feat(buzz): intercept Buzz invite links into the in-app window.nostr browser

A Buzz workspace invite (`https://<host>/invite/<token>`) is redeemed over HTTP,
and the Buzz web app already drives that flow (policy consent + NIP-98 claim)
through `window.nostr`. Amethyst's existing in-app browser (NappletBrowserActivity
via FavoriteAppLauncher.launchUrl) injects an origin-scoped window.nostr backed by
the user's signer into any https origin — so routing Buzz invites there lets the
SPA claim membership as the user's key, with no native re-implementation of the
consent UI.

Mirrors the Concord invite intercept, at all three entry points, keeping every
other link external by default:
- Deep link: AndroidManifest intent-filter for *.communities.buzz.xyz/invite/ +
  a `buzzInviteRoute()` branch in MainActivity.uriToRoute.
- Tapped in-content link: a BuzzInviteLinkSegment classified in RichTextParser
  (commons) + a ClickableBuzzInviteLink that routes to Route.BuzzInvite.
- Search bar: a branch in SearchBarViewModel.directRouteResolver.

Route.BuzzInvite → BuzzInviteScreen confirms the workspace (host + role parsed by
the quartz BuzzInviteLink), marks its relay as a Buzz dialect, and opens the
in-app browser at the invite URL to finish joining. The matcher is host-agnostic
(BuzzInviteLink.parse), so self-hosted Buzz invites intercept via tap/search even
without a manifest filter.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J8KBSw6smQRyXLiWHeDsZ8

amethyst/src/main/AndroidManifest.xml

@@ -212,6 +212,17 @@
                 <data android:pathPrefix="/invite/" />
             </intent-filter>
 
+            <!-- Buzz workspace invite links: https://<team>.communities.buzz.xyz/invite/<token> -->
+            <intent-filter android:label="Amethyst">
+                <action android:name="android.intent.action.VIEW" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.BROWSABLE" />
+                <data android:scheme="https" />
+                <data android:host="communities.buzz.xyz" />
+                <data android:host="*.communities.buzz.xyz" />
+                <data android:pathPrefix="/invite/" />
+            </intent-filter>
+
             <intent-filter android:label="zap.stream">
                 <action android:name="android.intent.action.VIEW" />
                 <category android:name="android.intent.category.DEFAULT" />

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/MainActivity.kt

@@ -42,6 +42,7 @@ import com.vitorpamplona.amethyst.ui.navigation.routes.routeFor
 import com.vitorpamplona.amethyst.ui.note.elements.NowProvider
 import com.vitorpamplona.amethyst.ui.screen.AccountScreen
 import com.vitorpamplona.amethyst.ui.theme.AmethystTheme
+import com.vitorpamplona.quartz.buzz.invite.BuzzInviteLink
 import com.vitorpamplona.quartz.nip01Core.core.AddressableEvent
 import com.vitorpamplona.quartz.nip19Bech32.Nip19Parser
 import com.vitorpamplona.quartz.nip19Bech32.entities.NAddress
@@ -233,6 +234,7 @@ fun uriToRoute(
 
     relayGroupInviteRoute(uri)?.let { return it }
     concordInviteRoute(uri)?.let { return it }
+    buzzInviteRoute(uri)?.let { return it }
 
     val parsedNip19 = Nip19Parser.uriToRoute(uri)
     val nip19 = parsedNip19?.entity
@@ -384,3 +386,15 @@ private fun concordInviteRoute(uri: String): Route? =
     } else {
         null
     }
+
+/**
+ * A Buzz workspace invite (`https://<host>/invite/<token>`) — a plain `/invite/` https URL with
+ * no fragment, so disjoint from the Concord shape above. Opens the in-app join flow
+ * ([Route.BuzzInvite]) instead of the external browser so the claim signs with the user's key.
+ */
+private fun buzzInviteRoute(uri: String): Route? =
+    if (uri.contains("/invite/") && BuzzInviteLink.parse(uri) != null) {
+        Route.BuzzInvite(uri)
+    } else {
+        null
+    }

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

@@ -34,6 +34,7 @@ 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.BuzzInviteLinkSegment
 import com.vitorpamplona.amethyst.commons.richtext.CachedRichTextParser
 import com.vitorpamplona.amethyst.commons.richtext.CashuSegment
 import com.vitorpamplona.amethyst.commons.richtext.ClinkOfferSegment
@@ -218,6 +219,7 @@ class AmethystRichTextSegmentRenderer(
                 } else {
                     ClickableConcordInviteLink(segment.segmentText, nav)
                 }
+            is BuzzInviteLinkSegment -> ClickableBuzzInviteLink(segment.segmentText, nav)
             else -> Text(segment.segmentText)
         }
     }

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

@@ -0,0 +1,75 @@
+/*
+ * 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.combinedClickable
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.LocalClipboard
+import androidx.compose.ui.text.style.TextOverflow
+import com.vitorpamplona.amethyst.ui.components.util.setText
+import com.vitorpamplona.amethyst.ui.navigation.navs.INav
+import com.vitorpamplona.amethyst.ui.navigation.routes.Route
+import com.vitorpamplona.quartz.buzz.invite.BuzzInviteLink
+import kotlinx.coroutines.launch
+
+/**
+ * Renders a Buzz workspace invite link (`https://<host>/invite/<token>`) inline as a tappable
+ * link that opens the in-app join flow ([Route.BuzzInvite], which confirms the workspace and
+ * hands off to the `window.nostr` browser for the policy + NIP-98 claim) instead of the
+ * external browser. Long-press copies the full link. Falls back to plain text if the literal
+ * can't be parsed (detection should guarantee it does).
+ */
+@Composable
+fun ClickableBuzzInviteLink(
+    linkText: String,
+    nav: INav,
+) {
+    val clipboardManager = LocalClipboard.current
+    val scope = rememberCoroutineScope()
+
+    val parsed = remember(linkText) { BuzzInviteLink.parse(linkText) }
+
+    if (parsed == null) {
+        Text(text = linkText)
+        return
+    }
+
+    val clickableModifier =
+        remember(linkText) {
+            Modifier.combinedClickable(
+                onLongClick = { scope.launch { clipboardManager.setText(linkText) } },
+                onClick = { nav.nav(Route.BuzzInvite(linkText)) },
+            )
+        }
+
+    Text(
+        text = linkText,
+        modifier = clickableModifier,
+        color = MaterialTheme.colorScheme.primary,
+        overflow = TextOverflow.MiddleEllipsis,
+        maxLines = 1,
+    )
+}

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.BuzzInviteLinkSegment
 import com.vitorpamplona.amethyst.commons.richtext.CachedRichTextParser
 import com.vitorpamplona.amethyst.commons.richtext.CashuSegment
 import com.vitorpamplona.amethyst.commons.richtext.ClinkOfferSegment
@@ -492,6 +493,7 @@ private fun RenderWordWithoutPreview(
 
         is RelayGroupLinkSegment -> ClickableRelayGroupLink(word.segmentText, nav)
         is ConcordInviteLinkSegment -> ClickableConcordInviteLink(word.segmentText, nav)
+        is BuzzInviteLinkSegment -> ClickableBuzzInviteLink(word.segmentText, nav)
 
         is BlossomUriSegment -> BlossomUriRendererNoPreview(word.segmentText, accountViewModel)
 
@@ -533,6 +535,7 @@ private fun RenderWordWithPreview(
         is RelayUrlSegment -> ClickableRelayUrl(word.segmentText, nav)
         is RelayGroupLinkSegment -> RelayGroupCard(word.segmentText, accountViewModel, nav)
         is ConcordInviteLinkSegment -> ConcordInviteCard(word.segmentText, accountViewModel, nav)
+        is BuzzInviteLinkSegment -> ClickableBuzzInviteLink(word.segmentText, nav)
         is BlossomUriSegment -> BlossomUriRenderer(word.segmentText, state, callbackUri, accountViewModel)
         is SchemelessUrlSegment -> NoProtocolUrlRenderer(word.segmentText)
     }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/navigation/AppNavigation.kt

@@ -105,6 +105,7 @@ import com.vitorpamplona.amethyst.ui.screen.loggedIn.buzz.AgentPersonaEditScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.buzz.BuzzCanvasScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.buzz.BuzzDmListScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.buzz.BuzzForumPostScreen
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.buzz.BuzzInviteScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.buzz.BuzzNewDmScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.buzz.BuzzWorkspacesScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.calendars.CalendarCollectionsScreen
@@ -745,6 +746,8 @@ fun BuildNavigation(
             )
         }
 
+        composableFromEndArgs<Route.BuzzInvite> { BuzzInviteScreen(it.link, accountViewModel, nav) }
+
         composableFromEnd<Route.Concords> { ConcordHomeScreen(accountViewModel, nav) }
 
         composableFromEnd<Route.ConcordCreate> { ConcordCreateScreen(accountViewModel, nav) }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/navigation/routes/Routes.kt

@@ -756,6 +756,10 @@ sealed class Route {
         val link: String,
     ) : Route()
 
+    @Serializable data class BuzzInvite(
+        val link: String,
+    ) : Route()
+
     @Serializable object Concords : Route()
 
     // The "minichat" of a chat message: its kind-1111 thread replies, opened from the message and

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

@@ -0,0 +1,189 @@
+/*
+ * 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.screen.loggedIn.buzz
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.material3.Button
+import androidx.compose.material3.Card
+import androidx.compose.material3.CardDefaults
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.commons.icons.symbols.Icon
+import com.vitorpamplona.amethyst.commons.icons.symbols.MaterialSymbols
+import com.vitorpamplona.amethyst.commons.model.buzz.BuzzRelayDialect
+import com.vitorpamplona.amethyst.favorites.FavoriteAppLauncher
+import com.vitorpamplona.amethyst.ui.navigation.navs.INav
+import com.vitorpamplona.amethyst.ui.navigation.topbars.TopBarWithBackButton
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.amethyst.ui.stringRes
+import com.vitorpamplona.quartz.buzz.invite.BuzzInviteLink
+import com.vitorpamplona.quartz.nip01Core.relay.normalizer.RelayUrlNormalizer
+import com.vitorpamplona.quartz.utils.TimeUtils
+
+/**
+ * Landing screen for a Buzz workspace invite link (`https://<host>/invite/<token>`), reached
+ * from the deep-link / tapped-link / search interceptors instead of the external browser.
+ *
+ * A Buzz invite is redeemed over HTTP (accept the join policy, then a NIP-98-signed claim) —
+ * a flow the Buzz web app already implements and drives through `window.nostr`. So rather than
+ * re-implement the legally-sensitive age/privacy consent natively, this confirms the workspace,
+ * marks its relay as a Buzz dialect, and hands the URL to the in-app `window.nostr` browser
+ * ([FavoriteAppLauncher.launchUrl] → the sandboxed WebView), where the SPA signs the claim with
+ * the user's key. The user returns here (or to the app) once enrolled.
+ */
+@Composable
+fun BuzzInviteScreen(
+    link: String,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    val invite = remember(link) { BuzzInviteLink.parse(link) }
+    val context = LocalContext.current
+
+    Scaffold(
+        topBar = { TopBarWithBackButton(stringRes(R.string.buzz_invite_title), nav) },
+    ) { padding ->
+        Column(
+            modifier = Modifier.padding(padding).fillMaxSize().padding(20.dp),
+            verticalArrangement = Arrangement.spacedBy(16.dp),
+            horizontalAlignment = Alignment.CenterHorizontally,
+        ) {
+            if (invite == null) {
+                Text(stringRes(R.string.buzz_invite_invalid), style = MaterialTheme.typography.bodyLarge)
+                return@Column
+            }
+
+            val expired = remember(invite) { invite.isExpired(TimeUtils.now()) }
+
+            Spacer(Modifier.size(8.dp))
+            Box(
+                modifier =
+                    Modifier
+                        .size(72.dp)
+                        .clip(CircleShape)
+                        .background(MaterialTheme.colorScheme.primaryContainer),
+                contentAlignment = Alignment.Center,
+            ) {
+                Icon(
+                    symbol = MaterialSymbols.AutoAwesome,
+                    contentDescription = null,
+                    tint = MaterialTheme.colorScheme.onPrimaryContainer,
+                    modifier = Modifier.size(36.dp),
+                )
+            }
+
+            Text(
+                text = stringRes(R.string.buzz_invite_heading),
+                style = MaterialTheme.typography.titleLarge,
+                fontWeight = FontWeight.Bold,
+            )
+
+            Card(
+                modifier = Modifier.fillMaxWidth(),
+                colors = CardDefaults.cardColors(containerColor = MaterialTheme.colorScheme.surfaceVariant),
+            ) {
+                Column(
+                    modifier = Modifier.fillMaxWidth().padding(16.dp),
+                    verticalArrangement = Arrangement.spacedBy(8.dp),
+                ) {
+                    InviteRow(stringRes(R.string.buzz_invite_workspace), invite.host)
+                    InviteRow(stringRes(R.string.buzz_invite_role), invite.role)
+                }
+            }
+
+            Text(
+                text = stringRes(R.string.buzz_invite_body),
+                style = MaterialTheme.typography.bodyMedium,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+            )
+
+            if (expired) {
+                Text(
+                    text = stringRes(R.string.buzz_invite_expired),
+                    style = MaterialTheme.typography.bodyMedium,
+                    color = MaterialTheme.colorScheme.error,
+                )
+            }
+
+            Spacer(Modifier.weight(1f))
+
+            Button(
+                onClick = {
+                    // Recognize the workspace's relay as Buzz-dialect so its events are materialized
+                    // as workspace channels once membership is granted, then hand off to the in-app
+                    // window.nostr browser to accept terms + sign the claim.
+                    RelayUrlNormalizer.normalizeOrNull(invite.relayUrl())?.let { BuzzRelayDialect.mark(it) }
+                    FavoriteAppLauncher.launchUrl(context, link)
+                },
+                enabled = !expired,
+                modifier = Modifier.fillMaxWidth(),
+            ) {
+                Icon(symbol = MaterialSymbols.AutoMirrored.OpenInNew, contentDescription = null, modifier = Modifier.size(18.dp))
+                Spacer(Modifier.width(10.dp))
+                Text(stringRes(R.string.buzz_invite_continue))
+            }
+        }
+    }
+}
+
+@Composable
+private fun InviteRow(
+    label: String,
+    value: String,
+) {
+    Row(verticalAlignment = Alignment.CenterVertically) {
+        Text(
+            text = label,
+            style = MaterialTheme.typography.bodyMedium,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            modifier = Modifier.width(96.dp),
+        )
+        Text(
+            text = value,
+            style = MaterialTheme.typography.bodyMedium,
+            fontWeight = FontWeight.Bold,
+            maxLines = 1,
+            overflow = TextOverflow.Ellipsis,
+        )
+    }
+}

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

@@ -44,6 +44,7 @@ import com.vitorpamplona.amethyst.ui.navigation.routes.Route
 import com.vitorpamplona.amethyst.ui.navigation.routes.routeFor
 import com.vitorpamplona.amethyst.ui.note.creators.userSuggestions.userUriPrefixes
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.relays.common.relaySetupInfoBuilder
+import com.vitorpamplona.quartz.buzz.invite.BuzzInviteLink
 import com.vitorpamplona.quartz.concord.cord05Invites.bundle.ConcordInviteBundleEvent
 import com.vitorpamplona.quartz.nip01Core.core.toHexKey
 import com.vitorpamplona.quartz.nip01Core.relay.normalizer.NormalizedRelayUrl
@@ -197,6 +198,11 @@ class SearchBarViewModel(
                     return@mapLatest Route.ConcordInvite(term)
                 }
 
+                // A pasted Buzz workspace invite (`…/invite/<token>`) opens the in-app join flow.
+                if (term.contains("/invite/") && BuzzInviteLink.parse(term) != null) {
+                    return@mapLatest Route.BuzzInvite(term)
+                }
+
                 val parsed =
                     runCatching { Nip19Parser.uriToRoute(term)?.entity }
                         .onFailure { if (it is CancellationException) throw it }

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

@@ -3323,6 +3323,14 @@
     <string name="buzz_dm_start">Start conversation</string>
     <string name="buzz_dm_opening">Opening…</string>
     <string name="buzz_dm_remove">Remove</string>
+    <string name="buzz_invite_title">Workspace invite</string>
+    <string name="buzz_invite_heading">Join this workspace</string>
+    <string name="buzz_invite_workspace">Workspace</string>
+    <string name="buzz_invite_role">Role</string>
+    <string name="buzz_invite_body">You\'ll open the workspace in a secure in-app browser to review its terms and finish joining. It signs you in with your Amethyst key — no password.</string>
+    <string name="buzz_invite_continue">Continue in browser</string>
+    <string name="buzz_invite_invalid">This doesn\'t look like a valid Buzz invite link.</string>
+    <string name="buzz_invite_expired">This invite has expired. Ask for a new one.</string>
 
     <string name="chat_delivery_details_title">Message Delivery</string>
     <string name="close">Close</string>

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

@@ -24,6 +24,7 @@ import com.vitorpamplona.amethyst.commons.actions.ConcordActions
 import com.vitorpamplona.amethyst.commons.emojicoder.EmojiCoder
 import com.vitorpamplona.amethyst.commons.model.ImmutableListOfLists
 import com.vitorpamplona.amethyst.commons.util.isValidUrl
+import com.vitorpamplona.quartz.buzz.invite.BuzzInviteLink
 import com.vitorpamplona.quartz.experimental.clink.pointers.ClinkPointerParser
 import com.vitorpamplona.quartz.experimental.clink.pointers.NOffer
 import com.vitorpamplona.quartz.experimental.inlineMetadata.Nip54InlineMetadata
@@ -392,6 +393,11 @@ class RichTextParser {
             if (word.contains("/invite/") && word.contains('#') && ConcordActions.parseInviteLink(word) != null) {
                 return ConcordInviteLinkSegment(word)
             }
+            // A Buzz invite is a plain `…/invite/<token>` https URL (no fragment, so disjoint from
+            // the Concord shape above). Same cheap gate before the base64 parse.
+            if (word.contains("/invite/") && BuzzInviteLink.parse(word) != null) {
+                return BuzzInviteLinkSegment(word)
+            }
             parseNowhereLink(word)?.let { return it }
             return LinkSegment(word)
         }

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

@@ -174,6 +174,16 @@ class ConcordInviteLinkSegment(
     segment: String,
 ) : Segment(segment)
 
+/**
+ * A Buzz workspace invite link (`https://<host>/invite/<token>`). Rendered as a tappable
+ * chip that opens the in-app join browser instead of the external browser, so the Buzz web
+ * app can sign the NIP-98 claim with the user's key via the injected `window.nostr`.
+ */
+@Immutable
+class BuzzInviteLinkSegment(
+    segment: String,
+) : Segment(segment)
+
 @Immutable
 class BlossomUriSegment(
     segment: String,

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

@@ -54,6 +54,7 @@ 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.BuzzInviteLinkSegment
 import com.vitorpamplona.amethyst.commons.richtext.CashuSegment
 import com.vitorpamplona.amethyst.commons.richtext.ClinkOfferSegment
 import com.vitorpamplona.amethyst.commons.richtext.ConcordInviteLinkSegment
@@ -179,7 +180,7 @@ private fun RenderWord(
             renderer.Url("https://${word.segmentText}", word.segmentText, Modifier)
         is NowhereLinkSegment -> renderer.NowhereLink(word, canPreview, Modifier)
 
-        is RelayUrlSegment, is RelayGroupLinkSegment, is ConcordInviteLinkSegment ->
+        is RelayUrlSegment, is RelayGroupLinkSegment, is ConcordInviteLinkSegment, is BuzzInviteLinkSegment ->
             renderer.RelayLink(word, Modifier)
 
         is InvoiceSegment, is WithdrawSegment, is CashuSegment, is ClinkOfferSegment ->