Keep your own stories in a private archive

Android half of ios#54. Expired stories were gone from the author's
device too, so there was no way to look back at what you posted.

🔴 This keeps something the interface told everybody would disappear, so
the shape of the feature is the argument for it being acceptable: off
unless switched on, labelled as what it is, and only ever holding stories
this account posted. `Vault.archive` refuses anything else — the caller
filters too, and this is the guard that survives the caller being
rewritten.

🔴 The archive is deliberately NOT written through `saveStories`.
Everything in it is expired by definition, and that path drops expired
stories on write — so reusing it would empty the archive on the next
pass. Separate record, and a test named for exactly that.

Archiving happens in `stories()`, before `saveStories` drops the expired
ones: the only moment they can be caught, since expired bytes leave on
write. That runs on every load, so the fold is idempotent.

⚠️ The setting is injected into `Session` as a lambda. The engine layer
has no Android dependency and must not read preferences, and an absent
value has to read as OFF.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

PARITY.md

@@ -671,3 +671,23 @@ dropped — on exactly the path a story reply normally takes.
 ⚠️ **The disclosure comes before the first reply**, on both platforms.
 Replying tells the author you watched, which stories otherwise never reveal.
 Neither platform sends anything automatic when a story is merely opened.
+||||||| parent of 4c004eb (Keep your own stories in a private archive)
+## Private story archive (ios#54)
+Your own stories, kept past their expiry. Local only; no protocol change.
+🔴 **This keeps something the interface told everybody would disappear**, so
+the shape is the argument for it being acceptable: off unless switched on,
+labelled as what it is rather than as a feature, and **only ever your own**.
+`Vault.archive` / `E2EInbox.archive` refuse anything not the author's own — the
+callers filter too, but these are the guards that survive a caller being
+rewritten. Both are tested from both directions.
+⚠️ **Archiving happens at the moment expiry is applied**, which is the only
+moment it can. iOS catches it on restore (a story past its expiry is never
+loaded into `stories`); Android catches it in `Session.stories()` before
+`saveStories` drops it. Both run repeatedly, so the fold is idempotent —
+otherwise one long-expired story would be appended on every pass.
+🔴 **The archive is not swept by the expiry rule.** Everything in it is expired
+by definition, so reusing `saveStories` would empty it on the next write.
+Android has a separate record and a test named for exactly that.
+⚠️ Android injects the setting into `Session` as a lambda rather than reading
+preferences in the engine layer, which has no Android dependency. An absent
+value reads as OFF on both platforms.

app/src/main/kotlin/io/flamenet/messenger/app/ChatScreens.kt

@@ -738,6 +738,9 @@ fun ColumnScope.AccountScreen(
 
     SectionBand()
     SettingsSection { StoryAudienceSection(model, phase) }
+    // ios#54 — beside the audience setting, because both answer "what happens
+    // to my stories".
+    SettingsSection { StoryArchiveSection(model, phase) }
 
     SectionBand()
     SettingsSection { AppLockSection() }
@@ -1110,6 +1113,67 @@ private fun storyLifetimeLabel(hours: Int): String = when {
     else -> (hours / 24).let { if (it == 1) "1 day" else "$it days" }
 }
 
+/**
+ * Stories this account posted, kept past their expiry (ios#54).
+ *
+ * 🔴 **Labelled as what it is, not as a feature.** This holds copies of things
+ * the app told everybody would disappear. Somebody looking at it should be in
+ * no doubt that these are kept, that they are kept only here, and that nobody
+ * else's stories are or can be in it.
+ */
+@Composable
+fun ColumnScope.StoryArchiveSection(
+    model: MessengerViewModel,
+    phase: MessengerViewModel.Phase.SignedIn,
+) {
+    LaunchedEffect(Unit) { model.refreshStoryArchive() }
+    Text("Your story archive", style = MaterialTheme.typography.titleMedium)
+    Row(
+        modifier = Modifier.fillMaxWidth().padding(vertical = Space.sm),
+        verticalAlignment = Alignment.CenterVertically,
+    ) {
+        Text("Keep my stories", modifier = Modifier.weight(1f))
+        androidx.compose.material3.Switch(
+            checked = phase.storyArchiveOn,
+            onCheckedChange = { model.setStoryArchiveEnabled(it) },
+            modifier = Modifier.testTag("story-archive-toggle"),
+        )
+    }
+    Text(
+        "Your stories disappear for everyone, including you. With this on, a copy of "
+            + "the ones YOU posted stays on this device after they expire. It never "
+            + "keeps anybody else's — theirs disappear as they were told they would.",
+        fontSize = 12.sp,
+        color = Palette.SecondaryText,
+    )
+    if (phase.storyArchive.isEmpty()) {
+        Text(
+            if (phase.storyArchiveOn) {
+                "Nothing kept yet. Stories you post from now on appear here once they expire."
+            } else {
+                "Nothing kept. Turn the switch on to start keeping your own."
+            },
+            fontSize = 12.sp,
+            color = Palette.SecondaryText,
+            modifier = Modifier.padding(top = Space.sm),
+        )
+    } else {
+        phase.storyArchive.forEach { kept ->
+            Text(
+                kept.caption.ifBlank { "No caption" },
+                modifier = Modifier.padding(top = Space.sm).testTag("kept-${kept.id}"),
+            )
+        }
+        Spacer(Modifier.size(Space.sm))
+        KitChip(
+            text = "Delete everything kept",
+            selected = false,
+            onClick = { model.clearStoryArchive() },
+            tag = "clear-story-archive",
+        )
+    }
+}
+
 @Composable
 private fun ColumnScope.StoryAudienceSection(
     model: MessengerViewModel,

app/src/main/kotlin/io/flamenet/messenger/app/MediaSettings.kt

@@ -49,6 +49,18 @@ class MediaSettings(context: Context) {
     /** Seconds, as [io.flamenet.client.Conversations.postStory] wants it. */
     val storyLifetimeSeconds: Double get() = storyLifetimeHours * 60.0 * 60.0
 
+    /**
+     * Keep your own stories after they expire, in a private archive (ios#54).
+     *
+     * 🔴 **Off unless switched on, and an absent value reads as false.** This
+     * keeps something the interface told everybody would disappear, so it
+     * cannot be the quiet default — and it only ever holds stories this
+     * account posted.
+     */
+    var storyArchiveEnabled: Boolean
+        get() = prefs.getBoolean("stories.archiveEnabled", false)
+        set(value) { prefs.edit().putBoolean("stories.archiveEnabled", value).apply() }
+
     /**
      * Refuse to send unless the relay can prove the recipient's keys appear in
      * the log it publishes.

app/src/main/kotlin/io/flamenet/messenger/app/MessengerViewModel.kt

@@ -149,6 +149,10 @@ class MessengerViewModel(app: Application) : AndroidViewModel(app) {
 
             /** Who may see this account's stories. */
             val storyAudience: Session.StoryAudience = Session.StoryAudience(),
+            /** Stories this account posted, kept past expiry (ios#54). */
+            val storyArchive: List<Vault.Story> = emptyList(),
+            /** Whether the archive is switched on (ios#54). */
+            val storyArchiveOn: Boolean = false,
             val myAvatar: io.flamenet.e2e.Attachment.Ref? = null,
             /** Live stories, newest first (§6.6). */
             val stories: List<Vault.Story> = emptyList(),
@@ -360,7 +364,13 @@ class MessengerViewModel(app: Application) : AndroidViewModel(app) {
                         relay = relay,
                         api = MessengerApi(
                             credential.relayBaseUrl, credential.username, credential.appPassword),
-                    )
+                    ).also {
+                        // ios#54 — injected, because the engine layer has no
+                        // Android dependency and must not read preferences.
+                        it.archiveEnabled = {
+                            MediaSettings(getApplication()).storyArchiveEnabled
+                        }
+                    }
                     val fetchedBuddies = runCatching { session!!.roster() }
                     val fetchedGroups = runCatching { session!!.namedGroups() }
                     stored to Phase.SignedIn(
@@ -570,7 +580,9 @@ class MessengerViewModel(app: Application) : AndroidViewModel(app) {
             vault = vault,
             relay = relay,
             api = io.flamenet.client.MessengerApi(config.baseUrl, account.username, credential),
-        )
+        ).also {
+            it.archiveEnabled = { MediaSettings(getApplication()).storyArchiveEnabled }
+        }
 
         // 🔴 **Our return address, before the first federated send.** A relay
         // that accepts a federated envelope records no sender, and our user id
@@ -2017,6 +2029,36 @@ class MessengerViewModel(app: Application) : AndroidViewModel(app) {
         }
     }
 
+    /**
+     * Keep your own stories after they expire (ios#54).
+     *
+     * 🔴 Off unless switched on. This keeps something the interface told
+     * everybody would disappear, so it cannot be the quiet default — and it
+     * only ever holds stories this account posted.
+     */
+    fun setStoryArchiveEnabled(on: Boolean) = viewModelScope.launch {
+        MediaSettings(getApplication()).storyArchiveEnabled = on
+        update { it.copy(storyArchiveOn = on) }
+        refreshStoryArchive()
+    }
+
+    fun refreshStoryArchive() = viewModelScope.launch {
+        val current = session ?: return@launch
+        val on = MediaSettings(getApplication()).storyArchiveEnabled
+        update { it.copy(storyArchiveOn = on) }
+        val kept = withContext(Dispatchers.IO) {
+            runCatching { current.storyArchive() }.getOrNull()
+        } ?: return@launch
+        update { it.copy(storyArchive = kept) }
+    }
+
+    /** Empty the archive (ios#54). */
+    fun clearStoryArchive() = viewModelScope.launch {
+        val current = session ?: return@launch
+        withContext(Dispatchers.IO) { runCatching { current.clearStoryArchive() } }
+        update { it.copy(storyArchive = emptyList()) }
+    }
+
     /** Change who may see this account's stories. */
     fun setStoryAudience(audience: Session.StoryAudience) = viewModelScope.launch {
         val current = session ?: return@launch

app/src/main/kotlin/io/flamenet/messenger/app/Session.kt

@@ -887,7 +887,18 @@ class Session(
     /** Everything still live, newest first. */
     fun stories(): List<Vault.Story> {
         val now = System.currentTimeMillis() / 1000.0
-        val live = vault.loadStories().filter { it.isActive(now) }
+        val all = vault.loadStories()
+        val live = all.filter { it.isActive(now) }
+        // ios#54 — anything of YOUR OWN that has expired is archived here,
+        // before `saveStories` drops it. This is the only moment it can be
+        // caught: expired stories leave on write, so nothing downstream sees
+        // them again.
+        if (archiveEnabled()) {
+            val expiredMine = all.filter { it.mine && !it.isActive(now) }
+            if (expiredMine.isNotEmpty()) {
+                vault.saveStoryArchive(Vault.archive(vault.storyArchive(), expiredMine))
+            }
+        }
         // Written back so expired bytes leave the device rather than lingering
         // until the next post.
         //
@@ -1105,6 +1116,21 @@ class Session(
         return reached
     }
 
+    /**
+     * Whether the private story archive is switched on (ios#54).
+     *
+     * ⚠️ Injected rather than read from a context here: the engine layer has
+     * no Android dependency, and an unset value must read as OFF — the archive
+     * keeps something the interface said would disappear.
+     */
+    var archiveEnabled: () -> Boolean = { false }
+
+    /** Stories this account posted, kept past their expiry (ios#54). */
+    fun storyArchive(): List<Vault.Story> = vault.storyArchive()
+
+    /** Empty the archive (ios#54). */
+    fun clearStoryArchive() = vault.saveStoryArchive(emptyList())
+
     /**
      * Members of a group we are in, or null if the relay does not list it for
      * us (audit H1). Cached for a short window: a poll pass can carry many

engine/src/main/kotlin/io/flamenet/e2e/Vault.kt

@@ -83,6 +83,8 @@ class Vault(private val storage: Storage, private val key: SecretKey) {
         private const val CALL_LOG = "call-log"
         private const val STORY_AUDIENCE = "story-audience"
         private const val MUTED_STORIES = "muted-stories"
+
+        private const val STORY_ARCHIVE = "story-archive"
         private const val DISAPPEAR = "disappear"
         private const val SNOOZE = "snooze"
         private const val REPLY_REMINDER = "reply-reminder"
@@ -152,6 +154,28 @@ class Vault(private val storage: Storage, private val key: SecretKey) {
          */
         fun isSaveable(mine: Boolean, hasBlob: Boolean): Boolean = mine && hasBlob
 
+        /**
+         * Fold newly-expired stories into the archive (ios#54).
+         *
+         * 🔴 **Refuses anything not the author's own.** The caller filters as
+         * well, and this is the guard that survives the caller being
+         * rewritten — an archive holding somebody else's expired story breaks
+         * the promise the app made to them, and "it is private to you" does
+         * not repair that.
+         *
+         * ⚠️ De-duplicated by id, because the sweep runs on every load and a
+         * story that expired weeks ago would otherwise be appended each time.
+         * Newest first, so the screen needs no sort.
+         */
+        fun archive(existing: List<Story>, adding: List<Story>): List<Story> {
+            val seen = existing.map { it.id }.toMutableSet()
+            val result = existing.toMutableList()
+            adding.forEach { story ->
+                if (story.mine && seen.add(story.id)) result += story
+            }
+            return result.sortedByDescending { it.postedAt }
+        }
+
         fun threadForUser(userId: Long) = "user:$userId"
         fun threadForGroup(groupId: String) = "group:$groupId"
 
@@ -705,8 +729,11 @@ class Vault(private val storage: Storage, private val key: SecretKey) {
         if (ref == null) storage.delete(MY_AVATAR) else writeJson(MY_AVATAR, ref.toJson())
     }
 
-    fun loadStories(): List<Story> {
-        val array = readJson(STORIES)?.optJSONArray("items") ?: return emptyList()
+    fun loadStories(): List<Story> = storiesFrom(readJson(STORIES))
+
+    /** Shared by the live set and the archive (ios#54). */
+    private fun storiesFrom(record: JSONObject?): List<Story> {
+        val array = record?.optJSONArray("items") ?: return emptyList()
         return (0 until array.length()).mapNotNull { i ->
             val o = array.getJSONObject(i)
             // §6.21 — a text story has no `ref`. Absent is legitimate now, so
@@ -741,8 +768,13 @@ class Vault(private val storage: Storage, private val key: SecretKey) {
      */
     fun saveStories(stories: List<Story>, nowSeconds: Double) {
         val live = stories.filter { it.isActive(nowSeconds) }
+        writeJson(STORIES, JSONObject().put("items", storiesToJson(live)))
+    }
+
+    /** Shared by the live set and the archive (ios#54). */
+    private fun storiesToJson(stories: List<Story>): org.json.JSONArray {
         val array = org.json.JSONArray()
-        live.forEach { story ->
+        stories.forEach { story ->
             array.put(JSONObject()
                 .put("id", story.id)
                 .put("author", story.authorId)
@@ -756,7 +788,7 @@ class Vault(private val storage: Storage, private val key: SecretKey) {
                 .put("at", story.postedAt)
                 .put("seen", story.seen))
         }
-        writeJson(STORIES, JSONObject().put("items", array))
+        return array
     }
 
     // -- Key-log pin (§19.3) -------------------------------------------------
@@ -1198,6 +1230,17 @@ class Vault(private val storage: Storage, private val key: SecretKey) {
      * ⚠️ In the vault. An audience list is a statement about who somebody
      * trusts, which is exactly the metadata this app exists to keep private.
      */
+    /**
+     * Stories this account posted, kept past their expiry (ios#54).
+     *
+     * 🔴 Only ever your own, and only when the setting is on. This keeps
+     * something the interface told everybody would disappear.
+     */
+    fun storyArchive(): List<Story> = storiesFrom(readJson(STORY_ARCHIVE))
+
+    fun saveStoryArchive(stories: List<Story>) =
+        writeJson(STORY_ARCHIVE, JSONObject().put("items", storiesToJson(stories)))
+
     fun storyAudience(): JSONObject? = readJson(STORY_AUDIENCE)
 
     fun saveStoryAudience(audience: JSONObject) = writeJson(STORY_AUDIENCE, audience)

engine/src/test/kotlin/io/flamenet/e2e/StoryArchiveTest.kt

@@ -0,0 +1,93 @@
+package io.flamenet.e2e
+
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertTrue
+
+/**
+ * A private archive of your own stories (ios#54).
+ *
+ * 🔴 **This keeps something the interface said would disappear.** So it is
+ * opt-in, and it only ever holds stories this account posted — an archive of
+ * other people's expiring stories is the exact opposite of what they were
+ * promised, and "it is private to you" does not repair that.
+ */
+class StoryArchiveTest {
+
+    private fun story(id: String, mine: Boolean, at: Long) = Vault.Story(
+        id = id, authorId = if (mine) 1L else 7L, mine = mine,
+        ref = Attachment.Ref(
+            kind = Attachment.STORY, id = "b$id", key = ByteArray(32),
+            digest = ByteArray(32), bytes = 1, mime = "image/jpeg",
+            width = 1, height = 1, duration = 0.0, expires = 1.0,
+        ),
+        caption = "c$id", postedAt = at,
+    )
+
+    @Test
+    fun `your own expired story is kept`() {
+        assertEquals(listOf("1"),
+            Vault.archive(emptyList(), listOf(story("1", true, 100))).map { it.id })
+    }
+
+    /** 🔴 The rule the whole feature turns on. */
+    @Test
+    fun `somebody elses expired story is never kept`() {
+        assertTrue(Vault.archive(emptyList(), listOf(story("2", false, 100))).isEmpty())
+    }
+
+    @Test
+    fun `a mixed batch keeps only your own`() {
+        val result = Vault.archive(emptyList(), listOf(
+            story("1", true, 100), story("2", false, 200), story("3", true, 300)))
+        assertEquals(setOf("1", "3"), result.map { it.id }.toSet())
+    }
+
+    /** ⚠️ The sweep runs on every load; without this, one story piles up. */
+    @Test
+    fun `archiving is idempotent`() {
+        val one = story("1", true, 100)
+        val first = Vault.archive(emptyList(), listOf(one))
+        assertEquals(1, Vault.archive(first, listOf(one)).size)
+    }
+
+    /** ⚠️ Newest first, so the screen needs no sort. */
+    @Test
+    fun `the archive is newest first`() {
+        val result = Vault.archive(emptyList(), listOf(
+            story("1", true, 100), story("3", true, 300), story("2", true, 200)))
+        assertEquals(listOf("3", "2", "1"), result.map { it.id })
+    }
+
+    private class MapStorage : Vault.Storage {
+        val records = LinkedHashMap<String, ByteArray>()
+        override fun read(name: String) = records[name]
+        override fun write(name: String, bytes: ByteArray) { records[name] = bytes }
+        override fun delete(name: String) { records.remove(name) }
+        override fun names() = records.keys.toList()
+    }
+
+    private fun key() = javax.crypto.KeyGenerator.getInstance("AES")
+        .apply { init(256) }.generateKey()
+
+    /** ⚠️ Kept in the vault, like everything else about somebody's stories. */
+    @Test
+    fun `the archive round-trips through the vault`() {
+        val vault = Vault(MapStorage(), key())
+        assertTrue(vault.storyArchive().isEmpty())
+        vault.saveStoryArchive(listOf(story("1", true, 100)))
+        assertEquals(listOf("1"), vault.storyArchive().map { it.id })
+    }
+
+    /**
+     * 🔴 The archive must NOT be swept by the expiry rule the live set uses —
+     * everything in it is expired by definition, so reusing `saveStories`
+     * would empty it on the next write.
+     */
+    @Test
+    fun `an expired story survives in the archive`() {
+        val vault = Vault(MapStorage(), key())
+        vault.saveStoryArchive(listOf(story("1", true, 100)))
+        assertEquals(1, vault.storyArchive().size)
+    }
+}