diff --git a/commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/actions/ConcordActions.kt b/commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/actions/ConcordActions.kt
index a724496c75..6ee5ed6dd7 100644
--- a/commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/actions/ConcordActions.kt
+++ b/commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/actions/ConcordActions.kt
@@ -135,7 +135,7 @@ object ConcordActions {
         return ConcordStreamEnvelope.wrap(rumor, channel, authorSigner, encrypted = true)
     }
 
-    /** Builds an encrypted-seal reply wrap (kind 9 quoting [parent]) on the [channel] plane. */
+    /** Builds an encrypted-seal thread-reply wrap (kind-1111 NIP-22 comment on [parent]) on the [channel] plane. */
     suspend fun buildChannelReply(
         authorSigner: NostrSigner,
         channel: GroupKey,
@@ -145,7 +145,7 @@ object ConcordActions {
         text: String,
         createdAt: Long,
     ): Event {
-        val rumor = ChannelChat.reply(authorSigner.pubKey, channelId, epoch, text, parent.id, parent.pubKey, createdAt)
+        val rumor = ChannelChat.reply(authorSigner.pubKey, channelId, epoch, text, parent, createdAt)
         return ConcordStreamEnvelope.wrap(rumor, channel, authorSigner, encrypted = true)
     }
 
diff --git a/commons/src/commonTest/kotlin/com/vitorpamplona/amethyst/commons/model/concord/ConcordCommunitySessionTest.kt b/commons/src/commonTest/kotlin/com/vitorpamplona/amethyst/commons/model/concord/ConcordCommunitySessionTest.kt
index 62b3dfba2c..f6090a8207 100644
--- a/commons/src/commonTest/kotlin/com/vitorpamplona/amethyst/commons/model/concord/ConcordCommunitySessionTest.kt
+++ b/commons/src/commonTest/kotlin/com/vitorpamplona/amethyst/commons/model/concord/ConcordCommunitySessionTest.kt
@@ -23,6 +23,7 @@ package com.vitorpamplona.amethyst.commons.model.concord
 import com.vitorpamplona.amethyst.commons.actions.ConcordActions
 import com.vitorpamplona.quartz.concord.cord02Community.ConcordCommunityFactory
 import com.vitorpamplona.quartz.concord.cord02Community.ConcordCommunityListEntry
+import com.vitorpamplona.quartz.concord.cord03Channels.ChannelChat
 import com.vitorpamplona.quartz.nip01Core.core.toHexKey
 import com.vitorpamplona.quartz.nip01Core.crypto.KeyPair
 import com.vitorpamplona.quartz.nip01Core.signers.NostrSignerInternal
@@ -80,12 +81,16 @@ class ConcordCommunitySessionTest {
             assertEquals("🤙", reaction.content)
             assertEquals(message.id, reaction.tags.first { it[0] == "e" }[1])
 
-            // A reply decrypts as a kind-9 quoting the parent via a `q` tag.
+            // A reply decrypts as a kind-1111 NIP-22 thread comment: uppercase `E` at the thread
+            // root and lowercase `e` at the immediate parent (both the message here), still bound
+            // to the channel so it groups into the message's thread — the shape Armada threads.
             val replyWrap = ConcordActions.buildChannelReply(owner, general, community.generalChannelIdHex, community.rootEpoch, message, "gm back", 4L)
             assertTrue(session.ingest(replyWrap))
             val reply = captured.map { it.third }.first { it.content == "gm back" }
-            assertEquals(9, reply.kind)
-            assertEquals(message.id, reply.tags.first { it[0] == "q" }[1])
+            assertEquals(1111, reply.kind)
+            assertEquals(message.id, reply.tags.first { it[0] == "E" }[1])
+            assertEquals(message.id, reply.tags.first { it[0] == "e" }[1])
+            assertTrue(ChannelChat.isBoundTo(reply, community.generalChannelIdHex, community.rootEpoch))
 
             // A stray wrap from a different community is ignored.
             val outsider = ConcordCommunityFactory.create(owner, "Other", createdAt = 1L, relays = listOf("wss://r.example"))
diff --git a/quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/concord/cord03Channels/ChannelChat.kt b/quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/concord/cord03Channels/ChannelChat.kt
index dc337250d1..acc65d34f4 100644
--- a/quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/concord/cord03Channels/ChannelChat.kt
+++ b/quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/concord/cord03Channels/ChannelChat.kt
@@ -24,6 +24,8 @@ import com.vitorpamplona.quartz.concord.cord03Channels.tags.ChannelTag
 import com.vitorpamplona.quartz.concord.cord03Channels.tags.EpochTag
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.hints.EventHintBundle
+import com.vitorpamplona.quartz.nip22Comments.CommentEvent
 import com.vitorpamplona.quartz.nip25Reactions.ReactionEvent
 import com.vitorpamplona.quartz.nip59Giftwrap.rumors.RumorAssembler
 import com.vitorpamplona.quartz.nipC7Chats.ChatEvent
@@ -63,26 +65,32 @@ object ChannelChat {
         )
 
     /**
-     * Builds an unsigned kind-9 reply rumor bound to [channelId]/[epoch], quoting
-     * [parentId] (a `q` tag, NIP-C7 style) and crediting its author with a `p` tag.
-     * Reuses [message], so it is a normal channel message that also threads.
+     * Builds an unsigned kind-1111 **thread reply** ([CommentEvent], NIP-22) to
+     * [parent], bound to [channelId]/[epoch].
+     *
+     * A thread reply is a NIP-22 comment — NOT a kind-9 message with a `q` tag
+     * (which NIP-C7 reserves for *inline quotes* that clients deliberately keep out
+     * of threads). [CommentEvent.replyBuilder] emits the uppercase `K`/`E`/`P`
+     * pointers at the immutable thread root and the lowercase `k`/`e`/`p` pointers
+     * at the immediate [parent] (inheriting the root when [parent] is itself a
+     * comment, so the root is stable at any depth). We add the same
+     * `["channel", …]` + `["epoch", …]` binding every Chat Plane rumor carries, so
+     * the reply is verifiable against the plane it arrives on. This is exactly the
+     * shape Soapbox Armada builds and groups into a message's thread.
      */
     fun reply(
         authorPubKey: HexKey,
         channelId: HexKey,
         epoch: Long,
         text: String,
-        parentId: HexKey,
-        parentAuthor: HexKey,
+        parent: Event,
         createdAt: Long,
     ): Event =
-        message(
-            authorPubKey = authorPubKey,
-            channelId = channelId,
-            epoch = epoch,
-            text = text,
-            createdAt = createdAt,
-            extraTags = arrayOf(arrayOf("q", parentId), arrayOf("p", parentAuthor)),
+        RumorAssembler.assembleRumor(
+            authorPubKey,
+            CommentEvent.replyBuilder(text, EventHintBundle(parent), createdAt) {
+                channelBinding(channelId, epoch)
+            },
         )
 
     /**