Merge pull request #3600 from vitorpamplona/claude/amethyst-note-ui-refactor-n36nvd

refactor: converge rich-text rendering across Android + Desktop into commons

amethyst/src/main/java/com/vitorpamplona/amethyst/AppModules.kt

@@ -28,6 +28,7 @@ import coil3.disk.DiskCache
 import coil3.memory.MemoryCache
 import com.vitorpamplona.amethyst.commons.model.NoteState
 import com.vitorpamplona.amethyst.commons.relayClient.BlockedRelayFilteringClient
+import com.vitorpamplona.amethyst.commons.richtext.CachedRichTextParser
 import com.vitorpamplona.amethyst.commons.robohash.CachedRobohash
 import com.vitorpamplona.amethyst.commons.scheduledposts.ScheduledPostStore
 import com.vitorpamplona.amethyst.commons.service.lnurl.OkHttpLnurlEndpointResolver
@@ -51,7 +52,6 @@ import com.vitorpamplona.amethyst.model.torState.AccountsTorStateConnector
 import com.vitorpamplona.amethyst.model.torState.TorRelayState
 import com.vitorpamplona.amethyst.napplet.DataStoreNappletPermissionStore
 import com.vitorpamplona.amethyst.napplet.DataStoreNostrSignerPermissionStore
-import com.vitorpamplona.amethyst.service.CachedRichTextParser
 import com.vitorpamplona.amethyst.service.calendar.CalendarReminderPrefs
 import com.vitorpamplona.amethyst.service.calendar.CalendarReminderWorker
 import com.vitorpamplona.amethyst.service.cast.CastRegistry

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

@@ -20,99 +20,12 @@
  */
 package com.vitorpamplona.amethyst.model
 
-import androidx.compose.foundation.layout.padding
-import androidx.compose.material3.Text
-import androidx.compose.runtime.Composable
-import androidx.compose.runtime.Immutable
-import androidx.compose.ui.Modifier
-import androidx.compose.ui.graphics.vector.ImageVector
-import androidx.compose.ui.tooling.preview.Preview
-import androidx.compose.ui.unit.dp
-import com.vitorpamplona.amethyst.commons.hashtags.Amethyst
-import com.vitorpamplona.amethyst.commons.hashtags.Btc
-import com.vitorpamplona.amethyst.commons.hashtags.Cashu
-import com.vitorpamplona.amethyst.commons.hashtags.Coffee
-import com.vitorpamplona.amethyst.commons.hashtags.CustomHashTagIcons
-import com.vitorpamplona.amethyst.commons.hashtags.Flowerstr
-import com.vitorpamplona.amethyst.commons.hashtags.Footstr
-import com.vitorpamplona.amethyst.commons.hashtags.Gamestr
-import com.vitorpamplona.amethyst.commons.hashtags.Grownostr
-import com.vitorpamplona.amethyst.commons.hashtags.Lightning
-import com.vitorpamplona.amethyst.commons.hashtags.Mate
-import com.vitorpamplona.amethyst.commons.hashtags.Nostr
-import com.vitorpamplona.amethyst.commons.hashtags.Plebs
-import com.vitorpamplona.amethyst.commons.hashtags.Skull
-import com.vitorpamplona.amethyst.commons.hashtags.Tunestr
-import com.vitorpamplona.amethyst.commons.hashtags.Weed
-import com.vitorpamplona.amethyst.commons.hashtags.Zap
-import com.vitorpamplona.amethyst.commons.model.EmptyTagList
-import com.vitorpamplona.amethyst.commons.richtext.HashTagSegment
-import com.vitorpamplona.amethyst.commons.richtext.RegularTextSegment
-import com.vitorpamplona.amethyst.ui.components.HashTag
-import com.vitorpamplona.amethyst.ui.components.RenderRegular
-import com.vitorpamplona.amethyst.ui.components.RenderTextParagraph
-import com.vitorpamplona.amethyst.ui.navigation.navs.EmptyNav
-import com.vitorpamplona.amethyst.ui.theme.ThemeComparisonColumn
+import com.vitorpamplona.amethyst.commons.ui.richtext.HashtagIcon as CommonsHashtagIcon
+import com.vitorpamplona.amethyst.commons.ui.richtext.checkForHashtagWithIcon as commonsCheckForHashtagWithIcon
 
-@Preview
-@Composable
-fun RenderHashTagIconsPreview() {
-    ThemeComparisonColumn {
-        RenderRegular(
-            "Testing rendering of hashtags: #flowerstr #Bitcoin, #nostr, #lightning, #zap, #amethyst, #cashu, #plebs, #coffee, #skullofsatoshi, #grownostr, #footstr, #tunestr, #weed, #mate, #gamestr, #gamechain",
-            EmptyTagList,
-        ) { paragraph, _, spaceWidth, modifier ->
-            RenderTextParagraph(paragraph, spaceWidth, modifier) { word ->
-                when (word) {
-                    is HashTagSegment -> HashTag(word, EmptyNav())
-                    is RegularTextSegment -> Text(word.segmentText)
-                }
-            }
-        }
-    }
-}
+// The hashtag-icon table now lives in commons/ui/richtext so the shared
+// RichTextViewer and both front ends resolve the same icons. These re-exports keep
+// the historical `com.vitorpamplona.amethyst.model` call sites working.
+typealias HashtagIcon = CommonsHashtagIcon
 
-fun checkForHashtagWithIcon(tag: String): HashtagIcon? =
-    when (tag.lowercase()) {
-        "₿itcoin", "bitcoin", "btc", "timechain", "bitcoiner", "bitcoiners" -> bitcoin
-        "nostr", "nostrich", "nostriches", "thenostr" -> nostr
-        "lightning", "lightningnetwork" -> lightning
-        "zap", "zaps", "zapper", "zappers", "zapping", "zapped", "zapathon", "zapraiser", "zaplife", "zapchain" -> zap
-        "amethyst" -> amethyst
-        "cashu", "ecash", "nut", "nuts", "deeznuts" -> cashu
-        "plebs", "pleb", "plebchain" -> plebs
-        "coffee", "coffeechain", "cafe" -> coffee
-        "skullofsatoshi" -> skull
-        "grownostr", "gardening", "garden" -> growstr
-        "footstr" -> footstr
-        "flowerstr" -> flowerstr
-        "tunestr", "music", "nowplaying" -> tunestr
-        "mate", "matechain", "matestr" -> matestr
-        "weed", "weedstr", "420", "cannabis", "marijuana" -> weed
-        "gamestr", "gaming", "gamechain" -> gamestr
-        else -> null
-    }
-
-val bitcoin = HashtagIcon(CustomHashTagIcons.Btc, "Bitcoin", Modifier.padding(start = 1.dp, bottom = 1.dp, top = 1.dp))
-val nostr = HashtagIcon(CustomHashTagIcons.Nostr, "Nostr", Modifier.padding(start = 1.dp, bottom = 1.dp, top = 1.dp))
-val lightning = HashtagIcon(CustomHashTagIcons.Lightning, "Lightning", Modifier.padding(start = 1.dp, bottom = 1.dp, top = 1.dp))
-val zap = HashtagIcon(CustomHashTagIcons.Zap, "Zap", Modifier.padding(start = 1.dp, bottom = 1.dp, top = 1.dp))
-val amethyst = HashtagIcon(CustomHashTagIcons.Amethyst, "Amethyst", Modifier.padding(start = 2.dp, bottom = 1.dp, top = 1.dp))
-val cashu = HashtagIcon(CustomHashTagIcons.Cashu, "Cashu", Modifier.padding(start = 1.dp, bottom = 1.dp, top = 1.dp))
-val plebs = HashtagIcon(CustomHashTagIcons.Plebs, "Pleb", Modifier.padding(start = 2.dp, bottom = 1.dp, top = 1.dp))
-val coffee = HashtagIcon(CustomHashTagIcons.Coffee, "Coffee", Modifier.padding(start = 3.dp, bottom = 1.dp, top = 1.dp))
-val skull = HashtagIcon(CustomHashTagIcons.Skull, "SkullofSatoshi", Modifier.padding(start = 1.dp, bottom = 1.dp, top = 1.dp))
-val growstr = HashtagIcon(CustomHashTagIcons.Grownostr, "GrowNostr", Modifier.padding(start = 1.dp, bottom = 1.dp, top = 1.dp))
-val footstr = HashtagIcon(CustomHashTagIcons.Footstr, "Footstr", Modifier.padding(start = 2.dp, bottom = 1.dp, top = 1.dp))
-val flowerstr = HashtagIcon(CustomHashTagIcons.Flowerstr, "Flowerstr", Modifier.padding(start = 2.dp, bottom = 1.dp, top = 1.dp))
-val tunestr = HashtagIcon(CustomHashTagIcons.Tunestr, "Tunestr", Modifier.padding(start = 1.dp, bottom = 1.dp, top = 1.dp))
-val weed = HashtagIcon(CustomHashTagIcons.Weed, "Weed", Modifier.padding(start = 1.dp, bottom = 0.dp, top = 0.dp))
-val matestr = HashtagIcon(CustomHashTagIcons.Mate, "Mate", Modifier.padding(start = 1.dp, bottom = 0.dp, top = 0.dp))
-val gamestr = HashtagIcon(CustomHashTagIcons.Gamestr, "GameStr", Modifier.padding(start = 1.dp, bottom = 0.dp, top = 0.dp))
-
-@Immutable
-class HashtagIcon(
-    val icon: ImageVector,
-    val description: String,
-    val modifier: Modifier = Modifier,
-)
+fun checkForHashtagWithIcon(tag: String): HashtagIcon? = commonsCheckForHashtagWithIcon(tag)

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

@@ -0,0 +1,308 @@
+/*
+ * 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.components
+
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.runtime.MutableState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.layout.ContentScale
+import com.vitorpamplona.amethyst.commons.model.ImmutableListOfLists
+import com.vitorpamplona.amethyst.commons.richtext.BlossomUriSegment
+import com.vitorpamplona.amethyst.commons.richtext.CachedRichTextParser
+import com.vitorpamplona.amethyst.commons.richtext.CashuSegment
+import com.vitorpamplona.amethyst.commons.richtext.ClinkOfferSegment
+import com.vitorpamplona.amethyst.commons.richtext.ConcordInviteLinkSegment
+import com.vitorpamplona.amethyst.commons.richtext.HashIndexEventSegment
+import com.vitorpamplona.amethyst.commons.richtext.HashIndexUserSegment
+import com.vitorpamplona.amethyst.commons.richtext.ImageGalleryParagraph
+import com.vitorpamplona.amethyst.commons.richtext.InvoiceSegment
+import com.vitorpamplona.amethyst.commons.richtext.MathSegment
+import com.vitorpamplona.amethyst.commons.richtext.NowhereLinkSegment
+import com.vitorpamplona.amethyst.commons.richtext.RelayGroupLinkSegment
+import com.vitorpamplona.amethyst.commons.richtext.RelayUrlSegment
+import com.vitorpamplona.amethyst.commons.richtext.RichTextViewerState
+import com.vitorpamplona.amethyst.commons.richtext.SecretEmoji
+import com.vitorpamplona.amethyst.commons.richtext.Segment
+import com.vitorpamplona.amethyst.commons.richtext.WithdrawSegment
+import com.vitorpamplona.amethyst.commons.ui.richtext.LocalRichTextInteractions
+import com.vitorpamplona.amethyst.commons.ui.richtext.LocalRichTextSegmentRenderer
+import com.vitorpamplona.amethyst.commons.ui.richtext.RichTextInteractions
+import com.vitorpamplona.amethyst.commons.ui.richtext.RichTextSegmentRenderer
+import com.vitorpamplona.amethyst.ui.components.markdown.RenderContentAsMarkdown
+import com.vitorpamplona.amethyst.ui.navigation.navs.INav
+import com.vitorpamplona.amethyst.ui.navigation.routes.Route
+import com.vitorpamplona.amethyst.ui.note.creators.invoice.ClinkOfferPreview
+import com.vitorpamplona.amethyst.ui.note.creators.invoice.MayBeInvoicePreview
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.amethyst.ui.theme.HalfVertPadding
+import com.vitorpamplona.amethyst.commons.ui.richtext.RichTextViewer as CommonsRichTextViewer
+
+/**
+ * The Android implementation of the shared [RichTextSegmentRenderer] contract: it
+ * wires each platform-divergent segment to Amethyst's existing touch-first leaf
+ * composables, closing over the [AccountViewModel], [INav], the parent
+ * [backgroundColor], the [callbackUri], and the [canPreview] mode that those
+ * leaves need but that the cross-platform contract deliberately keeps out of its
+ * method signatures.
+ *
+ * Recreate one per [CommonsBackedRichTextViewer] call (it captures per-call state);
+ * it is cheap and [remember]ed against its inputs so the CompositionLocal doesn't
+ * churn its readers.
+ */
+class AmethystRichTextSegmentRenderer(
+    private val accountViewModel: AccountViewModel,
+    private val nav: INav,
+    private val backgroundColor: MutableState<Color>,
+    private val callbackUri: String?,
+    private val canPreview: Boolean,
+) : RichTextSegmentRenderer {
+    @Composable
+    override fun Media(
+        segment: Segment,
+        state: RichTextViewerState,
+        modifier: Modifier,
+    ) {
+        if (segment is BlossomUriSegment) {
+            if (canPreview) {
+                BlossomUriRenderer(segment.segmentText, state, callbackUri, accountViewModel)
+            } else {
+                BlossomUriRendererNoPreview(segment.segmentText, accountViewModel)
+            }
+            return
+        }
+
+        if (canPreview) {
+            state.mediaForPager[segment.segmentText]?.let {
+                Box(HalfVertPadding) {
+                    ZoomableContentView(
+                        content = it,
+                        images = state.mediaList,
+                        roundedCorner = true,
+                        contentScale = ContentScale.FillWidth,
+                        accountViewModel = accountViewModel,
+                    )
+                }
+            }
+        } else {
+            ClickableUrl(segment.segmentText, segment.segmentText)
+        }
+    }
+
+    @Composable
+    override fun Gallery(
+        paragraph: ImageGalleryParagraph,
+        state: RichTextViewerState,
+        modifier: Modifier,
+    ) = ImageGallery(paragraph, state, accountViewModel, modifier, roundedCorner = true)
+
+    @Composable
+    override fun Equation(
+        segment: MathSegment,
+        modifier: Modifier,
+    ) = LatexEquation(segment.latex, segment.displayMode, segment.leading, segment.trailing)
+
+    @Composable
+    override fun NostrEntity(
+        bech: String,
+        canPreview: Boolean,
+        quotesLeft: Int,
+        modifier: Modifier,
+    ) = BechLink(bech, canPreview, quotesLeft, backgroundColor, accountViewModel, nav)
+
+    @Composable
+    override fun QuotedEvent(
+        eventHex: String,
+        addedChars: String?,
+        canPreview: Boolean,
+        quotesLeft: Int,
+        modifier: Modifier,
+    ) {
+        val segment = remember(eventHex, addedChars) { HashIndexEventSegment(eventHex, eventHex, addedChars) }
+        TagLink(segment, canPreview, quotesLeft, backgroundColor, accountViewModel, nav)
+    }
+
+    @Composable
+    override fun UserMention(
+        userHex: String,
+        addedChars: String?,
+        modifier: Modifier,
+    ) {
+        val segment = remember(userHex, addedChars) { HashIndexUserSegment(userHex, userHex, addedChars) }
+        TagLink(segment, accountViewModel, nav)
+    }
+
+    @Composable
+    override fun Payment(
+        segment: Segment,
+        modifier: Modifier,
+    ) {
+        when (segment) {
+            // Matches the original no-preview switchboard: don't surface a pay/withdraw
+            // affordance when previews are suppressed — show the raw text instead.
+            is InvoiceSegment -> if (canPreview) MayBeInvoicePreview(segment.segmentText, accountViewModel) else Text(segment.segmentText)
+            is WithdrawSegment -> if (canPreview) MayBeWithdrawal(segment.segmentText, accountViewModel) else Text(segment.segmentText)
+            // Cashu + Clink decode locally (network only on tap), so they render in both modes.
+            is CashuSegment -> CashuPreview(segment.segmentText, accountViewModel)
+            is ClinkOfferSegment -> ClinkOfferPreview(segment.offer, accountViewModel, nav)
+            else -> Text(segment.segmentText)
+        }
+    }
+
+    @Composable
+    override fun LinkPreview(
+        url: String,
+        modifier: Modifier,
+    ) = LoadUrlPreview(url, url, callbackUri, accountViewModel, nav)
+
+    @Composable
+    override fun Url(
+        url: String,
+        displayText: String,
+        modifier: Modifier,
+    ) = ClickableUrl(displayText, url)
+
+    @Composable
+    override fun Email(
+        address: String,
+        modifier: Modifier,
+    ) = ClickableEmail(address)
+
+    @Composable
+    override fun Phone(
+        number: String,
+        modifier: Modifier,
+    ) = ClickablePhone(number)
+
+    @Composable
+    override fun RelayLink(
+        segment: Segment,
+        modifier: Modifier,
+    ) {
+        when (segment) {
+            is RelayUrlSegment -> ClickableRelayUrl(segment.segmentText, nav)
+            is RelayGroupLinkSegment ->
+                if (canPreview) {
+                    RelayGroupCard(segment.segmentText, accountViewModel, nav)
+                } else {
+                    ClickableRelayGroupLink(segment.segmentText, nav)
+                }
+            is ConcordInviteLinkSegment ->
+                if (canPreview) {
+                    ConcordInviteCard(segment.segmentText, accountViewModel, nav)
+                } else {
+                    ClickableConcordInviteLink(segment.segmentText, nav)
+                }
+            else -> Text(segment.segmentText)
+        }
+    }
+
+    @Composable
+    override fun NowhereLink(
+        segment: NowhereLinkSegment,
+        canPreview: Boolean,
+        modifier: Modifier,
+    ) {
+        if (canPreview) {
+            NowhereLinkCard(segment)
+        } else {
+            ClickableUrl(segment.segmentText, segment.segmentText)
+        }
+    }
+
+    @Composable
+    override fun SecretMessage(
+        segment: SecretEmoji,
+        state: RichTextViewerState,
+        canPreview: Boolean,
+        quotesLeft: Int,
+        modifier: Modifier,
+    ) = DisplaySecretEmoji(segment, state, callbackUri, canPreview, quotesLeft, backgroundColor, accountViewModel, nav)
+}
+
+/**
+ * Renders rich text through the shared cross-platform [CommonsRichTextViewer] core.
+ * This is the production plain-text path that [RichTextViewer] delegates to: it
+ * parses with the existing [CachedRichTextParser], keeps the markdown path native,
+ * and for plain rich text provides the Android segment renderer
+ * ([AmethystRichTextSegmentRenderer]) plus the universal interactions into the two
+ * CompositionLocals the core reads.
+ *
+ * The core renders text, custom emoji, and hashtags (with their shared inline
+ * icons) itself; every divergent segment routes back to Amethyst's existing
+ * leaves through the renderer. Note: url/email/phone open via the platform URI
+ * handler rather than Amethyst's per-type Clickable* composables, so their tap
+ * behavior is the generic open action (rendering is unchanged clickable text).
+ */
+@Composable
+fun CommonsBackedRichTextViewer(
+    content: String,
+    canPreview: Boolean,
+    quotesLeft: Int,
+    modifier: Modifier,
+    tags: ImmutableListOfLists<String>,
+    backgroundColor: MutableState<Color>,
+    callbackUri: String? = null,
+    authorPubKey: String? = null,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    Column(modifier = modifier) {
+        if (remember(content) { CachedRichTextParser.isMarkdown(content) }) {
+            RenderContentAsMarkdown(content, tags, canPreview, quotesLeft, backgroundColor, callbackUri, accountViewModel, nav)
+            return@Column
+        }
+
+        val state by remember(content, tags) {
+            mutableStateOf(CachedRichTextParser.parseText(content, tags, callbackUri, authorPubKey))
+        }
+
+        val renderer =
+            remember(accountViewModel, nav, backgroundColor, callbackUri, canPreview) {
+                AmethystRichTextSegmentRenderer(accountViewModel, nav, backgroundColor, callbackUri, canPreview)
+            }
+
+        val interactions =
+            remember(nav) {
+                RichTextInteractions(
+                    onClickHashtag = { nav.nav(Route.Hashtag(it.lowercase())) },
+                )
+            }
+
+        CompositionLocalProvider(
+            LocalRichTextSegmentRenderer provides renderer,
+            LocalRichTextInteractions provides interactions,
+        ) {
+            CommonsRichTextViewer(
+                state = state,
+                canPreview = canPreview,
+                quotesLeft = quotesLeft,
+            )
+        }
+    }
+}

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

@@ -23,12 +23,18 @@ package com.vitorpamplona.amethyst.ui.components
 import androidx.compose.material3.LocalTextStyle
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.platform.LocalContext
-import androidx.compose.ui.platform.LocalUriHandler
 import androidx.compose.ui.text.TextStyle
 import androidx.compose.ui.text.style.TextOverflow
 import com.vitorpamplona.amethyst.commons.ui.components.ClickableTextPrimary
 import com.vitorpamplona.amethyst.service.uploads.blossom.bud10.openBlossomUriAsIntent
+import com.vitorpamplona.amethyst.commons.ui.components.ClickableUrl as SharedClickableUrl
 
+/**
+ * A clickable URL. Plain http(s) links delegate to the shared cross-platform
+ * [SharedClickableUrl] (opens via `LocalUriHandler`); only the Android-specific
+ * `blossom:` case — opening a Blossom media URI in an external app via an Intent —
+ * stays here. Touch front end, so no underline.
+ */
 @Composable
 fun ClickableUrl(
     urlText: String,
@@ -36,23 +42,16 @@ fun ClickableUrl(
     style: TextStyle = LocalTextStyle.current,
     onError: (Int, Int) -> Unit = { _, _ -> },
 ) {
-    val uri = LocalUriHandler.current
-    val context = LocalContext.current
-
-    ClickableTextPrimary(
-        text = urlText,
-        style = style,
-        maxLines = 1,
-        overflow = TextOverflow.MiddleEllipsis,
-        onClick = {
-            if (url.startsWith("blossom:")) {
-                openBlossomUriAsIntent(context, url, onError)
-            } else {
-                runCatching {
-                    val doubleCheckedUrl = if (url.contains("://")) url else "https://$url"
-                    uri.openUri(doubleCheckedUrl)
-                }
-            }
-        },
-    )
+    if (url.startsWith("blossom:")) {
+        val context = LocalContext.current
+        ClickableTextPrimary(
+            text = urlText,
+            style = style,
+            maxLines = 1,
+            overflow = TextOverflow.MiddleEllipsis,
+            onClick = { openBlossomUriAsIntent(context, url, onError) },
+        )
+    } else {
+        SharedClickableUrl(url = url, displayText = urlText, style = style)
+    }
 }

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

@@ -69,6 +69,7 @@ import com.vitorpamplona.amethyst.commons.model.ImmutableListOfLists
 import com.vitorpamplona.amethyst.commons.richtext.Base64Segment
 import com.vitorpamplona.amethyst.commons.richtext.BechSegment
 import com.vitorpamplona.amethyst.commons.richtext.BlossomUriSegment
+import com.vitorpamplona.amethyst.commons.richtext.CachedRichTextParser
 import com.vitorpamplona.amethyst.commons.richtext.CashuSegment
 import com.vitorpamplona.amethyst.commons.richtext.ClinkOfferSegment
 import com.vitorpamplona.amethyst.commons.richtext.ConcordInviteLinkSegment
@@ -77,7 +78,6 @@ import com.vitorpamplona.amethyst.commons.richtext.EmojiSegment
 import com.vitorpamplona.amethyst.commons.richtext.HashIndexEventSegment
 import com.vitorpamplona.amethyst.commons.richtext.HashIndexUserSegment
 import com.vitorpamplona.amethyst.commons.richtext.HashTagSegment
-import com.vitorpamplona.amethyst.commons.richtext.ImageGalleryParagraph
 import com.vitorpamplona.amethyst.commons.richtext.ImageSegment
 import com.vitorpamplona.amethyst.commons.richtext.InvoiceSegment
 import com.vitorpamplona.amethyst.commons.richtext.LinkSegment
@@ -103,13 +103,11 @@ import com.vitorpamplona.amethyst.model.LocalCache
 import com.vitorpamplona.amethyst.model.Note
 import com.vitorpamplona.amethyst.model.User
 import com.vitorpamplona.amethyst.model.checkForHashtagWithIcon
-import com.vitorpamplona.amethyst.service.CachedRichTextParser
 import com.vitorpamplona.amethyst.service.relayClient.reqCommand.user.UserFinderFilterAssemblerSubscription
 import com.vitorpamplona.amethyst.service.relayClient.reqCommand.user.observeUserInfo
 import com.vitorpamplona.amethyst.service.relayClient.reqCommand.user.observeUserNickname
 import com.vitorpamplona.amethyst.service.uploads.blossom.bud10.openBlossomUriAsIntent
 import com.vitorpamplona.amethyst.ui.actions.CrossfadeIfEnabled
-import com.vitorpamplona.amethyst.ui.components.markdown.RenderContentAsMarkdown
 import com.vitorpamplona.amethyst.ui.navigation.navs.EmptyNav
 import com.vitorpamplona.amethyst.ui.navigation.navs.INav
 import com.vitorpamplona.amethyst.ui.navigation.routes.Route
@@ -129,6 +127,12 @@ import com.vitorpamplona.quartz.nipB7Blossom.BlossomUri
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
 
+/**
+ * Renders Nostr rich text. The plain (non-markdown) path now runs through the
+ * cross-platform [com.vitorpamplona.amethyst.commons.ui.richtext.RichTextViewer]
+ * core via [CommonsBackedRichTextViewer]; this entry is kept so its ~55 call sites
+ * are untouched. The Android-specific markdown path stays here.
+ */
 @Composable
 fun RichTextViewer(
     content: String,
@@ -141,15 +145,18 @@ fun RichTextViewer(
     authorPubKey: String? = null,
     accountViewModel: AccountViewModel,
     nav: INav,
-) {
-    Column(modifier = modifier) {
-        if (remember(content) { CachedRichTextParser.isMarkdown(content) }) {
-            RenderContentAsMarkdown(content, tags, canPreview, quotesLeft, backgroundColor, callbackUri, accountViewModel, nav)
-        } else {
-            RenderRegular(content, tags, canPreview, quotesLeft, backgroundColor, callbackUri, authorPubKey, accountViewModel, nav)
-        }
-    }
-}
+) = CommonsBackedRichTextViewer(
+    content = content,
+    canPreview = canPreview,
+    quotesLeft = quotesLeft,
+    modifier = modifier,
+    tags = tags,
+    backgroundColor = backgroundColor,
+    callbackUri = callbackUri,
+    authorPubKey = authorPubKey,
+    accountViewModel = accountViewModel,
+    nav = nav,
+)
 
 @Preview
 @Composable
@@ -338,57 +345,6 @@ fun RenderRegularPreview3() {
     }
 }
 
-@Composable
-private fun RenderRegular(
-    content: String,
-    tags: ImmutableListOfLists<String>,
-    canPreview: Boolean,
-    quotesLeft: Int,
-    backgroundColor: MutableState<Color>,
-    callbackUri: String? = null,
-    authorPubKey: String? = null,
-    accountViewModel: AccountViewModel,
-    nav: INav,
-) {
-    if (canPreview) {
-        RenderRegular(content, tags, callbackUri, authorPubKey) { paragraph, state, spaceWidth, modifier ->
-            if (paragraph is ImageGalleryParagraph) {
-                ImageGallery(
-                    images = paragraph,
-                    state = state,
-                    accountViewModel = accountViewModel,
-                    modifier = modifier,
-                    roundedCorner = true,
-                )
-            } else {
-                RenderTextParagraph(paragraph, spaceWidth, modifier) { word ->
-                    RenderWordWithPreview(
-                        word,
-                        state,
-                        backgroundColor,
-                        quotesLeft,
-                        callbackUri,
-                        accountViewModel,
-                        nav,
-                    )
-                }
-            }
-        }
-    } else {
-        RenderRegular(content, tags, callbackUri, authorPubKey) { paragraph, state, spaceWidth, modifier ->
-            RenderTextParagraph(paragraph, spaceWidth, modifier) { word ->
-                RenderWordWithoutPreview(
-                    word,
-                    state,
-                    backgroundColor,
-                    accountViewModel,
-                    nav,
-                )
-            }
-        }
-    }
-}
-
 @Composable
 fun RenderTextParagraph(
     paragraph: ParagraphState,

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/feeds/PrefetchFeedMedia.kt

@@ -35,6 +35,7 @@ import coil3.imageLoader
 import coil3.request.ImageRequest
 import coil3.request.SuccessResult
 import com.vitorpamplona.amethyst.commons.model.toImmutableListOfLists
+import com.vitorpamplona.amethyst.commons.richtext.CachedRichTextParser
 import com.vitorpamplona.amethyst.commons.richtext.MediaUrlImage
 import com.vitorpamplona.amethyst.commons.richtext.MediaUrlVideo
 import com.vitorpamplona.amethyst.commons.richtext.RichTextParser
@@ -44,7 +45,6 @@ import com.vitorpamplona.amethyst.commons.ui.feeds.FeedState
 import com.vitorpamplona.amethyst.model.MediaAspectRatioCache
 import com.vitorpamplona.amethyst.model.Note
 import com.vitorpamplona.amethyst.model.UrlCachedPreviewer
-import com.vitorpamplona.amethyst.service.CachedRichTextParser
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip10Notes.TextNoteEvent

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

@@ -69,11 +69,11 @@ import com.vitorpamplona.amethyst.commons.emojicoder.EmojiCoder
 import com.vitorpamplona.amethyst.commons.hashtags.Cashu
 import com.vitorpamplona.amethyst.commons.hashtags.CustomHashTagIcons
 import com.vitorpamplona.amethyst.commons.model.EmptyTagList
+import com.vitorpamplona.amethyst.commons.richtext.CachedRichTextParser
 import com.vitorpamplona.amethyst.commons.ui.components.AnimatedBorderTextCornerRadius
 import com.vitorpamplona.amethyst.model.Note
 import com.vitorpamplona.amethyst.model.NoteState
 import com.vitorpamplona.amethyst.model.User
-import com.vitorpamplona.amethyst.service.CachedRichTextParser
 import com.vitorpamplona.amethyst.service.relayClient.reqCommand.user.UserFinderFilterAssemblerSubscription
 import com.vitorpamplona.amethyst.service.relayClient.reqCommand.user.observeUserContactCardsScore
 import com.vitorpamplona.amethyst.service.relayClient.reqCommand.user.observeUserPicture

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/creators/previews/PreviewState.kt

@@ -21,7 +21,7 @@
 package com.vitorpamplona.amethyst.ui.note.creators.previews
 
 import androidx.compose.runtime.Stable
-import com.vitorpamplona.amethyst.service.CachedUrlParser
+import com.vitorpamplona.amethyst.commons.richtext.CachedUrlParser
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.FlowPreview
 import kotlinx.coroutines.flow.MutableStateFlow

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/elements/DisplayUncitedHashtags.kt

@@ -27,9 +27,9 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.produceState
 import com.vitorpamplona.amethyst.commons.model.toImmutableListOfLists
+import com.vitorpamplona.amethyst.commons.richtext.CachedRichTextParser
 import com.vitorpamplona.amethyst.commons.richtext.HashTagSegment
 import com.vitorpamplona.amethyst.commons.ui.components.ClickableTextColor
-import com.vitorpamplona.amethyst.service.CachedRichTextParser
 import com.vitorpamplona.amethyst.ui.navigation.navs.INav
 import com.vitorpamplona.amethyst.ui.navigation.routes.Route
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel

amethyst/src/test/java/com/vitorpamplona/amethyst/CachedRichTextParserMarkdownTest.kt

@@ -20,7 +20,7 @@
  */
 package com.vitorpamplona.amethyst
 
-import com.vitorpamplona.amethyst.service.CachedRichTextParser
+import com.vitorpamplona.amethyst.commons.richtext.CachedRichTextParser
 import org.junit.Assert.assertFalse
 import org.junit.Assert.assertTrue
 import org.junit.Test

commons/plans/2026-07-16-note-ui-commons-extraction.md

@@ -0,0 +1,390 @@
+---
+title: "refactor(commons): extract note-type rendering to commons"
+type: refactor
+status: proposed
+date: 2026-07-16
+owner: commons
+consumers: amethyst, desktopApp, cli
+---
+
+# refactor(commons): extract `ui.note` rendering into commons
+
+> **Status:** review / proposal. No code moved yet. This is the study
+> requested on branch `claude/amethyst-note-ui-refactor` — a per-event
+> generalization plan for pulling the *rendering* half of
+> `com.vitorpamplona.amethyst.ui.note` down into `commons`, leaving only the
+> nav/AccountViewModel-bound *entry* composables in the Android app.
+> _Authored 2026-07-16._
+
+## 0. Goal (as requested)
+
+Leave the **entry composable** — the one that takes `AccountViewModel` + `INav`
+and decodes the `Note`/`Event` — in the mobile app. Move the **actual
+rendering** (the Compose layout, specific functions, and their local UI state)
+into `commons`, where it takes plain values, immutable state objects, and
+**lambda callbacks** instead of `AccountViewModel`/`INav`. The Android package
+then shrinks to a thin adapter that wires the lambdas.
+
+This is deliberately narrower than the two standing plans and complementary to
+both:
+
+- `commons/plans/2026-04-21-event-renderer.md` — a UI-agnostic
+  `RenderedEvent` data model. Ambitious, still "proposed", nothing built.
+- `commons/plans/2026-05-30-amethyst-to-commons-migration.md` — the full app
+  migration; its §4 puts `ui/note` (184 files, ~50–70% shareable) behind the
+  **Account keystone (Phase A)**, which is untouched.
+
+The key insight of *this* plan: **we do not need the Account keystone to start.**
+The `Render → Display` split lets each event's layout move now, because the
+`Display` half never touches `AccountViewModel` — the `Render` half (staying in
+`amethyst`) does the account/relay work and hands down primitives + callbacks.
+
+## 1. What the package looks like today
+
+`amethyst/ui/note`: **214 files, ~48.7k LOC**.
+- `types/` — **89 files, ~21.9k LOC**: one `RenderXxx` composable per Nostr
+  event kind (the dispatch targets).
+- top level — 39 files, ~14.7k LOC: `NoteCompose.kt` (2180 LOC, the central
+  dispatcher), avatars, reaction/zap rows, dialogs, formatters.
+- `creators/` (post editor), `elements/`, `buttons/`, `nip22Comments/`,
+  `share/` — mostly interactive, largely stays native (see §7).
+
+### The dispatcher stays native
+
+`NoteCompose.kt` → `RenderNoteRow()` is a giant `when (baseNote.event)` that
+routes each kind to its `RenderXxx(...)`. This is the natural home of the
+**entry** layer and should *not* move — it is inherently coupled to
+`AccountViewModel`, `INav`, feed state, the quick-action menu, drag/swipe, and
+report/block gating.
+
+### A two-tier pattern is already emerging
+
+Several types already split `RenderXxx(note, …)` (decodes the event) from a
+`DisplayXxx(…decomposed params…)` (renders). `Highlight.kt` is the clearest:
+`RenderHighlight(note, …)` → `DisplayHighlight(comment, highlight, context,
+authorHex, url, postAddress, …)`. **But `DisplayHighlight` still takes
+`accountViewModel` + `nav`.** The work of this plan is to push that boundary the
+last mile so the `Display*` layer takes callbacks/state instead — then relocate
+it to `commons`.
+
+### The target already has a reference implementation
+
+`commons/ui/note/StaticWebsiteCard.kt` is exactly the end-state shape: pure
+value params, lambda slots (`onOpen: (() -> Unit)?`, `headerActions:
+@Composable (() -> Unit)?`), commons `Res.string`, commons icons, Coil
+`AsyncImage` — **zero `AccountViewModel`/`INav`**. Also already extracted into
+`commons/ui/note/`: `CollapsedSpamNote`, `HeaderPill`, `QuietMark`,
+`ReplyContext`, `ReplyToLabel`. Do not re-propose these — copy their convention.
+
+## 2. The canonical signature (the generalization anchor)
+
+Across `types/`, the entry composable is remarkably uniform. Parameter frequency
+(public `@Composable` entry fns):
+
+```
+accountViewModel 198   note/baseNote 152   backgroundColor 71
+nav 157             quotesLeft 41       makeItShort 38   canPreview 35
+```
+
+So the near-universal entry shape is:
+
+```kotlin
+@Composable
+fun RenderXxx(
+    note: Note,
+    quotesLeft: Int,               // recursion budget for embedded quotes
+    backgroundColor: MutableState<Color>,
+    makeItShort: Boolean,          // compact feed vs full thread view
+    canPreview: Boolean,           // expand link/media previews inline
+    accountViewModel: AccountViewModel,
+    nav: INav,
+)
+```
+
+`backgroundColor`, `quotesLeft`, `makeItShort`, `canPreview` are **pure display
+inputs** and travel straight into `commons` unchanged. Only `accountViewModel`
+and `nav` need a seam.
+
+## 3. The dependency surface to cross
+
+### 3a. `AccountViewModel` — smaller behavioral surface than it looks
+
+`accountViewModel` appears 198× in `types/`, but most are **pass-through** to
+leaf composables, not direct calls. The actual method surface across the whole
+`note` package, grouped:
+
+- **Lookups** (resolve a hex/address to a `Note`/`User`): `getNoteIfExists`,
+  `getOrCreateAddressableNote`, `getUserIfExists`, `checkGetOrCreateUser`,
+  `loadParticipants`, `loadUsers`, `userProfile`. → **read through the commons
+  cache port, not a lambda** (see §3d). Async participant/user loads that need
+  relay round-trips still resolve on the entry side.
+- **Config/settings**: `settings`, `zapAmountChoices`, `showSensitiveContent`,
+  `httpClientBuilder`, `nip`. → passed as plain values / a small settings holder.
+- **Actions (write + signer)**: `zap`, `follow`/`unfollow`, `delete`, `hide`,
+  `reactToOrDelete`, `decrypt`, `launchSigner`, `addPublicBookmark`,
+  `muteThread`. → become **callback lambdas** (`onZap: () -> Unit`, …).
+- **Predicates**: `isLoggedUser`, `isWriteable`, `isThreadMutedFor`. → plain
+  `Boolean` params.
+- **Infra**: `toastManager`, `runOnIO`, `tempManualPaymentCache`. → stay native;
+  surfaced as callbacks (`onError: (msg) -> Unit`) where they cross the seam.
+
+### 3b. `INav` — trivial
+
+Already an interface; the migration plan §1 prescribes the answer: shared
+composables take `onClick*` / `onNavigate` lambdas, not `INav`. Each nav target
+in a `Display*` body becomes one lambda (`onClickUser: (User) -> Unit`,
+`onClickNote`, `onClickHashtag`, …).
+
+### 3c. `R.string` (52/89 type files) — solved pattern
+
+Migrate the needed strings to `commons/.../composeResources/values/strings.xml`
+and swap `stringResource(R.string.x)` → `stringResource(Res.string.x)`. No new
+abstraction (see `StaticWebsiteCard`, which already does this). This is the
+single biggest *mechanical* cost, but it is rote.
+
+### 3d. Reads cross the seam via the **cache port**, not lambdas
+
+The cache is already commons-shaped — we should read through it rather than
+re-passing every lookup as a lambda:
+
+- `LocalCache` is declared `object LocalCache : ILocalCache, ICacheProvider`
+  (`amethyst/model/LocalCache.kt:351`). The read ports `ICacheProvider` +
+  `ICacheEventStream` already live in `commons/model/cache/`.
+- `Account` **already holds the cache as an injected instance**:
+  `Account.kt:379` `val cache: LocalCache`. So `account.cache` is a real path
+  today — and once `LocalCache` becomes a class (migration §8 end-state) it
+  becomes the correct *per-account* instance instead of a global singleton.
+- **`IAccount` does not expose it yet** — it only carries
+  `privateZapsDecryptionCache`. **Proposed:** add `val cache: ICacheProvider`
+  to `IAccount` (commons), implemented by `Account` (it already has the field).
+
+Two consequences for the split:
+
+1. **`AccountViewModel`'s lookups currently bypass `account.cache`** and call the
+   `object LocalCache` singleton directly (`getNoteIfExists =
+   LocalCache.getNoteIfExists(hex)`, and ~30 more). Re-point these at
+   `account.cache.…` as part of the extraction — it's the same call, but through
+   the instance/port, which is what makes them commons-reachable and
+   multi-account-correct.
+2. **Commons render code that needs a read takes the port, not a lambda.** A
+   `Display*` body that must resolve an embedded note/user depends on
+   `ICacheProvider` (or `IAccount`, for hide/mute predicates like
+   `isAcceptable`/`isHidden`) — both already commons-side. **Lambdas are then
+   reserved for nav and write/signer actions**, which genuinely can't move.
+
+Prefer this over the "loader lambda" framing in §3a wherever the lookup is a
+synchronous cache read.
+
+### 3e. The **leaf-composable toolkit** — the real blocker
+
+The render bodies don't just lay out boxes; they recursively call a handful of
+heavy shared composables that *themselves* take `accountViewModel`/`nav`. Top
+leaf deps in `types/`:
+
+```
+TranslatableRichTextViewer 55   observeNoteEvent 23   LoadNote 18
+UserPicture 16                  observeNote 15         LoadUser 13
+NoteCompose 12                  LoadDecryptedContent 6 ClickableUrl 6
+```
+
+Two sub-problems:
+
+1. **`TranslatableRichTextViewer` is flavor-specific** (#1 dependency, 55 uses)
+   and cannot be naively moved. But the fix is not a per-call slot — it is a
+   one-time restructure of the rich-text stack (**§3f, Phase 0**). After that
+   restructure, nested/inline rich text in `Display*` bodies calls the **commons
+   renderer directly**; only the single top-level translatable post body still
+   routes through the native translation wrapper, supplied by the entry.
+2. **`LoadNote`/`LoadUser`/`observe*` are relay-subscription + LocalCache
+   bound.** These live in `amethyst/service/relayClient/reqCommand/`. Per the
+   migration plan they stay native orchestration. **Resolution:** resolve on the
+   entry side and pass the loaded `Note`/`User` (or a small immutable snapshot)
+   down; or pass embedded-content as a slot the same way as rich text.
+
+### 3f. Phase 0 — restructure the rich-text stack (gating prerequisite)
+
+Rich text is the #1 dependency and blocks all of Tier 2. It is **not** a wall,
+because the stack is already layered — it just needs the core decoupled:
+
+```
+TranslatableRichTextViewer   flavor-specific (play=ML-Kit, fdroid=no-op)  ← translation
+  └─ ExpandableRichTextViewer   "show more/less" expansion                 ← middle
+       └─ RichTextViewer.kt (1031 LOC)   paragraphs, URLs, blossom,        ← RENDER CORE
+          custom emoji, bech links, hashtags, note/user embeds
+```
+
+Two facts make the core movable:
+
+- **The translation *state* is already in commons** —
+  `commons/ui/components/TranslationConfig`. Only the *service*
+  (`service/lang/LanguageTranslatorService`, `TranslationsCache`, ML-Kit) is
+  Android. So translation was never really entangled with rendering; it wraps it.
+- **The 1031-LOC core's real `accountViewModel` surface is only 5 members**
+  (despite 87 pass-through refs): `account` (for language settings only),
+  `bechLinkCache`, `checkGetOrCreateNote`, `getNoteIfExists`, `toastManager`.
+  Three are cache reads → the **`ICacheProvider` port (§3d)**; `toastManager` →
+  an `onError`/`onToast` callback; `nav` → `onClick*` callbacks.
+
+**Restructure:**
+
+1. Move `RichTextViewer` + `ExpandableRichTextViewer` to
+   `commons/ui/text/` (or `ui/components/`), taking `ICacheProvider` + nav/error
+   callbacks instead of `AccountViewModel`/`INav`. Language settings arrive as
+   plain values.
+2. Leave `TranslatableRichTextViewer` native and thin: it computes the
+   `TranslationConfig` via the native service, renders the status bar (drivable
+   from the commons `TranslationConfig`), and calls the **commons** renderer with
+   the final string. The `src/play`↔`src/fdroid` flavor split stays exactly where
+   it is.
+3. **The one edge that stays a slot:** `RichTextViewer` embeds *full notes*
+   inline (`DisplayFullNote`/`BechLink` → `NoteCompose`). That recurses into the
+   native dispatcher (§1), so full-note embeds take a
+   `renderEmbeddedNote: @Composable (Note) -> Unit` slot. Inline text, URLs,
+   emoji, hashtags, user mentions — everything else — moves cleanly.
+
+**Payoff:** once the core is in commons, Tier 2's rich text is a direct call, not
+a slot on every renderer. This is why Phase 0 gates the rest and should land
+before scaling Tier 2. It also directly advances migration-plan §4's
+"formatters → `ui/text`" line.
+
+**This is the crux of the generalization:** the seam is not "primitives only"
+(too limiting for content that embeds other notes/users), it is
+**primitives + immutable state objects + `@Composable` slots for recursive
+content + lambda callbacks for actions.** `StaticWebsiteCard`'s `headerActions`
+slot is the pattern in miniature.
+
+## 4. The proposed split contract
+
+For each event kind, produce two composables:
+
+**Entry (stays in `amethyst/ui/note/types/`), thin adapter:**
+```kotlin
+@Composable
+fun RenderXxx(note, quotesLeft, backgroundColor, makeItShort, canPreview,
+              accountViewModel, nav) {
+    val event = note.event as? XxxEvent ?: return
+    // decode event → values; resolve users/notes via accountViewModel;
+    // build callbacks that close over accountViewModel + nav
+    XxxCard(                                   // commons
+        title = event.title(), …,
+        makeItShort = makeItShort,
+        richText = { txt -> TranslatableRichTextViewer(txt, …, accountViewModel, nav) },
+        onClickAuthor = { nav.nav(routeFor(author)) },
+        onZap = { accountViewModel.zap(note, …) },
+    )
+}
+```
+
+**Display (moves to `commons`), pure:**
+```kotlin
+@Composable
+fun XxxCard(
+    title: String?, …,                         // decoded values
+    makeItShort: Boolean,
+    richText: @Composable (String) -> Unit,    // slot for flavor-coupled leaf
+    onClickAuthor: () -> Unit,                  // nav callback
+    onZap: (() -> Unit)? = null,                // action callback (null = hidden)
+) { /* Compose layout only */ }
+```
+
+**Seam types to introduce in `commons/ui/note/`:**
+- A small `@Immutable` snapshot per family where many primitives travel together
+  (e.g. `AuthorLine(name, pubkeyHex, avatarUrl, nip05)`), so signatures stay
+  sane. Prefer these over 15-arg functions.
+- Reuse existing commons atoms: `UserAvatar`, `Nip05OrPubkeyLine`,
+  `ClickableTexts`, `RobohashImage`, `GenericLoadable`, the icon set, `Res`
+  strings. Several avatar/user-line needs are **already** in
+  `commons/ui/components`.
+
+**Where files land** (per `commons/ARCHITECTURE.md` + migration §4): a
+cross-cutting card → `commons/ui/note/`; a NIP-specific renderer → the owning
+`commons/.../<nipNN>/ui/` package. Follow whatever the existing
+`commons/ui/note/*` files already do.
+
+## 5. Tiered categorization of the 89 `types/`
+
+Classified by the seam each needs (method: `accountViewModel` refs, leaf-dep
+grep, `launchSigner`/dialog grep).
+
+### Tier 0 — no `AccountViewModel` at all (13 files, ~2.2k LOC) — **do first**
+`ActivityCard, Birdex, CodeSnippet, EcashMint, GitDiffView, GitStatusPill,
+ImetaContent, MusicFormatting, PodcastChips, PodcastSoundbites,
+PodcastValueSplits, Ps1Save, RoadEvent`.
+These are already value-in/Compose-out. Mostly just an `R.string` sweep + a
+package move. **Ideal pilots** — several are also self-contained cards (no rich
+text, no loaders).
+
+### Tier 1 — decode-only, no loaders, no rich text
+Read-only renderers that only need `nav` callbacks + `R.string` (e.g. relay/list
+cards, badge display, goal/fundraiser headers, calendar/road cards). Split is
+mechanical: decode in entry, pass primitives + `onClick*` down. Bulk of the
+value.
+
+### Tier 2 — need recursive content slots (rich text and/or embedded note/user)
+23 use `TranslatableRichTextViewer`; 23 use `LoadNote/LoadUser/observe*`:
+`Text, TextModification, Highlight, PublicMessage, PrivateMessage, Report,
+Chat, CommunityHeader, FollowList, Git, InteractiveStory, MusicTrack,
+MusicPlaylist, PodcastEpisode, PodcastMetadata, Video, PictureDisplay,
+Attestation, NIP90ContentDiscoveryResponse, ZapPoll, AudioTrack, …`.
+Movable, but **only via the `@Composable` slot pattern** (§3e/§4). The layout
+moves to commons; rich-text/embeds stay app-supplied. `Highlight` is the
+recommended Tier-2 pilot (already half-split).
+
+### Tier 3 — interactive: signer / dialogs / write actions — **stay native or last**
+5 use `launchSigner`: `AppDefinition, Badge, CalendarRsvpRow, GitStatusActions,
+Poll`. Plus zap/reaction dialogs, `Poll`/`ZapPoll` voting, `Chess`. The
+**visual card** can still move (as a Tier-2 body with `onVote`/`onSign`
+callbacks), but the interaction/signer flow stays in `amethyst`. Don't force
+these early.
+
+## 6. Recommended sequencing
+
+1. **Pilot (1 PR, Tier 0):** move 2–3 pure cards (e.g. `RoadEvent`, `EcashMint`,
+   `CodeSnippet`) to `commons/ui/note/`, migrate their strings, leave a thin
+   `RenderXxx` entry. Proves the string + package + preview-test loop end to end
+   and sets the reviewable template. Verify with `./gradlew :commons:build` and
+   a Compose `@Preview`.
+2. **Bulk Tier 0/1** — mechanical, parallelizable, one small PR per event family.
+   These need neither rich text nor the cache port, so they don't wait on Phase 0.
+3. **Phase 0 — rich-text restructure (§3f), the gate for Tier 2.** Move
+   `RichTextViewer`/`ExpandableRichTextViewer` to commons behind `ICacheProvider`
+   + callbacks, with a `renderEmbeddedNote` slot for full-note embeds; leave
+   `TranslatableRichTextViewer` native and thin. Depends on adding
+   `IAccount.cache: ICacheProvider` (§3d). This is the load-bearing PR — review
+   it carefully before scaling.
+4. **Tier 2 pilot:** `Highlight` → move `DisplayHighlight` to commons calling the
+   new commons renderer directly + `onClickAuthor`/`onClickNote` callbacks.
+   Confirms the post-Phase-0 shape.
+5. **Tier 2 family by family** (podcast ×13, git ×5, calendar ×4, music ×3,
+   chat ×3) once the pilot is settled.
+6. **Tier 3** last, and only the visual shell; leave signer flows native.
+
+Each step is small, compile-verifiable, and deletes an app-side render body —
+exactly the "manually, event by event" cadence you called for.
+
+## 7. Out of scope (stays native)
+
+- `NoteCompose.kt` dispatcher, feed/thread scaffolding, drag/swipe,
+  quick-action menu, report/block gating.
+- `creators/` (post editor), `buttons/`, most of `share/` — interactive,
+  signer- and Context-bound.
+- The flavor-specific `TranslatableRichTextViewer` **translation wrapper** and
+  the ML-Kit `service/lang/*` — stay native (the *renderer core* underneath them
+  moves; see §3f).
+- The `service/relayClient/reqCommand` observers/loaders — resolved on the entry
+  side or consumed via slots, not moved.
+
+## 8. Risks
+
+- **Slot proliferation.** If every embed becomes a slot, entries get noisy.
+  Mitigate with per-family `@Immutable` snapshot types and by reusing existing
+  commons atoms rather than re-passing avatars/user-lines as slots.
+- **String drift.** Moving strings piecemeal risks duplicate keys between
+  `amethyst` `R.string` and commons `Res.string`. Migrate + delete the app copy
+  in the same PR; don't leave both.
+- **Preview coverage.** The `types/` files carry `@Preview`s (see
+  `Highlight.kt`). Move the previews with the body so commons keeps visual
+  regression cover; they also become desktop/cli-testable fixtures.
+- **Desktop double-benefit vs. drift.** Desktop currently re-parses some of
+  this; extracting to commons is the chance to converge — but only if Desktop is
+  pointed at the new card in the same or an immediately following PR.

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/ui/components/ClickableLinks.kt

@@ -0,0 +1,93 @@
+/*
+ * 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.ui.components
+
+import androidx.compose.foundation.clickable
+import androidx.compose.material3.LocalTextStyle
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.input.pointer.PointerIcon
+import androidx.compose.ui.input.pointer.pointerHoverIcon
+import androidx.compose.ui.platform.LocalUriHandler
+import androidx.compose.ui.text.TextStyle
+import androidx.compose.ui.text.style.TextDecoration
+import androidx.compose.ui.text.style.TextOverflow
+
+/**
+ * A primary-colored, single-line clickable URL that opens via the platform
+ * [LocalUriHandler] — the browser on Android, `Desktop.browse` on JVM — so the
+ * "open a link" behavior is identical on every front end without a seam.
+ *
+ * [underline] + the hover cursor are mouse-first affordances: Desktop passes
+ * `true`; touch front ends leave it `false`. A scheme-less [url] is opened as
+ * `https://`.
+ */
+@Composable
+fun ClickableUrl(
+    url: String,
+    displayText: String = url,
+    modifier: Modifier = Modifier,
+    underline: Boolean = false,
+    style: TextStyle = LocalTextStyle.current,
+) {
+    val uriHandler = LocalUriHandler.current
+    Text(
+        text = displayText,
+        style = style,
+        color = MaterialTheme.colorScheme.primary,
+        textDecoration = if (underline) TextDecoration.Underline else null,
+        maxLines = 1,
+        overflow = TextOverflow.MiddleEllipsis,
+        modifier =
+            modifier.pointerHoverIcon(PointerIcon.Hand).clickable {
+                runCatching {
+                    uriHandler.openUri(if (url.contains("://")) url else "https://$url")
+                }
+            },
+    )
+}
+
+/**
+ * A primary-colored clickable email that opens the platform mail client via
+ * [LocalUriHandler] (`mailto:`). Strips a leading `mailto:` from the display text.
+ * [underline] + hover cursor are the Desktop mouse-first affordances.
+ */
+@Composable
+fun ClickableEmail(
+    address: String,
+    modifier: Modifier = Modifier,
+    underline: Boolean = false,
+) {
+    val uriHandler = LocalUriHandler.current
+    val display = remember(address) { address.removePrefix("mailto:") }
+    Text(
+        text = display,
+        color = MaterialTheme.colorScheme.primary,
+        textDecoration = if (underline) TextDecoration.Underline else null,
+        modifier =
+            modifier.pointerHoverIcon(PointerIcon.Hand).clickable {
+                runCatching { uriHandler.openUri("mailto:$display") }
+            },
+    )
+}

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/ui/richtext/CustomEmojiRenderer.kt

@@ -0,0 +1,129 @@
+/*
+ * 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.ui.richtext
+
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.text.InlineTextContent
+import androidx.compose.foundation.text.appendInlineContent
+import androidx.compose.material3.LocalTextStyle
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.Placeholder
+import androidx.compose.ui.text.PlaceholderVerticalAlign
+import androidx.compose.ui.text.SpanStyle
+import androidx.compose.ui.text.buildAnnotatedString
+import androidx.compose.ui.text.withStyle
+import androidx.compose.ui.unit.TextUnit
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import coil3.compose.AsyncImage
+import com.vitorpamplona.quartz.nip30CustomEmoji.CustomEmoji
+import kotlinx.collections.immutable.ImmutableList
+import kotlinx.collections.immutable.ImmutableMap
+
+/**
+ * Inline custom emoji: renders [text], replacing each `:shortcode:` present in
+ * [emojis] with its image. Universal to every front end, so it lives in the
+ * shared core rather than the platform seam. Falls back to plain [Text] when the
+ * text carries no known emoji.
+ *
+ * Cross-platform equivalent of Amethyst's `CreateTextWithEmoji`, built on quartz's
+ * [CustomEmoji.assembleAnnotatedList] + [InLineIconRenderer].
+ */
+@Composable
+fun RenderCustomEmoji(
+    text: String,
+    emojis: ImmutableMap<String, String>,
+    modifier: Modifier = Modifier,
+) {
+    val renderable = remember(text, emojis) { CustomEmoji.assembleAnnotatedList(text, emojis) }
+
+    if (renderable.isNullOrEmpty()) {
+        Text(text, modifier)
+    } else {
+        InLineIconRenderer(renderable, LocalTextStyle.current.toSpanStyle(), modifier = modifier)
+    }
+}
+
+/**
+ * Renders an already-assembled list of [CustomEmoji.Renderable]s: text spans as
+ * text, image spans as inline [AsyncImage]s sized to ~1.1× the current font.
+ */
+@Composable
+fun InLineIconRenderer(
+    wordsInOrder: ImmutableList<CustomEmoji.Renderable>,
+    style: SpanStyle,
+    fontSize: TextUnit = TextUnit.Unspecified,
+    modifier: Modifier = Modifier,
+) {
+    val placeholderSize =
+        remember(fontSize) {
+            if (fontSize == TextUnit.Unspecified) 22.sp else fontSize.times(1.1f)
+        }
+
+    val inlineContent =
+        wordsInOrder
+            .mapIndexedNotNull { idx, value ->
+                if (value is CustomEmoji.ImageUrlType) {
+                    "inlineContent$idx" to
+                        InlineTextContent(
+                            Placeholder(
+                                width = placeholderSize,
+                                height = placeholderSize,
+                                placeholderVerticalAlign = PlaceholderVerticalAlign.Center,
+                            ),
+                        ) {
+                            AsyncImage(
+                                model = value.url,
+                                contentDescription = null,
+                                modifier = Modifier.fillMaxSize().padding(horizontal = 0.dp),
+                            )
+                        }
+                } else {
+                    null
+                }
+            }.associate { it.first to it.second }
+
+    val annotatedText =
+        remember(wordsInOrder, style) {
+            buildAnnotatedString {
+                wordsInOrder.forEachIndexed { idx, value ->
+                    withStyle(style) {
+                        when (value) {
+                            is CustomEmoji.TextType -> append(value.text)
+                            is CustomEmoji.ImageUrlType -> appendInlineContent("inlineContent$idx", "[icon]")
+                            else -> {}
+                        }
+                    }
+                }
+            }
+        }
+
+    Text(
+        text = annotatedText,
+        inlineContent = inlineContent,
+        fontSize = fontSize,
+        modifier = modifier,
+    )
+}

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/ui/richtext/HashtagIcons.kt

@@ -0,0 +1,96 @@
+/*
+ * 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.ui.richtext
+
+import androidx.compose.foundation.layout.padding
+import androidx.compose.runtime.Immutable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.vector.ImageVector
+import androidx.compose.ui.unit.dp
+import com.vitorpamplona.amethyst.commons.hashtags.Amethyst
+import com.vitorpamplona.amethyst.commons.hashtags.Btc
+import com.vitorpamplona.amethyst.commons.hashtags.Cashu
+import com.vitorpamplona.amethyst.commons.hashtags.Coffee
+import com.vitorpamplona.amethyst.commons.hashtags.CustomHashTagIcons
+import com.vitorpamplona.amethyst.commons.hashtags.Flowerstr
+import com.vitorpamplona.amethyst.commons.hashtags.Footstr
+import com.vitorpamplona.amethyst.commons.hashtags.Gamestr
+import com.vitorpamplona.amethyst.commons.hashtags.Grownostr
+import com.vitorpamplona.amethyst.commons.hashtags.Lightning
+import com.vitorpamplona.amethyst.commons.hashtags.Mate
+import com.vitorpamplona.amethyst.commons.hashtags.Nostr
+import com.vitorpamplona.amethyst.commons.hashtags.Plebs
+import com.vitorpamplona.amethyst.commons.hashtags.Skull
+import com.vitorpamplona.amethyst.commons.hashtags.Tunestr
+import com.vitorpamplona.amethyst.commons.hashtags.Weed
+import com.vitorpamplona.amethyst.commons.hashtags.Zap
+
+/**
+ * A custom vector icon rendered inline next to a well-known hashtag. The icon set
+ * itself already lives in `commons/hashtags`; this table is the mapping the shared
+ * [RichTextViewer] uses so every front end shows the same badge for `#bitcoin`,
+ * `#nostr`, `#zap`, etc.
+ */
+@Immutable
+class HashtagIcon(
+    val icon: ImageVector,
+    val description: String,
+    val modifier: Modifier = Modifier,
+)
+
+/** The known-hashtag → [HashtagIcon] mapping (case-insensitive, includes common aliases). */
+fun checkForHashtagWithIcon(tag: String): HashtagIcon? =
+    when (tag.lowercase()) {
+        "₿itcoin", "bitcoin", "btc", "timechain", "bitcoiner", "bitcoiners" -> bitcoin
+        "nostr", "nostrich", "nostriches", "thenostr" -> nostr
+        "lightning", "lightningnetwork" -> lightning
+        "zap", "zaps", "zapper", "zappers", "zapping", "zapped", "zapathon", "zapraiser", "zaplife", "zapchain" -> zap
+        "amethyst" -> amethyst
+        "cashu", "ecash", "nut", "nuts", "deeznuts" -> cashu
+        "plebs", "pleb", "plebchain" -> plebs
+        "coffee", "coffeechain", "cafe" -> coffee
+        "skullofsatoshi" -> skull
+        "grownostr", "gardening", "garden" -> growstr
+        "footstr" -> footstr
+        "flowerstr" -> flowerstr
+        "tunestr", "music", "nowplaying" -> tunestr
+        "mate", "matechain", "matestr" -> matestr
+        "weed", "weedstr", "420", "cannabis", "marijuana" -> weed
+        "gamestr", "gaming", "gamechain" -> gamestr
+        else -> null
+    }
+
+val bitcoin = HashtagIcon(CustomHashTagIcons.Btc, "Bitcoin", Modifier.padding(start = 1.dp, bottom = 1.dp, top = 1.dp))
+val nostr = HashtagIcon(CustomHashTagIcons.Nostr, "Nostr", Modifier.padding(start = 1.dp, bottom = 1.dp, top = 1.dp))
+val lightning = HashtagIcon(CustomHashTagIcons.Lightning, "Lightning", Modifier.padding(start = 1.dp, bottom = 1.dp, top = 1.dp))
+val zap = HashtagIcon(CustomHashTagIcons.Zap, "Zap", Modifier.padding(start = 1.dp, bottom = 1.dp, top = 1.dp))
+val amethyst = HashtagIcon(CustomHashTagIcons.Amethyst, "Amethyst", Modifier.padding(start = 2.dp, bottom = 1.dp, top = 1.dp))
+val cashu = HashtagIcon(CustomHashTagIcons.Cashu, "Cashu", Modifier.padding(start = 1.dp, bottom = 1.dp, top = 1.dp))
+val plebs = HashtagIcon(CustomHashTagIcons.Plebs, "Pleb", Modifier.padding(start = 2.dp, bottom = 1.dp, top = 1.dp))
+val coffee = HashtagIcon(CustomHashTagIcons.Coffee, "Coffee", Modifier.padding(start = 3.dp, bottom = 1.dp, top = 1.dp))
+val skull = HashtagIcon(CustomHashTagIcons.Skull, "SkullofSatoshi", Modifier.padding(start = 1.dp, bottom = 1.dp, top = 1.dp))
+val growstr = HashtagIcon(CustomHashTagIcons.Grownostr, "GrowNostr", Modifier.padding(start = 1.dp, bottom = 1.dp, top = 1.dp))
+val footstr = HashtagIcon(CustomHashTagIcons.Footstr, "Footstr", Modifier.padding(start = 2.dp, bottom = 1.dp, top = 1.dp))
+val flowerstr = HashtagIcon(CustomHashTagIcons.Flowerstr, "Flowerstr", Modifier.padding(start = 2.dp, bottom = 1.dp, top = 1.dp))
+val tunestr = HashtagIcon(CustomHashTagIcons.Tunestr, "Tunestr", Modifier.padding(start = 1.dp, bottom = 1.dp, top = 1.dp))
+val weed = HashtagIcon(CustomHashTagIcons.Weed, "Weed", Modifier.padding(start = 1.dp, bottom = 0.dp, top = 0.dp))
+val matestr = HashtagIcon(CustomHashTagIcons.Mate, "Mate", Modifier.padding(start = 1.dp, bottom = 0.dp, top = 0.dp))
+val gamestr = HashtagIcon(CustomHashTagIcons.Gamestr, "GameStr", Modifier.padding(start = 1.dp, bottom = 0.dp, top = 0.dp))

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/ui/richtext/README.md

@@ -0,0 +1,64 @@
+# commons/ui/richtext — shared rich-text rendering contract
+
+A **prototype** of one cross-platform rich-text renderer that Amethyst Android
+(touch) and Amethyst Desktop (mouse-first) can both drive, replacing the two
+current forks (`amethyst/ui/components/RichTextViewer.kt` ~1031 LOC and
+`desktopApp/…/DesktopRichTextViewer.kt` ~745 LOC).
+
+## What lives here
+
+- **`RichTextViewer.kt`** — the shared skeleton. Owns everything identical on
+  every front end: paragraph splitting, RTL, FlowRow word layout, plain text,
+  inline custom emoji, and hashtags. Takes an already-parsed
+  `RichTextViewerState` (the parser is pure and already in `commons/richtext`);
+  it holds **no** account, nav, or cache handle.
+- **`RichTextSegmentRenderer.kt`** — the seam. Two things the host provides:
+  - `RichTextSegmentRenderer` (via `LocalRichTextSegmentRenderer`) — one method
+    per **platform-divergent** segment (media, equation, quoted event, user
+    mention, payment, link preview, relay/invite chip, secret message). The
+    platform owns both the **visual** and the **call-to-action** for these.
+  - `RichTextInteractions` (via `LocalRichTextInteractions`) — plain callbacks
+    for segments whose **action is universal** and only the trigger styling
+    differs (open URL/email/phone, jump to hashtag).
+
+## Why this split (and not desktop's callback-only bag)
+
+The divergent segments differ in *two* ways at once between touch and mouse: the
+**presentation** (a tap-to-zoom media pager vs. an inline image that opens in a
+window) *and* the **call-to-action** (a bottom sheet vs. a popover; navigate on
+tap vs. a hover-card). A callbacks-only contract assumes shared rendering + a
+different click handler — which isn't true here — so the platform must own the
+whole rendering of those segments. Hence a renderer strategy, not just callbacks.
+
+This is the same idiom the codebase already uses for inline quotes
+(`LocalInlineQuoteRenderer`), generalised to every divergent segment: a
+CompositionLocal set at the shell, read deep in the recursive tree, re-providable
+per subtree — no parameter threading through 55+ call sites.
+
+**Feature parity, not presentation parity.** Desktop being simpler today is a
+gap, not the design; it is expected to cover the same range over time, its own
+mouse-first way. Every method has a plain-text default (`PlainTextSegmentRenderer`)
+so an unimplemented kind degrades to readable text and the core stays usable from
+previews, `commonTest`, and headless callers.
+
+## How each front end plugs in (next steps — not in this prototype)
+
+- **Android** (`amethyst`): implement `RichTextSegmentRenderer` by wrapping the
+  existing leaf composables (`ZoomableContentView`, `LoadUrlPreview`,
+  `CashuPreview`, `MayBeInvoicePreview`, `LatexEquation`, `BechLink` →
+  `LocalInlineQuoteRenderer`, …), closing over `AccountViewModel`/`INav`. The
+  Android `RichTextViewer` becomes a thin wrapper that parses the content, then
+  provides the two CompositionLocals and calls this shared core — keeping its
+  current signature so no call site changes. The flavor-specific
+  `TranslatableRichTextViewer` stays native and feeds the final string in.
+- **Desktop** (`desktopApp`): implement the strategy with `AsyncImage` +
+  window-open for media, `RenderMarkdown` for markdown, popovers for payments,
+  hover-cards for mentions — then delete `DesktopRichTextViewer`.
+
+## Status
+
+Compiles in `:commons` (`compileCommonMainKotlinMetadata`). No consumer is wired
+yet — this is the contract + skeleton for review before the per-platform
+implementations and the fork deletions land. Known follow-ups: share the custom
+emoji **icon** table (hashtag icons) and a `CreateTextWithEmoji` equivalent;
+unify the two `CachedRichTextParser` forks so callers don't each parse.

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/ui/richtext/RichTextSegmentRenderer.kt

@@ -0,0 +1,321 @@
+/*
+ * 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.ui.richtext
+
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.Immutable
+import androidx.compose.runtime.Stable
+import androidx.compose.runtime.compositionLocalOf
+import androidx.compose.runtime.staticCompositionLocalOf
+import androidx.compose.ui.Modifier
+import com.vitorpamplona.amethyst.commons.richtext.ImageGalleryParagraph
+import com.vitorpamplona.amethyst.commons.richtext.MathSegment
+import com.vitorpamplona.amethyst.commons.richtext.NowhereLinkSegment
+import com.vitorpamplona.amethyst.commons.richtext.RichTextViewerState
+import com.vitorpamplona.amethyst.commons.richtext.SecretEmoji
+import com.vitorpamplona.amethyst.commons.richtext.Segment
+
+/**
+ * The seam that lets one shared [RichTextViewer] serve every front end.
+ *
+ * ## Why a strategy and not a callback bag
+ *
+ * The parse → paragraph/word-layout → plain-text/emoji/hashtag rendering is
+ * *identical* on every platform, so the shared core owns it outright. But a
+ * handful of segment kinds — media, embedded notes, mentions, payments, link
+ * unfurls, LaTeX — differ between a **touch** front end (Amethyst Android) and a
+ * **mouse-first** one (Desktop). They differ in *two* ways at once:
+ *
+ * - **Presentation.** A phone shows an image in a full-bleed, tap-to-zoom pager;
+ *   a desktop shows it inline with a hover affordance and opens it in a window.
+ * - **Call-to-action.** A phone opens a lightning invoice in a bottom sheet; a
+ *   desktop opens a popover. A phone navigates on a mention tap; a desktop may
+ *   show a hover-card first.
+ *
+ * Because *both* the visual and the interaction diverge (not just the click
+ * handler), a callback-only contract is not enough — the platform has to own the
+ * whole rendering of these segments. So each divergent kind is a method here, and
+ * the platform provides an implementation via [LocalRichTextSegmentRenderer].
+ *
+ * This is the same idiom the codebase already uses for inline quotes
+ * (`LocalInlineQuoteRenderer`), generalised to every platform-divergent segment:
+ * a [androidx.compose.runtime.CompositionLocal] set once at the app shell, read
+ * deep inside the recursive render tree, and re-providable per subtree (e.g. chat
+ * bubbles vs. the feed) without threading a parameter through every call site.
+ *
+ * ## Feature parity, not presentation parity
+ *
+ * A platform is expected to *cover the same range* of segments over time — the
+ * Desktop being simpler today is a gap, not the design. What it is **not**
+ * expected to do is render them the same way. Every method has a plain-text
+ * default (see [PlainTextSegmentRenderer]) so an unimplemented kind degrades to
+ * readable text rather than vanishing, which also keeps the core usable from
+ * tests, previews, and headless callers.
+ *
+ * Every method receives a [Modifier] the core already aligned for RTL; draw into
+ * it. `quotesLeft` is the remaining recursion budget for embedded content — a
+ * renderer that recurses back into [RichTextViewer] must decrement it.
+ */
+@Stable
+interface RichTextSegmentRenderer {
+    /** A single image / video / pdf / base64 / blossom-uri media word. */
+    @Composable
+    fun Media(
+        segment: Segment,
+        state: RichTextViewerState,
+        modifier: Modifier,
+    )
+
+    /** A whole paragraph that is nothing but images — laid out as a grid/gallery. */
+    @Composable
+    fun Gallery(
+        paragraph: ImageGalleryParagraph,
+        state: RichTextViewerState,
+        modifier: Modifier,
+    )
+
+    /** An inline/display LaTeX equation (platform math renderer). */
+    @Composable
+    fun Equation(
+        segment: MathSegment,
+        modifier: Modifier,
+    )
+
+    /** A bare `nostr:` bech entity whose kind (user vs event) the renderer resolves. */
+    @Composable
+    fun NostrEntity(
+        bech: String,
+        canPreview: Boolean,
+        quotesLeft: Int,
+        modifier: Modifier,
+    )
+
+    /** A `#[i]`-style event mention resolved to [eventHex]; renders the quoted note. */
+    @Composable
+    fun QuotedEvent(
+        eventHex: String,
+        addedChars: String?,
+        canPreview: Boolean,
+        quotesLeft: Int,
+        modifier: Modifier,
+    )
+
+    /** A `#[i]`-style user mention resolved to [userHex]. */
+    @Composable
+    fun UserMention(
+        userHex: String,
+        addedChars: String?,
+        modifier: Modifier,
+    )
+
+    /** A payable token: lightning invoice, LNURL-withdraw, Cashu token, or Clink offer. */
+    @Composable
+    fun Payment(
+        segment: Segment,
+        modifier: Modifier,
+    )
+
+    /** An external link that may unfurl into a preview card (touch) or hover card (mouse). */
+    @Composable
+    fun LinkPreview(
+        url: String,
+        modifier: Modifier,
+    )
+
+    /**
+     * A plain external link rendered inline (no preview): the no-preview [LinkPreview]
+     * fallback and schemeless URLs. [displayText] is what the user sees; [url] is where
+     * it opens. Each front end styles the link and owns how it opens.
+     */
+    @Composable
+    fun Url(
+        url: String,
+        displayText: String,
+        modifier: Modifier,
+    )
+
+    /** An email address. Each front end styles it and owns the compose/open action. */
+    @Composable
+    fun Email(
+        address: String,
+        modifier: Modifier,
+    )
+
+    /** A phone number. Each front end styles it and owns the dial action. */
+    @Composable
+    fun Phone(
+        number: String,
+        modifier: Modifier,
+    )
+
+    /** A relay URL, NIP-29 group invite, or Concord invite chip. */
+    @Composable
+    fun RelayLink(
+        segment: Segment,
+        modifier: Modifier,
+    )
+
+    /** A "nowhere.ink" ephemeral-tool link — a card when previewing, a link otherwise. */
+    @Composable
+    fun NowhereLink(
+        segment: NowhereLinkSegment,
+        canPreview: Boolean,
+        modifier: Modifier,
+    )
+
+    /** A NIP-C0 secret-emoji span that expands into its own decoded rich-text message. */
+    @Composable
+    fun SecretMessage(
+        segment: SecretEmoji,
+        state: RichTextViewerState,
+        canPreview: Boolean,
+        quotesLeft: Int,
+        modifier: Modifier,
+    )
+}
+
+/**
+ * Activations for the segments the shared core renders itself. Only hashtags
+ * qualify: the core draws the chip (with the shared inline icon) identically on
+ * every platform, and only the navigation target differs — a pure callback. Links,
+ * mail, phone, mentions, etc. render *and* act per-platform, so they live on
+ * [RichTextSegmentRenderer], not here.
+ */
+@Immutable
+data class RichTextInteractions(
+    val onClickHashtag: (hashtag: String) -> Unit = {},
+)
+
+/**
+ * The default: render every divergent segment as its raw text. Safe for previews,
+ * `commonTest`, and headless callers; a real front end replaces it wholesale.
+ */
+object PlainTextSegmentRenderer : RichTextSegmentRenderer {
+    @Composable
+    override fun Media(
+        segment: Segment,
+        state: RichTextViewerState,
+        modifier: Modifier,
+    ) = Text(segment.segmentText, modifier)
+
+    @Composable
+    override fun Gallery(
+        paragraph: ImageGalleryParagraph,
+        state: RichTextViewerState,
+        modifier: Modifier,
+    ) = Text(paragraph.words.joinToString(" ") { it.segmentText }, modifier)
+
+    @Composable
+    override fun Equation(
+        segment: MathSegment,
+        modifier: Modifier,
+    ) = Text(segment.segmentText, modifier)
+
+    @Composable
+    override fun NostrEntity(
+        bech: String,
+        canPreview: Boolean,
+        quotesLeft: Int,
+        modifier: Modifier,
+    ) = Text(bech, modifier)
+
+    @Composable
+    override fun QuotedEvent(
+        eventHex: String,
+        addedChars: String?,
+        canPreview: Boolean,
+        quotesLeft: Int,
+        modifier: Modifier,
+    ) = Text(addedChars?.let { "$eventHex$it" } ?: eventHex, modifier)
+
+    @Composable
+    override fun UserMention(
+        userHex: String,
+        addedChars: String?,
+        modifier: Modifier,
+    ) = Text(addedChars?.let { "$userHex$it" } ?: userHex, modifier)
+
+    @Composable
+    override fun Payment(
+        segment: Segment,
+        modifier: Modifier,
+    ) = Text(segment.segmentText, modifier)
+
+    @Composable
+    override fun LinkPreview(
+        url: String,
+        modifier: Modifier,
+    ) = Text(url, modifier)
+
+    @Composable
+    override fun Url(
+        url: String,
+        displayText: String,
+        modifier: Modifier,
+    ) = Text(displayText, modifier)
+
+    @Composable
+    override fun Email(
+        address: String,
+        modifier: Modifier,
+    ) = Text(address, modifier)
+
+    @Composable
+    override fun Phone(
+        number: String,
+        modifier: Modifier,
+    ) = Text(number, modifier)
+
+    @Composable
+    override fun RelayLink(
+        segment: Segment,
+        modifier: Modifier,
+    ) = Text(segment.segmentText, modifier)
+
+    @Composable
+    override fun NowhereLink(
+        segment: NowhereLinkSegment,
+        canPreview: Boolean,
+        modifier: Modifier,
+    ) = Text(segment.segmentText, modifier)
+
+    @Composable
+    override fun SecretMessage(
+        segment: SecretEmoji,
+        state: RichTextViewerState,
+        canPreview: Boolean,
+        quotesLeft: Int,
+        modifier: Modifier,
+    ) = Text(segment.segmentText, modifier)
+}
+
+/**
+ * Deep-tree seam for platform-divergent segment rendering. Uses [compositionLocalOf]
+ * (not static) so a subtree can re-provide a variant — e.g. a compact renderer in a
+ * preview card — and only the readers under it recompose.
+ */
+val LocalRichTextSegmentRenderer =
+    compositionLocalOf<RichTextSegmentRenderer> { PlainTextSegmentRenderer }
+
+/** Universal activations for core-rendered segments. Static: it changes at the shell, rarely below. */
+val LocalRichTextInteractions =
+    staticCompositionLocalOf { RichTextInteractions() }

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/ui/richtext/RichTextViewer.kt

@@ -0,0 +1,262 @@
+/*
+ * 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.ui.richtext
+
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.ExperimentalLayoutApi
+import androidx.compose.foundation.layout.FlowRow
+import androidx.compose.foundation.text.InlineTextContent
+import androidx.compose.foundation.text.appendInlineContent
+import androidx.compose.material3.Icon
+import androidx.compose.material3.LocalTextStyle
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.platform.LocalFontFamilyResolver
+import androidx.compose.ui.platform.LocalLayoutDirection
+import androidx.compose.ui.text.Placeholder
+import androidx.compose.ui.text.PlaceholderVerticalAlign
+import androidx.compose.ui.text.SpanStyle
+import androidx.compose.ui.text.TextMeasurer
+import androidx.compose.ui.text.TextStyle
+import androidx.compose.ui.text.buildAnnotatedString
+import androidx.compose.ui.text.withStyle
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.LayoutDirection
+import androidx.compose.ui.unit.em
+import androidx.compose.ui.unit.sp
+import com.vitorpamplona.amethyst.commons.richtext.Base64Segment
+import com.vitorpamplona.amethyst.commons.richtext.BechSegment
+import com.vitorpamplona.amethyst.commons.richtext.BlossomUriSegment
+import com.vitorpamplona.amethyst.commons.richtext.CashuSegment
+import com.vitorpamplona.amethyst.commons.richtext.ClinkOfferSegment
+import com.vitorpamplona.amethyst.commons.richtext.ConcordInviteLinkSegment
+import com.vitorpamplona.amethyst.commons.richtext.EmailSegment
+import com.vitorpamplona.amethyst.commons.richtext.EmojiSegment
+import com.vitorpamplona.amethyst.commons.richtext.HashIndexEventSegment
+import com.vitorpamplona.amethyst.commons.richtext.HashIndexUserSegment
+import com.vitorpamplona.amethyst.commons.richtext.HashTagSegment
+import com.vitorpamplona.amethyst.commons.richtext.ImageGalleryParagraph
+import com.vitorpamplona.amethyst.commons.richtext.ImageSegment
+import com.vitorpamplona.amethyst.commons.richtext.InvoiceSegment
+import com.vitorpamplona.amethyst.commons.richtext.LinkSegment
+import com.vitorpamplona.amethyst.commons.richtext.MathSegment
+import com.vitorpamplona.amethyst.commons.richtext.NowhereLinkSegment
+import com.vitorpamplona.amethyst.commons.richtext.ParagraphState
+import com.vitorpamplona.amethyst.commons.richtext.PdfSegment
+import com.vitorpamplona.amethyst.commons.richtext.PhoneSegment
+import com.vitorpamplona.amethyst.commons.richtext.RegularTextSegment
+import com.vitorpamplona.amethyst.commons.richtext.RelayGroupLinkSegment
+import com.vitorpamplona.amethyst.commons.richtext.RelayUrlSegment
+import com.vitorpamplona.amethyst.commons.richtext.RichTextViewerState
+import com.vitorpamplona.amethyst.commons.richtext.SchemelessUrlSegment
+import com.vitorpamplona.amethyst.commons.richtext.SecretEmoji
+import com.vitorpamplona.amethyst.commons.richtext.Segment
+import com.vitorpamplona.amethyst.commons.richtext.VideoSegment
+import com.vitorpamplona.amethyst.commons.richtext.WithdrawSegment
+
+/**
+ * Cross-platform rich-text renderer. Owns everything identical on every front
+ * end — paragraph splitting, RTL, word layout, plain text, custom emoji, and
+ * hashtags — and delegates every platform-divergent segment to the
+ * [LocalRichTextSegmentRenderer] and universal activations to
+ * [LocalRichTextInteractions]. See [RichTextSegmentRenderer] for the rationale.
+ *
+ * Callers pass an already-parsed [RichTextViewerState] (the parser is pure and
+ * lives in `commons/richtext`), so this composable takes no account, navigation,
+ * or cache handle of its own — those enter through the two CompositionLocals the
+ * host provides.
+ */
+@Composable
+fun RichTextViewer(
+    state: RichTextViewerState,
+    canPreview: Boolean,
+    quotesLeft: Int,
+    modifier: Modifier = Modifier,
+) {
+    val renderer = LocalRichTextSegmentRenderer.current
+    val baseStyle = LocalTextStyle.current
+    val paragraphStyle = remember(baseStyle) { baseStyle.copy(lineHeight = 1.3.em) }
+
+    Column(modifier) {
+        state.paragraphs.forEach { paragraph ->
+            val align = if (paragraph.isRTL) Alignment.End else Alignment.Start
+            if (paragraph is ImageGalleryParagraph) {
+                renderer.Gallery(paragraph, state, Modifier.align(align))
+            } else {
+                CompositionLocalProvider(
+                    LocalLayoutDirection provides if (paragraph.isRTL) LayoutDirection.Rtl else LayoutDirection.Ltr,
+                    LocalTextStyle provides paragraphStyle,
+                ) {
+                    RenderParagraph(paragraph, state, canPreview, quotesLeft, Modifier.align(align))
+                }
+            }
+        }
+    }
+}
+
+@OptIn(ExperimentalLayoutApi::class)
+@Composable
+private fun RenderParagraph(
+    paragraph: ParagraphState,
+    state: RichTextViewerState,
+    canPreview: Boolean,
+    quotesLeft: Int,
+    modifier: Modifier,
+) {
+    val spaceWidth = measureSpaceWidth(LocalTextStyle.current)
+    FlowRow(
+        modifier = modifier,
+        horizontalArrangement = Arrangement.spacedBy(spaceWidth),
+        itemVerticalAlignment = Alignment.CenterVertically,
+    ) {
+        paragraph.words.forEach { word ->
+            RenderWord(word, state, canPreview, quotesLeft)
+        }
+    }
+}
+
+@Composable
+private fun RenderWord(
+    word: Segment,
+    state: RichTextViewerState,
+    canPreview: Boolean,
+    quotesLeft: Int,
+) {
+    val renderer = LocalRichTextSegmentRenderer.current
+    val actions = LocalRichTextInteractions.current
+
+    when (word) {
+        is RegularTextSegment -> Text(word.segmentText)
+        is EmojiSegment -> RenderCustomEmoji(word.segmentText, state.customEmoji)
+        is HashTagSegment -> HashTagText(word) { actions.onClickHashtag(word.hashtag) }
+
+        // Presentation + CTA are platform-owned: each front end styles its own
+        // clickable link/mail/phone and decides how to open it.
+        is EmailSegment -> renderer.Email(word.segmentText, Modifier)
+        is PhoneSegment -> renderer.Phone(word.segmentText, Modifier)
+
+        // Divergent media — presentation and CTA are platform-owned.
+        is ImageSegment, is VideoSegment, is PdfSegment, is Base64Segment, is BlossomUriSegment ->
+            renderer.Media(word, state, Modifier)
+
+        is MathSegment -> renderer.Equation(word, Modifier)
+
+        is LinkSegment ->
+            if (canPreview) {
+                renderer.LinkPreview(word.segmentText, Modifier)
+            } else {
+                renderer.Url(word.segmentText, word.segmentText, Modifier)
+            }
+
+        is SchemelessUrlSegment ->
+            renderer.Url("https://${word.segmentText}", word.segmentText, Modifier)
+        is NowhereLinkSegment -> renderer.NowhereLink(word, canPreview, Modifier)
+
+        is RelayUrlSegment, is RelayGroupLinkSegment, is ConcordInviteLinkSegment ->
+            renderer.RelayLink(word, Modifier)
+
+        is InvoiceSegment, is WithdrawSegment, is CashuSegment, is ClinkOfferSegment ->
+            renderer.Payment(word, Modifier)
+
+        is HashIndexUserSegment -> renderer.UserMention(word.hex, word.extras, Modifier)
+        is HashIndexEventSegment -> renderer.QuotedEvent(word.hex, word.extras, canPreview, quotesLeft, Modifier)
+        is BechSegment -> renderer.NostrEntity(word.segmentText, canPreview, quotesLeft, Modifier)
+        is SecretEmoji -> renderer.SecretMessage(word, state, canPreview, quotesLeft, Modifier)
+
+        // Unknown/other segments fall back to their raw text.
+        else -> Text(word.segmentText)
+    }
+}
+
+private val HashtagIconPlaceholder =
+    Placeholder(width = 17.sp, height = 17.sp, placeholderVerticalAlign = PlaceholderVerticalAlign.Center)
+
+/**
+ * A `#hashtag` chip in the theme's primary color, with the shared inline icon for
+ * well-known tags (see [checkForHashtagWithIcon]). Any trailing punctuation glued
+ * to the tag ([HashTagSegment.extras]) renders in the normal text color.
+ */
+@Composable
+private fun HashTagText(
+    segment: HashTagSegment,
+    onClick: () -> Unit,
+) {
+    val primary = MaterialTheme.colorScheme.primary
+    val background = MaterialTheme.colorScheme.onBackground
+    val hashtagIcon = remember(segment.hashtag) { checkForHashtagWithIcon(segment.hashtag) }
+
+    val annotated =
+        remember(segment.segmentText, primary, background) {
+            buildAnnotatedString {
+                withStyle(SpanStyle(color = primary)) { append("#${segment.hashtag}") }
+                if (hashtagIcon != null) {
+                    withStyle(SpanStyle(color = primary)) { appendInlineContent("inlineContent", "[icon]") }
+                }
+                segment.extras?.let { withStyle(SpanStyle(color = background)) { append(it) } }
+            }
+        }
+
+    Text(
+        text = annotated,
+        modifier = Modifier.clickable(onClick = onClick),
+        inlineContent =
+            if (hashtagIcon != null) {
+                mapOf(
+                    "inlineContent" to
+                        InlineTextContent(HashtagIconPlaceholder) {
+                            Icon(
+                                imageVector = hashtagIcon.icon,
+                                contentDescription = hashtagIcon.description,
+                                tint = Color.Unspecified,
+                                modifier = hashtagIcon.modifier,
+                            )
+                        },
+                )
+            } else {
+                emptyMap()
+            },
+    )
+}
+
+/** Width of a single space in [textStyle], used to space FlowRow words. */
+@Composable
+fun measureSpaceWidth(textStyle: TextStyle): Dp {
+    val fontFamilyResolver = LocalFontFamilyResolver.current
+    val density = LocalDensity.current
+    val layoutDirection = LocalLayoutDirection.current
+    return remember(fontFamilyResolver, density, layoutDirection, textStyle) {
+        val widthPx =
+            TextMeasurer(fontFamilyResolver, density, layoutDirection, 1)
+                .measure(" ", textStyle)
+                .size
+                .width
+        with(density) { widthPx.toDp() }
+    }
+}

commons/src/jvmAndroid/kotlin/com/vitorpamplona/amethyst/commons/richtext/CachedRichTextParser.kt

@@ -18,21 +18,27 @@
  * 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
+package com.vitorpamplona.amethyst.commons.richtext
 
-import android.util.LruCache
 import com.vitorpamplona.amethyst.commons.model.ImmutableListOfLists
-import com.vitorpamplona.amethyst.commons.richtext.RichTextParser
-import com.vitorpamplona.amethyst.commons.richtext.RichTextViewerState
-import com.vitorpamplona.amethyst.commons.richtext.UrlParser
+import com.vitorpamplona.quartz.utils.cache.ConcurrentLruCache
 
+/**
+ * The shared, cross-platform cache in front of [RichTextParser]. Both Amethyst
+ * Android and Amethyst Desktop render the same parsed [RichTextViewerState] from
+ * one place, so the same content quoted in multiple notes is only parsed once.
+ *
+ * Lives in `jvmAndroid` because it depends on [ConcurrentLruCache] (a JCA-free,
+ * lock-free-read LRU that is not in `commonMain`). iOS/`commonMain` callers use
+ * the uncached [RichTextParser] directly until a KMP cache is available.
+ */
 object CachedRichTextParser {
     // Global across every feed. Sized to hold the active feed's visible + prefetched
-    // (see PrefetchFeedMedia) working set plus a few other feeds' recent entries, so
-    // pre-parsed bodies survive until the render reads them and feed switches don't
-    // thrash. Each entry is one note's parsed segments — typically single-digit KB.
-    private val richTextCache = LruCache<Int, RichTextViewerState>(500)
-    private val isMarkdownCache = LruCache<Int, Boolean>(200)
+    // working set plus a few other feeds' recent entries, so pre-parsed bodies survive
+    // until the render reads them and feed switches don't thrash. Each entry is one
+    // note's parsed segments — typically single-digit KB.
+    private val richTextCache = ConcurrentLruCache<Int, RichTextViewerState>(500)
+    private val isMarkdownCache = ConcurrentLruCache<Int, Boolean>(200)
 
     private fun hashCodeCache(
         content: String,
@@ -69,7 +75,7 @@ object CachedRichTextParser {
         tags: ImmutableListOfLists<String>,
         callbackUri: String? = null,
         authorPubKey: String? = null,
-    ): RichTextViewerState? = richTextCache[hashCodeCache(content, tags, callbackUri, authorPubKey)]
+    ): RichTextViewerState? = richTextCache.get(hashCodeCache(content, tags, callbackUri, authorPubKey))
 
     fun parseText(
         content: String,
@@ -78,13 +84,13 @@ object CachedRichTextParser {
         authorPubKey: String? = null,
     ): RichTextViewerState {
         val key = hashCodeCache(content, tags, callbackUri, authorPubKey)
-        val cached = richTextCache[key]
+        val cached = richTextCache.get(key)
         return if (cached != null) {
             cached
         } else {
-            val newUrls = RichTextParser().parseText(content, tags, callbackUri, authorPubKey)
-            richTextCache.put(key, newUrls)
-            newUrls
+            val newState = RichTextParser().parseText(content, tags, callbackUri, authorPubKey)
+            richTextCache.put(key, newState)
+            newState
         }
     }
 
@@ -92,7 +98,7 @@ object CachedRichTextParser {
     // notes only pays for the scan once. The decision is purely a function of `content`.
     fun isMarkdown(content: String): Boolean {
         val key = content.hashCode()
-        isMarkdownCache[key]?.let { return it }
+        isMarkdownCache.get(key)?.let { return it }
         val result = computeIsMarkdown(content)
         isMarkdownCache.put(key, result)
         return result
@@ -296,15 +302,15 @@ object CachedRichTextParser {
 }
 
 object CachedUrlParser {
-    private val parsedUrlsCache = LruCache<Int, List<String>>(10)
+    private val parsedUrlsCache = ConcurrentLruCache<Int, List<String>>(10)
 
-    fun cachedParseValidUrls(content: String): List<String> = parsedUrlsCache[content.hashCode()]
+    fun cachedParseValidUrls(content: String): List<String>? = parsedUrlsCache.get(content.hashCode())
 
     fun parseValidUrls(content: String): List<String> {
         if (content.isEmpty()) return emptyList()
 
         val key = content.hashCode()
-        val cached = parsedUrlsCache[key]
+        val cached = parsedUrlsCache.get(key)
         return if (cached != null) {
             cached
         } else {

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/service/DesktopCachedRichTextParser.kt

@@ -1,54 +0,0 @@
-/*
- * 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.desktop.service
-
-import com.vitorpamplona.amethyst.commons.model.ImmutableListOfLists
-import com.vitorpamplona.amethyst.commons.richtext.RichTextParser
-import com.vitorpamplona.amethyst.commons.richtext.RichTextViewerState
-import com.vitorpamplona.quartz.utils.cache.ConcurrentLruCache
-
-object DesktopCachedRichTextParser {
-    private const val MAX_CACHE_SIZE = 50
-
-    // Lock-free get on the feed rich-text render path; the previous access-order
-    // synchronizedMap took a monitor even on reads.
-    private val cache = ConcurrentLruCache<String, RichTextViewerState>(MAX_CACHE_SIZE)
-
-    fun parseText(
-        content: String,
-        tags: ImmutableListOfLists<String>,
-        callbackUri: String? = null,
-    ): RichTextViewerState {
-        cache.get(content)?.let { return it }
-        val state = RichTextParser().parseText(content, tags, callbackUri)
-        cache.put(content, state)
-        return state
-    }
-
-    fun isMarkdown(content: String): Boolean =
-        content.startsWith("> ") ||
-            content.startsWith("# ") ||
-            content.contains("##") ||
-            content.contains("__") ||
-            content.contains("**") ||
-            content.contains("```") ||
-            content.contains("](")
-}

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

@@ -23,8 +23,6 @@ package com.vitorpamplona.amethyst.desktop.ui.note
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
-import androidx.compose.foundation.layout.ExperimentalLayoutApi
-import androidx.compose.foundation.layout.FlowRow
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxWidth
@@ -39,6 +37,7 @@ import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
@@ -58,41 +57,37 @@ import com.vitorpamplona.amethyst.commons.icons.symbols.Icon
 import com.vitorpamplona.amethyst.commons.icons.symbols.MaterialSymbols
 import com.vitorpamplona.amethyst.commons.richtext.Base64Segment
 import com.vitorpamplona.amethyst.commons.richtext.BechSegment
-import com.vitorpamplona.amethyst.commons.richtext.BlossomUriSegment
+import com.vitorpamplona.amethyst.commons.richtext.CachedRichTextParser
 import com.vitorpamplona.amethyst.commons.richtext.CashuSegment
-import com.vitorpamplona.amethyst.commons.richtext.EmailSegment
-import com.vitorpamplona.amethyst.commons.richtext.EmojiSegment
-import com.vitorpamplona.amethyst.commons.richtext.HashIndexEventSegment
-import com.vitorpamplona.amethyst.commons.richtext.HashIndexUserSegment
-import com.vitorpamplona.amethyst.commons.richtext.HashTagSegment
 import com.vitorpamplona.amethyst.commons.richtext.ImageGalleryParagraph
 import com.vitorpamplona.amethyst.commons.richtext.ImageSegment
 import com.vitorpamplona.amethyst.commons.richtext.InvoiceSegment
-import com.vitorpamplona.amethyst.commons.richtext.LinkSegment
+import com.vitorpamplona.amethyst.commons.richtext.MathSegment
 import com.vitorpamplona.amethyst.commons.richtext.NowhereLinkSegment
 import com.vitorpamplona.amethyst.commons.richtext.PdfSegment
-import com.vitorpamplona.amethyst.commons.richtext.PhoneSegment
-import com.vitorpamplona.amethyst.commons.richtext.RegularTextSegment
 import com.vitorpamplona.amethyst.commons.richtext.RelayUrlSegment
 import com.vitorpamplona.amethyst.commons.richtext.RichTextViewerState
-import com.vitorpamplona.amethyst.commons.richtext.SchemelessUrlSegment
 import com.vitorpamplona.amethyst.commons.richtext.SecretEmoji
 import com.vitorpamplona.amethyst.commons.richtext.Segment
-import com.vitorpamplona.amethyst.commons.richtext.VideoSegment
 import com.vitorpamplona.amethyst.commons.richtext.WithdrawSegment
+import com.vitorpamplona.amethyst.commons.ui.components.ClickableEmail
+import com.vitorpamplona.amethyst.commons.ui.components.ClickableUrl
 import com.vitorpamplona.amethyst.commons.ui.markdown.RenderMarkdown
+import com.vitorpamplona.amethyst.commons.ui.richtext.LocalRichTextInteractions
+import com.vitorpamplona.amethyst.commons.ui.richtext.LocalRichTextSegmentRenderer
+import com.vitorpamplona.amethyst.commons.ui.richtext.RichTextInteractions
+import com.vitorpamplona.amethyst.commons.ui.richtext.RichTextSegmentRenderer
 import com.vitorpamplona.amethyst.desktop.cache.DesktopLocalCache
-import com.vitorpamplona.amethyst.desktop.service.DesktopCachedRichTextParser
 import com.vitorpamplona.quartz.lightning.LnInvoiceUtil
 import com.vitorpamplona.quartz.nip19Bech32.Nip19Parser
 import com.vitorpamplona.quartz.nip19Bech32.entities.NEvent
 import com.vitorpamplona.quartz.nip19Bech32.entities.NNote
 import com.vitorpamplona.quartz.nip19Bech32.entities.NProfile
 import com.vitorpamplona.quartz.nip19Bech32.entities.NPub
-import kotlinx.collections.immutable.ImmutableMap
 import java.awt.Toolkit
 import java.awt.datatransfer.StringSelection
 import java.net.URI
+import com.vitorpamplona.amethyst.commons.ui.richtext.RichTextViewer as CommonsRichTextViewer
 
 data class RichTextCallbacks(
     val onMentionClick: ((String) -> Unit)? = null,
@@ -102,335 +97,270 @@ data class RichTextCallbacks(
     val onPayInvoice: ((String) -> Unit)? = null,
 )
 
-@OptIn(ExperimentalLayoutApi::class)
+/**
+ * Renders Nostr rich text on Desktop through the shared cross-platform
+ * [CommonsRichTextViewer] core. Markdown stays on the native [RenderMarkdown]
+ * path; plain rich text is dispatched by the shared core, with every
+ * platform-divergent segment drawn mouse-first by [DesktopRichTextSegmentRenderer].
+ *
+ * Replaces the former hand-rolled `DesktopRichTextViewer` switchboard so Desktop
+ * and Android render the same segment model from one place.
+ */
 @Composable
-fun DesktopRichTextViewer(
+fun DesktopRichText(
     content: String,
     state: RichTextViewerState,
     localCache: DesktopLocalCache? = null,
     callbacks: RichTextCallbacks = RichTextCallbacks(),
     modifier: Modifier = Modifier,
 ) {
-    if (DesktopCachedRichTextParser.isMarkdown(content)) {
+    if (CachedRichTextParser.isMarkdown(content)) {
         RenderMarkdown(
             content = content,
-            onLinkClick = { url ->
-                when {
-                    url.startsWith("nostr:") -> {
-                        val parsed = Nip19Parser.uriToRoute(url)
-                        when (val entity = parsed?.entity) {
-                            is NPub -> {
-                                callbacks.onMentionClick?.invoke(entity.hex)
-                            }
-
-                            is NProfile -> {
-                                callbacks.onMentionClick?.invoke(entity.hex)
-                            }
-
-                            is NNote -> {
-                                callbacks.onNavigateToThread?.invoke(entity.hex)
-                            }
-
-                            is NEvent -> {
-                                callbacks.onNavigateToThread?.invoke(entity.hex)
-                            }
-
-                            else -> {}
-                        }
-                    }
-
-                    else -> {
-                        runCatching {
-                            java.awt.Desktop
-                                .getDesktop()
-                                .browse(URI(url))
-                        }
-                    }
-                }
-            },
+            onLinkClick = { url -> handleDesktopLinkClick(url, callbacks) },
             modifier = modifier,
         )
         return
     }
 
-    Column(modifier = modifier) {
-        for (paragraph in state.paragraphs) {
-            when (paragraph) {
-                is ImageGalleryParagraph -> {
-                    val urls = paragraph.words.map { it.segmentText }
-                    Row(
-                        horizontalArrangement = Arrangement.spacedBy(4.dp),
-                        modifier = Modifier.fillMaxWidth(),
-                    ) {
-                        for ((index, segment) in paragraph.words.withIndex()) {
-                            AsyncImage(
-                                model = segment.segmentText,
-                                contentDescription = null,
-                                modifier =
-                                    Modifier
-                                        .weight(1f)
-                                        .heightIn(max = 300.dp)
-                                        .clip(MaterialTheme.shapes.small)
-                                        .then(
-                                            if (callbacks.onImageClick != null) {
-                                                Modifier.clickable { callbacks.onImageClick.invoke(urls, index) }
-                                            } else {
-                                                Modifier
-                                            },
-                                        ),
-                                contentScale = ContentScale.Crop,
-                            )
-                        }
-                    }
-                }
+    val renderer = remember(localCache, callbacks) { DesktopRichTextSegmentRenderer(localCache, callbacks) }
+    val interactions =
+        remember(callbacks) {
+            RichTextInteractions(
+                onClickHashtag = { callbacks.onHashtagClick?.invoke(it) },
+            )
+        }
 
-                else -> {
-                    val hasOnlyText = paragraph.words.all { it is RegularTextSegment }
-                    if (hasOnlyText) {
-                        Text(
-                            text = paragraph.words.joinToString("") { it.segmentText },
-                            style = MaterialTheme.typography.bodyMedium,
-                            color = MaterialTheme.colorScheme.onSurface,
-                            modifier = Modifier.fillMaxWidth(),
-                        )
-                    } else {
-                        // RichTextParser splits paragraphs on ' ' so each segment is one
-                        // space-delimited token; the source space lives BETWEEN segments,
-                        // not within them. spacedBy(4.dp) restores that inter-word gap
-                        // so mixed-content paragraphs (text + mention/hashtag/link) don't
-                        // render as a wall of glued-together words.
-                        FlowRow(
-                            modifier = Modifier.fillMaxWidth(),
-                            horizontalArrangement =
-                                Arrangement.spacedBy(
-                                    4.dp,
-                                    if (paragraph.isRTL) Alignment.End else Alignment.Start,
-                                ),
-                        ) {
-                            for (word in paragraph.words) {
-                                RenderSegment(word, state, localCache, callbacks)
-                            }
-                        }
-                    }
-                }
+    CompositionLocalProvider(
+        LocalRichTextSegmentRenderer provides renderer,
+        LocalRichTextInteractions provides interactions,
+    ) {
+        CommonsRichTextViewer(
+            state = state,
+            canPreview = true,
+            quotesLeft = 1,
+            modifier = modifier,
+        )
+    }
+}
+
+private fun handleDesktopLinkClick(
+    url: String,
+    callbacks: RichTextCallbacks,
+) {
+    when {
+        url.startsWith("nostr:") -> {
+            val parsed = Nip19Parser.uriToRoute(url)
+            when (val entity = parsed?.entity) {
+                is NPub -> callbacks.onMentionClick?.invoke(entity.hex)
+                is NProfile -> callbacks.onMentionClick?.invoke(entity.hex)
+                is NNote -> callbacks.onNavigateToThread?.invoke(entity.hex)
+                is NEvent -> callbacks.onNavigateToThread?.invoke(entity.hex)
+                else -> {}
+            }
+        }
+
+        else -> {
+            runCatching {
+                java.awt.Desktop
+                    .getDesktop()
+                    .browse(URI(url))
             }
         }
     }
 }
 
-@Composable
-private fun RenderSegment(
-    segment: Segment,
-    state: RichTextViewerState,
-    localCache: DesktopLocalCache?,
-    callbacks: RichTextCallbacks,
-) {
-    when (segment) {
-        is RegularTextSegment -> {
-            Text(
-                text = segment.segmentText,
-                style = MaterialTheme.typography.bodyMedium,
-                color = MaterialTheme.colorScheme.onSurface,
-            )
-        }
-
-        is LinkSegment -> {
-            ClickableLink(segment.segmentText, segment.segmentText)
-        }
-
-        is SchemelessUrlSegment -> {
-            ClickableLink("https://${segment.segmentText}", segment.segmentText)
-        }
-
-        is BechSegment -> {
-            RenderBechSegment(segment, localCache, callbacks)
-        }
-
-        is HashTagSegment -> {
-            val display = "#${segment.hashtag}" + (segment.extras ?: "")
-            Text(
-                text = display,
-                style = MaterialTheme.typography.bodyMedium,
-                color = MaterialTheme.colorScheme.primary,
-                modifier =
-                    Modifier
-                        .pointerHoverIcon(PointerIcon.Hand)
-                        .clickable { callbacks.onHashtagClick?.invoke(segment.hashtag) },
-            )
-        }
-
-        is HashIndexUserSegment -> {
-            val user = localCache?.getUserIfExists(segment.hex)
-            val display = "@${user?.toBestDisplayName() ?: segment.hex.take(8) + "..."}"
-            Text(
-                text = display + (segment.extras ?: ""),
-                style = MaterialTheme.typography.bodyMedium,
-                color = MaterialTheme.colorScheme.primary,
-                modifier =
-                    Modifier
-                        .pointerHoverIcon(PointerIcon.Hand)
-                        .clickable { callbacks.onMentionClick?.invoke(segment.hex) },
-            )
-        }
-
-        is HashIndexEventSegment -> {
-            QuotedNoteEmbed(
-                noteId = segment.hex,
-                localCache = localCache,
-                onMentionClick = callbacks.onMentionClick,
-                onNavigateToThread = callbacks.onNavigateToThread,
-            )
-        }
-
-        is EmailSegment -> {
-            Text(
-                text = segment.segmentText,
-                style = MaterialTheme.typography.bodyMedium,
-                color = MaterialTheme.colorScheme.primary,
-                textDecoration = TextDecoration.Underline,
-                modifier =
-                    Modifier
-                        .pointerHoverIcon(PointerIcon.Hand)
-                        .clickable {
-                            runCatching {
-                                java.awt.Desktop
-                                    .getDesktop()
-                                    .browse(URI("mailto:${segment.segmentText}"))
-                            }
-                        },
-            )
-        }
-
-        is PhoneSegment -> {
-            Text(
-                text = segment.segmentText,
-                style = MaterialTheme.typography.bodyMedium,
-                color = MaterialTheme.colorScheme.onSurface,
-            )
-        }
-
-        is RelayUrlSegment -> {
-            Text(
-                text = segment.segmentText,
-                style = MaterialTheme.typography.bodyMedium,
-                color = MaterialTheme.colorScheme.primary,
-                modifier =
-                    Modifier
-                        .pointerHoverIcon(PointerIcon.Hand)
-                        .clickable { copyToClipboard(segment.segmentText) },
-            )
-        }
-
-        is EmojiSegment -> {
-            RenderCustomEmojiSegment(segment.segmentText, state.customEmoji)
-        }
-
-        is NowhereLinkSegment -> {
-            RenderNowhereLinkCard(segment)
-        }
-
-        is InvoiceSegment -> {
-            RenderInvoiceCard(segment.segmentText, callbacks)
-        }
-
-        is CashuSegment -> {
-            RenderCashuCard(segment.segmentText)
-        }
-
-        is WithdrawSegment -> {
-            ClickableLink(segment.segmentText, segment.segmentText)
-        }
-
-        is BlossomUriSegment -> {
-            ClickableLink(segment.segmentText, segment.segmentText)
-        }
-
-        is PdfSegment -> {
-            RenderPdfCard(segment.segmentText)
-        }
-
-        is Base64Segment -> {
-            AsyncImage(
-                model = segment.segmentText,
-                contentDescription = null,
-                modifier =
-                    Modifier
-                        .fillMaxWidth()
-                        .heightIn(max = 300.dp)
-                        .clip(MaterialTheme.shapes.small),
-                contentScale = ContentScale.Fit,
-            )
-        }
-
-        is ImageSegment -> {
-            AsyncImage(
-                model = segment.segmentText,
-                contentDescription = null,
-                modifier =
-                    Modifier
-                        .fillMaxWidth()
-                        .heightIn(max = 300.dp)
-                        .clip(MaterialTheme.shapes.small),
-                contentScale = ContentScale.Fit,
-            )
-        }
-
-        is VideoSegment -> {
-            Text(
-                text = segment.segmentText,
-                style = MaterialTheme.typography.bodyMedium,
-                color = MaterialTheme.colorScheme.primary,
-                textDecoration = TextDecoration.Underline,
-                modifier =
-                    Modifier
-                        .pointerHoverIcon(PointerIcon.Hand)
-                        .clickable {
-                            runCatching {
-                                java.awt.Desktop
-                                    .getDesktop()
-                                    .browse(URI(segment.segmentText))
-                            }
-                        },
-            )
-        }
-
-        is SecretEmoji -> {
-            RenderSecretEmoji(segment.segmentText)
-        }
-
-        else -> {
-            Text(
-                text = segment.segmentText,
-                style = MaterialTheme.typography.bodyMedium,
-                color = MaterialTheme.colorScheme.onSurface,
-            )
+/**
+ * Desktop (mouse-first) implementation of the shared [RichTextSegmentRenderer].
+ * Each method draws a segment with the existing Desktop leaf composables in this
+ * file (and `NoteCard`), so Desktop keeps its own presentation and interaction
+ * while sharing the parse + dispatch with Android.
+ */
+class DesktopRichTextSegmentRenderer(
+    private val localCache: DesktopLocalCache?,
+    private val callbacks: RichTextCallbacks,
+) : RichTextSegmentRenderer {
+    @Composable
+    override fun Media(
+        segment: Segment,
+        state: RichTextViewerState,
+        modifier: Modifier,
+    ) {
+        when (segment) {
+            is ImageSegment, is Base64Segment ->
+                AsyncImage(
+                    model = segment.segmentText,
+                    contentDescription = null,
+                    modifier =
+                        Modifier
+                            .fillMaxWidth()
+                            .heightIn(max = 300.dp)
+                            .clip(MaterialTheme.shapes.small)
+                            .then(
+                                if (callbacks.onImageClick != null) {
+                                    Modifier.clickable { callbacks.onImageClick.invoke(listOf(segment.segmentText), 0) }
+                                } else {
+                                    Modifier
+                                },
+                            ),
+                    contentScale = ContentScale.Fit,
+                )
+            is PdfSegment -> RenderPdfCard(segment.segmentText)
+            else -> ClickableUrl(segment.segmentText, underline = true)
         }
     }
-}
 
-@Composable
-private fun ClickableLink(
-    url: String,
-    displayText: String,
-) {
-    Text(
-        text = displayText,
-        style = MaterialTheme.typography.bodyMedium,
-        color = MaterialTheme.colorScheme.primary,
-        textDecoration = TextDecoration.Underline,
-        maxLines = 1,
-        overflow = TextOverflow.Ellipsis,
-        modifier =
-            Modifier
-                .pointerHoverIcon(PointerIcon.Hand)
-                .clickable {
-                    runCatching {
-                        java.awt.Desktop
-                            .getDesktop()
-                            .browse(URI(url))
-                    }
-                },
+    @Composable
+    override fun Gallery(
+        paragraph: ImageGalleryParagraph,
+        state: RichTextViewerState,
+        modifier: Modifier,
+    ) {
+        val urls = remember(paragraph) { paragraph.words.map { it.segmentText } }
+        Row(horizontalArrangement = Arrangement.spacedBy(4.dp), modifier = modifier.fillMaxWidth()) {
+            paragraph.words.forEachIndexed { index, segment ->
+                AsyncImage(
+                    model = segment.segmentText,
+                    contentDescription = null,
+                    modifier =
+                        Modifier
+                            .weight(1f)
+                            .heightIn(max = 300.dp)
+                            .clip(MaterialTheme.shapes.small)
+                            .then(
+                                if (callbacks.onImageClick != null) {
+                                    Modifier.clickable { callbacks.onImageClick.invoke(urls, index) }
+                                } else {
+                                    Modifier
+                                },
+                            ),
+                    contentScale = ContentScale.Crop,
+                )
+            }
+        }
+    }
+
+    @Composable
+    override fun Equation(
+        segment: MathSegment,
+        modifier: Modifier,
+    ) = Text(segment.segmentText, style = MaterialTheme.typography.bodyMedium, color = MaterialTheme.colorScheme.onSurface)
+
+    @Composable
+    override fun NostrEntity(
+        bech: String,
+        canPreview: Boolean,
+        quotesLeft: Int,
+        modifier: Modifier,
+    ) {
+        val segment = remember(bech) { BechSegment(bech) }
+        RenderBechSegment(segment, localCache, callbacks)
+    }
+
+    @Composable
+    override fun QuotedEvent(
+        eventHex: String,
+        addedChars: String?,
+        canPreview: Boolean,
+        quotesLeft: Int,
+        modifier: Modifier,
+    ) = QuotedNoteEmbed(
+        noteId = eventHex,
+        localCache = localCache,
+        onMentionClick = callbacks.onMentionClick,
+        onNavigateToThread = callbacks.onNavigateToThread,
     )
+
+    @Composable
+    override fun UserMention(
+        userHex: String,
+        addedChars: String?,
+        modifier: Modifier,
+    ) {
+        val user = localCache?.getUserIfExists(userHex)
+        val display = "@${user?.toBestDisplayName() ?: (userHex.take(8) + "...")}"
+        Text(
+            text = display + (addedChars ?: ""),
+            style = MaterialTheme.typography.bodyMedium,
+            color = MaterialTheme.colorScheme.primary,
+            modifier = Modifier.pointerHoverIcon(PointerIcon.Hand).clickable { callbacks.onMentionClick?.invoke(userHex) },
+        )
+    }
+
+    @Composable
+    override fun Payment(
+        segment: Segment,
+        modifier: Modifier,
+    ) {
+        when (segment) {
+            is InvoiceSegment -> RenderInvoiceCard(segment.segmentText, callbacks)
+            is CashuSegment -> RenderCashuCard(segment.segmentText)
+            is WithdrawSegment -> ClickableUrl(segment.segmentText, underline = true)
+            else -> Text(segment.segmentText, style = MaterialTheme.typography.bodyMedium, color = MaterialTheme.colorScheme.onSurface)
+        }
+    }
+
+    @Composable
+    override fun LinkPreview(
+        url: String,
+        modifier: Modifier,
+    ) = ClickableUrl(url, underline = true)
+
+    @Composable
+    override fun Url(
+        url: String,
+        displayText: String,
+        modifier: Modifier,
+    ) = ClickableUrl(url, displayText, underline = true)
+
+    @Composable
+    override fun Email(
+        address: String,
+        modifier: Modifier,
+    ) = ClickableEmail(address, underline = true)
+
+    @Composable
+    override fun Phone(
+        number: String,
+        modifier: Modifier,
+    ) = Text(
+        text = number,
+        style = MaterialTheme.typography.bodyMedium,
+        color = MaterialTheme.colorScheme.onSurface,
+    )
+
+    @Composable
+    override fun RelayLink(
+        segment: Segment,
+        modifier: Modifier,
+    ) {
+        if (segment is RelayUrlSegment) {
+            Text(
+                text = segment.segmentText,
+                style = MaterialTheme.typography.bodyMedium,
+                color = MaterialTheme.colorScheme.primary,
+                modifier = Modifier.pointerHoverIcon(PointerIcon.Hand).clickable { copyToClipboard(segment.segmentText) },
+            )
+        } else {
+            Text(segment.segmentText, style = MaterialTheme.typography.bodyMedium, color = MaterialTheme.colorScheme.onSurface)
+        }
+    }
+
+    @Composable
+    override fun NowhereLink(
+        segment: NowhereLinkSegment,
+        canPreview: Boolean,
+        modifier: Modifier,
+    ) = RenderNowhereLinkCard(segment)
+
+    @Composable
+    override fun SecretMessage(
+        segment: SecretEmoji,
+        state: RichTextViewerState,
+        canPreview: Boolean,
+        quotesLeft: Int,
+        modifier: Modifier,
+    ) = RenderSecretEmoji(segment.segmentText)
 }
 
 @Composable
@@ -664,33 +594,6 @@ private fun RenderSecretEmoji(text: String) {
     }
 }
 
-@Composable
-private fun RenderCustomEmojiSegment(
-    word: String,
-    customEmoji: ImmutableMap<String, String>,
-) {
-    val matchedEmoji = remember(word, customEmoji) { customEmoji.entries.firstOrNull { word.contains(it.key) } }
-    if (matchedEmoji != null) {
-        val parts = word.split(matchedEmoji.key, limit = 2)
-        Row(verticalAlignment = Alignment.CenterVertically) {
-            if (parts[0].isNotEmpty()) {
-                Text(parts[0], style = MaterialTheme.typography.bodyMedium)
-            }
-            AsyncImage(
-                model = matchedEmoji.value,
-                contentDescription = matchedEmoji.key,
-                modifier = Modifier.size(20.dp),
-                contentScale = ContentScale.Fit,
-            )
-            if (parts.size > 1 && parts[1].isNotEmpty()) {
-                Text(parts[1], style = MaterialTheme.typography.bodyMedium)
-            }
-        }
-    } else {
-        Text(word, style = MaterialTheme.typography.bodyMedium)
-    }
-}
-
 private val nowhereToolLabels =
     mapOf(
         "e" to "Nowhere Event",

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

@@ -56,12 +56,12 @@ import androidx.compose.ui.unit.dp
 import coil3.compose.AsyncImage
 import com.vitorpamplona.amethyst.commons.model.EmptyTagList
 import com.vitorpamplona.amethyst.commons.model.ImmutableListOfLists
+import com.vitorpamplona.amethyst.commons.richtext.CachedRichTextParser
 import com.vitorpamplona.amethyst.commons.richtext.RichTextParser
 import com.vitorpamplona.amethyst.commons.richtext.UrlParser
 import com.vitorpamplona.amethyst.commons.ui.note.ReplyContext
 import com.vitorpamplona.amethyst.commons.ui.note.ReplyToLabel
 import com.vitorpamplona.amethyst.desktop.cache.DesktopLocalCache
-import com.vitorpamplona.amethyst.desktop.service.DesktopCachedRichTextParser
 import com.vitorpamplona.amethyst.desktop.ui.components.ToggleableTimeAgoText
 import com.vitorpamplona.amethyst.desktop.ui.media.AnimatedGifImage
 import com.vitorpamplona.amethyst.desktop.ui.media.AudioPlayer
@@ -293,9 +293,9 @@ fun NoteCard(
                 if (strippedContent.isNotBlank()) {
                     val richState =
                         remember(strippedContent, note.tags) {
-                            DesktopCachedRichTextParser.parseText(strippedContent, note.tags)
+                            CachedRichTextParser.parseText(strippedContent, note.tags)
                         }
-                    DesktopRichTextViewer(
+                    DesktopRichText(
                         content = strippedContent,
                         state = richState,
                         localCache = localCache,

quartz/src/jvmAndroid/kotlin/com/vitorpamplona/quartz/utils/cache/ConcurrentLruCache.kt

@@ -87,5 +87,19 @@ class ConcurrentLruCache<K : Any, V : Any>(
         }
     }
 
+    /**
+     * Evicts the oldest entries until at most [maxItems] remain. Used to shed
+     * memory on pressure (e.g. `onTrimMemory`). A [maxItems] of 0 or less clears
+     * the cache; values above the current size are a no-op.
+     */
+    fun trimToSize(maxItems: Int) {
+        synchronized(writeLock) {
+            while (order.size > maxItems) {
+                val oldest = order.removeFirstOrNull() ?: break
+                map.remove(oldest)
+            }
+        }
+    }
+
     fun size(): Int = map.size
 }

quartz/src/jvmAndroidTest/kotlin/com/vitorpamplona/quartz/utils/cache/ConcurrentLruCacheTest.kt

@@ -100,6 +100,38 @@ class ConcurrentLruCacheTest {
         assertNull(cache.get("a"))
     }
 
+    @Test
+    fun `trimToSize evicts oldest down to the target`() {
+        val cache = ConcurrentLruCache<String, Int>(10)
+        cache.put("a", 1)
+        cache.put("b", 2)
+        cache.put("c", 3)
+        cache.trimToSize(1)
+        assertEquals(1, cache.size())
+        // Oldest (a, b) evicted; newest (c) kept.
+        assertNull(cache.get("a"))
+        assertNull(cache.get("b"))
+        assertEquals(3, cache.get("c"))
+    }
+
+    @Test
+    fun `trimToSize above current size is a no-op`() {
+        val cache = ConcurrentLruCache<String, Int>(10)
+        cache.put("a", 1)
+        cache.put("b", 2)
+        cache.trimToSize(5)
+        assertEquals(2, cache.size())
+    }
+
+    @Test
+    fun `trimToSize to zero clears`() {
+        val cache = ConcurrentLruCache<String, Int>(10)
+        cache.put("a", 1)
+        cache.trimToSize(0)
+        assertEquals(0, cache.size())
+        assertNull(cache.get("a"))
+    }
+
     @Test
     fun `size never exceeds capacity under concurrent puts`() {
         val cap = 100