // as one would print "root" under the player as though it were a person's role.
+    private val THREADING_MARKERS = setOf("root", "reply")
+
+    /**
+     * Reads every credited reference off a video's tags, in published order.
+     *
+     * The marker's *position* is not fixed, because two conventions collide: divine-mobile writes
+     * `["p", <pubkey>, <relay>, "inspired-by"]` while divine-web's collaborator invite writes
+     * `["p", <pubkey>, "Collaborator"]`. Both are unambiguous once you ask whether slot 2 parses
+     * as a relay — the same test [PTag] already uses to decide whether it holds a hint.
+     */
+    fun parse(tags: TagArray): List<VideoCredit> =
+        tags.mapNotNull { tag ->
+            when {
+                tag.size > 1 && tag[0] == PTag.TAG_NAME && tag[1].length == 64 ->
+                    VideoCredit(CreditTarget.Person(tag[1], relayHintAt(tag, 2)), labelAfterOptionalRelay(tag))
+
+                tag.size > 1 && tag[0] == ATag.TAG_NAME ->
+                    ATag.parse(tag[1], tag.getOrNull(2))?.let { address ->
+                        val label = labelAfterOptionalRelay(tag)
+                        if (label in THREADING_MARKERS) null else VideoCredit(CreditTarget.Video(address), label)
+                    }
+
+                tag.size > 1 && tag[0] == ETag.TAG_NAME && tag[1].length == 64 -> {
+                    // Unlike `p` and `a`, a bare `e` tag on a video says nothing — it is only a
+                    // credit when something names what the reference is for (divine.video writes
+                    // "audio" for a reused soundtrack). No marker, no credit.
+                    val label = labelAfterOptionalRelay(tag)
+                    if (label == null || label in THREADING_MARKERS) {
+                        null
+                    } else {
+                        VideoCredit(CreditTarget.Event(tag[1], relayHintAt(tag, 2)), label)
+                    }
+                }
+
+                else -> null
+            }
+        }
+
+    private fun relayHintAt(
+        tag: Array<String>,
+        index: Int,
+    ): NormalizedRelayUrl? {
+        if (!tag.has(index)) return null
+        if (tag[index].length <= 7 || !RelayUrlNormalizer.isRelayUrl(tag[index])) return null
+        return RelayUrlNormalizer.normalizeOrNull(tag[index])
+    }
+
+    // Slot 2 is either a relay hint or the label itself; the label follows it when it is a relay.
+    private fun labelAfterOptionalRelay(tag: Array<String>): String? {
+        val slot2 = tag.getOrNull(2)
+        val label =
+            if (slot2 != null && slot2.length > 7 && RelayUrlNormalizer.isRelayUrl(slot2)) {
+                tag.getOrNull(3)
+            } else {
+                slot2
+            }
+        return label?.takeIf { it.isNotBlank() }
+    }
+}

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip71Video/tags/HlsImetaTag.kt

@@ -0,0 +1,40 @@
+/*
+ * 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.quartz.nip71Video.tags
+
+/**
+ * Non-standard `hls` property inside a NIP-71 `imeta` tag: the adaptive HLS manifest for the
+ * same footage the entry's `url` serves progressively.
+ *
+ * NIP-71 itself expects a ladder to be published as separate `imeta` entries, one of which
+ * carries an HLS media type. divine.video instead keeps one `imeta` per video and hangs the
+ * manifest off this key (see `divine-web/src/lib/videoParser.ts`), so a client that only reads
+ * `url` is pinned to the progressive rendition and never adapts. Quartz reads both shapes;
+ * `selectVideoTrack()` turns an `hls` property into a playable variant of its own.
+ */
+class HlsImetaTag {
+    companion object {
+        const val TAG_NAME = "hls"
+
+        /** The media type an `hls` url is served with; NIP-71's own ladder example uses it too. */
+        const val MIME_TYPE = "application/vnd.apple.mpegurl"
+    }
+}

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip71Video/tags/TextTrackTag.kt

@@ -20,16 +20,34 @@
  */
 package com.vitorpamplona.quartz.nip71Video.tags
 
-import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.has
-import com.vitorpamplona.quartz.utils.arrayOfNotNull
 import com.vitorpamplona.quartz.utils.ensure
 
+/**
+ * NIP-71 `text-track`: supplementary timed text for a video (captions, subtitles, chapters,
+ * metadata).
+ *
+ * The spec is inconsistent about the payload — its prose calls [ref] a "link to WebVTT file"
+ * while its example writes an encoded event — and publishers use both. divine.video emits a
+ * Blossom URL and an addressable `39307:<pubkey>:subtitles:<d>` coordinate for the same track,
+ * so [ref] is deliberately untyped: whatever identifies the track. Positions 3 and 4 carry the
+ * kind of information and its language code, per the prose.
+ */
 data class TextTrackTag(
-    val eventId: HexKey,
-    var relay: String? = null,
+    val ref: String,
+    val relay: String? = null,
+    val type: String? = null,
+    val language: String? = null,
 ) {
-    fun toTagArray() = arrayOfNotNull(TAG_NAME, eventId, relay)
+    // Positions are meaningful, so a gap before a field that IS set has to be written as an
+    // empty string rather than dropped — otherwise `language` would be read as `type`.
+    fun toTagArray(): Array<String> =
+        when {
+            language != null -> arrayOf(TAG_NAME, ref, relay ?: "", type ?: "", language)
+            type != null -> arrayOf(TAG_NAME, ref, relay ?: "", type)
+            relay != null -> arrayOf(TAG_NAME, ref, relay)
+            else -> arrayOf(TAG_NAME, ref)
+        }
 
     companion object {
         const val TAG_NAME = "text-track"
@@ -38,12 +56,19 @@ data class TextTrackTag(
             ensure(tag.has(1)) { return null }
             ensure(tag[0] == TAG_NAME) { return null }
             ensure(tag[1].isNotEmpty()) { return null }
-            return TextTrackTag(tag[1], tag.getOrNull(2))
+            return TextTrackTag(
+                ref = tag[1],
+                relay = tag.getOrNull(2)?.ifBlank { null },
+                type = tag.getOrNull(3)?.ifBlank { null },
+                language = tag.getOrNull(4)?.ifBlank { null },
+            )
         }
 
         fun assemble(
-            eventId: HexKey,
+            ref: String,
             relay: String?,
-        ) = arrayOfNotNull(TAG_NAME, eventId, relay)
+            type: String? = null,
+            language: String? = null,
+        ) = TextTrackTag(ref, relay, type, language).toTagArray()
     }
 }

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip71Video/textTrack/LanguageTag.kt

@@ -0,0 +1,46 @@
+/*
+ * 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.quartz.nip71Video.textTrack
+
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
+/**
+ * The bare `["l", "<code>"]` language tag a [TextTrackEvent] carries.
+ *
+ * NIP-32 spells a label as `["l", "<value>", "<namespace>"]`; publishers of subtitle events drop
+ * the namespace and use the slot for a plain ISO-639-1 code, so this reads position 1 and ignores
+ * whatever follows.
+ */
+class LanguageTag {
+    companion object {
+        const val TAG_NAME = "l"
+
+        fun parse(tag: Array<String>): String? {
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
+            return tag[1]
+        }
+
+        fun assemble(languageCode: String) = arrayOf(TAG_NAME, languageCode)
+    }
+}

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip71Video/textTrack/TextTrackEvent.kt

@@ -0,0 +1,103 @@
+/*
+ * 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.quartz.nip71Video.textTrack
+
+import androidx.compose.runtime.Immutable
+import com.vitorpamplona.quartz.nip01Core.core.BaseAddressableEvent
+import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
+import com.vitorpamplona.quartz.nip01Core.hints.AddressHintProvider
+import com.vitorpamplona.quartz.nip01Core.signers.eventTemplate
+import com.vitorpamplona.quartz.nip01Core.tags.aTag.ATag
+import com.vitorpamplona.quartz.nip01Core.tags.dTag.dTag
+import com.vitorpamplona.quartz.nip50Search.IndexableFieldVisitor
+import com.vitorpamplona.quartz.nip50Search.SearchableEvent
+import com.vitorpamplona.quartz.nip94FileMetadata.tags.MimeTypeTag
+import com.vitorpamplona.quartz.nip94FileMetadata.tags.UrlTag
+import com.vitorpamplona.quartz.utils.TimeUtils
+
+/**
+ * An addressable timed-text track for a NIP-71 video — captions, subtitles, chapters or
+ * metadata — referenced from the video's `text-track` tag.
+ *
+ * NIP-71 only says a `text-track` points at "a WebVTT file"; publishers that want the track to be
+ * replaceable (retranslated, corrected) wrap it in this event instead, and reference it by
+ * coordinate. divine.video does both at once: the same track appears on the video as a raw
+ * Blossom URL *and* as `39307:<pubkey>:subtitles:<video-d>`.
+ *
+ * The cue text lives in [content] as WebVTT, which makes the event self-contained; [url] is the
+ * same document hosted as a file. Prefer the URL when there is one — the player streams it and
+ * only parses the cues it needs — and fall back to the inline copy when the host is gone.
+ */
+@Immutable
+class TextTrackEvent(
+    id: HexKey,
+    pubKey: HexKey,
+    createdAt: Long,
+    tags: Array<Array<String>>,
+    content: String,
+    sig: HexKey,
+) : BaseAddressableEvent(id, pubKey, createdAt, KIND, tags, content, sig),
+    AddressHintProvider,
+    SearchableEvent {
+    // The cue text is the only searchable thing here: the `d` tag is a slug and the rest is
+    // plumbing. Indexing it makes a video findable by what is said in it.
+    override fun indexableContent() = content
+
+    override fun forEachIndexableField(visitor: IndexableFieldVisitor) {
+        visitor.visit(content)
+    }
+
+    override fun addressHints() = tags.mapNotNull(ATag::parseAsHint)
+
+    override fun linkedAddressIds() = tags.mapNotNull(ATag::parseAddressId)
+
+    /** The video this track belongs to. */
+    fun video() = tags.firstNotNullOfOrNull(ATag::parseAddress)
+
+    fun url() = tags.firstNotNullOfOrNull(UrlTag::parse)
+
+    fun mimeType() = tags.firstNotNullOfOrNull(MimeTypeTag::parse)
+
+    /** ISO-639-1 code, from the NIP-32 style single-letter `l` tag publishers use here. */
+    fun language() = tags.firstNotNullOfOrNull(LanguageTag::parse)
+
+    companion object {
+        const val KIND = 39307
+        const val DEFAULT_MIME_TYPE = "text/vtt"
+
+        /** `subtitles:<video d tag>` — the convention divine.video publishes under. */
+        fun identifierFor(
+            type: String,
+            videoDTag: String,
+        ) = "$type:$videoDTag"
+
+        fun build(
+            webVtt: String,
+            dTag: String,
+            createdAt: Long = TimeUtils.now(),
+            initializer: TagArrayBuilder<TextTrackEvent>.() -> Unit = {},
+        ) = eventTemplate(KIND, webVtt, createdAt) {
+            dTag(dTag)
+            initializer()
+        }
+    }
+}

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip88Polls/poll/tags/OptionTag.kt

@@ -32,6 +32,10 @@ class OptionTag(
     companion object {
         const val TAG_NAME = "option"
 
+        // Both fields are required. NIP-88 defines an option as an id "followed by an option
+        // label field", and an option nobody can read is not a choice anyone can make: rendering
+        // it as a blank, tappable row would collect votes for a question the voter never saw.
+        // A poll that ships one is malformed, and the option is dropped rather than shown empty.
         fun isTag(tag: Array<String>) = tag.has(2) && tag[0] == TAG_NAME && tag[1].isNotEmpty() && tag[2].isNotEmpty()
 
         fun parse(tag: Array<String>): OptionTag? {

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip88Polls/poll/tags/PollTypeTag.kt

@@ -34,7 +34,9 @@ class PollTypeTag {
     companion object {
         const val TAG_NAME = "polltype"
 
-        fun isTag(tag: Array<String>) = tag.has(2) && tag[0] == TAG_NAME && tag[1].isNotEmpty()
+        // has(1), matching parse: NIP-88's tag is `["polltype", "<type>"]` with nothing after it,
+        // so requiring a third element made this answer false for every conformant tag.
+        fun isTag(tag: Array<String>) = tag.has(1) && tag[0] == TAG_NAME && tag[1].isNotEmpty()
 
         fun parse(tag: Array<String>): PollType? {
             ensure(tag.has(1)) { return null }

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip88Polls/response/PollResponseEvent.kt

@@ -61,11 +61,48 @@ class PollResponseEvent(
     companion object {
         const val KIND = 1018
 
-        fun build(
+        /**
+         * The answer to a single-choice poll.
+         *
+         * NIP-88: "polltype: singlechoice: The first response tag is to be considered the actual
+         * response." One code in, one `response` tag out — there is no way to express an answer
+         * whose meaning depends on which tag the reader happens to look at first.
+         */
+        fun buildSingleChoice(
+            poll: EventHintBundle<PollEvent>,
+            response: String,
+            createdAt: Long = TimeUtils.now(),
+            initializer: TagArrayBuilder<PollResponseEvent>.() -> Unit = {},
+        ) = build(poll, listOf(response), createdAt, initializer)
+
+        /**
+         * The answer to a multiple-choice poll.
+         *
+         * NIP-88: "the first response tag pointing to each id is considered the actual response,
+         * without considering the order of the response tags" — so a Set is exactly the right
+         * shape here, and the conversion to a list below is only about writing them down.
+         */
+        fun buildMultipleChoice(
             poll: EventHintBundle<PollEvent>,
             responses: Set<String>,
             createdAt: Long = TimeUtils.now(),
             initializer: TagArrayBuilder<PollResponseEvent>.() -> Unit = {},
+        ) = build(poll, responses.toList(), createdAt, initializer)
+
+        /**
+         * Writes [responses] as `response` tags in the order given.
+         *
+         * Prefer [buildSingleChoice] / [buildMultipleChoice]: the poll type decides whether order
+         * matters, and this overload cannot know which one it is being used for. It takes a List
+         * rather than a Set so that a caller who does know keeps control of the order — passing an
+         * unordered Set here would hand a single-choice answer to whatever iteration order the
+         * collection happened to have.
+         */
+        fun build(
+            poll: EventHintBundle<PollEvent>,
+            responses: List<String>,
+            createdAt: Long = TimeUtils.now(),
+            initializer: TagArrayBuilder<PollResponseEvent>.() -> Unit = {},
         ) = eventTemplate(KIND, "", createdAt) {
             poll(poll)
             notifyAuthor(poll)

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip88Polls/response/TagArrayBuilderExt.kt

@@ -29,6 +29,6 @@ import com.vitorpamplona.quartz.nip88Polls.response.tags.ResponseTag
 
 fun TagArrayBuilder<PollResponseEvent>.poll(pollHint: EventHintBundle<PollEvent>) = addUnique(PollTag.assemble(pollHint))
 
-fun TagArrayBuilder<PollResponseEvent>.responses(responses: Set<String>) = addAll(ResponseTag.assemble(responses))
+fun TagArrayBuilder<PollResponseEvent>.responses(responses: List<String>) = addAll(ResponseTag.assemble(responses))
 
 fun TagArrayBuilder<PollResponseEvent>.notifyAuthor(pollHint: EventHintBundle<PollEvent>) = add(pollHint.toPTag().toTagArray())

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip88Polls/response/tags/ResponseTag.kt

@@ -38,6 +38,9 @@ class ResponseTag {
 
         fun assemble(code: String) = arrayOf(TAG_NAME, code)
 
-        fun assemble(responses: Set<String>) = responses.map { code -> assemble(code) }
+        // A List, not a Set: NIP-88 reads a single-choice answer as "the first response tag",
+        // so the order these are written in is load-bearing and an unordered Set would leave the
+        // recorded answer to iteration order.
+        fun assemble(responses: List<String>) = responses.map { code -> assemble(code) }
     }
 }

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/utils/EventFactory.kt

@@ -155,6 +155,7 @@ import com.vitorpamplona.quartz.experimental.trustedLists.addressables.Addressab
 import com.vitorpamplona.quartz.experimental.trustedLists.events.EventTrustedListEvent
 import com.vitorpamplona.quartz.experimental.trustedLists.externalIds.ExternalIdTrustedListEvent
 import com.vitorpamplona.quartz.experimental.trustedLists.users.UserTrustedListEvent
+import com.vitorpamplona.quartz.experimental.videoCollaboration.VideoCollaborationEvent
 import com.vitorpamplona.quartz.experimental.zapPolls.ZapPollEvent
 import com.vitorpamplona.quartz.marmot.mip00KeyPackages.KeyPackageEvent
 import com.vitorpamplona.quartz.marmot.mip00KeyPackages.KeyPackageRelayListEvent
@@ -333,6 +334,7 @@ import com.vitorpamplona.quartz.nip71Video.VideoHorizontalEvent
 import com.vitorpamplona.quartz.nip71Video.VideoNormalEvent
 import com.vitorpamplona.quartz.nip71Video.VideoShortEvent
 import com.vitorpamplona.quartz.nip71Video.VideoVerticalEvent
+import com.vitorpamplona.quartz.nip71Video.textTrack.TextTrackEvent
 import com.vitorpamplona.quartz.nip72ModCommunities.approval.CommunityPostApprovalEvent
 import com.vitorpamplona.quartz.nip72ModCommunities.definition.CommunityDefinitionEvent
 import com.vitorpamplona.quartz.nip72ModCommunities.follow.CommunityListEvent
@@ -871,6 +873,8 @@ class EventFactory {
                 VideoCurationSetEvent.KIND -> VideoCurationSetEvent(id, pubKey, createdAt, tags, content, sig)
                 VideoHorizontalEvent.KIND -> VideoHorizontalEvent(id, pubKey, createdAt, tags, content, sig)
                 VideoVerticalEvent.KIND -> VideoVerticalEvent(id, pubKey, createdAt, tags, content, sig)
+                TextTrackEvent.KIND -> TextTrackEvent(id, pubKey, createdAt, tags, content, sig)
+                VideoCollaborationEvent.KIND -> VideoCollaborationEvent(id, pubKey, createdAt, tags, content, sig)
                 VideoNormalEvent.KIND -> VideoNormalEvent(id, pubKey, createdAt, tags, content, sig)
                 VideoShortEvent.KIND -> VideoShortEvent(id, pubKey, createdAt, tags, content, sig)
                 VoiceEvent.KIND -> VoiceEvent(id, pubKey, createdAt, tags, content, sig)

quartz/src/commonTest/kotlin/com/vitorpamplona/quartz/nip88Polls/Nip88PollTagsTest.kt

@@ -0,0 +1,215 @@
+/*
+ * 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.quartz.nip88Polls
+
+import com.vitorpamplona.quartz.nip01Core.core.Event
+import com.vitorpamplona.quartz.nip01Core.hints.EventHintBundle
+import com.vitorpamplona.quartz.nip01Core.relay.normalizer.RelayUrlNormalizer
+import com.vitorpamplona.quartz.nip88Polls.poll.PollEvent
+import com.vitorpamplona.quartz.nip88Polls.poll.endsAt
+import com.vitorpamplona.quartz.nip88Polls.poll.options
+import com.vitorpamplona.quartz.nip88Polls.poll.pollType
+import com.vitorpamplona.quartz.nip88Polls.poll.relays
+import com.vitorpamplona.quartz.nip88Polls.poll.tags.EndsAtTag
+import com.vitorpamplona.quartz.nip88Polls.poll.tags.OptionTag
+import com.vitorpamplona.quartz.nip88Polls.poll.tags.PollType
+import com.vitorpamplona.quartz.nip88Polls.poll.tags.PollTypeTag
+import com.vitorpamplona.quartz.nip88Polls.poll.tags.RelayTag
+import com.vitorpamplona.quartz.nip88Polls.response.PollResponseEvent
+import com.vitorpamplona.quartz.nip88Polls.response.poll
+import com.vitorpamplona.quartz.nip88Polls.response.responses
+import com.vitorpamplona.quartz.nip88Polls.response.tags.PollTag
+import com.vitorpamplona.quartz.nip88Polls.response.tags.ResponseTag
+import kotlin.test.Test
+import kotlin.test.assertContentEquals
+import kotlin.test.assertEquals
+import kotlin.test.assertFalse
+import kotlin.test.assertNull
+import kotlin.test.assertTrue
+
+/**
+ * The NIP-88 tag layer against the spec's own example events.
+ *
+ * Both halves are checked, because a parser and a serializer can be wrong in opposite directions
+ * and still agree with each other: the examples are parsed field by field, and what the builders
+ * emit is compared to the literal tag arrays the spec prints.
+ */
+class Nip88PollTagsTest {
+    // Verbatim from NIP-88, "Poll Event".
+    private val specPoll =
+        """{
+          "content": "Pineapple on pizza",
+          "created_at": 1719888496,
+          "id": "9d1b6b9562e66f2ecf35eb0a3c2decc736c47fddb13d6fb8f87185a153ea3634",
+          "kind": 1068,
+          "pubkey": "dee45a23c4f1d93f3a2043650c5081e4ac14a778e0acbef03de3768e4f81ac7b",
+          "sig": "7fa93bf3c430eaef784b0dacc217d3cd5eff1c520e7ef5d961381bc0f014dde6286618048d924808e54d1be03f2f2c2f0f8b5c9c2082a4480caf45a565ca9797",
+          "tags": [
+            ["option", "qj518h583", "Yay"],
+            ["option", "gga6cdnqj", "Nay"],
+            ["relay", "wss://relay.damus.io"],
+            ["relay", "wss://nos.lol"],
+            ["polltype", "singlechoice"],
+            ["endsAt", "1719988496"]
+          ]
+        }"""
+
+    // Verbatim from NIP-88, "Responses".
+    private val specResponse =
+        """{
+          "content": "",
+          "created_at": 1720097117,
+          "id": "60a005e32e9596c3f544a841a9bc4e46d3020ca3650d6a739c95c1568e33f6d8",
+          "kind": 1018,
+          "pubkey": "1bc70a0148b3f316da33fe7e89f23e3e71ac4ff998027ec712b905cd24f6a411",
+          "sig": "30071a633c65db8f3a075c7a8de757fbd8ce65e3607f4ba287fe6d7fbf839a380f94ff4e826fbba593f6faaa13683b7ea9114ade140720ecf4927010ebf3e44f",
+          "tags": [
+            ["e", "1fc80cf813f1af33d5a435862b7ef7fb96b47e68a48f1abcadf8081f5a545550"],
+            ["response", "gga6cdnqj"],
+            ["response", "m3agjsdq1"]
+          ]
+        }"""
+
+    @Test
+    fun theSpecsPollExampleParsesFieldForField() {
+        val event = Event.fromJson(specPoll)
+        assertTrue(event is PollEvent)
+        val poll = event as PollEvent
+
+        assertEquals("Pineapple on pizza", poll.content)
+        assertEquals(listOf("qj518h583" to "Yay", "gga6cdnqj" to "Nay"), poll.options().map { it.code to it.label })
+        assertEquals(listOf("wss://relay.damus.io/", "wss://nos.lol/"), poll.relays().map { it.url })
+        assertEquals(PollType.SINGLE_CHOICE, poll.pollType())
+        assertEquals(1719988496L, poll.endsAt())
+    }
+
+    @Test
+    fun theSpecsResponseExampleParsesFieldForField() {
+        val event = Event.fromJson(specResponse)
+        assertTrue(event is PollResponseEvent)
+        val response = event as PollResponseEvent
+
+        assertEquals("1fc80cf813f1af33d5a435862b7ef7fb96b47e68a48f1abcadf8081f5a545550", response.poll()?.eventId)
+        // Both tags are read. Which of them counts is the polltype's business, not the parser's.
+        assertEquals(listOf("gga6cdnqj", "m3agjsdq1"), response.responses())
+    }
+
+    @Test
+    fun aPollWithNoPollTypeIsSingleChoice() {
+        // "Polls that do not have a polltype should be considered a singlechoice poll."
+        val untyped = Event.fromJson(specPoll.replace("""["polltype", "singlechoice"],""", ""))
+        assertEquals(PollType.SINGLE_CHOICE, (untyped as PollEvent).pollType())
+
+        // An unrecognised one falls back the same way rather than being treated as multi-choice,
+        // which would let one response cast several votes.
+        val unknown = Event.fromJson(specPoll.replace("singlechoice", "rankedchoice"))
+        assertEquals(PollType.SINGLE_CHOICE, (unknown as PollEvent).pollType())
+    }
+
+    @Test
+    fun aWellFormedPollTypeTagIsRecognisedAsOne() {
+        // isTag and parse have to agree: the spec's tag has exactly two elements, and a stricter
+        // isTag makes `tags.any(PollTypeTag::isTag)` answer "no poll declares a type".
+        assertTrue(PollTypeTag.isTag(arrayOf("polltype", "singlechoice")))
+        assertTrue(PollTypeTag.isTag(arrayOf("polltype", "multiplechoice")))
+        assertFalse(PollTypeTag.isTag(arrayOf("polltype")))
+        assertFalse(PollTypeTag.isTag(arrayOf("endsAt", "1719988496")))
+    }
+
+    @Test
+    fun anOptionNeedsBothAnIdAndALabel() {
+        assertEquals("qj518h583" to "Yay", OptionTag.parse(arrayOf("option", "qj518h583", "Yay"))?.let { it.code to it.label })
+
+        // NIP-88 defines an option as an id "followed by an option label field", and an option
+        // nobody can read is not a choice anyone can make — a blank tappable row would collect
+        // votes for a question the voter never saw. Both fields are required, and isTag agrees
+        // with parse about that.
+        assertNull(OptionTag.parse(arrayOf("option", "qj518h583", "")))
+        assertNull(OptionTag.parse(arrayOf("option", "qj518h583")))
+        assertNull(OptionTag.parse(arrayOf("option", "", "Yay")))
+        assertNull(OptionTag.parse(arrayOf("option")))
+        assertNull(OptionTag.parse(arrayOf("response", "qj518h583", "Yay")))
+
+        assertTrue(OptionTag.isTag(arrayOf("option", "qj518h583", "Yay")))
+        assertFalse(OptionTag.isTag(arrayOf("option", "qj518h583", "")))
+        assertFalse(OptionTag.isTag(arrayOf("option", "qj518h583")))
+    }
+
+    @Test
+    fun theBuildersEmitTheTagsTheSpecPrints() {
+        val template =
+            PollEvent.build(
+                description = "Pineapple on pizza",
+                options = listOf(OptionTag("qj518h583", "Yay"), OptionTag("gga6cdnqj", "Nay")),
+                endsAt = 1719988496L,
+                relays = listOfNotNull(RelayUrlNormalizer.normalizeOrNull("wss://relay.damus.io")),
+                pollType = PollType.SINGLE_CHOICE,
+            )
+
+        assertEquals("Pineapple on pizza", template.content)
+        assertEquals(PollEvent.KIND, template.kind)
+        val tags = template.tags.associateBy({ it[0] }, { it.toList() })
+        assertContentEquals(listOf("polltype", "singlechoice"), tags["polltype"])
+        assertContentEquals(listOf("endsAt", "1719988496"), tags["endsAt"])
+        assertContentEquals(listOf("relay", "wss://relay.damus.io/"), tags["relay"])
+        assertContentEquals(
+            listOf(listOf("option", "qj518h583", "Yay"), listOf("option", "gga6cdnqj", "Nay")),
+            template.tags.filter { it[0] == "option" }.map { it.toList() },
+        )
+    }
+
+    @Test
+    fun aSingleChoiceAnswerCanOnlyBeOneTag() {
+        val poll = EventHintBundle(Event.fromJson(specPoll) as PollEvent, null)
+
+        val template = PollResponseEvent.buildSingleChoice(poll, "gga6cdnqj")
+        val responses = template.tags.filter { it[0] == "response" }
+
+        // The spec reads the FIRST response tag as the answer, so a single-choice event that
+        // carries more than one is ambiguous by construction. The typed builder cannot emit one.
+        assertEquals(listOf(listOf("response", "gga6cdnqj")), responses.map { it.toList() })
+        assertEquals(PollResponseEvent.KIND, template.kind)
+    }
+
+    @Test
+    fun aMultipleChoiceAnswerWritesEveryCodeItWasGiven() {
+        val poll = EventHintBundle(Event.fromJson(specPoll) as PollEvent, null)
+
+        val template = PollResponseEvent.buildMultipleChoice(poll, setOf("qj518h583", "gga6cdnqj"))
+        val codes = template.tags.filter { it[0] == "response" }.map { it[1] }
+
+        assertEquals(setOf("qj518h583", "gga6cdnqj"), codes.toSet())
+    }
+
+    @Test
+    fun theTagNamesAreSpelledTheWayTheSpecSpellsThem() {
+        // `endsAt` is camelCase in NIP-88 while almost every other nostr tag is lowercase, so it
+        // is the one most likely to be "corrected" into something no other client reads.
+        assertEquals("endsAt", EndsAtTag.TAG_NAME)
+        assertEquals("polltype", PollTypeTag.TAG_NAME)
+        assertEquals("option", OptionTag.TAG_NAME)
+        assertEquals("relay", RelayTag.TAG_NAME)
+        assertEquals("response", ResponseTag.TAG_NAME)
+        assertEquals("e", PollTag.TAG_NAME)
+        assertEquals("singlechoice", PollType.SINGLE_CHOICE.code)
+        assertEquals("multiplechoice", PollType.MULTI_CHOICE.code)
+    }
+}

quartz/src/jvmTest/kotlin/com/vitorpamplona/quartz/nip50Search/IndexableContentGoldenTest.kt

@@ -31,7 +31,7 @@ import java.io.File
  * `indexableContent()` is not an internal detail: the SQLite and filesystem stores index through
  * it, and `references/searchable-kinds.md` — which external engines mirror at version bumps — is a
  * transcription of it. A body that changes silently ships stale results downstream and needs a
- * `reindexFullTextSearch()` on every existing database. So the output of all 126 kinds is recorded
+ * `reindexFullTextSearch()` on every existing database. So the output of all 127 kinds is recorded
  * in `indexable-content.golden` and compared here.
  *
  * A deliberate change to what a kind indexes is fine — regenerate the golden file with

quartz/src/jvmTest/resources/indexable-content.golden

@@ -137,6 +137,7 @@
 39000	The Name\nThe About
 39089	The Title\nThe Description
 39092	The Title\nThe Description
+39307	The content body.
 39701	The Title\nThe content body.
 40002	The content body.
 40100	The content body.