refactor(concord): chat plane reuses standard events + typed binding tags

First slice of the nip88Polls-structure refactor (plan in quartz/plans/ 2026-07-11-concord-event-classes.md). A Concord chat rumor IS a standard Nostr event plus a channel/epoch binding, so stop re-deriving it by kind number: - New cord03Channels/tags/ChannelTag + EpochTag (typed, parse/assemble), plus TagArrayBuilderExt (channel/epoch/channelBinding) and TagArrayExt (concordChannel/concordEpoch/isConcordBoundTo) — the poll-package shape. - ChannelChat.message/reply now build via ChatEvent.build{ channelBinding(...) } and assemble the template into a rumor; reaction reuses ReactionEvent.KIND. The minimal e/p/k reaction tags and q/p reply tags are kept byte-identical for Armada interop (guarded by the Concord round-trip tests, which pass). - Drop the ConcordKinds.MESSAGE/COMMENT/REACTION/DELETE aliases (they shadowed ChatEvent/CommentEvent/ReactionEvent/DeletionEvent KINDs); callers use the real event KINDs. VoicePresence uses the new tag classes instead of bindingTags. Remaining Concord-specific kinds (control 3308, invites, guestbook, rekey, voice, seals/wrap) get their own per-kind packages in later slices per the plan. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01CzJ2Cwo8tg4oZq43oRa3ig
2026-10-05 19:28:25 +00:00 · 2026-07-11 04:05:07 +00:00
parent f18ba03a48
commit c2cbd602bc
10 changed files with 316 additions and 52 deletions
@@ -40,6 +40,7 @@ import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.hexToByteArray
 import com.vitorpamplona.quartz.nip01Core.relay.filters.Filter
 import com.vitorpamplona.quartz.nip01Core.signers.NostrSigner
+import com.vitorpamplona.quartz.nipC7Chats.ChatEvent

 /** One decrypted, verified Concord channel message projected for display. */
 data class ConcordChatMessage(
@@ -173,7 +174,7 @@ object ConcordActions {
    ): List<ConcordChatMessage> =
        wraps
            .mapNotNull { wrap -> ConcordStreamEnvelope.openOrNull(wrap, channel)?.rumor }
-            .filter { it.kind == ConcordKinds.MESSAGE && ChannelChat.isBoundTo(it, channelId, epoch) }
+            .filter { it.kind == ChatEvent.KIND && ChannelChat.isBoundTo(it, channelId, epoch) }
            .map { ConcordChatMessage(it.id, it.pubKey, it.content, it.createdAt, channelId, epoch) }
            .sortedWith(compareBy({ it.createdAt }, { it.id }))

@@ -23,10 +23,10 @@ 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.events.ConcordKinds
 import com.vitorpamplona.quartz.nip01Core.core.toHexKey
 import com.vitorpamplona.quartz.nip01Core.crypto.KeyPair
 import com.vitorpamplona.quartz.nip01Core.signers.NostrSignerInternal
+import com.vitorpamplona.quartz.nipC7Chats.ChatEvent
 import kotlinx.coroutines.test.runTest
 import kotlin.test.Test
 import kotlin.test.assertEquals
@@ -73,7 +73,7 @@ class ConcordPlaneRegistryTest {
            assertNotNull(routedMsg)
            assertEquals(ConcordPlaneKind.CHANNEL, routedMsg.plane.kind)
            assertEquals(community.generalChannelIdHex, routedMsg.plane.channelId?.channelId)
-            assertEquals(ConcordKinds.MESSAGE, routedMsg.opened.rumor.kind)
+            assertEquals(ChatEvent.KIND, routedMsg.opened.rumor.kind)
            assertEquals("gm", routedMsg.opened.rumor.content)

            // A wrap from an unrelated plane (different community) is not ours.
@@ -0,0 +1,82 @@
+# Concord event layer → per-kind Event classes (nip88Polls structure)
+
+## Why
+
+The Concord quartz layer currently centralizes wire kinds in a single
+`concord/events/ConcordKinds.kt` constant object and hand-rolls rumors with raw
+string tags (see `cord03Channels/ChannelChat.kt`:
+`RumorAssembler.assembleRumor(kind = ConcordKinds.MESSAGE, tags = arrayOf(arrayOf("q", …)))`).
+Two problems:
+
+1. **Duplicates standard Nostr kinds.** `ConcordKinds.MESSAGE=9`, `REACTION=7`,
+   `DELETE=5`, `COMMENT=1111`, `EDIT=3302` shadow `ChatEvent.KIND`,
+   `ReactionEvent.KIND`, `DeletionEvent.KIND`, `CommentEvent.KIND`. Concord chat
+   rumors *are* those standard events (they already parse back as `ChatEvent`
+   etc. on read) — the build side should reuse the classes, not re-derive by
+   number.
+2. **No per-event structure.** Every other protocol in quartz gives each event
+   kind a package: `XxxEvent.kt` (the `Event` subclass + `build`), plus
+   `TagArrayBuilderExt.kt` / `TagArrayExt.kt` and a `tags/` folder of typed tag
+   classes (`nip88Polls/poll/…` is the reference). Concord instead has loose
+   builders (`ChannelChat`, `ControlEditionBuilder`) and stringly-typed tags.
+
+Target: match the `nip88Polls` shape. Reuse standard events where the protocol
+uses standard kinds; give each genuinely-Concord kind its own package.
+
+## Reuse standard events (chat plane, CORD-03)
+
+A Concord chat rumor is a standard event + a `["channel", id]` + `["epoch", n]`
+binding. Introduce a binding-tag package and reuse the standard builders:
+
+- `cord03Channels/tags/ChannelTag.kt`, `tags/EpochTag.kt` — typed tags.
+- `cord03Channels/TagArrayBuilderExt.kt` — `channel(id)`, `epoch(n)` on the DSL.
+- `cord03Channels/TagArrayExt.kt` — `channelId()`, `epoch()`, `isBoundTo(...)`.
+
+| rumor | reuse | binding |
+|---|---|---|
+| message (9) | `ChatEvent.build` | `channel` + `epoch` |
+| reply (9 + q) | `ChatEvent.build` + `q`/`p` | `channel` + `epoch` |
+| reaction (7) | `ReactionEvent.build` | `channel` + `epoch` |
+| delete (5) | `DeletionEvent.build` | `channel` + `epoch` |
+
+`ChannelChat` keeps its public API (returns unsigned rumors via `RumorAssembler`)
+but builds tags from the standard event's DSL + the binding ext. Delete
+`ConcordKinds.MESSAGE/REACTION/DELETE/COMMENT/EDIT`.
+
+**Interop guard:** the exact on-wire tags must stay byte-identical to today's
+output (Armada compat). Keep `["q", parentId]` + `["p", parentAuthor]` for
+replies and `["e"/"p"/"k"]` for reactions — do not switch to `QEventTag`'s
+3-element form. Verify with `ConcordPlaneRegistryTest` + an amy↔Armada round-trip.
+
+## New per-kind Event classes (genuinely Concord)
+
+Each gets `concord/<cordXX>/<name>/XxxEvent.kt` + `TagArrayBuilderExt` +
+`TagArrayExt` + `tags/`:
+
+| kind | event | CORD |
+|---|---|---|
+| 3308 | `ControlEditionEvent` (from `ControlEdition`/`ControlEditionBuilder`) | 02/04/06 |
+| 3303 | `RekeyEvent` | 06 |
+| 3306 / 3309 / 3312 | `GuestbookJoinLeaveEvent` / `KickEvent` / `SnapshotEvent` | 02 |
+| 3313 | `DirectInviteEvent` | 05 |
+| 23311 / 23313 | `TypingEvent` / `VoicePresenceEvent` | 03/07 |
+| 3310 | `WebxdcEvent` | 03 |
+| 33301 | `InviteBundleEvent` (from `ConcordInviteBundle`) | 05 |
+| 13303 | `InviteListEvent` | 05 |
+| 20013 / 20014 / 1059 / 21059 | envelope seals + inverted wrap | 01 |
+
+`ConcordCommunityListEvent` (13302) is already an `Event` class (now a
+`BaseReplaceableEvent`) — keep, just move under a per-kind package if desired.
+
+After the move, `ConcordKinds` retains only the truly-Concord kinds (envelope,
+control, rekey, guestbook, invites, voice), not the standard-Nostr aliases.
+
+## Sequencing (incremental, compile + interop-test each)
+
+1. Chat plane reuse (this doc's first section) — smallest blast radius (4 refs),
+   highest clarity. **← start here.**
+2. Control plane 3308 → `ControlEditionEvent` package.
+3. Invites 33301 / 3313 / 13303.
+4. Guestbook + voice + rekey.
+5. Envelope seals/wrap.
+6. Shrink `ConcordKinds`, delete dead constants, update `EventFactory`.
@@ -20,36 +20,31 @@
 */
 package com.vitorpamplona.quartz.concord.cord03Channels

-import com.vitorpamplona.quartz.concord.events.ConcordKinds
+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.core.firstTagValue
+import com.vitorpamplona.quartz.nip25Reactions.ReactionEvent
 import com.vitorpamplona.quartz.nip59Giftwrap.rumors.RumorAssembler
+import com.vitorpamplona.quartz.nipC7Chats.ChatEvent

 /**
 * Chat Plane message binding (CORD-03).
 *
- * Every Chat Plane rumor — a message, reply, reaction, edit, or delete — commits
- * to the channel and epoch it belongs to via `["channel", <id>]` and
- * `["epoch", <n>]` tags inside the author-signed rumor. Recipients enforce this
- * binding ([isBoundTo]) so an event lifted from one channel/epoch can't be
- * replayed into another.
+ * A Concord chat rumor **is** a standard Nostr event — a kind-9 [ChatEvent]
+ * message/reply or a kind-7 [ReactionEvent] — that additionally commits to the
+ * channel and epoch it belongs to via `["channel", <id>]` + `["epoch", <n>]` tags
+ * (see [channel]/[epoch] and [ChannelTag]/[EpochTag]). This object reuses the
+ * standard event builders and only adds the binding, so the same event classes
+ * that render everywhere else in the app render Concord messages too. Recipients
+ * enforce the binding ([TagArray.isConcordBoundTo]) so an event lifted from one
+ * channel/epoch can't be replayed into another.
 */
 object ChannelChat {
-    const val TAG_CHANNEL = "channel"
-    const val TAG_EPOCH = "epoch"
-
-    /** Builds the channel/epoch binding tags shared by every Chat Plane rumor. */
-    fun bindingTags(
-        channelId: HexKey,
-        epoch: Long,
-    ): Array<Array<String>> = arrayOf(arrayOf(TAG_CHANNEL, channelId), arrayOf(TAG_EPOCH, epoch.toString()))
-
    /**
-     * Builds an unsigned kind-9 chat message rumor bound to [channelId]/[epoch].
+     * Builds an unsigned kind-9 [ChatEvent] rumor bound to [channelId]/[epoch].
     * Wrap it for the channel plane with
-     * [com.vitorpamplona.quartz.concord.envelope.ConcordStreamEnvelope] (encrypted
-     * seal) to publish.
+     * [com.vitorpamplona.quartz.concord.envelope.ConcordStreamEnvelope] to publish.
     */
    fun message(
        authorPubKey: HexKey,
@@ -60,11 +55,11 @@ object ChannelChat {
        extraTags: Array<Array<String>> = emptyArray(),
    ): Event =
        RumorAssembler.assembleRumor(
-            pubKey = authorPubKey,
-            createdAt = createdAt,
-            kind = ConcordKinds.MESSAGE,
-            tags = bindingTags(channelId, epoch) + extraTags,
-            content = text,
+            authorPubKey,
+            ChatEvent.build(text, createdAt) {
+                channelBinding(channelId, epoch)
+                extraTags.forEach { addUnique(it) }
+            },
        )

    /**
@@ -91,10 +86,12 @@ object ChannelChat {
        )

    /**
-     * Builds an unsigned kind-7 reaction rumor bound to [channelId]/[epoch] against
-     * the target message ([targetId]/[targetAuthor]/[targetKind]). [content] is the
-     * reaction (e.g. `"+"`, `"🤙"`). On the receiving side this decrypts to a normal
-     * kind-7 that wires to its target Note by the `e` tag through the shared cache.
+     * Builds an unsigned kind-7 [ReactionEvent] rumor bound to [channelId]/[epoch]
+     * against the target message ([targetId]/[targetAuthor]/[targetKind]). [content]
+     * is the reaction (e.g. `"+"`, `"🤙"`). Kept to the minimal `e`/`p`/`k` tag form
+     * (no relay hints) so it stays wire-identical across clients. On the receiving
+     * side it decrypts to a normal kind-7 that wires to its target Note by the `e`
+     * tag through the shared cache.
     */
    fun reaction(
        authorPubKey: HexKey,
@@ -106,34 +103,34 @@ object ChannelChat {
        content: String,
        createdAt: Long,
    ): Event =
-        RumorAssembler.assembleRumor(
+        RumorAssembler.assembleRumor<ReactionEvent>(
            pubKey = authorPubKey,
            createdAt = createdAt,
-            kind = ConcordKinds.REACTION,
+            kind = ReactionEvent.KIND,
            tags =
-                bindingTags(channelId, epoch) +
-                    arrayOf(
-                        arrayOf("e", targetId),
-                        arrayOf("p", targetAuthor),
-                        arrayOf("k", targetKind.toString()),
-                    ),
+                arrayOf(
+                    ChannelTag.assemble(channelId),
+                    EpochTag.assemble(epoch),
+                    arrayOf("e", targetId),
+                    arrayOf("p", targetAuthor),
+                    arrayOf("k", targetKind.toString()),
+                ),
            content = content,
        )

    /** The channel id a Chat Plane [rumor] is bound to, or null if unbound. */
-    fun channelOf(rumor: Event): HexKey? = rumor.tags.firstTagValue(TAG_CHANNEL)
+    fun channelOf(rumor: Event): HexKey? = rumor.tags.concordChannel()

    /** The epoch a Chat Plane [rumor] is bound to, or null if unbound/malformed. */
-    fun epochOf(rumor: Event): Long? = rumor.tags.firstTagValue(TAG_EPOCH)?.toLongOrNull()
+    fun epochOf(rumor: Event): Long? = rumor.tags.concordEpoch()

    /**
-     * True when [rumor] is bound to exactly [channelId] and [epoch]. Recipients
-     * must reject any Chat Plane event whose binding does not match the plane it
-     * arrived on.
+     * True when [rumor] is bound to exactly [channelId] and [epoch]. Recipients must
+     * reject any Chat Plane event whose binding does not match the plane it arrived on.
     */
    fun isBoundTo(
        rumor: Event,
        channelId: HexKey,
        epoch: Long,
-    ): Boolean = channelOf(rumor) == channelId && epochOf(rumor) == epoch
+    ): Boolean = rumor.tags.isConcordBoundTo(channelId, epoch)
 }
@@ -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.concord.cord03Channels
+
+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.core.TagArrayBuilder
+
+/**
+ * The Concord Chat Plane binding, added to any standard event (kind 9 chat, 7
+ * reaction, 5 delete, …) that is published on a channel plane. Because the binding
+ * layers onto reused standard events, these extensions are generic over the event
+ * type instead of pinned to a Concord-specific one.
+ */
+fun <T : Event> TagArrayBuilder<T>.channel(channelId: HexKey) = addUnique(ChannelTag.assemble(channelId))
+
+fun <T : Event> TagArrayBuilder<T>.epoch(epoch: Long) = addUnique(EpochTag.assemble(epoch))
+
+/** Binds an event to [channelId] at [epoch] — both tags every Chat Plane rumor carries. */
+fun <T : Event> TagArrayBuilder<T>.channelBinding(
+    channelId: HexKey,
+    epoch: Long,
+) = apply {
+    channel(channelId)
+    epoch(epoch)
+}
@@ -0,0 +1,41 @@
+/*
+ * 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.concord.cord03Channels
+
+import com.vitorpamplona.quartz.concord.cord03Channels.tags.ChannelTag
+import com.vitorpamplona.quartz.concord.cord03Channels.tags.EpochTag
+import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.core.TagArray
+
+/** The channel id this Chat Plane rumor is bound to, or null if unbound. */
+fun TagArray.concordChannel(): HexKey? = firstNotNullOfOrNull(ChannelTag::parse)
+
+/** The epoch this Chat Plane rumor is bound to, or null if unbound/malformed. */
+fun TagArray.concordEpoch(): Long? = firstNotNullOfOrNull(EpochTag::parse)
+
+/**
+ * True when these tags bind to exactly [channelId] and [epoch]. Recipients must
+ * reject any Chat Plane event whose binding does not match the plane it arrived on.
+ */
+fun TagArray.isConcordBoundTo(
+    channelId: HexKey,
+    epoch: Long,
+): Boolean = concordChannel() == channelId && concordEpoch() == epoch
@@ -0,0 +1,47 @@
+/*
+ * 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.concord.cord03Channels.tags
+
+import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
+/**
+ * The `["channel", <id>]` tag that binds a Concord Chat Plane rumor to the channel
+ * it belongs to (CORD-03). Present on every message/reply/reaction/edit/delete so a
+ * recipient can reject an event lifted from another channel.
+ */
+class ChannelTag {
+    companion object {
+        const val TAG_NAME = "channel"
+
+        fun isTag(tag: Array<String>) = tag.has(1) && tag[0] == TAG_NAME && tag[1].isNotEmpty()
+
+        fun parse(tag: Array<String>): HexKey? {
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
+            return tag[1]
+        }
+
+        fun assemble(channelId: HexKey) = arrayOf(TAG_NAME, channelId)
+    }
+}
@@ -0,0 +1,47 @@
+/*
+ * 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.concord.cord03Channels.tags
+
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
+/**
+ * The `["epoch", <n>]` tag that binds a Concord Chat Plane rumor to the community
+ * epoch it was authored under (CORD-03). Paired with [ChannelTag]; an event whose
+ * epoch does not match the plane it arrived on is rejected, so a message can't be
+ * replayed across a rekey.
+ */
+class EpochTag {
+    companion object {
+        const val TAG_NAME = "epoch"
+
+        fun isTag(tag: Array<String>) = tag.has(1) && tag[0] == TAG_NAME && tag[1].isNotEmpty()
+
+        fun parse(tag: Array<String>): Long? {
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
+            return tag[1].toLongOrNull()
+        }
+
+        fun assemble(epoch: Long) = arrayOf(TAG_NAME, epoch.toString())
+    }
+}
@@ -21,6 +21,8 @@
 package com.vitorpamplona.quartz.concord.cord07Voice

 import com.vitorpamplona.quartz.concord.cord03Channels.ChannelChat
+import com.vitorpamplona.quartz.concord.cord03Channels.tags.ChannelTag
+import com.vitorpamplona.quartz.concord.cord03Channels.tags.EpochTag
 import com.vitorpamplona.quartz.concord.events.ConcordKinds
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
@@ -69,7 +71,8 @@ object VoicePresence {
        subMs: Int? = null,
    ): Event {
        val tags = ArrayList<Array<String>>()
-        tags.addAll(ChannelChat.bindingTags(channelId, epoch))
+        tags.add(ChannelTag.assemble(channelId))
+        tags.add(EpochTag.assemble(epoch))
        tags.add(arrayOf(TAG_IDENTITY, identity))
        if (broker != null) tags.add(arrayOf(TAG_BROKER, broker))
        if (subMs != null) tags.add(arrayOf("ms", subMs.toString()))
@@ -82,7 +85,7 @@ object VoicePresence {
        channelId: HexKey,
        epoch: Long,
        createdAt: Long,
-    ): Event = RumorAssembler.assembleRumor(authorPubKey, createdAt, KIND, ChannelChat.bindingTags(channelId, epoch), CONTENT_LEFT)
+    ): Event = RumorAssembler.assembleRumor(authorPubKey, createdAt, KIND, arrayOf(ChannelTag.assemble(channelId), EpochTag.assemble(epoch)), CONTENT_LEFT)

    fun parse(rumor: Event): VoicePresenceInfo? {
        if (rumor.kind != KIND) return null
@@ -37,11 +37,11 @@ object ConcordKinds {
    const val SEAL_ENCRYPTED = 20013
    const val SEAL_PLAINTEXT = 20014

-    // Chat Plane rumors (CORD-03)
-    const val MESSAGE = 9
-    const val COMMENT = 1111
-    const val REACTION = 7
-    const val DELETE = 5
+    // Chat Plane rumors (CORD-03).
+    // Messages (kind 9), replies (9 + q), reactions (7), and deletes (5) are standard
+    // Nostr events — Concord reuses ChatEvent / ReactionEvent / DeletionEvent and only
+    // adds the channel/epoch binding (see cord03Channels/ChannelChat + tags/), so they
+    // are NOT aliased here. Only the Concord-specific chat kinds remain.
    const val EDIT = 3302
    const val WEBXDC = 3310
    const val TYPING = 23311