refactor(buzz): typed thread/p tags in composer + dialect bootstrap + live join/leave proof

Review feedback: the 40002 composer branch hand-rolled raw arrayOf tags. Now:

- New shared `buzz/threading` package: `buzzThread(root, parent)` builder verb
  emitting Buzz's exact thread_tags wire form (["e",root,"","root"] +
  ["e",parent,"","reply"], collapsing when parent==root; the empty relay slot
  is deliberate — MarkedETag.assemble's arrayOfNotNull would slide the marker
  into the relay slot) and `buzzThreadRoot()/buzzThreadReply()` positional
  readers. The forum verbs now delegate to it (streams and forum comments share
  thread_tags in buzz-sdk), and the composer uses buzzThread + the typed
  pTag(PTag(...)) verb instead of raw arrays.

- Dialect bootstrap fix: the single-group open-channel REQ now always includes
  the Buzz timeline kinds. Without this, an undiscovered Buzz relay was a
  chicken-and-egg: fleet subs only widen after BuzzRelayDialect marks the
  relay, but the mark comes from consuming a Buzz kind no filter asked for.
  Opening a channel is explicit one-group intent, so the wider ask is cheap and
  matches nothing on vanilla relays; fleet-wide subs stay dialect-gated
  (both behaviors pinned in BuzzTimelineKindsTest). The live relay's NIP-11
  ("Buzz Relay", supported_extensions=[nip-er,nip-pl]) is a future
  connect-time marker.

- Live proof of the full workspace lifecycle against the running Buzz relay
  (BuzzRelayLiveInteropTest, 3/3 green): discover the channel via its
  relay-signed 39000 (queryable by #d), join with NIP-29 kind-9021 from a
  second member, post a 40002 after joining, and leave with kind-9022 — the
  exact Quartz events Amethyst's group UI sends.

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

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/publicChannels/relayGroup/datasource/RelayGroupFilterBuilders.kt

@@ -180,7 +180,15 @@ fun buildRelayGroupJoinedChatTailFilters(
         )
     }
 
-/** The recent-chat live tail for a single open group, `#h`-scoped on its host relay. */
+/**
+ * The recent-chat live tail for a single open group, `#h`-scoped on its host relay.
+ *
+ * Always requests the FULL kind set (NIP-29 + Buzz): this single-group REQ is the
+ * dialect-detection bootstrap. Fleet-wide subs only widen once [BuzzRelayDialect] marks
+ * the relay, but the mark comes from consuming a Buzz kind — which never arrives if no
+ * filter asks for one. Opening a channel is explicit user intent on one group, so the
+ * wider ask is cheap, and on a vanilla relay the extra kinds simply match nothing.
+ */
 fun buildRelayGroupOpenChatTailFilter(
     groupId: GroupId,
     sinceEpoch: Long,
@@ -189,7 +197,7 @@ fun buildRelayGroupOpenChatTailFilter(
         relay = groupId.relayUrl,
         filter =
             Filter(
-                kinds = relayGroupTimelineKinds(groupId.relayUrl),
+                kinds = RELAY_GROUP_TIMELINE_KINDS + BUZZ_RELAY_GROUP_TIMELINE_EXTRA_KINDS,
                 tags = mapOf(GroupIdTag.TAG_NAME to listOf(groupId.id)),
                 since = sinceEpoch,
             ),

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/publicChannels/send/ChannelNewMessageViewModel.kt

@@ -70,6 +70,8 @@ import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.utils.ChatFileUploadS
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.home.UserSuggestionAnchor
 import com.vitorpamplona.amethyst.ui.stringRes
 import com.vitorpamplona.quartz.buzz.stream.StreamMessageV2Event
+import com.vitorpamplona.quartz.buzz.threading.buzzThread
+import com.vitorpamplona.quartz.buzz.threading.buzzThreadRoot
 import com.vitorpamplona.quartz.experimental.bitchat.geohash.GeohashChatEvent
 import com.vitorpamplona.quartz.experimental.ephemChat.chat.EphemeralChatEvent
 import com.vitorpamplona.quartz.experimental.nip95.data.FileStorageEvent
@@ -87,6 +89,7 @@ import com.vitorpamplona.quartz.nip01Core.tags.events.ETag
 import com.vitorpamplona.quartz.nip01Core.tags.geohash.geohash
 import com.vitorpamplona.quartz.nip01Core.tags.geohash.getGeoHash
 import com.vitorpamplona.quartz.nip01Core.tags.hashtags.hashtags
+import com.vitorpamplona.quartz.nip01Core.tags.people.PTag
 import com.vitorpamplona.quartz.nip01Core.tags.people.pTag
 import com.vitorpamplona.quartz.nip01Core.tags.people.toPTag
 import com.vitorpamplona.quartz.nip01Core.tags.references.references
@@ -688,16 +691,13 @@ open class ChannelNewMessageViewModel :
                 // clients send. Checked BEFORE RelayGroupChannel: Buzz is a subclass.
                 StreamMessageV2Event.build(channel.groupId.id, tagger.message) {
                     replyTo.value?.let { parent ->
-                        val parentRoot =
-                            parent.event
-                                ?.tags
-                                ?.firstOrNull { it.size >= 4 && it[0] == "e" && it[3] == "root" }
-                                ?.get(1)
-                        if (parentRoot != null && parentRoot != parent.idHex) {
-                            add(arrayOf("e", parentRoot, "", "root"))
-                        }
-                        add(arrayOf("e", parent.idHex, "", "reply"))
-                        parent.author?.pubkeyHex?.let { add(arrayOf("p", it)) }
+                        // Replying inside the parent's thread: the parent's own root
+                        // marker (when it is itself a reply) becomes our root, else the
+                        // parent starts the thread. buzzThread collapses to a single
+                        // "reply" marker when root == parent, per thread_tags.
+                        val root = parent.event?.tags?.buzzThreadRoot() ?: parent.idHex
+                        buzzThread(root, parent.idHex)
+                        parent.author?.pubkeyHex?.let { pTag(PTag(it)) }
                     }
 
                     hashtags(findHashtags(tagger.message))

amethyst/src/test/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/publicChannels/relayGroup/datasource/BuzzTimelineKindsTest.kt

@@ -24,6 +24,7 @@ import com.vitorpamplona.amethyst.commons.model.buzz.BuzzRelayDialect
 import com.vitorpamplona.quartz.buzz.stream.StreamMessageV2Event
 import com.vitorpamplona.quartz.nip01Core.relay.normalizer.RelayUrlNormalizer
 import com.vitorpamplona.quartz.nip29RelayGroups.GroupId
+import com.vitorpamplona.quartz.nip51Lists.simpleGroupList.GroupTag
 import org.junit.After
 import org.junit.Assert.assertEquals
 import org.junit.Assert.assertFalse
@@ -67,13 +68,29 @@ class BuzzTimelineKindsTest {
     }
 
     @Test
-    fun openChatTailFilterCarriesBuzzKindsOnlyOnBuzzRelays() {
+    fun openChatTailAlwaysCarriesBuzzKindsAsDialectBootstrap() {
+        // The single-group open-channel REQ is what DISCOVERS the dialect: with no
+        // filter asking for a Buzz kind, none ever arrives and the relay is never
+        // marked. It therefore always includes the Buzz kinds, even unmarked.
+        val vanillaFilter = buildRelayGroupOpenChatTailFilter(GroupId("g1", vanillaRelay), sinceEpoch = 0L)
+        assertTrue(vanillaFilter.filter.kinds!!.contains(StreamMessageV2Event.KIND))
+    }
+
+    @Test
+    fun fleetWideJoinedTailWidensOnlyOnMarkedRelays() {
         BuzzRelayDialect.mark(buzzRelay)
 
-        val buzzFilter = buildRelayGroupOpenChatTailFilter(GroupId("g1", buzzRelay), sinceEpoch = 0L)
-        val vanillaFilter = buildRelayGroupOpenChatTailFilter(GroupId("g1", vanillaRelay), sinceEpoch = 0L)
+        val filters =
+            buildRelayGroupJoinedChatTailFilters(
+                listOf(
+                    GroupTag("g1", buzzRelay.url),
+                    GroupTag("g2", vanillaRelay.url),
+                ),
+                sinceEpoch = 0L,
+            )
 
-        assertTrue(buzzFilter.filter.kinds!!.contains(StreamMessageV2Event.KIND))
-        assertFalse(vanillaFilter.filter.kinds!!.contains(StreamMessageV2Event.KIND))
+        val byRelay = filters.associateBy { it.relay }
+        assertTrue(byRelay[buzzRelay]!!.filter.kinds!!.contains(StreamMessageV2Event.KIND))
+        assertFalse(byRelay[vanillaRelay]!!.filter.kinds!!.contains(StreamMessageV2Event.KIND))
     }
 }

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/buzz/forum/TagArrayBuilderExt.kt

@@ -20,12 +20,12 @@
  */
 package com.vitorpamplona.quartz.buzz.forum
 
+import com.vitorpamplona.quartz.buzz.threading.buzzThread
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
 import com.vitorpamplona.quartz.nip01Core.tags.events.ETag
 import com.vitorpamplona.quartz.nip01Core.tags.people.PTag
-import com.vitorpamplona.quartz.nip10Notes.tags.MarkedETag
 import com.vitorpamplona.quartz.nip29RelayGroups.tags.GroupIdTag
 
 /** The `h` channel tag (NIP-29) scoping a Buzz forum event to its channel UUID. */
@@ -38,19 +38,11 @@ fun <T : Event> TagArrayBuilder<T>.forumMentions(mentions: List<HexKey>) = menti
 fun <T : Event> TagArrayBuilder<T>.forumVoteTarget(targetEventId: HexKey) = addUnique(ETag.assemble(targetEventId, null, null))
 
 /**
- * NIP-10 thread e-tags for a forum comment, matching `thread_tags` in `builders.rs`:
- * - direct reply (`root == parent`): one `["e", root, "", "reply"]`
- * - nested reply (`root != parent`): `["e", root, "", "root"]` + `["e", parent, "", "reply"]`
- *
- * The empty relay slot is emitted verbatim so the marker stays at index 3, matching the
- * reference wire form.
+ * NIP-10 thread e-tags for a forum comment. Buzz threads streams and forum comments
+ * identically (`thread_tags` in `builders.rs`), so this delegates to the shared
+ * [buzzThread] verb.
  */
 fun <T : Event> TagArrayBuilder<T>.forumThread(
     rootEventId: HexKey,
     parentEventId: HexKey,
-) = if (rootEventId == parentEventId) {
-    add(arrayOf(MarkedETag.TAG_NAME, rootEventId, "", MarkedETag.MARKER.REPLY.code))
-} else {
-    add(arrayOf(MarkedETag.TAG_NAME, rootEventId, "", MarkedETag.MARKER.ROOT.code))
-    add(arrayOf(MarkedETag.TAG_NAME, parentEventId, "", MarkedETag.MARKER.REPLY.code))
-}
+) = buzzThread(rootEventId, parentEventId)

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/buzz/forum/TagArrayExt.kt

@@ -20,12 +20,13 @@
  */
 package com.vitorpamplona.quartz.buzz.forum
 
+import com.vitorpamplona.quartz.buzz.threading.buzzThreadReply
+import com.vitorpamplona.quartz.buzz.threading.buzzThreadRoot
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.TagArray
 import com.vitorpamplona.quartz.nip01Core.core.firstTagValue
 import com.vitorpamplona.quartz.nip01Core.tags.events.ETag
 import com.vitorpamplona.quartz.nip01Core.tags.people.PTag
-import com.vitorpamplona.quartz.nip10Notes.tags.MarkedETag
 import com.vitorpamplona.quartz.nip29RelayGroups.tags.GroupIdTag
 
 /** The `h` channel UUID this forum event belongs to. */
@@ -37,17 +38,8 @@ fun TagArray.forumMentions(): List<HexKey> = mapNotNull(PTag::parseKey)
 /** The `e` target event of a forum vote (`kind:45002`). */
 fun TagArray.forumVoteTarget(): HexKey? = firstNotNullOfOrNull(ETag::parseId)
 
-// Reads the NIP-10 marker positionally: the Buzz wire form keeps an explicit empty
-// relay slot (`["e", id, "", "reply"]`), so the marker sits at index 3. A relay-less
-// 3-element form (`["e", id, "reply"]`) is tolerated with the marker at index 2.
-private fun Array<String>.markedEventId(marker: MarkedETag.MARKER): HexKey? {
-    if (size < 3 || this[0] != MarkedETag.TAG_NAME || this[1].length != 64) return null
-    val code = marker.code
-    return if ((size >= 4 && this[3] == code) || this[2] == code) this[1] else null
-}
-
 /** The NIP-10 `root`-marked thread event id of a forum comment (null for a direct reply). */
-fun TagArray.forumThreadRoot(): HexKey? = firstNotNullOfOrNull { it.markedEventId(MarkedETag.MARKER.ROOT) }
+fun TagArray.forumThreadRoot(): HexKey? = buzzThreadRoot()
 
 /** The NIP-10 `reply`-marked immediate-parent event id of a forum comment. */
-fun TagArray.forumThreadReply(): HexKey? = firstNotNullOfOrNull { it.markedEventId(MarkedETag.MARKER.REPLY) }
+fun TagArray.forumThreadReply(): HexKey? = buzzThreadReply()

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/buzz/threading/TagArrayBuilderExt.kt

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.quartz.buzz.threading
+
+import com.vitorpamplona.quartz.nip01Core.core.Event
+import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.core.TagArrayBuilder
+import com.vitorpamplona.quartz.nip10Notes.tags.MarkedETag
+
+/**
+ * Buzz's NIP-10 thread e-tags, shared by stream messages (40002) and forum comments
+ * (45003) — both mirror `thread_tags` in `buzz-sdk/src/builders.rs`:
+ * - direct reply (`root == parent`): one `["e", root, "", "reply"]`
+ * - nested reply (`root != parent`): `["e", root, "", "root"]` + `["e", parent, "", "reply"]`
+ *
+ * The empty relay slot is emitted verbatim so the marker stays at index 3, matching the
+ * reference wire form. ([MarkedETag.assemble] cannot be used here: its `arrayOfNotNull`
+ * drops the null relay slot, sliding the marker into index 2.)
+ */
+fun <T : Event> TagArrayBuilder<T>.buzzThread(
+    rootEventId: HexKey,
+    parentEventId: HexKey,
+) = if (rootEventId == parentEventId) {
+    add(arrayOf(MarkedETag.TAG_NAME, rootEventId, "", MarkedETag.MARKER.REPLY.code))
+} else {
+    add(arrayOf(MarkedETag.TAG_NAME, rootEventId, "", MarkedETag.MARKER.ROOT.code))
+    add(arrayOf(MarkedETag.TAG_NAME, parentEventId, "", MarkedETag.MARKER.REPLY.code))
+}

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/buzz/threading/TagArrayExt.kt

@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.quartz.buzz.threading
+
+import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.core.TagArray
+import com.vitorpamplona.quartz.nip10Notes.tags.MarkedETag
+
+/**
+ * Positional reader for Buzz's thread e-tags (`["e", id, "", "root"|"reply"]`).
+ * [MarkedETag.parse] rejects the empty relay slot Buzz emits, so the marker is read
+ * positionally: index 3 in the canonical 4-element form, tolerating the relay-less
+ * 3-element form (`["e", id, "reply"]`) with the marker at index 2.
+ */
+private fun Array<String>.buzzMarkedEventId(marker: MarkedETag.MARKER): HexKey? {
+    if (size < 3 || this[0] != MarkedETag.TAG_NAME || this[1].length != 64) return null
+    val code = marker.code
+    return if ((size >= 4 && this[3] == code) || this[2] == code) this[1] else null
+}
+
+/** The thread root this event replies under, from its marked `root` e-tag. */
+fun TagArray.buzzThreadRoot(): HexKey? = firstNotNullOfOrNull { it.buzzMarkedEventId(MarkedETag.MARKER.ROOT) }
+
+/** The direct parent this event replies to, from its marked `reply` e-tag. */
+fun TagArray.buzzThreadReply(): HexKey? = firstNotNullOfOrNull { it.buzzMarkedEventId(MarkedETag.MARKER.REPLY) }

quartz/src/jvmTest/kotlin/com/vitorpamplona/quartz/buzz/interop/BuzzRelayLiveInteropTest.kt

@@ -29,6 +29,8 @@ import com.vitorpamplona.quartz.nip01Core.crypto.KeyPair
 import com.vitorpamplona.quartz.nip01Core.relay.normalizer.RelayUrlNormalizer
 import com.vitorpamplona.quartz.nip01Core.signers.NostrSignerInternal
 import com.vitorpamplona.quartz.nip29RelayGroups.moderation.CreateGroupEvent
+import com.vitorpamplona.quartz.nip29RelayGroups.request.JoinRequestEvent
+import com.vitorpamplona.quartz.nip29RelayGroups.request.LeaveRequestEvent
 import com.vitorpamplona.quartz.nip42RelayAuth.RelayAuthEvent
 import kotlinx.coroutines.runBlocking
 import okhttp3.OkHttpClient
@@ -192,6 +194,71 @@ class BuzzRelayLiveInteropTest {
         }
     }
 
+    /**
+     * The workspace lifecycle Amethyst's group UI drives: discover the channel via its
+     * relay-signed 39000 metadata, join it with a NIP-29 kind-9021 request from a
+     * different member, post into it, then leave with kind-9022 — all against the real
+     * relay, using the exact Quartz events the UI sends.
+     */
+    @Test
+    fun discoverJoinPostAndLeave() {
+        if (!envReady() || ownerSk == null) {
+            println("SKIP: BUZZ_RELAY_WS / BUZZ_MEMBER_SK / BUZZ_OWNER_SK not set")
+            return
+        }
+        runBlocking {
+            val creator = NostrSignerInternal(KeyPair(memberSk!!.hexToByteArray()))
+            val (ws, frames) = authedSocket(creator)
+
+            val channelId = UUID.randomUUID().toString()
+            val create =
+                creator.sign(
+                    CreateGroupEvent.build(channelId) {
+                        add(arrayOf("name", "amethyst-lifecycle"))
+                    },
+                )
+            ws.send("""["EVENT",${create.toJson()}]""")
+            assertTrue("true" in frames.nextOf("OK"))
+
+            // SEE: the relay-signed kind-39000 discovery metadata must be queryable —
+            // this is what materializes the channel in Amethyst's group directory.
+            ws.send("""["REQ","meta",{"kinds":[39000],"#d":["$channelId"]}]""")
+            val metaFrame = frames.nextOf("EVENT")
+            val meta = Event.fromJson(metaFrame.substringAfter(",\"meta\",").dropLast(1))
+            assertEquals(39000, meta.kind)
+            assertTrue(
+                meta.tags.any { it.size > 1 && it[0] == "d" && it[1] == channelId },
+                "39000 must be addressed by the channel id",
+            )
+            frames.nextOf("EOSE")
+
+            // JOIN: a different workspace member requests membership with kind 9021 —
+            // the same event Amethyst's NIP-29 Join button sends.
+            val joiner = NostrSignerInternal(KeyPair(ownerSk.hexToByteArray()))
+            val (ws2, frames2) = authedSocket(joiner)
+            val join =
+                joiner.sign(
+                    JoinRequestEvent.build(channelId),
+                )
+            ws2.send("""["EVENT",${join.toJson()}]""")
+            val joinOk = frames2.nextOf("OK")
+            assertTrue("true" in joinOk, "join (9021) should be accepted: $joinOk")
+
+            // POST: the joiner can now publish a 40002 into the channel.
+            val msg = joiner.sign(StreamMessageV2Event.build(channelId, "joined and posting"))
+            ws2.send("""["EVENT",${msg.toJson()}]""")
+            assertTrue("true" in frames2.nextOf("OK"), "post after join should be accepted")
+
+            // LEAVE: kind 9022, the NIP-29 leave request.
+            val leave = joiner.sign(LeaveRequestEvent.build(channelId))
+            ws2.send("""["EVENT",${leave.toJson()}]""")
+            assertTrue("true" in frames2.nextOf("OK"), "leave (9022) should be accepted")
+
+            ws.close(1000, "done")
+            ws2.close(1000, "done")
+        }
+    }
+
     @Test
     fun agentAuthenticatesViaOwnerAttestation() {
         if (!envReady() || ownerSk == null) {