diff --git a/commons/src/jvmTest/kotlin/com/vitorpamplona/amethyst/commons/model/nip29RelayGroups/RelayGroupChannelTest.kt b/commons/src/jvmTest/kotlin/com/vitorpamplona/amethyst/commons/model/nip29RelayGroups/RelayGroupChannelTest.kt
new file mode 100644
index 0000000000..ba992c399f
--- /dev/null
+++ b/commons/src/jvmTest/kotlin/com/vitorpamplona/amethyst/commons/model/nip29RelayGroups/RelayGroupChannelTest.kt
@@ -0,0 +1,167 @@
+/*
+ * 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.model.nip29RelayGroups
+
+import com.vitorpamplona.quartz.nip01Core.relay.normalizer.RelayUrlNormalizer
+import com.vitorpamplona.quartz.nip29RelayGroups.GroupId
+import com.vitorpamplona.quartz.nip29RelayGroups.metadata.GroupAdminsEvent
+import com.vitorpamplona.quartz.nip29RelayGroups.metadata.GroupMembersEvent
+import com.vitorpamplona.quartz.nip29RelayGroups.metadata.GroupMetadataEvent
+import com.vitorpamplona.quartz.utils.EventFactory
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFalse
+import kotlin.test.assertTrue
+
+/**
+ * Client-side derivations in [RelayGroupChannel] — the relay-signed roster is the
+ * source of truth, so this exercises how the channel folds 39000/39001/39002 into
+ * a membership answer and a member count, and that the `createdAt` supersede
+ * guards drop stale events. Protocol parsing itself is covered by Quartz's
+ * Nip29ArmadaInteropTest; here we test the fold, not the parse.
+ */
+class RelayGroupChannelTest {
+    private val relaySelf = "aa".repeat(32)
+    private val alice = "bb".repeat(32)
+    private val bob = "cc".repeat(32)
+    private val carol = "dd".repeat(32)
+    private val gid = "0123456789abcdef"
+    private val relay = RelayUrlNormalizer.normalize("wss://relay.example.com")
+
+    private fun channel() = RelayGroupChannel(GroupId(gid, relay))
+
+    private fun metadata(
+        createdAt: Long,
+        flags: List<String> = emptyList(),
+        name: String? = null,
+    ): GroupMetadataEvent {
+        val tags =
+            buildList {
+                add(arrayOf("d", gid))
+                name?.let { add(arrayOf("name", it)) }
+                flags.forEach { add(arrayOf(it)) }
+            }.toTypedArray()
+        return EventFactory.create("00".repeat(32), relaySelf, createdAt, GroupMetadataEvent.KIND, tags, "", "22".repeat(64)) as GroupMetadataEvent
+    }
+
+    private fun members(
+        createdAt: Long,
+        vararg pubkeys: String,
+    ): GroupMembersEvent {
+        val tags = (listOf(arrayOf("d", gid)) + pubkeys.map { arrayOf("p", it) }).toTypedArray()
+        return EventFactory.create("00".repeat(32), relaySelf, createdAt, GroupMembersEvent.KIND, tags, "", "22".repeat(64)) as GroupMembersEvent
+    }
+
+    private fun admins(
+        createdAt: Long,
+        vararg entries: Pair<String, List<String>>,
+    ): GroupAdminsEvent {
+        val tags = (listOf(arrayOf("d", gid)) + entries.map { (pk, roles) -> arrayOf("p", pk, *roles.toTypedArray()) }).toTypedArray()
+        return EventFactory.create("00".repeat(32), relaySelf, createdAt, GroupAdminsEvent.KIND, tags, "", "22".repeat(64)) as GroupAdminsEvent
+    }
+
+    @Test
+    fun membershipFromRolesAndMembers() {
+        val c = channel()
+        c.updateAdmins(admins(100, alice to listOf("admin"), bob to listOf("moderator")))
+        c.updateMembers(members(100, alice, bob, carol))
+
+        assertEquals(RelayGroupMembership.ADMIN, c.membershipOf(alice))
+        assertEquals(RelayGroupMembership.MODERATOR, c.membershipOf(bob))
+        // carol is only in the members list — a plain member.
+        assertEquals(RelayGroupMembership.MEMBER, c.membershipOf(carol))
+        // unknown key.
+        assertEquals(RelayGroupMembership.NONE, c.membershipOf("ee".repeat(32)))
+    }
+
+    @Test
+    fun adminInAdminsListButAbsentFromMembersStillCounts() {
+        // Relays commonly list admins in 39001 only, not 39002. The admin must
+        // still resolve as a member, not NONE.
+        val c = channel()
+        c.updateAdmins(admins(100, alice to listOf("admin")))
+        c.updateMembers(members(100, bob))
+
+        assertEquals(RelayGroupMembership.ADMIN, c.membershipOf(alice))
+        assertTrue(c.membershipOf(alice).isMember())
+    }
+
+    @Test
+    fun adminWithoutKnownRoleIsPlainMember() {
+        val c = channel()
+        c.updateAdmins(admins(100, alice to listOf("ceo")))
+        assertEquals(RelayGroupMembership.MEMBER, c.membershipOf(alice))
+    }
+
+    @Test
+    fun memberCountDedupesAdminsAndMembers() {
+        val c = channel()
+        // alice appears in BOTH lists; she must be counted once.
+        c.updateAdmins(admins(100, alice to listOf("admin")))
+        c.updateMembers(members(100, alice, bob, carol))
+        assertEquals(3, c.memberCount())
+    }
+
+    @Test
+    fun staleMembersEventDoesNotSupersede() {
+        val c = channel()
+        c.updateMembers(members(200, alice, bob))
+        // An OLDER roster arrives late (out-of-order relay delivery) — ignore it.
+        c.updateMembers(members(100, alice))
+        assertEquals(2, c.memberCount())
+        assertEquals(RelayGroupMembership.MEMBER, c.membershipOf(bob))
+    }
+
+    @Test
+    fun newerMembersEventReplaces() {
+        val c = channel()
+        c.updateMembers(members(100, alice))
+        c.updateMembers(members(200, alice, bob))
+        assertEquals(RelayGroupMembership.MEMBER, c.membershipOf(bob))
+        assertEquals(2, c.memberCount())
+    }
+
+    @Test
+    fun staleMetadataDoesNotSupersedeFlagsOrName() {
+        val c = channel()
+        c.updateGroupInfo(metadata(200, flags = listOf("private", "closed"), name = "Newer"))
+        c.updateGroupInfo(metadata(100, flags = emptyList(), name = "Older"))
+
+        assertEquals("Newer", c.toBestDisplayName())
+        assertTrue(c.isPrivate())
+        assertTrue(c.isClosed())
+    }
+
+    @Test
+    fun flagsReflectLatestMetadata() {
+        val c = channel()
+        assertFalse(c.isPrivate())
+        assertFalse(c.isClosed())
+        c.updateGroupInfo(metadata(100, flags = listOf("private")))
+        assertTrue(c.isPrivate())
+        assertFalse(c.isClosed())
+    }
+
+    @Test
+    fun displayNameFallsBackToGroupIdWithoutMetadata() {
+        assertEquals(gid, channel().toBestDisplayName())
+    }
+}
diff --git a/commons/src/jvmTest/kotlin/com/vitorpamplona/amethyst/commons/model/nip29RelayGroups/RelayGroupListDecryptionTest.kt b/commons/src/jvmTest/kotlin/com/vitorpamplona/amethyst/commons/model/nip29RelayGroups/RelayGroupListDecryptionTest.kt
new file mode 100644
index 0000000000..cdea377148
--- /dev/null
+++ b/commons/src/jvmTest/kotlin/com/vitorpamplona/amethyst/commons/model/nip29RelayGroups/RelayGroupListDecryptionTest.kt
@@ -0,0 +1,83 @@
+/*
+ * 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.model.nip29RelayGroups
+
+import com.vitorpamplona.quartz.nip01Core.crypto.KeyPair
+import com.vitorpamplona.quartz.nip01Core.signers.NostrSignerInternal
+import com.vitorpamplona.quartz.nip51Lists.simpleGroupList.GroupTag
+import com.vitorpamplona.quartz.nip51Lists.simpleGroupList.SimpleGroupListEvent
+import kotlinx.coroutines.runBlocking
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFalse
+import kotlin.test.assertTrue
+
+/**
+ * The join/leave paths store groups as NIP-44 private items in the kind-10009
+ * list (encrypted to self). This drives the exact `create`/`add`/`remove` calls
+ * that [RelayGroupListState.follow] / `unfollow` delegate to, then reads them
+ * back through [RelayGroupListDecryptionCache] — proving a followed group
+ * survives the encrypt→sign→decrypt round-trip and that unfollow removes it.
+ */
+class RelayGroupListDecryptionTest {
+    private val signer = NostrSignerInternal(KeyPair())
+    private val cache = RelayGroupListDecryptionCache(signer)
+
+    private val relay = "wss://relay.example.com"
+    private val groupA = GroupTag("aaaa", relay, "Alpha")
+    private val groupB = GroupTag("bbbb", relay, "Beta")
+
+    private fun keysIn(event: SimpleGroupListEvent) = runBlocking { cache.groupSet(event).map { it.groupId }.toSet() }
+
+    @Test
+    fun followedPrivateGroupRoundTripsThroughDecryption() =
+        runBlocking {
+            val list = SimpleGroupListEvent.create(privateGroups = listOf(groupA), signer = signer)
+
+            // The group is NOT a public tag — it lives encrypted in content.
+            assertTrue(list.publicGroups().isEmpty())
+            assertEquals(setOf("aaaa"), keysIn(list))
+        }
+
+    @Test
+    fun addingASecondGroupKeepsBoth() =
+        runBlocking {
+            val first = SimpleGroupListEvent.create(privateGroups = listOf(groupA), signer = signer)
+            val second = SimpleGroupListEvent.add(first, groupB, isPrivate = true, signer = signer)
+            assertEquals(setOf("aaaa", "bbbb"), keysIn(second))
+        }
+
+    @Test
+    fun unfollowRemovesOnlyThatGroup() =
+        runBlocking {
+            val both =
+                SimpleGroupListEvent.add(
+                    SimpleGroupListEvent.create(privateGroups = listOf(groupA), signer = signer),
+                    groupB,
+                    isPrivate = true,
+                    signer = signer,
+                )
+            val afterRemove = SimpleGroupListEvent.remove(both, groupA, signer = signer)
+            val keys = keysIn(afterRemove)
+            assertFalse("aaaa" in keys)
+            assertTrue("bbbb" in keys)
+        }
+}