feat(stealth): mask identities and notify admins on login

design/index.md

@@ -4,7 +4,9 @@ okf_version: "0.1"
 
 # Spigot Stealth Design
 
-Spigot Stealth rewards players who spend time under invisibility effects from potions they drink, then lets unlocked players conceal their identity for a later session.
+Spigot Stealth rewards players who spend time under invisibility effects from potions they drink, then lets unlocked players conceal their identity for a later session. [Session concealment](user-stories/us-002-rejoin-without-visible-identity.md) includes command-suggestion filtering and scrambled message and overhead names.
+
+[Administration](user-stories/us-004-administer-player-stealth.md) provides private concealed-player counts at login and command-based inspection.
 
 ## Explore
 

design/log.md

@@ -1,5 +1,22 @@
 # Spigot Stealth Design Log
 
+## 2026-09-06
+
+- **Completion**: Extended US-004 with permission-gated private concealed-player counts for joining admins and arrival notices for online admins, including command hints, zero-count silence, and no duplicate notice for concealed admins. Verified all 70 tests, the JAR build, and OKF validation; not deployed or live-server tested.
+
+- **Completion**: Extended US-002 with concealed-username suggestion filtering, scrambled default chat and vanilla message/advancement names, scrambled overhead tags, and display-name restoration. Verified 65 automated tests, the Gradle JAR build, and OKF validation; live-server compatibility remains untested and custom chat/scoreboard integrations are outside this slice.
+
+## 2026-09-05
+
+- **Fix**: Reworked US-002 server-list filtering for Purpur's native `NameAndId` samples by filtering names through Bukkit, limiting ProtocolLib to guarded count adjustment, and rate-limiting compatibility warnings; verified the complete Gradle build and OKF bundle.
+- **Completion**: Extended US-002, US-004, and US-005 with a persistent, permission-gated sleep-count policy that excludes concealed players by default, applies immediately, restores prior player state, and supports contextual administration; verified the complete Gradle build and OKF bundle.
+- **Completion**: Extended US-002 with ProtocolLib filtering of concealed sessions from multiplayer server-list counts and player samples while preserving actual online state and advertised capacity; verified the complete Gradle build and OKF bundle.
+
+## 2026-09-04
+
+- **Completion**: Extended US-002 so concealed players disconnect without a public quit announcement while ordinary quit messages remain unchanged; verified listener tests, the complete Gradle build, and the OKF bundle.
+- **Completion**: Extended US-003 and US-004 with contextual, prefix-filtered command completion that suppresses generic player suggestions, plus an administrative list of all known online and offline unlocked players; verified the complete Gradle build and OKF bundle.
+
 ## 2026-08-14
 
 - **Completion**: Completed US-004 with exact known online and offline targeting, complete status, idempotent grants, confirmed resets, active concealment discovery, operator-default permissions, asynchronous persisted replies, and console audits; verified the full Gradle build.

design/user-stories/index.md

@@ -1,8 +1,8 @@
 # Spigot Stealth User Stories
 
 1. [US-001: Accumulate invisibility time and unlock stealth](us-001-accumulate-invisibility-and-unlock.md) - Earn stealth by spending eight hours under invisibility effects from directly consumed potions.
-2. [US-002: Rejoin without a visible identity](us-002-rejoin-without-visible-identity.md) - Turn a qualifying invisible disconnect into one concealed online session.
+2. [US-002: Rejoin without a visible identity](us-002-rejoin-without-visible-identity.md) - Turn a qualifying invisible disconnect into one concealed online session with filtered name suggestions and scrambled message and overhead names.
 3. [US-003: Check personal stealth progress](us-003-check-personal-progress.md) - View accumulated time, remaining time, and unlock status.
-4. [US-004: Inspect and manage player stealth](us-004-administer-player-stealth.md) - Inspect and modify online or offline progression and find concealed players.
+4. [US-004: Inspect and manage player stealth](us-004-administer-player-stealth.md) - Inspect and modify online or offline progression, find concealed players, and receive private login count notices.
 5. [US-005: Configure and persist stealth progression](us-005-configure-and-persist-progression.md) - Keep progression durable and operator-configurable.
 6. [US-006: Build, test, and release the plugin](us-006-build-test-and-release.md) - Provide repeatable Gradle builds and Gitea delivery.

design/user-stories/us-002-rejoin-without-visible-identity.md

@@ -15,8 +15,25 @@ As an **unlocked player**, I want to disconnect while invisibility from a potion
 - [x] A player who has not unlocked stealth cannot prepare a concealed login.
 - [x] An ordinary disconnect without an active qualifying effect clears any preparation for the next login.
 - [x] On a prepared login, no public join announcement is shown.
+- [x] When a concealed player disconnects, no public quit or disconnect announcement is shown.
+- [x] Ordinary players' quit messages remain unchanged.
+- [x] Concealment is checked before disconnect cleanup so announcement suppression is reliable.
 - [x] Throughout the concealed session, the player is absent from every other player's tab list, including administrators' tab lists.
-- [x] Throughout the concealed session, no overhead name tag identifies the player to any other player, including administrators.
+- [x] The multiplayer server list's online-player count excludes currently concealed players.
+- [x] Concealed players are excluded from any player-name sample shown for the server-list count, while ordinary players remain represented.
+- [x] The public count never becomes negative, and the configured maximum-player count remains unchanged.
+- [x] Server-list concealment changes only the public ping response and does not alter actual online-player state or gameplay.
+- [x] Server-list filtering remains error-free when Purpur represents player samples with native `NameAndId` values rather than Mojang `GameProfile` values.
+- [x] A server-ping compatibility failure leaves the original response usable and does not produce repeated unhandled listener exceptions.
+- [x] By default, concealed players are excluded from sleep-percentage calculations.
+- [x] When the sleep-count policy is `include`, concealed players count normally; ordinary players are never modified by either policy.
+- [x] A player's previous sleeping-ignore state is restored when concealment ends, the player disconnects or is reset, the policy changes to `include`, or the plugin disables.
+- [x] Policy changes apply immediately to currently concealed players.
+- [x] Throughout the concealed session, the overhead name is rendered as scrambled magic text, including for administrators, while the physical character stays visible.
+- [x] Concealed usernames are excluded from outgoing command suggestions, including `/msg`, `/tell`, and `/w`; manually addressing a known username remains possible.
+- [x] Default chat display names and vanilla private-message and advancement name components are scrambled without changing message content or signed chat bodies.
+- [x] Masked message name components do not expose the original identity through hover or click actions.
+- [x] Previous display names and ordinary suggestions return when concealment ends; ordinary players remain unaffected.
 - [x] The concealed player's physical character remains visible in the world and retains ordinary movement, interaction, combat, and permission behavior.
 - [x] The concealed player receives a private message explaining that stealth is active for the session.
 - [x] Concealment lasts until the player disconnects and is handled predictably across death and plugin reload or disable events.
@@ -26,7 +43,17 @@ As an **unlocked player**, I want to disconnect while invisibility from a potion
 
 ## Validation
 
-Automated tests verify unlocked and locked disconnect transitions, ordinary-disconnect clearing, one-login consumption, announcement suppression, private activation messaging, ordinary-login presentation, tab removal for existing and new observers, overhead-name suppression, and the absence of entity-hiding calls. ProtocolLib is declared as a required dependency, prepared state round trips through YAML, and `./gradlew clean check jar` passes.
+Automated tests verify unlocked and locked disconnect transitions, ordinary-disconnect clearing, one-login consumption, concealed join and quit announcement suppression, preservation of ordinary announcements, private activation messaging, ordinary-login presentation, tab removal for existing and new observers, overhead-name suppression, active concealed-session tracking, ProtocolLib-independent native player-sample filtering, guarded public server-list count adjustment, nonnegative counts, unchanged maximum capacity, default sleep-count exclusion, immediate policy changes, restoration of prior sleeping-ignore state, and the absence of entity-hiding calls. ProtocolLib is declared as a required dependency, prepared state round trips through YAML, and `./gradlew clean check jar` passes.
+
+Identity masking verification (2026-09-06): `./gradlew --offline clean check jar` passed all 65 tests and OKF validation. Tests cover semantic name slots, preserved message content, stripped identifying actions, reflected suggestion entries and chat-bound records, safe packet failure handling, immutable name snapshots, overhead formatting, and display-name restoration after repeated concealment. Presentation tests first failed to compile against the missing snapshot API, then passed after implementation. These are automated unit checks, not a live-client smoke test.
+
+## Identity masking scope
+
+Masking applies to active concealed sessions, not every potion effect. Outgoing username suggestions are filtered across commands; entering a known username manually still works. Default Bukkit chat uses a temporary scrambled `Anonymous` display name. Vanilla translated announcements and chat-type bound names are masked at the packet boundary without editing signed message bodies. The overhead tag uses scoreboard magic formatting on the profile name, not a profile rename; this is visual concealment, not anonymity against modified clients.
+
+Custom chat formats that ignore Bukkit display names, nicknames, custom scoreboards, and third-party messaging plugins may need dedicated integration. Unsupported packet layouts retain the original packet and emit one warning per packet type rather than interrupting chat delivery. Live-server/client compatibility still requires a smoke test, particularly after Minecraft or ProtocolLib upgrades.
+
+Implementation: [identity presentation](../../src/main/java/games/dmg/spigotstealth/BukkitIdentityPresentation.java), [packet listener](../../src/main/java/games/dmg/spigotstealth/ProtocolLibIdentityMaskingListener.java), and [semantic name masking](../../src/main/java/games/dmg/spigotstealth/StealthChatMasker.java).
 
 ## Related
 

design/user-stories/us-003-check-personal-progress.md

@@ -18,10 +18,12 @@ As a **player**, I want to check my stealth progress so that I know how close I
 - [x] Durations are presented in a concise, human-readable form.
 - [x] Repeated command use does not change progression or concealment state.
 - [x] The command has clear usage metadata and an appropriate player permission.
+- [x] `/stealth` tab-completes `progress`, filtered by the entered prefix.
+- [x] Unsupported argument positions return no suggestions instead of Bukkit's generic player list.
 
 ## Validation
 
-Automated tests verify concise duration formatting, live in-flight progress, configured target and remaining output, command non-mutation, and unlocked usage guidance. Command metadata and the complete `./gradlew clean check jar` lifecycle pass.
+Automated tests verify concise duration formatting, live in-flight progress, configured target and remaining output, command non-mutation, unlocked usage guidance, prefix-filtered completion, and suppression of irrelevant suggestions. Command metadata and the complete `./gradlew clean check jar` lifecycle pass.
 
 ## Related
 

design/user-stories/us-004-administer-player-stealth.md

@@ -19,15 +19,33 @@ As a **server administrator**, I want to inspect and correct player stealth stat
 - [x] `/stealthadmin reset <player|uuid> confirm` clears accumulated time, unlock ownership, prepared-login state, and current concealment for an online or known offline player.
 - [x] Reset requires explicit confirmation and safely restores an online concealed player to ordinary identity presentation.
 - [x] `/stealthadmin list` lists every currently online concealed player and clearly reports when there are none.
-- [x] Concealed players remain absent from administrators' ordinary tab lists and retain hidden overhead name tags; the admin command is the supported discovery mechanism.
+- [x] Concealed players remain absent from administrators' ordinary tab lists and retain scrambled overhead names; the admin command is the supported discovery mechanism.
+- [x] An administrator joining while concealed players are online receives a private count and a hint to use `/stealthadmin list`.
+- [x] When a concealed player joins, online administrators receive a private arrival notice, the updated concealed-player count, and the command hint.
+- [x] Notifications require `spigotstealth.admin`; ordinary players receive no administrative notice.
+- [x] Counts include the newly joined concealed player, and a joining concealed administrator receives only one administrative notification.
+- [x] An administrator joining when no concealed players are online receives no notification.
 - [x] Commands clearly reject unknown, ambiguous, malformed, or otherwise invalid targets without creating unintended player records.
 - [x] Administrative inspection and modification require an operator-default administrative permission.
 - [x] State-changing operations persist before success is reported and are safe under retries.
 - [x] Grant and reset actions record the administrator, target UUID, and action in the server log without blocking the server tick thread.
+- [x] `/stealthadmin` tab-completes `status`, `grant`, `reset`, and `list`, filtered by the entered prefix.
+- [x] Target positions for `status`, `grant`, and `reset` suggest known player names, and reset's final argument suggests `confirm`.
+- [x] Administrative completions require the administrative permission, and irrelevant positions return no suggestions instead of Bukkit's generic player list.
+- [x] `/stealthadmin list unlocked` lists every known online or offline player with stealth unlocked.
+- [x] The unlocked list is sorted case-insensitively, identifies nameless records by UUID, and clearly reports when it is empty.
+- [x] Existing `/stealthadmin list` behavior continues to list currently concealed online players.
+- [x] `/stealthadmin sleepcount status` reports whether concealed players are included in or excluded from sleep-percentage calculations.
+- [x] `/stealthadmin sleepcount <include|exclude>` persists the policy before reporting success, applies it immediately, and records the administrator and policy in the server log.
+- [x] The `sleepcount`, `status`, `include`, and `exclude` arguments are permission-gated and contextually tab-completed.
 
 ## Validation
 
-Automated tests verify exact offline name and UUID resolution, ambiguous and unknown rejection without record creation, complete status output, idempotent grants and notification, complete resets with presentation cleanup, online concealed-player filtering, confirmation and permission gates, persisted-before-success replies, and audit records. The complete `./gradlew clean check jar` lifecycle passes.
+Automated tests verify exact offline name and UUID resolution, ambiguous and unknown rejection without record creation, complete status output, idempotent grants and notification, complete resets with presentation cleanup, online concealed-player filtering, online and offline unlocked-player listing, contextual permission-gated completion, durable sleep-count status and policy changes, immediate policy refresh, confirmation and permission gates, persisted-before-success replies, and audit records. The complete `./gradlew clean check jar` lifecycle passes.
+
+Login notice verification (2026-09-06): `./gradlew --offline clean check jar` passed all 70 tests and OKF validation. New tests first failed against the absent listener, then passed after implementation. Tests cover permission gates, zero-count silence, singular/plural counts, concealed-admin deduplication, ordinary-join silence for existing admins, and a prepared-login transition followed by an accurate administrative notice. Live-server verification remains pending.
+
+Implementation: [admin join listener](../../src/main/java/games/dmg/spigotstealth/StealthAdminJoinListener.java), registered at `MONITOR` after the session listener's `HIGHEST` login transition. Notices expose only counts; names remain available through `/stealthadmin list`.
 
 ## Related
 

design/user-stories/us-005-configure-and-persist-progression.md

@@ -23,10 +23,11 @@ As a **server operator**, I want stealth progression to be configurable and dura
 - [x] Corrupt, unknown, or invalid records cannot silently grant time, an unlock, a prepared login, or concealment.
 - [x] Unknown forward-compatible fields are preserved where practical.
 - [x] Persistence work does not perform blocking file operations on the server tick thread.
+- [x] The sleep-count policy persists in `state.yml` and defaults safely to `exclude` when missing or invalid.
 
 ## Validation
 
-Verified settings defaults and rejection, packaged configuration, safe UUID-state defaults, RFC 3339 round trips, unknown-field preservation, invalid-record rejection, atomic repository writes, and dedicated-thread loading and saving with automated tests and `./gradlew clean check jar`.
+Verified settings defaults and rejection, packaged configuration, safe UUID-state defaults, sleep-count policy defaults and round trips, RFC 3339 round trips, unknown-field preservation, invalid-record rejection, atomic repository writes, and dedicated-thread loading and saving with automated tests and `./gradlew clean check jar`.
 
 ## Related
 

src/main/java/games/dmg/spigotstealth/BukkitIdentityPresentation.java

@@ -15,25 +15,54 @@ public final class BukkitIdentityPresentation implements IdentityPresentation {
     private final Supplier<? extends Collection<? extends Player>> onlinePlayers;
     private final Scoreboard scoreboard;
     private final TabListController tabLists;
+    private final Supplier<SleepCountPolicy> sleepCountPolicy;
     private final Map<UUID, Player> concealedPlayers = new LinkedHashMap<>();
+    private final Map<UUID, Boolean> previousSleepingIgnored = new LinkedHashMap<>();
+    private final Map<UUID, String> previousDisplayNames = new LinkedHashMap<>();
+    private volatile java.util.Set<String> concealedNames = java.util.Set.of();
+
+    /** Immutable snapshot safe to read from outgoing packet threads. */
+    public java.util.Set<String> concealedNames() {
+        return concealedNames;
+    }
+
+    private void publishNames() {
+        concealedNames = concealedPlayers.values().stream().map(Player::getName)
+                .collect(java.util.stream.Collectors.toUnmodifiableSet());
+    }
 
     public BukkitIdentityPresentation(
             Supplier<? extends Collection<? extends Player>> onlinePlayers,
             Scoreboard scoreboard,
             TabListController tabLists) {
+        this(onlinePlayers, scoreboard, tabLists, () -> SleepCountPolicy.EXCLUDE);
+    }
+
+    public BukkitIdentityPresentation(
+            Supplier<? extends Collection<? extends Player>> onlinePlayers,
+            Scoreboard scoreboard,
+            TabListController tabLists,
+            Supplier<SleepCountPolicy> sleepCountPolicy) {
         this.onlinePlayers = Objects.requireNonNull(onlinePlayers, "onlinePlayers");
         this.scoreboard = Objects.requireNonNull(scoreboard, "scoreboard");
         this.tabLists = Objects.requireNonNull(tabLists, "tabLists");
+        this.sleepCountPolicy = Objects.requireNonNull(sleepCountPolicy, "sleepCountPolicy");
     }
 
     @Override
     public void conceal(Player player) {
         concealedPlayers.put(player.getUniqueId(), player);
+        publishNames();
+        previousDisplayNames.putIfAbsent(player.getUniqueId(), player.getDisplayName());
+        player.setDisplayName("§kAnonymous§r");
+        applySleepCountPolicy(player);
         Team team = scoreboard.getTeam(teamName(player.getUniqueId()));
         if (team == null) {
             team = scoreboard.registerNewTeam(teamName(player.getUniqueId()));
         }
-        team.setOption(Team.Option.NAME_TAG_VISIBILITY, Team.OptionStatus.NEVER);
+        team.setOption(Team.Option.NAME_TAG_VISIBILITY, Team.OptionStatus.ALWAYS);
+        team.setPrefix("§k");
+        team.setSuffix("§r");
         team.addEntry(player.getName());
         for (Player observer : onlinePlayers.get()) {
             if (!observer.getUniqueId().equals(player.getUniqueId())) {
@@ -45,6 +74,11 @@ public final class BukkitIdentityPresentation implements IdentityPresentation {
     @Override
     public void reveal(Player player) {
         boolean wasConcealed = concealedPlayers.remove(player.getUniqueId()) != null;
+        publishNames();
+        if (previousDisplayNames.containsKey(player.getUniqueId())) {
+            player.setDisplayName(previousDisplayNames.remove(player.getUniqueId()));
+        }
+        restoreSleepingIgnored(player);
         Team team = scoreboard.getTeam(teamName(player.getUniqueId()));
         if (team != null) {
             wasConcealed = true;
@@ -69,6 +103,29 @@ public final class BukkitIdentityPresentation implements IdentityPresentation {
         }
     }
 
+    @Override
+    public void refreshSleepCountPolicy() {
+        for (Player player : concealedPlayers.values()) {
+            applySleepCountPolicy(player);
+        }
+    }
+
+    private void applySleepCountPolicy(Player player) {
+        if (sleepCountPolicy.get() == SleepCountPolicy.EXCLUDE) {
+            previousSleepingIgnored.computeIfAbsent(player.getUniqueId(), ignored -> player.isSleepingIgnored());
+            player.setSleepingIgnored(true);
+        } else {
+            restoreSleepingIgnored(player);
+        }
+    }
+
+    private void restoreSleepingIgnored(Player player) {
+        Boolean previous = previousSleepingIgnored.remove(player.getUniqueId());
+        if (previous != null) {
+            player.setSleepingIgnored(previous);
+        }
+    }
+
     public static String teamName(UUID playerId) {
         return "stlth" + playerId.toString().replace("-", "").substring(0, 11);
     }

src/main/java/games/dmg/spigotstealth/IdentityPacketFields.java

@@ -0,0 +1,46 @@
+package games.dmg.spigotstealth;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Method;
+import java.lang.reflect.RecordComponent;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+import java.util.function.UnaryOperator;
+
+/** Small reflective bridge: avoids a compile/runtime dependency on a specific NMS or Brigadier version. */
+final class IdentityPacketFields {
+    private IdentityPacketFields() { }
+
+    static List<?> filterEntries(List<?> entries, StealthChatMasker masker) throws ReflectiveOperationException {
+        List<Object> filtered = new ArrayList<>();
+        for (Object entry : entries) {
+            Method text;
+            try {
+                text = entry.getClass().getMethod("text");
+            } catch (NoSuchMethodException exception) {
+                text = entry.getClass().getMethod("getText");
+            }
+            if (!masker.isConcealedName((String) text.invoke(entry))) {
+                filtered.add(entry);
+            }
+        }
+        return List.copyOf(filtered);
+    }
+
+    static Object mapRecord(Object record, UnaryOperator<Object> mapper) throws ReflectiveOperationException {
+        RecordComponent[] components = record.getClass().getRecordComponents();
+        if (components == null) {
+            throw new IllegalArgumentException("Unsupported non-record chat binding");
+        }
+        Class<?>[] types = new Class<?>[components.length];
+        Object[] values = new Object[components.length];
+        for (int i = 0; i < components.length; i++) {
+            types[i] = components[i].getType();
+            Object value = components[i].getAccessor().invoke(record);
+            values[i] = value instanceof Optional<?> optional ? optional.map(mapper) : mapper.apply(value);
+        }
+        Constructor<?> constructor = record.getClass().getDeclaredConstructor(types);
+        return constructor.newInstance(values);
+    }
+}

src/main/java/games/dmg/spigotstealth/IdentityPresentation.java

@@ -9,4 +9,6 @@ public interface IdentityPresentation {
     void reveal(Player player);
 
     void refreshForObserver(Player observer);
+
+    void refreshSleepCountPolicy();
 }

src/main/java/games/dmg/spigotstealth/KnownPlayerResolver.java

@@ -21,6 +21,17 @@ public final class KnownPlayerResolver {
         this.onlinePlayers = Objects.requireNonNull(onlinePlayers, "onlinePlayers");
     }
 
+    public java.util.List<String> completeNames(String prefix) {
+        String normalized = prefix == null ? "" : prefix.toLowerCase(Locale.ROOT);
+        return knownPlayers().values().stream()
+                .map(KnownPlayer::name)
+                .filter(Objects::nonNull)
+                .distinct()
+                .filter(name -> name.toLowerCase(Locale.ROOT).startsWith(normalized))
+                .sorted(String.CASE_INSENSITIVE_ORDER)
+                .toList();
+    }
+
     public Resolution resolve(String query) {
         if (query == null || query.isBlank()) {
             return new Resolution(Status.UNKNOWN, null);

src/main/java/games/dmg/spigotstealth/PersistentStealthState.java

@@ -8,12 +8,20 @@ import java.util.UUID;
 /** Immutable snapshot of all durable plugin state. */
 public record PersistentStealthState(
         Map<UUID, PlayerStealthState> players,
+        SleepCountPolicy sleepCountPolicy,
         Map<String, Object> unknownFields) {
     public PersistentStealthState {
         players = Map.copyOf(new LinkedHashMap<>(Objects.requireNonNull(players, "players")));
+        Objects.requireNonNull(sleepCountPolicy, "sleepCountPolicy");
         unknownFields = Map.copyOf(new LinkedHashMap<>(Objects.requireNonNull(unknownFields, "unknownFields")));
     }
 
+    public PersistentStealthState(
+            Map<UUID, PlayerStealthState> players,
+            Map<String, Object> unknownFields) {
+        this(players, SleepCountPolicy.EXCLUDE, unknownFields);
+    }
+
     public PlayerStealthState player(UUID playerId) {
         return players.getOrDefault(playerId, PlayerStealthState.empty(playerId));
     }
@@ -21,6 +29,10 @@ public record PersistentStealthState(
     public PersistentStealthState withPlayer(PlayerStealthState player) {
         Map<UUID, PlayerStealthState> updated = new LinkedHashMap<>(players);
         updated.put(player.playerId(), player);
-        return new PersistentStealthState(updated, unknownFields);
+        return new PersistentStealthState(updated, sleepCountPolicy, unknownFields);
+    }
+
+    public PersistentStealthState withSleepCountPolicy(SleepCountPolicy policy) {
+        return new PersistentStealthState(players, policy, unknownFields);
     }
 }

src/main/java/games/dmg/spigotstealth/ProtocolLibIdentityMaskingListener.java

@@ -0,0 +1,136 @@
+package games.dmg.spigotstealth;
+
+import com.comphenix.protocol.PacketType;
+import com.comphenix.protocol.events.ListenerPriority;
+import com.comphenix.protocol.events.PacketAdapter;
+import com.comphenix.protocol.events.PacketContainer;
+import com.comphenix.protocol.events.PacketEvent;
+import com.comphenix.protocol.reflect.StructureModifier;
+import com.comphenix.protocol.utility.MinecraftReflection;
+import com.comphenix.protocol.wrappers.WrappedChatComponent;
+import java.util.List;
+import java.util.Objects;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.function.Consumer;
+import java.util.function.Supplier;
+import org.bukkit.plugin.Plugin;
+
+/**
+ * Outgoing identity-only masking. Registration is deliberately left to the plugin.
+ * The supplier must return an immutable, safely published snapshot (for example AtomicReference::get).
+ * It must not inspect Bukkit players or mutable session collections on the packet thread.
+ */
+public final class ProtocolLibIdentityMaskingListener extends PacketAdapter {
+    private final Supplier<Set<String>> concealedNames;
+    private final Consumer<String> warningLog;
+    private final Set<PacketType> warned = ConcurrentHashMap.newKeySet();
+
+    public ProtocolLibIdentityMaskingListener(
+            Plugin plugin, Supplier<Set<String>> concealedNames, Consumer<String> warningLog) {
+        // ProtocolLib calls the vanilla PLAYER_CHAT packet CHAT.
+        super(plugin, ListenerPriority.HIGHEST, PacketType.Play.Server.TAB_COMPLETE,
+                PacketType.Play.Server.SYSTEM_CHAT, PacketType.Play.Server.CHAT,
+                PacketType.Play.Server.DISGUISED_CHAT);
+        this.concealedNames = Objects.requireNonNull(concealedNames, "concealedNames");
+        this.warningLog = Objects.requireNonNull(warningLog, "warningLog");
+    }
+
+    @Override
+    public void onPacketSending(PacketEvent event) {
+        if (event.isCancelled()) {
+            return;
+        }
+        try {
+            Set<String> snapshot = concealedNames.get();
+            if (snapshot.isEmpty()) {
+                return;
+            }
+            StealthChatMasker masker = new StealthChatMasker(snapshot);
+            PacketContainer packet = event.getPacket().shallowClone();
+            if (event.getPacketType().equals(PacketType.Play.Server.TAB_COMPLETE)) {
+                filterSuggestions(packet, masker);
+            } else if (event.getPacketType().equals(PacketType.Play.Server.SYSTEM_CHAT)) {
+                maskSystemChat(packet, masker);
+            } else {
+                maskBoundNames(packet, masker);
+            }
+            event.setPacket(packet);
+        } catch (ReflectiveOperationException | RuntimeException exception) {
+            // Keep delivery usable; do not cancel signed chat and break the acknowledgement chain.
+            if (warned.add(event.getPacketType())) {
+                warningLog.accept("Stealth identity masking unavailable for " + event.getPacketType()
+                        + "; original packet retained. Failure: " + exception.getClass().getSimpleName());
+            }
+        }
+    }
+
+    private static void filterSuggestions(PacketContainer packet, StealthChatMasker masker)
+            throws ReflectiveOperationException {
+        StructureModifier<Object> fields = packet.getModifier();
+        for (int i = 0; i < fields.size(); i++) {
+            Object value = fields.read(i);
+            if (value instanceof List<?> entries) {
+                // Modern ClientboundCommandSuggestionsPacket stores its Entry list directly.
+                fields.write(i, IdentityPacketFields.filterEntries(entries, masker));
+                return;
+            }
+            if (value != null && value.getClass().getName().equals("com.mojang.brigadier.suggestion.Suggestions")) {
+                Object range = value.getClass().getMethod("getRange").invoke(value);
+                List<?> entries = (List<?>) value.getClass().getMethod("getList").invoke(value);
+                List<?> filtered = IdentityPacketFields.filterEntries(entries, masker);
+                fields.write(i, value.getClass().getConstructor(range.getClass(), List.class).newInstance(range, filtered));
+                return;
+            }
+        }
+        // Pre-Brigadier protocol compatibility.
+        StructureModifier<String[]> arrays = packet.getStringArrays();
+        if (arrays.size() > 0) {
+            arrays.write(0, java.util.Arrays.stream(arrays.read(0))
+                    .filter(name -> !masker.isConcealedName(name)).toArray(String[]::new));
+            return;
+        }
+        throw new IllegalStateException("Unsupported command suggestions layout");
+    }
+
+    private static void maskSystemChat(PacketContainer packet, StealthChatMasker masker) {
+        StructureModifier<WrappedChatComponent> components = packet.getChatComponents();
+        if (components.size() > 0) {
+            WrappedChatComponent original = components.read(0);
+            String json = original.getJson();
+            String masked = masker.maskAnnouncement(json);
+            if (!json.equals(masked)) {
+                components.write(0, WrappedChatComponent.fromJson(masked));
+            }
+        } else if (packet.getStrings().size() > 0) {
+            // Older SYSTEM_CHAT represents its component as JSON text.
+            String json = packet.getStrings().read(0);
+            packet.getStrings().write(0, masker.maskAnnouncement(json));
+        } else {
+            throw new IllegalStateException("Unsupported system chat layout");
+        }
+    }
+
+    private static void maskBoundNames(PacketContainer packet, StealthChatMasker masker)
+            throws ReflectiveOperationException {
+        StructureModifier<Object> fields = packet.getModifier();
+        for (int i = 0; i < fields.size(); i++) {
+            Object value = fields.read(i);
+            if (value != null && (value.getClass().getName().endsWith("ChatType$BoundNetwork")
+                    || value.getClass().getName().endsWith("ChatType$Bound"))) {
+                Object masked = IdentityPacketFields.mapRecord(value, field -> {
+                    if (field != null && MinecraftReflection.getIChatBaseComponentClass().isInstance(field)) {
+                        String json = WrappedChatComponent.fromHandle(field).getJson();
+                        String replacement = masker.maskDisplayName(json);
+                        return json.equals(replacement) ? field : WrappedChatComponent.fromJson(replacement).getHandle();
+                    }
+                    return field;
+                });
+                fields.write(i, masked);
+                return;
+            }
+        }
+        // Intentionally never touch signed body, unsigned body, UUID, signature, or filter mask.
+        throw new IllegalStateException("Unsupported player chat display-name layout");
+    }
+}

src/main/java/games/dmg/spigotstealth/ProtocolLibServerListPingListener.java

@@ -0,0 +1,37 @@
+package games.dmg.spigotstealth;
+
+import com.comphenix.protocol.PacketType;
+import com.comphenix.protocol.events.PacketAdapter;
+import com.comphenix.protocol.events.PacketEvent;
+import com.comphenix.protocol.wrappers.WrappedServerPing;
+import java.util.Objects;
+import java.util.Set;
+import java.util.UUID;
+import java.util.function.Consumer;
+import java.util.function.Supplier;
+import org.bukkit.plugin.Plugin;
+
+/** Adjusts only the count in outgoing server-list responses through ProtocolLib. */
+public final class ProtocolLibServerListPingListener extends PacketAdapter {
+    private final Supplier<Set<UUID>> concealedPlayerIds;
+    private final ServerPingCompatibilityGuard compatibilityGuard;
+
+    public ProtocolLibServerListPingListener(
+            Plugin plugin,
+            Supplier<Set<UUID>> concealedPlayerIds,
+            Consumer<String> warningLog) {
+        super(plugin, PacketType.Status.Server.SERVER_INFO);
+        this.concealedPlayerIds = Objects.requireNonNull(concealedPlayerIds, "concealedPlayerIds");
+        this.compatibilityGuard = new ServerPingCompatibilityGuard(warningLog);
+    }
+
+    @Override
+    public void onPacketSending(PacketEvent event) {
+        compatibilityGuard.run(() -> {
+            WrappedServerPing ping = event.getPacket().getServerPings().read(0);
+            int visiblePlayers = ServerListPingVisibility.visibleOnlineCount(
+                    ping.getPlayersOnline(), concealedPlayerIds.get().size());
+            ping.setPlayersOnline(visiblePlayers);
+        });
+    }
+}

src/main/java/games/dmg/spigotstealth/ServerListPingListener.java

@@ -0,0 +1,32 @@
+package games.dmg.spigotstealth;
+
+import java.util.Iterator;
+import java.util.Objects;
+import java.util.Set;
+import java.util.UUID;
+import java.util.function.Supplier;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.Listener;
+import org.bukkit.event.server.ServerListPingEvent;
+
+/** Filters concealed players through Bukkit's native server-list sample representation. */
+public final class ServerListPingListener implements Listener {
+    private final Supplier<Set<UUID>> concealedPlayerIds;
+
+    public ServerListPingListener(Supplier<Set<UUID>> concealedPlayerIds) {
+        this.concealedPlayerIds = Objects.requireNonNull(concealedPlayerIds, "concealedPlayerIds");
+    }
+
+    @EventHandler(priority = EventPriority.HIGHEST)
+    public void onServerListPing(ServerListPingEvent event) {
+        Set<UUID> concealed = concealedPlayerIds.get();
+        Iterator<Player> sample = event.iterator();
+        while (sample.hasNext()) {
+            if (concealed.contains(sample.next().getUniqueId())) {
+                sample.remove();
+            }
+        }
+    }
+}

src/main/java/games/dmg/spigotstealth/ServerListPingVisibility.java

@@ -0,0 +1,37 @@
+package games.dmg.spigotstealth;
+
+import java.util.List;
+import java.util.Objects;
+import java.util.Set;
+import java.util.UUID;
+
+/** Computes the public multiplayer server-list view for concealed sessions. */
+public final class ServerListPingVisibility {
+    private ServerListPingVisibility() { }
+
+    public static Snapshot adjust(
+            int playersOnline,
+            int playersMaximum,
+            List<UUID> samplePlayerIds,
+            Set<UUID> concealedPlayerIds) {
+        Objects.requireNonNull(samplePlayerIds, "samplePlayerIds");
+        Objects.requireNonNull(concealedPlayerIds, "concealedPlayerIds");
+        List<UUID> visibleSample = samplePlayerIds.stream()
+                .filter(playerId -> !concealedPlayerIds.contains(playerId))
+                .toList();
+        return new Snapshot(
+                visibleOnlineCount(playersOnline, concealedPlayerIds.size()),
+                playersMaximum,
+                visibleSample);
+    }
+
+    public static int visibleOnlineCount(int playersOnline, int concealedPlayers) {
+        return Math.max(0, playersOnline - concealedPlayers);
+    }
+
+    public record Snapshot(int playersOnline, int playersMaximum, List<UUID> samplePlayerIds) {
+        public Snapshot {
+            samplePlayerIds = List.copyOf(samplePlayerIds);
+        }
+    }
+}

src/main/java/games/dmg/spigotstealth/ServerPingCompatibilityGuard.java

@@ -0,0 +1,26 @@
+package games.dmg.spigotstealth;
+
+import java.util.Objects;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.function.Consumer;
+
+/** Keeps an incompatible server-ping adapter from breaking responses or flooding logs. */
+public final class ServerPingCompatibilityGuard {
+    private final Consumer<String> warningLog;
+    private final AtomicBoolean warningLogged = new AtomicBoolean();
+
+    public ServerPingCompatibilityGuard(Consumer<String> warningLog) {
+        this.warningLog = Objects.requireNonNull(warningLog, "warningLog");
+    }
+
+    public void run(Runnable edit) {
+        try {
+            edit.run();
+        } catch (RuntimeException exception) {
+            if (warningLogged.compareAndSet(false, true)) {
+                warningLog.accept("Unable to adjust the public server-list player count; "
+                        + "the original response will be used: " + exception.getMessage());
+            }
+        }
+    }
+}

src/main/java/games/dmg/spigotstealth/SleepCountPolicy.java

@@ -0,0 +1,24 @@
+package games.dmg.spigotstealth;
+
+import java.util.Locale;
+
+/** Whether concealed players participate in the server's sleep percentage. */
+public enum SleepCountPolicy {
+    INCLUDE,
+    EXCLUDE;
+
+    public static SleepCountPolicy fromPersisted(Object value) {
+        if (value instanceof String text) {
+            try {
+                return valueOf(text.toUpperCase(Locale.ROOT));
+            } catch (IllegalArgumentException ignored) {
+                // Invalid values use the privacy-preserving default.
+            }
+        }
+        return EXCLUDE;
+    }
+
+    public String persistedValue() {
+        return name().toLowerCase(Locale.ROOT);
+    }
+}

src/main/java/games/dmg/spigotstealth/SpigotStealthPlugin.java

@@ -1,6 +1,7 @@
 package games.dmg.spigotstealth;
 
 import com.comphenix.protocol.ProtocolLibrary;
+import com.comphenix.protocol.ProtocolManager;
 import java.nio.file.Path;
 import java.time.Clock;
 import java.util.Objects;
@@ -15,6 +16,7 @@ public final class SpigotStealthPlugin extends JavaPlugin {
     private QualifyingInvisibilityService progression;
     private StealthSessionService sessions;
     private IdentityPresentation identityPresentation;
+    private ProtocolManager protocolManager;
 
     @Override
     public void onEnable() {
@@ -41,6 +43,9 @@ public final class SpigotStealthPlugin extends JavaPlugin {
 
     @Override
     public void onDisable() {
+        if (protocolManager != null) {
+            protocolManager.removePacketListeners(this);
+        }
         if (identityPresentation != null && sessions != null) {
             for (org.bukkit.entity.Player player : getServer().getOnlinePlayers()) {
                 if (sessions.isConcealed(player.getUniqueId())) {
@@ -71,26 +76,43 @@ public final class SpigotStealthPlugin extends JavaPlugin {
         progression = new QualifyingInvisibilityService(
                 manager, settings.unlockThreshold(), System::nanoTime, notifier);
         sessions = new StealthSessionService(manager, progression);
-        identityPresentation = new BukkitIdentityPresentation(
+        protocolManager = ProtocolLibrary.getProtocolManager();
+        BukkitIdentityPresentation bukkitPresentation = new BukkitIdentityPresentation(
                 getServer()::getOnlinePlayers,
                 Objects.requireNonNull(getServer().getScoreboardManager(), "scoreboard manager").getMainScoreboard(),
-                new ProtocolLibTabListController(ProtocolLibrary.getProtocolManager()));
+                new ProtocolLibTabListController(protocolManager),
+                () -> manager.snapshot().sleepCountPolicy());
+        identityPresentation = bukkitPresentation;
+        protocolManager.addPacketListener(new ProtocolLibIdentityMaskingListener(
+                this, bukkitPresentation::concealedNames, getLogger()::warning));
+        protocolManager.addPacketListener(new ProtocolLibServerListPingListener(
+                this, sessions::concealedPlayerIds, getLogger()::warning));
+        getServer().getPluginManager().registerEvents(
+                new ServerListPingListener(sessions::concealedPlayerIds), this);
         getServer().getPluginManager().registerEvents(
                 new InvisibilityEffectListener(progression, Clock.systemUTC()), this);
         getServer().getPluginManager().registerEvents(
                 new StealthSessionListener(sessions, identityPresentation, settings.concealedMessage()), this);
-        Objects.requireNonNull(getCommand("stealth"), "stealth command")
-                .setExecutor(new StealthCommand(manager, progression, settings));
+        getServer().getPluginManager().registerEvents(
+                new StealthAdminJoinListener(sessions, getServer()::getOnlinePlayers), this);
+        org.bukkit.command.PluginCommand stealthPluginCommand =
+                Objects.requireNonNull(getCommand("stealth"), "stealth command");
+        StealthCommand stealthCommand = new StealthCommand(manager, progression, settings);
+        stealthPluginCommand.setExecutor(stealthCommand);
+        stealthPluginCommand.setTabCompleter(stealthCommand);
         StealthAdministrationService administration = new StealthAdministrationService(
                 manager, progression, identityPresentation, notifier, getServer()::getOnlinePlayers);
         KnownPlayerResolver resolver = new KnownPlayerResolver(manager::snapshot, getServer()::getOnlinePlayers);
-        Objects.requireNonNull(getCommand("stealthadmin"), "stealthadmin command")
-                .setExecutor(new StealthAdminCommand(
-                        administration,
-                        resolver,
-                        mainThread,
-                        getLogger()::info,
-                        settings.unlockThreshold()));
+        org.bukkit.command.PluginCommand stealthAdminPluginCommand =
+                Objects.requireNonNull(getCommand("stealthadmin"), "stealthadmin command");
+        StealthAdminCommand stealthAdminCommand = new StealthAdminCommand(
+                administration,
+                resolver,
+                mainThread,
+                getLogger()::info,
+                settings.unlockThreshold());
+        stealthAdminPluginCommand.setExecutor(stealthAdminCommand);
+        stealthAdminPluginCommand.setTabCompleter(stealthAdminCommand);
         getServer().getScheduler().runTaskTimer(this, ignored -> {
             for (java.util.UUID playerId : progression.activePlayerIds()) {
                 logSaveFailure(progression.checkpoint(playerId));

src/main/java/games/dmg/spigotstealth/StealthAdminCommand.java

@@ -9,10 +9,12 @@ import java.util.function.Consumer;
 import org.bukkit.command.Command;
 import org.bukkit.command.CommandExecutor;
 import org.bukkit.command.CommandSender;
+import org.bukkit.command.TabCompleter;
 
 /** Permission-gated administrative command for online and known offline players. */
-public final class StealthAdminCommand implements CommandExecutor {
+public final class StealthAdminCommand implements CommandExecutor, TabCompleter {
     private static final String PERMISSION = "spigotstealth.admin";
+    private static final List<String> OPERATIONS = List.of("status", "grant", "reset", "list", "sleepcount");
     private final StealthAdministrationService administration;
     private final KnownPlayerResolver resolver;
     private final Consumer<Runnable> mainThread;
@@ -32,17 +34,63 @@ public final class StealthAdminCommand implements CommandExecutor {
         this.unlockThreshold = Objects.requireNonNull(unlockThreshold, "unlockThreshold");
     }
 
+    @Override
+    public List<String> onTabComplete(
+            CommandSender sender, Command command, String label, String[] arguments) {
+        if (!sender.hasPermission(PERMISSION)) {
+            return List.of();
+        }
+        if (arguments.length == 1) {
+            return matching(OPERATIONS, arguments[0]);
+        }
+        String operation = arguments[0].toLowerCase(Locale.ROOT);
+        if (arguments.length == 2) {
+            if (List.of("status", "grant", "reset").contains(operation)) {
+                return resolver.completeNames(arguments[1]);
+            }
+            if ("list".equals(operation)) {
+                return matching(List.of("unlocked"), arguments[1]);
+            }
+            if ("sleepcount".equals(operation)) {
+                return matching(List.of("status", "include", "exclude"), arguments[1]);
+            }
+        }
+        if (arguments.length == 3 && "reset".equals(operation)) {
+            return matching(List.of("confirm"), arguments[2]);
+        }
+        return List.of();
+    }
+
+    private static List<String> matching(List<String> candidates, String prefix) {
+        String normalized = prefix.toLowerCase(Locale.ROOT);
+        return candidates.stream().filter(candidate -> candidate.startsWith(normalized)).toList();
+    }
+
     @Override
     public boolean onCommand(CommandSender sender, Command command, String label, String[] arguments) {
         if (!sender.hasPermission(PERMISSION)) {
             sender.sendMessage("You do not have permission to administer Spigot Stealth.");
             return true;
         }
-        if (arguments.length == 1 && "list".equalsIgnoreCase(arguments[0])) {
-            List<String> names = administration.concealedOnlineNames();
-            sender.sendMessage(names.isEmpty()
-                    ? "No players are currently concealed."
-                    : "Currently concealed: " + String.join(", ", names));
+        if (arguments.length > 0 && "sleepcount".equalsIgnoreCase(arguments[0])) {
+            return sleepCount(sender, label, arguments);
+        }
+        if (arguments.length > 0 && "list".equalsIgnoreCase(arguments[0])) {
+            if (arguments.length == 1) {
+                List<String> names = administration.concealedOnlineNames();
+                sender.sendMessage(names.isEmpty()
+                        ? "No players are currently concealed."
+                        : "Currently concealed: " + String.join(", ", names));
+                return true;
+            }
+            if (arguments.length == 2 && "unlocked".equalsIgnoreCase(arguments[1])) {
+                List<String> names = administration.unlockedPlayerNames();
+                sender.sendMessage(names.isEmpty()
+                        ? "No players have unlocked stealth."
+                        : "Stealth unlocked: " + String.join(", ", names));
+                return true;
+            }
+            sendUsage(sender, label);
             return true;
         }
         if (arguments.length < 2) {
@@ -69,6 +117,44 @@ public final class StealthAdminCommand implements CommandExecutor {
         };
     }
 
+    private boolean sleepCount(CommandSender sender, String label, String[] arguments) {
+        if (arguments.length != 2) {
+            sendUsage(sender, label);
+            return true;
+        }
+        String action = arguments[1].toLowerCase(Locale.ROOT);
+        if ("status".equals(action)) {
+            sender.sendMessage("Concealed players are "
+                    + policyDescription(administration.sleepCountPolicy())
+                    + " sleep-percentage calculations.");
+            return true;
+        }
+        SleepCountPolicy policy = switch (action) {
+            case "include" -> SleepCountPolicy.INCLUDE;
+            case "exclude" -> SleepCountPolicy.EXCLUDE;
+            default -> null;
+        };
+        if (policy == null) {
+            sendUsage(sender, label);
+            return true;
+        }
+        administration.setSleepCountPolicy(policy).whenComplete((result, failure) -> mainThread.accept(() -> {
+            if (failure != null) {
+                sender.sendMessage("Unable to persist the sleep-count policy; check the server log.");
+                return;
+            }
+            administration.refreshSleepCountPolicy();
+            sender.sendMessage(result.changed()
+                    ? "Concealed players are now " + policyDescription(policy)
+                            + " sleep-percentage calculations."
+                    : "Concealed players are already " + policyDescription(policy)
+                            + " sleep-percentage calculations.");
+            auditLog.accept("stealthadmin sleepcount administrator=" + sender.getName()
+                    + " policy=" + policy.persistedValue() + " changed=" + result.changed());
+        }));
+        return true;
+    }
+
     private boolean status(CommandSender sender, KnownPlayerResolver.KnownPlayer target) {
         StealthAdministrationService.PlayerStatus status = administration.status(target.playerId());
         sender.sendMessage("Stealth status for " + displayName(target) + " (" + target.playerId() + "):");
@@ -121,13 +207,17 @@ public final class StealthAdminCommand implements CommandExecutor {
     }
 
     private static void sendUsage(CommandSender sender, String label) {
-        sender.sendMessage("Usage: /" + label + " <status <player|uuid>|grant <player|uuid>|reset <player|uuid> confirm|list>");
+        sender.sendMessage("Usage: /" + label + " <status <player|uuid>|grant <player|uuid>|reset <player|uuid> confirm|list [unlocked]|sleepcount <status|include|exclude>>");
     }
 
     private static String displayName(KnownPlayerResolver.KnownPlayer player) {
         return player.name() == null ? player.playerId().toString() : player.name();
     }
 
+    private static String policyDescription(SleepCountPolicy policy) {
+        return policy == SleepCountPolicy.EXCLUDE ? "excluded from" : "included in";
+    }
+
     private static String yesNo(boolean value) {
         return value ? "yes" : "no";
     }

src/main/java/games/dmg/spigotstealth/StealthAdminJoinListener.java

@@ -0,0 +1,49 @@
+package games.dmg.spigotstealth;
+
+import java.util.Collection;
+import java.util.Objects;
+import java.util.Set;
+import java.util.UUID;
+import java.util.function.Supplier;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.Listener;
+import org.bukkit.event.player.PlayerJoinEvent;
+
+/** Private administrative notices after the HIGHEST-priority session transition. */
+public final class StealthAdminJoinListener implements Listener {
+    private static final String PERMISSION = "spigotstealth.admin";
+    private static final String HINT = " Use /stealthadmin list to see who.";
+    private final StealthSessionService sessions;
+    private final Supplier<? extends Collection<? extends Player>> onlinePlayers;
+
+    public StealthAdminJoinListener(
+            StealthSessionService sessions,
+            Supplier<? extends Collection<? extends Player>> onlinePlayers) {
+        this.sessions = Objects.requireNonNull(sessions, "sessions");
+        this.onlinePlayers = Objects.requireNonNull(onlinePlayers, "onlinePlayers");
+    }
+
+    @EventHandler(priority = EventPriority.MONITOR)
+    public void onJoin(PlayerJoinEvent event) {
+        Player joining = event.getPlayer();
+        Set<UUID> concealed = sessions.concealedPlayerIds();
+        int count = concealed.size();
+        if (count == 0) {
+            return;
+        }
+        String quantity = count + (count == 1 ? " player is" : " players are");
+        if (joining.hasPermission(PERMISSION)) {
+            joining.sendMessage("[Stealth] " + quantity + " invisible." + HINT);
+        }
+        if (concealed.contains(joining.getUniqueId())) {
+            String notice = "[Stealth] An invisible player joined. " + quantity + " now invisible." + HINT;
+            for (Player observer : onlinePlayers.get()) {
+                if (!observer.getUniqueId().equals(joining.getUniqueId()) && observer.hasPermission(PERMISSION)) {
+                    observer.sendMessage(notice);
+                }
+            }
+        }
+    }
+}

src/main/java/games/dmg/spigotstealth/StealthAdministrationService.java

@@ -31,6 +31,26 @@ public final class StealthAdministrationService {
         this.onlinePlayers = Objects.requireNonNull(onlinePlayers, "onlinePlayers");
     }
 
+    public SleepCountPolicy sleepCountPolicy() {
+        return stateManager.snapshot().sleepCountPolicy();
+    }
+
+    public CompletableFuture<ChangeResult> setSleepCountPolicy(SleepCountPolicy policy) {
+        Objects.requireNonNull(policy, "policy");
+        AtomicBoolean changed = new AtomicBoolean();
+        return stateManager.update(state -> {
+            if (state.sleepCountPolicy() == policy) {
+                return state;
+            }
+            changed.set(true);
+            return state.withSleepCountPolicy(policy);
+        }).thenApply(ignored -> new ChangeResult(changed.get()));
+    }
+
+    public void refreshSleepCountPolicy() {
+        presentation.refreshSleepCountPolicy();
+    }
+
     public PlayerStatus status(UUID playerId) {
         PlayerStealthState player = stateManager.snapshot().player(playerId);
         return new PlayerStatus(
@@ -73,6 +93,17 @@ public final class StealthAdministrationService {
         return CompletableFuture.allOf(stopped, reset);
     }
 
+    public List<String> unlockedPlayerNames() {
+        return stateManager.snapshot().players().entrySet().stream()
+                .filter(entry -> entry.getValue().unlocked())
+                .map(entry -> {
+                    String name = entry.getValue().lastKnownName();
+                    return name == null || name.isBlank() ? entry.getKey().toString() : name;
+                })
+                .sorted(String.CASE_INSENSITIVE_ORDER)
+                .toList();
+    }
+
     public List<String> concealedOnlineNames() {
         return onlinePlayers.get().stream()
                 .filter(player -> stateManager.snapshot().player(player.getUniqueId()).concealed())

src/main/java/games/dmg/spigotstealth/StealthChatMasker.java

@@ -0,0 +1,117 @@
+package games.dmg.spigotstealth;
+
+import com.google.gson.JsonArray;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParseException;
+import com.google.gson.JsonParser;
+import java.util.Locale;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+/** Masks semantic name slots, never searching/replacing user-authored message text. */
+public final class StealthChatMasker {
+    private static final Set<String> NAME_FIRST_TRANSLATIONS = Set.of(
+            "chat.type.text", "chat.type.announcement", "chat.type.emote",
+            "commands.message.display.incoming", "commands.message.display.outgoing",
+            "chat.type.advancement.task", "chat.type.advancement.goal", "chat.type.advancement.challenge");
+    private final Set<String> names;
+
+    public StealthChatMasker(Set<String> concealedNames) {
+        names = concealedNames.stream().map(name -> name.toLowerCase(Locale.ROOT)).collect(Collectors.toUnmodifiableSet());
+    }
+
+    public boolean isConcealedName(String text) {
+        return names.contains(text.toLowerCase(Locale.ROOT));
+    }
+
+    public String maskAnnouncement(String json) {
+        try {
+            JsonElement component = JsonParser.parseString(json);
+            return maskAnnouncement(component) ? component.toString() : json;
+        } catch (JsonParseException | IllegalStateException exception) {
+            return json;
+        }
+    }
+
+    public String maskDisplayName(String json) {
+        try {
+            return isConcealedName(plainName(JsonParser.parseString(json))) ? anonymous().toString() : json;
+        } catch (JsonParseException | IllegalStateException exception) {
+            return json;
+        }
+    }
+
+    private boolean maskAnnouncement(JsonElement component) {
+        boolean changed = false;
+        if (component.isJsonArray()) {
+            for (JsonElement child : component.getAsJsonArray()) {
+                changed |= maskAnnouncement(child);
+            }
+            if (changed && !component.getAsJsonArray().isEmpty()) {
+                clearInheritedActions(component.getAsJsonArray().get(0));
+            }
+        } else if (component.isJsonObject()) {
+            JsonObject object = component.getAsJsonObject();
+            // Translation arguments other than the explicitly known name slot are message content.
+            if (object.has("translate") && object.get("translate").isJsonPrimitive()
+                    && NAME_FIRST_TRANSLATIONS.contains(object.get("translate").getAsString())
+                    && object.has("with") && object.get("with").isJsonArray()) {
+                JsonArray arguments = object.getAsJsonArray("with");
+                if (!arguments.isEmpty() && isConcealedName(plainName(arguments.get(0)))) {
+                    arguments.set(0, anonymous());
+                    changed = true;
+                }
+            }
+            if (object.has("extra")) {
+                changed |= maskAnnouncement(object.get("extra"));
+            }
+            // Prevent masked descendants from inheriting an identifying action from their parent.
+            if (changed) {
+                clearInheritedActions(object);
+            }
+        }
+        return changed;
+    }
+
+    private static void clearInheritedActions(JsonElement component) {
+        if (component.isJsonObject()) {
+            for (String key : Set.of("hoverEvent", "clickEvent", "hover_event", "click_event", "insertion")) {
+                component.getAsJsonObject().remove(key);
+            }
+        } else if (component.isJsonArray() && !component.getAsJsonArray().isEmpty()) {
+            clearInheritedActions(component.getAsJsonArray().get(0));
+        }
+    }
+
+    private static String plainName(JsonElement component) {
+        if (component.isJsonPrimitive()) {
+            return component.getAsString();
+        }
+        StringBuilder text = new StringBuilder();
+        if (component.isJsonArray()) {
+            for (JsonElement child : component.getAsJsonArray()) {
+                text.append(plainName(child));
+            }
+        } else if (component.isJsonObject()) {
+            JsonObject object = component.getAsJsonObject();
+            if (object.has("text") && object.get("text").isJsonPrimitive()) {
+                text.append(object.get("text").getAsString());
+            }
+            if (object.has("extra")) {
+                text.append(plainName(object.get("extra")));
+            }
+        }
+        return text.toString();
+    }
+
+    private static JsonObject anonymous() {
+        JsonObject alias = new JsonObject();
+        alias.addProperty("text", "Anonymous");
+        alias.addProperty("obfuscated", true);
+        alias.add("hoverEvent", com.google.gson.JsonNull.INSTANCE);
+        alias.add("clickEvent", com.google.gson.JsonNull.INSTANCE);
+        alias.addProperty("insertion", "");
+        return alias;
+    }
+}

src/main/java/games/dmg/spigotstealth/StealthCommand.java

@@ -1,14 +1,16 @@
 package games.dmg.spigotstealth;
 
+import java.util.List;
 import java.util.Locale;
 import java.util.Objects;
 import org.bukkit.command.Command;
 import org.bukkit.command.CommandExecutor;
 import org.bukkit.command.CommandSender;
+import org.bukkit.command.TabCompleter;
 import org.bukkit.entity.Player;
 
 /** Player-facing progress command. */
-public final class StealthCommand implements CommandExecutor {
+public final class StealthCommand implements CommandExecutor, TabCompleter {
     private final StealthStateManager stateManager;
     private final QualifyingInvisibilityService progression;
     private final StealthSettings settings;
@@ -22,6 +24,15 @@ public final class StealthCommand implements CommandExecutor {
         this.settings = Objects.requireNonNull(settings, "settings");
     }
 
+    @Override
+    public List<String> onTabComplete(
+            CommandSender sender, Command command, String label, String[] arguments) {
+        if (arguments.length == 1 && "progress".startsWith(arguments[0].toLowerCase(Locale.ROOT))) {
+            return List.of("progress");
+        }
+        return List.of();
+    }
+
     @Override
     public boolean onCommand(CommandSender sender, Command command, String label, String[] arguments) {
         if (!(sender instanceof Player player)) {

src/main/java/games/dmg/spigotstealth/StealthSessionListener.java

@@ -38,10 +38,14 @@ public final class StealthSessionListener implements Listener {
         presentation.refreshForObserver(player);
     }
 
-    @EventHandler(priority = EventPriority.MONITOR)
+    @EventHandler(priority = EventPriority.HIGHEST)
     public void onQuit(PlayerQuitEvent event) {
-        presentation.reveal(event.getPlayer());
-        sessions.disconnect(event.getPlayer().getUniqueId());
+        Player player = event.getPlayer();
+        if (sessions.isConcealed(player.getUniqueId())) {
+            event.setQuitMessage(null);
+        }
+        presentation.reveal(player);
+        sessions.disconnect(player.getUniqueId());
     }
 
     @EventHandler(priority = EventPriority.MONITOR)

src/main/java/games/dmg/spigotstealth/StealthSessionService.java

@@ -1,7 +1,9 @@
 package games.dmg.spigotstealth;
 
 import java.util.Objects;
+import java.util.Set;
 import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.atomic.AtomicBoolean;
 
@@ -9,6 +11,7 @@ import java.util.concurrent.atomic.AtomicBoolean;
 public final class StealthSessionService {
     private final StealthStateManager stateManager;
     private final QualifyingInvisibilityService progression;
+    private final Set<UUID> concealedOnlinePlayerIds = ConcurrentHashMap.newKeySet();
 
     public StealthSessionService(
             StealthStateManager stateManager,
@@ -18,6 +21,7 @@ public final class StealthSessionService {
     }
 
     public CompletableFuture<Void> disconnect(UUID playerId) {
+        concealedOnlinePlayerIds.remove(playerId);
         boolean qualifyingAtDisconnect = progression.isQualifying(playerId);
         return progression.stop(playerId).thenCompose(ignored -> stateManager.update(state -> {
             PlayerStealthState player = state.player(playerId);
@@ -34,10 +38,16 @@ public final class StealthSessionService {
             concealed.set(conceal);
             return state.withPlayer(player.withSession(false, conceal).withQualifyingSince(null));
         });
+        if (concealed.get()) {
+            concealedOnlinePlayerIds.add(playerId);
+        } else {
+            concealedOnlinePlayerIds.remove(playerId);
+        }
         return new LoginTransition(concealed.get(), saved);
     }
 
     public CompletableFuture<Void> endConcealment(UUID playerId) {
+        concealedOnlinePlayerIds.remove(playerId);
         return stateManager.update(state -> {
             PlayerStealthState player = state.player(playerId);
             return state.withPlayer(player.withSession(player.preparedLogin(), false));
@@ -48,5 +58,12 @@ public final class StealthSessionService {
         return stateManager.snapshot().player(playerId).concealed();
     }
 
+    public Set<UUID> concealedPlayerIds() {
+        PersistentStealthState state = stateManager.snapshot();
+        return concealedOnlinePlayerIds.stream()
+                .filter(playerId -> state.player(playerId).concealed())
+                .collect(java.util.stream.Collectors.toUnmodifiableSet());
+    }
+
     public record LoginTransition(boolean concealed, CompletableFuture<Void> saved) { }
 }

src/main/java/games/dmg/spigotstealth/YamlStealthStateRepository.java

@@ -17,7 +17,7 @@ import org.bukkit.configuration.file.YamlConfiguration;
 
 /** Defensive YAML repository using atomic file replacement where available. */
 public final class YamlStealthStateRepository implements StealthStateRepository {
-    private static final Set<String> ROOT_FIELDS = Set.of("schema-version", "players");
+    private static final Set<String> ROOT_FIELDS = Set.of("schema-version", "sleep-count-policy", "players");
     private static final Set<String> PLAYER_FIELDS = Set.of(
             "last-known-name", "accumulated-millis", "unlocked", "prepared-login", "concealed", "qualifying-since");
     private final Path stateFile;
@@ -53,7 +53,10 @@ public final class YamlStealthStateRepository implements StealthStateRepository
                 }
             }
         }
-        return new PersistentStealthState(players, unknownRoot);
+        return new PersistentStealthState(
+                players,
+                SleepCountPolicy.fromPersisted(yaml.get("sleep-count-policy")),
+                unknownRoot);
     }
 
     @Override
@@ -61,6 +64,7 @@ public final class YamlStealthStateRepository implements StealthStateRepository
         YamlConfiguration yaml = new YamlConfiguration();
         state.unknownFields().forEach(yaml::set);
         yaml.set("schema-version", 1);
+        yaml.set("sleep-count-policy", state.sleepCountPolicy().persistedValue());
         for (PlayerStealthState player : state.players().values()) {
             String base = "players." + player.playerId() + ".";
             player.unknownFields().forEach((key, value) -> yaml.set(base + key, value));

src/main/resources/plugin.yml

@@ -12,7 +12,7 @@ commands:
     permission: spigotstealth.use
   stealthadmin:
     description: Inspect and administer Spigot Stealth.
-    usage: /stealthadmin <status|grant|reset|list>
+    usage: /stealthadmin <status <player|uuid>|grant <player|uuid>|reset <player|uuid> confirm|list [unlocked]|sleepcount <status|include|exclude>>
     permission: spigotstealth.admin
 permissions:
   spigotstealth.use:

src/test/java/games/dmg/spigotstealth/BukkitIdentityPresentationTest.java

@@ -7,6 +7,7 @@ import static org.mockito.Mockito.when;
 
 import java.util.List;
 import java.util.UUID;
+import java.util.concurrent.atomic.AtomicReference;
 import org.bukkit.entity.Player;
 import org.bukkit.scoreboard.Scoreboard;
 import org.bukkit.scoreboard.Team;
@@ -14,7 +15,69 @@ import org.junit.jupiter.api.Test;
 
 class BukkitIdentityPresentationTest {
     @Test
-    void concealRemovesTabEntryAndHidesNameTagWithoutHidingEntity() {
+    void excludedConcealmentIgnoresSleepCountAndRestoresPreviousState() {
+        UUID targetId = UUID.randomUUID();
+        Player target = player(targetId, "Alex");
+        when(target.isSleepingIgnored()).thenReturn(false);
+        Scoreboard scoreboard = mock(Scoreboard.class);
+        Team team = mock(Team.class);
+        when(scoreboard.getTeam(BukkitIdentityPresentation.teamName(targetId))).thenReturn(team);
+        BukkitIdentityPresentation presentation = new BukkitIdentityPresentation(
+                () -> List.of(target), scoreboard, mock(TabListController.class));
+
+        when(target.getDisplayName()).thenReturn("Original Alex");
+        presentation.conceal(target);
+        presentation.conceal(target);
+        presentation.reveal(target);
+
+        verify(target).setDisplayName("Original Alex");
+        org.junit.jupiter.api.Assertions.assertTrue(presentation.concealedNames().isEmpty());
+        verify(target, org.mockito.Mockito.times(2)).setSleepingIgnored(true);
+        verify(target).setSleepingIgnored(false);
+    }
+
+    @Test
+    void includedConcealmentDoesNotChangeOrdinarySleepParticipation() {
+        UUID targetId = UUID.randomUUID();
+        Player target = player(targetId, "Alex");
+        Scoreboard scoreboard = mock(Scoreboard.class);
+        Team team = mock(Team.class);
+        when(scoreboard.getTeam(BukkitIdentityPresentation.teamName(targetId))).thenReturn(team);
+        BukkitIdentityPresentation presentation = new BukkitIdentityPresentation(
+                () -> List.of(target),
+                scoreboard,
+                mock(TabListController.class),
+                () -> SleepCountPolicy.INCLUDE);
+
+        presentation.conceal(target);
+
+        verify(target, never()).setSleepingIgnored(org.mockito.ArgumentMatchers.anyBoolean());
+    }
+
+    @Test
+    void policyChangesImmediatelyRestoreAndReapplyConcealedSleepParticipation() {
+        UUID targetId = UUID.randomUUID();
+        Player target = player(targetId, "Alex");
+        when(target.isSleepingIgnored()).thenReturn(false);
+        Scoreboard scoreboard = mock(Scoreboard.class);
+        Team team = mock(Team.class);
+        when(scoreboard.getTeam(BukkitIdentityPresentation.teamName(targetId))).thenReturn(team);
+        AtomicReference<SleepCountPolicy> policy = new AtomicReference<>(SleepCountPolicy.EXCLUDE);
+        BukkitIdentityPresentation presentation = new BukkitIdentityPresentation(
+                () -> List.of(target), scoreboard, mock(TabListController.class), policy::get);
+        presentation.conceal(target);
+
+        policy.set(SleepCountPolicy.INCLUDE);
+        presentation.refreshSleepCountPolicy();
+        policy.set(SleepCountPolicy.EXCLUDE);
+        presentation.refreshSleepCountPolicy();
+
+        verify(target, org.mockito.Mockito.times(2)).setSleepingIgnored(true);
+        verify(target).setSleepingIgnored(false);
+    }
+
+    @Test
+    void concealRemovesTabEntryAndScramblesNameTagWithoutHidingEntity() {
         UUID targetId = UUID.randomUUID();
         Player target = player(targetId, "Alex");
         Player observer = player(UUID.randomUUID(), "Morgan");
@@ -28,7 +91,11 @@ class BukkitIdentityPresentationTest {
 
         presentation.conceal(target);
 
-        verify(team).setOption(Team.Option.NAME_TAG_VISIBILITY, Team.OptionStatus.NEVER);
+        verify(team).setOption(Team.Option.NAME_TAG_VISIBILITY, Team.OptionStatus.ALWAYS);
+        verify(team).setPrefix("§k");
+        verify(team).setSuffix("§r");
+        verify(target).setDisplayName("§kAnonymous§r");
+        org.junit.jupiter.api.Assertions.assertEquals(java.util.Set.of("Alex"), presentation.concealedNames());
         verify(team).addEntry("Alex");
         verify(tabLists).remove(observer, targetId);
         verify(observer, never()).hidePlayer(org.mockito.ArgumentMatchers.any(), org.mockito.ArgumentMatchers.any());

src/test/java/games/dmg/spigotstealth/IdentityPacketFieldsTest.java

@@ -0,0 +1,32 @@
+package games.dmg.spigotstealth;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.util.List;
+import java.util.Optional;
+import java.util.Set;
+import org.junit.jupiter.api.Test;
+
+class IdentityPacketFieldsTest {
+    private final StealthChatMasker masker = new StealthChatMasker(Set.of("Secret"));
+
+    record Entry(String text, Optional<String> tooltip) { }
+    record Bound(int chatType, String name, Optional<String> targetName) { }
+
+    @Test
+    void filtersModernSuggestionEntriesWithoutChangingOrdinaryEntries() throws ReflectiveOperationException {
+        Entry ordinary = new Entry("Someone", Optional.of("help"));
+        List<Entry> entries = List.of(new Entry("sEcReT", Optional.empty()), ordinary);
+        assertEquals(List.of(ordinary), IdentityPacketFields.filterEntries(entries, masker));
+        assertEquals(2, entries.size());
+    }
+
+    @Test
+    void rebuildsDisplayNameRecordWithoutMutatingOriginal() throws ReflectiveOperationException {
+        Bound original = new Bound(42, "Secret", Optional.of("Secret"));
+        Object copy = IdentityPacketFields.mapRecord(original,
+                value -> value.equals("Secret") ? "Anonymous" : value);
+        assertEquals(new Bound(42, "Anonymous", Optional.of("Anonymous")), copy);
+        assertEquals("Secret", original.name());
+    }
+}

src/test/java/games/dmg/spigotstealth/ProtocolLibIdentityMaskingListenerTest.java

@@ -0,0 +1,63 @@
+package games.dmg.spigotstealth;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.Mockito.*;
+
+import com.comphenix.protocol.PacketType;
+import com.comphenix.protocol.events.PacketEvent;
+import com.comphenix.protocol.utility.MinecraftReflection;
+import com.comphenix.protocol.utility.MinecraftVersion;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicReference;
+import org.bukkit.plugin.Plugin;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.mockito.MockedStatic;
+
+class ProtocolLibIdentityMaskingListenerTest {
+    private static MockedStatic<MinecraftReflection> reflection;
+
+    @BeforeAll
+    static void initializeProtocolTypesWithoutServer() {
+        MinecraftVersion.setCurrentVersion(new MinecraftVersion(1, 21, 8));
+        reflection = mockStatic(MinecraftReflection.class);
+    }
+
+    @AfterAll
+    static void resetProtocolEnvironment() {
+        reflection.close();
+        MinecraftVersion.setCurrentVersion(null);
+    }
+
+    @Test
+    void skipsPacketWorkWhenNobodyIsConcealed() {
+        AtomicReference<Set<String>> names = new AtomicReference<>(Set.of());
+        var listener = new ProtocolLibIdentityMaskingListener(mock(Plugin.class), names::get, ignored -> { });
+        PacketEvent event = mock(PacketEvent.class);
+        listener.onPacketSending(event);
+        verify(event, never()).getPacket();
+        assertTrue(listener.getSendingWhitelist().getTypes().contains(PacketType.Play.Server.CHAT));
+        assertTrue(listener.getSendingWhitelist().getTypes().contains(PacketType.Play.Server.SYSTEM_CHAT));
+    }
+
+    @Test
+    void readsFreshSnapshotAndWarnsOnceWithoutCancellingOrReplacingFailedPacket() {
+        List<String> warnings = new ArrayList<>();
+        AtomicReference<Set<String>> names = new AtomicReference<>(Set.of());
+        var listener = new ProtocolLibIdentityMaskingListener(mock(Plugin.class), names::get, warnings::add);
+        PacketEvent event = mock(PacketEvent.class);
+        when(event.getPacketType()).thenReturn(PacketType.Play.Server.CHAT);
+        listener.onPacketSending(event);
+        assertTrue(warnings.isEmpty());
+        names.set(Set.of("Secret"));
+        // No real NMS packet: the clone attempt fails and must leave event delivery untouched.
+        listener.onPacketSending(event);
+        listener.onPacketSending(event);
+        assertEquals(1, warnings.size());
+        verify(event, never()).setPacket(any());
+        verify(event, never()).setCancelled(anyBoolean());
+    }
+}

src/test/java/games/dmg/spigotstealth/ServerListPingListenerTest.java

@@ -0,0 +1,36 @@
+package games.dmg.spigotstealth;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Set;
+import java.util.UUID;
+import org.bukkit.entity.Player;
+import org.bukkit.event.server.ServerListPingEvent;
+import org.junit.jupiter.api.Test;
+
+class ServerListPingListenerTest {
+    @Test
+    void removesOnlyConcealedPlayersFromNativeServerPingSample() {
+        UUID concealedId = UUID.randomUUID();
+        Player visible = player(UUID.randomUUID());
+        Player concealed = player(concealedId);
+        ArrayList<Player> sample = new ArrayList<>(List.of(visible, concealed));
+        ServerListPingEvent event = mock(ServerListPingEvent.class);
+        when(event.iterator()).thenReturn(sample.iterator());
+        ServerListPingListener listener = new ServerListPingListener(() -> Set.of(concealedId));
+
+        listener.onServerListPing(event);
+
+        assertEquals(List.of(visible), sample);
+    }
+
+    private static Player player(UUID playerId) {
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(playerId);
+        return player;
+    }
+}

src/test/java/games/dmg/spigotstealth/ServerListPingVisibilityTest.java

@@ -0,0 +1,43 @@
+package games.dmg.spigotstealth;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.List;
+import java.util.Set;
+import java.util.UUID;
+import org.junit.jupiter.api.Test;
+
+class ServerListPingVisibilityTest {
+    @Test
+    void publicPlayerCountNeverBecomesNegative() {
+        ServerListPingVisibility.Snapshot adjusted = ServerListPingVisibility.adjust(
+                0, 100, List.of(), Set.of(UUID.randomUUID()));
+
+        assertEquals(0, adjusted.playersOnline());
+    }
+
+    @Test
+    void ordinaryPlayersRemainCountedAndSampled() {
+        UUID firstId = UUID.randomUUID();
+        UUID secondId = UUID.randomUUID();
+
+        ServerListPingVisibility.Snapshot adjusted = ServerListPingVisibility.adjust(
+                2, 100, List.of(firstId, secondId), Set.of());
+
+        assertEquals(2, adjusted.playersOnline());
+        assertEquals(List.of(firstId, secondId), adjusted.samplePlayerIds());
+    }
+
+    @Test
+    void excludesConcealedPlayersFromPublicCountAndSampleWithoutChangingMaximum() {
+        UUID visibleId = UUID.randomUUID();
+        UUID concealedId = UUID.randomUUID();
+
+        ServerListPingVisibility.Snapshot adjusted = ServerListPingVisibility.adjust(
+                2, 100, List.of(visibleId, concealedId), Set.of(concealedId));
+
+        assertEquals(1, adjusted.playersOnline());
+        assertEquals(100, adjusted.playersMaximum());
+        assertEquals(List.of(visibleId), adjusted.samplePlayerIds());
+    }
+}

src/test/java/games/dmg/spigotstealth/ServerPingCompatibilityGuardTest.java

@@ -0,0 +1,24 @@
+package games.dmg.spigotstealth;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+
+import java.util.ArrayList;
+import org.junit.jupiter.api.Test;
+
+class ServerPingCompatibilityGuardTest {
+    @Test
+    void compatibilityFailureLeavesPingHandlingUsableAndWarnsOnlyOnce() {
+        ArrayList<String> warnings = new ArrayList<>();
+        ServerPingCompatibilityGuard guard = new ServerPingCompatibilityGuard(warnings::add);
+
+        assertDoesNotThrow(() -> guard.run(() -> {
+            throw new IllegalArgumentException("unsupported profile representation");
+        }));
+        assertDoesNotThrow(() -> guard.run(() -> {
+            throw new IllegalArgumentException("unsupported profile representation");
+        }));
+
+        assertEquals(1, warnings.size());
+    }
+}

src/test/java/games/dmg/spigotstealth/StealthAdminCommandTest.java

@@ -1,5 +1,6 @@
 package games.dmg.spigotstealth;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.mockito.ArgumentMatchers.contains;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
@@ -16,6 +17,77 @@ import org.bukkit.command.CommandSender;
 import org.junit.jupiter.api.Test;
 
 class StealthAdminCommandTest {
+    @Test
+    void completesAdministrativeOperationsByPrefix() {
+        UUID playerId = UUID.randomUUID();
+        try (Fixture fixture = fixture(playerId)) {
+            assertEquals(
+                    List.of("grant"),
+                    fixture.command.onTabComplete(
+                            sender(true), mock(Command.class), "stealthadmin", new String[] {"gr"}));
+            assertEquals(
+                    List.of("status", "grant", "reset", "list", "sleepcount"),
+                    fixture.command.onTabComplete(
+                            sender(true), mock(Command.class), "stealthadmin", new String[] {""}));
+        }
+    }
+
+    @Test
+    void completesContextualArgumentsAndSuppressesIrrelevantSuggestions() {
+        UUID playerId = UUID.randomUUID();
+        try (Fixture fixture = fixture(playerId)) {
+            Command command = mock(Command.class);
+            CommandSender administrator = sender(true);
+
+            assertEquals(
+                    List.of("Alex"),
+                    fixture.command.onTabComplete(
+                            administrator, command, "stealthadmin", new String[] {"status", "al"}));
+            assertEquals(
+                    List.of("confirm"),
+                    fixture.command.onTabComplete(
+                            administrator, command, "stealthadmin", new String[] {"reset", "Alex", "co"}));
+            assertEquals(
+                    List.of("unlocked"),
+                    fixture.command.onTabComplete(
+                            administrator, command, "stealthadmin", new String[] {"list", "un"}));
+            assertEquals(
+                    List.of("status", "include", "exclude"),
+                    fixture.command.onTabComplete(
+                            administrator, command, "stealthadmin", new String[] {"sleepcount", ""}));
+            assertEquals(
+                    List.of(),
+                    fixture.command.onTabComplete(
+                            administrator, command, "stealthadmin", new String[] {"status", "Alex", ""}));
+            assertEquals(
+                    List.of(),
+                    fixture.command.onTabComplete(
+                            sender(false), command, "stealthadmin", new String[] {""}));
+        }
+    }
+
+    @Test
+    void reportsAndChangesPersistentSleepCountPolicyWithImmediateRefreshAndAudit() {
+        UUID playerId = UUID.randomUUID();
+        try (Fixture fixture = fixture(playerId)) {
+            CommandSender sender = sender(true);
+            Command command = mock(Command.class);
+
+            fixture.command.onCommand(
+                    sender, command, "stealthadmin", new String[] {"sleepcount", "status"});
+            verify(sender).sendMessage(contains("excluded"));
+
+            fixture.command.onCommand(
+                    sender, command, "stealthadmin", new String[] {"sleepcount", "include"});
+
+            verify(sender, org.mockito.Mockito.timeout(1000)).sendMessage(contains("now included"));
+            assertEquals(SleepCountPolicy.INCLUDE, fixture.manager.snapshot().sleepCountPolicy());
+            verify(fixture.presentation).refreshSleepCountPolicy();
+            org.junit.jupiter.api.Assertions.assertTrue(fixture.audit.stream()
+                    .anyMatch(message -> message.contains("sleepcount") && message.contains("include")));
+        }
+    }
+
     @Test
     void statusInspectsKnownOfflinePlayerAndReportsAllState() {
         UUID playerId = UUID.randomUUID();
@@ -28,6 +100,25 @@ class StealthAdminCommandTest {
         }
     }
 
+    @Test
+    void listsUnlockedPlayersAndClearlyReportsWhenThereAreNone() {
+        UUID playerId = UUID.randomUUID();
+        try (Fixture fixture = fixture(playerId)) {
+            Command command = mock(Command.class);
+            CommandSender emptySender = sender(true);
+            fixture.command.onCommand(
+                    emptySender, command, "stealthadmin", new String[] {"list", "unlocked"});
+            verify(emptySender).sendMessage("No players have unlocked stealth.");
+
+            fixture.manager.update(state -> state.withPlayer(
+                    state.player(playerId).withProgress(5000L, true))).join();
+            CommandSender populatedSender = sender(true);
+            fixture.command.onCommand(
+                    populatedSender, command, "stealthadmin", new String[] {"list", "unlocked"});
+            verify(populatedSender).sendMessage("Stealth unlocked: Alex");
+        }
+    }
+
     @Test
     void grantPersistsThenReportsAndAuditsAction() {
         UUID playerId = UUID.randomUUID();
@@ -71,18 +162,20 @@ class StealthAdminCommandTest {
         manager.update(state -> state.withPlayer(player)).join();
         QualifyingInvisibilityService progression = new QualifyingInvisibilityService(
                 manager, Duration.ofHours(8), System::nanoTime, ignored -> { });
+        IdentityPresentation presentation = mock(IdentityPresentation.class);
         StealthAdministrationService administration = new StealthAdministrationService(
-                manager, progression, mock(IdentityPresentation.class), ignored -> { }, List::of);
+                manager, progression, presentation, ignored -> { }, List::of);
         KnownPlayerResolver resolver = new KnownPlayerResolver(manager::snapshot, List::of);
         ArrayList<String> audit = new ArrayList<>();
         StealthAdminCommand command = new StealthAdminCommand(
                 administration, resolver, Runnable::run, audit::add, Duration.ofHours(8));
-        return new Fixture(manager, command, audit);
+        return new Fixture(manager, command, presentation, audit);
     }
 
     private record Fixture(
             StealthStateManager manager,
             StealthAdminCommand command,
+            IdentityPresentation presentation,
             ArrayList<String> audit) implements AutoCloseable {
         @Override public void close() { manager.close(); }
     }

src/test/java/games/dmg/spigotstealth/StealthAdminJoinListenerTest.java

@@ -0,0 +1,83 @@
+package games.dmg.spigotstealth;
+
+import static org.mockito.Mockito.*;
+
+import java.util.List;
+import java.util.Set;
+import java.util.UUID;
+import org.bukkit.entity.Player;
+import org.bukkit.event.player.PlayerJoinEvent;
+import org.junit.jupiter.api.Test;
+
+class StealthAdminJoinListenerTest {
+    @Test
+    void joiningAdminReceivesCountButExistingAdminsDoNotReceiveOrdinaryJoinNotice() {
+        Player joining = player(true);
+        Player existing = player(true);
+        StealthSessionService sessions = sessions(Set.of(UUID.randomUUID(), UUID.randomUUID()));
+        new StealthAdminJoinListener(sessions, () -> List.of(joining, existing)).onJoin(event(joining));
+        verify(joining).sendMessage("[Stealth] 2 players are invisible. Use /stealthadmin list to see who.");
+        verify(existing, never()).sendMessage(anyString());
+    }
+
+    @Test
+    void concealedJoinNotifiesOnlyAdminsWithUpdatedCount() {
+        Player joining = player(false);
+        Player admin = player(true);
+        Player ordinary = player(false);
+        StealthSessionService sessions = sessions(Set.of(joining.getUniqueId()));
+        new StealthAdminJoinListener(sessions, () -> List.of(joining, admin, ordinary)).onJoin(event(joining));
+        verify(admin).sendMessage("[Stealth] An invisible player joined. 1 player is now invisible. Use /stealthadmin list to see who.");
+        verify(joining, never()).sendMessage(anyString());
+        verify(ordinary, never()).sendMessage(anyString());
+    }
+
+    @Test
+    void concealedAdminGetsExactlyOneNoticeEvenWhenIncludedInOnlinePlayers() {
+        Player joining = player(true);
+        Player admin = player(true);
+        StealthSessionService sessions = sessions(Set.of(joining.getUniqueId(), UUID.randomUUID()));
+        new StealthAdminJoinListener(sessions, () -> List.of(joining, admin)).onJoin(event(joining));
+        verify(joining, times(1)).sendMessage("[Stealth] 2 players are invisible. Use /stealthadmin list to see who.");
+        verify(admin).sendMessage("[Stealth] An invisible player joined. 2 players are now invisible. Use /stealthadmin list to see who.");
+    }
+
+    @Test
+    void zeroCountIsSilent() {
+        Player joining = player(true);
+        new StealthAdminJoinListener(sessions(Set.of()), () -> List.of(joining)).onJoin(event(joining));
+        verify(joining, never()).sendMessage(anyString());
+    }
+
+    @Test
+    void ordinaryJoinIsSilentAndSinglePlayerCountUsesSingular() {
+        Player ordinary = player(false);
+        Player admin = player(true);
+        StealthAdminJoinListener listener = new StealthAdminJoinListener(
+                sessions(Set.of(UUID.randomUUID())), () -> List.of(ordinary, admin));
+        listener.onJoin(event(ordinary));
+        verify(ordinary, never()).sendMessage(anyString());
+        verify(admin, never()).sendMessage(anyString());
+        listener.onJoin(event(admin));
+        verify(admin).sendMessage("[Stealth] 1 player is invisible. Use /stealthadmin list to see who.");
+    }
+
+    private static StealthSessionService sessions(Set<UUID> ids) {
+        StealthSessionService sessions = mock(StealthSessionService.class);
+        when(sessions.concealedPlayerIds()).thenReturn(ids);
+        return sessions;
+    }
+
+    private static Player player(boolean admin) {
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(UUID.randomUUID());
+        when(player.hasPermission("spigotstealth.admin")).thenReturn(admin);
+        return player;
+    }
+
+    private static PlayerJoinEvent event(Player player) {
+        PlayerJoinEvent event = mock(PlayerJoinEvent.class);
+        when(event.getPlayer()).thenReturn(player);
+        return event;
+    }
+}

src/test/java/games/dmg/spigotstealth/StealthAdministrationServiceTest.java

@@ -16,6 +16,18 @@ import org.bukkit.entity.Player;
 import org.junit.jupiter.api.Test;
 
 class StealthAdministrationServiceTest {
+    @Test
+    void persistsSleepCountPolicyChangesIdempotently() {
+        try (StealthStateManager manager = manager()) {
+            StealthAdministrationService administration = service(manager, List::of, ignored -> { });
+
+            assertEquals(SleepCountPolicy.EXCLUDE, administration.sleepCountPolicy());
+            assertTrue(administration.setSleepCountPolicy(SleepCountPolicy.INCLUDE).join().changed());
+            assertEquals(SleepCountPolicy.INCLUDE, manager.snapshot().sleepCountPolicy());
+            assertFalse(administration.setSleepCountPolicy(SleepCountPolicy.INCLUDE).join().changed());
+        }
+    }
+
     @Test
     void grantsOfflineUnlockAndNotifiesExactlyOnce() {
         UUID playerId = UUID.randomUUID();
@@ -58,6 +70,29 @@ class StealthAdministrationServiceTest {
         }
     }
 
+    @Test
+    void listsAllUnlockedPlayersByNameOrUuidInCaseInsensitiveOrder() {
+        UUID namelessId = UUID.randomUUID();
+        UUID lockedId = UUID.randomUUID();
+        UUID zoeId = UUID.randomUUID();
+        UUID alexId = UUID.randomUUID();
+        try (StealthStateManager manager = manager()) {
+            manager.update(state -> state
+                    .withPlayer(PlayerStealthState.empty(namelessId).withProgress(0L, true))
+                    .withPlayer(PlayerStealthState.empty(lockedId).withLastKnownName("Locked"))
+                    .withPlayer(PlayerStealthState.empty(zoeId).withLastKnownName("zoe").withProgress(1L, true))
+                    .withPlayer(PlayerStealthState.empty(alexId).withLastKnownName("Alex").withProgress(2L, true)))
+                    .join();
+            StealthAdministrationService administration = service(manager, List::of, ignored -> { });
+
+            assertEquals(
+                    List.of("Alex", namelessId.toString(), "zoe").stream()
+                            .sorted(String.CASE_INSENSITIVE_ORDER)
+                            .toList(),
+                    administration.unlockedPlayerNames());
+        }
+    }
+
     @Test
     void listsOnlyCurrentlyOnlineConcealedPlayers() {
         UUID concealedId = UUID.randomUUID();

src/test/java/games/dmg/spigotstealth/StealthChatMaskerTest.java

@@ -0,0 +1,70 @@
+package games.dmg.spigotstealth;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import com.google.gson.JsonParser;
+import java.util.Set;
+import org.junit.jupiter.api.Test;
+
+class StealthChatMaskerTest {
+    private final StealthChatMasker masker = new StealthChatMasker(Set.of("Secret"));
+
+    @Test
+    void masksSenderAndRemovesIdentityMetadataWithoutChangingMessage() {
+        String input = """
+                {"translate":"chat.type.text","with":[
+                  {"text":"Secret","hoverEvent":{"action":"show_entity","contents":{"name":"Secret"}},
+                   "clickEvent":{"action":"suggest_command","value":"/msg Secret "}},
+                  {"text":"Secret says hello","clickEvent":{"action":"copy_to_clipboard","value":"Secret"}}]}
+                """;
+        var result = JsonParser.parseString(masker.maskAnnouncement(input)).getAsJsonObject();
+        var args = result.getAsJsonArray("with");
+        assertEquals(JsonParser.parseString("{\"text\":\"Anonymous\",\"obfuscated\":true,\"hoverEvent\":null,\"clickEvent\":null,\"insertion\":\"\"}"), args.get(0));
+        assertEquals(JsonParser.parseString(input).getAsJsonObject().getAsJsonArray("with").get(1), args.get(1));
+    }
+
+    @Test
+    void handlesPrivateMessagesAndAdvancementNamesOnly() {
+        for (String key : Set.of("commands.message.display.incoming", "commands.message.display.outgoing",
+                "chat.type.advancement.task", "chat.type.advancement.goal", "chat.type.advancement.challenge")) {
+            String input = "{\"translate\":\"" + key + "\",\"with\":[\"secret\",{\"text\":\"Secret\"}]}";
+            var args = JsonParser.parseString(masker.maskAnnouncement(input)).getAsJsonObject().getAsJsonArray("with");
+            assertEquals("Anonymous", args.get(0).getAsJsonObject().get("text").getAsString());
+            assertEquals("Secret", args.get(1).getAsJsonObject().get("text").getAsString());
+        }
+    }
+
+    @Test
+    void doesNotTraverseMessageBodyEvenWhenItContainsChatTranslations() {
+        String input = """
+                {"translate":"chat.type.text","with":["Ordinary",
+                  {"translate":"chat.type.text","with":["Secret","body"]}]}
+                """;
+        assertEquals(input, masker.maskAnnouncement(input));
+    }
+
+    @Test
+    void handlesNestedAnnouncementsButNotPlainTextOrUnknownTranslations() {
+        assertTrue(masker.maskAnnouncement("{\"text\":\"\",\"extra\":[{\"translate\":\"chat.type.text\",\"with\":[\"Secret\",\"hello\"]}]}").contains("Anonymous"));
+        for (String input : Set.of("{\"text\":\"Secret: hello\"}", "{\"translate\":\"custom\",\"with\":[\"Secret\"]}", "not json")) {
+            assertEquals(input, masker.maskAnnouncement(input));
+        }
+    }
+
+    @Test
+    void removesInheritedActionsFromArrayParent() {
+        String json = """
+                [{"text":"","hover_event":{"action":"show_text","value":"Secret"}},
+                 {"translate":"chat.type.text","with":["Secret","hello"]}]
+                """;
+        assertFalse(masker.maskAnnouncement(json).contains("Secret"));
+    }
+
+    @Test
+    void recognizesSplitNamesAndMasksWholeNameComponent() {
+        String name = "{\"text\":\"Sec\",\"extra\":[{\"text\":\"ret\"}],\"insertion\":\"Secret\"}";
+        assertTrue(masker.maskDisplayName(name).contains("Anonymous"));
+        assertFalse(masker.maskDisplayName(name).contains("Secret"));
+        assertEquals("\"NotSecret\"", masker.maskDisplayName("\"NotSecret\""));
+    }
+}

src/test/java/games/dmg/spigotstealth/StealthCommandTest.java

@@ -8,6 +8,7 @@ import static org.mockito.Mockito.when;
 
 import java.time.Duration;
 import java.time.Instant;
+import java.util.List;
 import java.util.Map;
 import java.util.UUID;
 import java.util.concurrent.atomic.AtomicLong;
@@ -16,6 +17,24 @@ import org.bukkit.entity.Player;
 import org.junit.jupiter.api.Test;
 
 class StealthCommandTest {
+    @Test
+    void completesProgressByPrefixWithoutSuggestingPlayersElsewhere() {
+        try (StealthStateManager manager = manager()) {
+            QualifyingInvisibilityService progression = new QualifyingInvisibilityService(
+                    manager, Duration.ofHours(8), System::nanoTime, ignored -> { });
+            StealthCommand command = new StealthCommand(manager, progression, StealthSettings.from(Map.of()));
+            Command bukkitCommand = mock(Command.class);
+            Player player = player(UUID.randomUUID());
+
+            org.junit.jupiter.api.Assertions.assertEquals(
+                    List.of("progress"),
+                    command.onTabComplete(player, bukkitCommand, "stealth", new String[] {"pr"}));
+            org.junit.jupiter.api.Assertions.assertEquals(
+                    List.of(),
+                    command.onTabComplete(player, bukkitCommand, "stealth", new String[] {"progress", ""}));
+        }
+    }
+
     @Test
     void reportsLiveProgressTargetAndRemainingTimeWithoutMutatingState() {
         UUID playerId = UUID.randomUUID();

src/test/java/games/dmg/spigotstealth/StealthSessionListenerTest.java

@@ -10,9 +10,50 @@ import java.util.Map;
 import java.util.UUID;
 import org.bukkit.entity.Player;
 import org.bukkit.event.player.PlayerJoinEvent;
+import org.bukkit.event.player.PlayerQuitEvent;
 import org.junit.jupiter.api.Test;
 
 class StealthSessionListenerTest {
+    @Test
+    void concealedDisconnectSuppressesPublicAnnouncementBeforeCleanup() {
+        UUID playerId = UUID.randomUUID();
+        try (StealthStateManager manager = manager()) {
+            manager.update(state -> state.withPlayer(unlocked(playerId).withSession(false, true))).join();
+            QualifyingInvisibilityService progression = new QualifyingInvisibilityService(
+                    manager, Duration.ofHours(8), System::nanoTime, ignored -> { });
+            StealthSessionService sessions = new StealthSessionService(manager, progression);
+            StealthSessionListener listener = new StealthSessionListener(
+                    sessions, mock(IdentityPresentation.class), "Stealth active");
+            PlayerQuitEvent event = mock(PlayerQuitEvent.class);
+            Player player = player(playerId);
+            when(event.getPlayer()).thenReturn(player);
+
+            listener.onQuit(event);
+
+            verify(event).setQuitMessage(null);
+        }
+    }
+
+    @Test
+    void ordinaryDisconnectRetainsPublicAnnouncement() {
+        UUID playerId = UUID.randomUUID();
+        try (StealthStateManager manager = manager()) {
+            QualifyingInvisibilityService progression = new QualifyingInvisibilityService(
+                    manager, Duration.ofHours(8), System::nanoTime, ignored -> { });
+            StealthSessionListener listener = new StealthSessionListener(
+                    new StealthSessionService(manager, progression),
+                    mock(IdentityPresentation.class),
+                    "Stealth active");
+            PlayerQuitEvent event = mock(PlayerQuitEvent.class);
+            Player player = player(playerId);
+            when(event.getPlayer()).thenReturn(player);
+
+            listener.onQuit(event);
+
+            verify(event, never()).setQuitMessage(null);
+        }
+    }
+
     @Test
     void preparedLoginSuppressesAnnouncementAndConcealsIdentityForSession() {
         UUID playerId = UUID.randomUUID();
@@ -21,8 +62,9 @@ class StealthSessionListenerTest {
             QualifyingInvisibilityService progression = new QualifyingInvisibilityService(
                     manager, Duration.ofHours(8), System::nanoTime, ignored -> { });
             IdentityPresentation presentation = mock(IdentityPresentation.class);
+            StealthSessionService sessions = new StealthSessionService(manager, progression);
             StealthSessionListener listener = new StealthSessionListener(
-                    new StealthSessionService(manager, progression), presentation, "Stealth active");
+                    sessions, presentation, "Stealth active");
             Player player = player(playerId);
             PlayerJoinEvent event = mock(PlayerJoinEvent.class);
             when(event.getPlayer()).thenReturn(player);
@@ -32,6 +74,10 @@ class StealthSessionListenerTest {
             verify(event).setJoinMessage(null);
             verify(presentation).conceal(player);
             verify(player).sendMessage("Stealth active");
+            Player admin = player(UUID.randomUUID());
+            when(admin.hasPermission("spigotstealth.admin")).thenReturn(true);
+            new StealthAdminJoinListener(sessions, () -> java.util.List.of(player, admin)).onJoin(event);
+            verify(admin).sendMessage("[Stealth] An invisible player joined. 1 player is now invisible. Use /stealthadmin list to see who.");
         }
     }
 

src/test/java/games/dmg/spigotstealth/StealthSessionServiceTest.java

@@ -1,15 +1,38 @@
 package games.dmg.spigotstealth;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.time.Duration;
 import java.time.Instant;
 import java.util.Map;
+import java.util.Set;
 import java.util.UUID;
 import org.junit.jupiter.api.Test;
 
 class StealthSessionServiceTest {
+    @Test
+    void reportsOnlyCurrentlyConcealedPlayerIdsForPublicPresentation() {
+        UUID concealedId = UUID.randomUUID();
+        UUID staleId = UUID.randomUUID();
+        try (StealthStateManager manager = manager()) {
+            manager.update(state -> state
+                    .withPlayer(unlocked(concealedId).withSession(true, false))
+                    .withPlayer(unlocked(staleId).withSession(false, true)))
+                    .join();
+            QualifyingInvisibilityService progression = new QualifyingInvisibilityService(
+                    manager, Duration.ofHours(8), System::nanoTime, ignored -> { });
+            StealthSessionService sessions = new StealthSessionService(manager, progression);
+            sessions.login(concealedId, "Hidden");
+
+            assertEquals(Set.of(concealedId), sessions.concealedPlayerIds());
+            manager.update(state -> state.withPlayer(
+                    state.player(concealedId).withSession(false, false))).join();
+            assertEquals(Set.of(), sessions.concealedPlayerIds());
+        }
+    }
+
     @Test
     void unlockedQualifyingDisconnectPreparesAndConsumesOneConcealedLogin() {
         UUID playerId = UUID.randomUUID();

src/test/java/games/dmg/spigotstealth/YamlStealthStateRepositoryTest.java

@@ -15,15 +15,28 @@ import org.junit.jupiter.api.io.TempDir;
 class YamlStealthStateRepositoryTest {
     @TempDir Path temporaryDirectory;
 
+    @Test
+    void missingOrInvalidSleepCountPolicyDefaultsToExclude() throws Exception {
+        Path missingFile = temporaryDirectory.resolve("missing.yml");
+        YamlStealthStateRepository missing = new YamlStealthStateRepository(missingFile);
+        assertEquals(SleepCountPolicy.EXCLUDE, missing.load().sleepCountPolicy());
+
+        Path invalidFile = temporaryDirectory.resolve("invalid.yml");
+        Files.writeString(invalidFile, "sleep-count-policy: surprise\n");
+        YamlStealthStateRepository invalid = new YamlStealthStateRepository(invalidFile);
+        assertEquals(SleepCountPolicy.EXCLUDE, invalid.load().sleepCountPolicy());
+    }
+
     @Test
     void roundTripsUuidStateAndPreservesUnknownFields() throws Exception {
         UUID playerId = UUID.randomUUID();
         Path stateFile = temporaryDirectory.resolve("state.yml");
-        Files.writeString(stateFile, "schema-version: 1\nfuture-root: keep\nplayers:\n  " + playerId + ":\n    accumulated-millis: 25\n    unlocked: false\n    prepared-login: true\n    concealed: false\n    qualifying-since: '2026-08-14T10:00:00Z'\n    last-known-name: Alex\n    future-player: keep-too\n");
+        Files.writeString(stateFile, "schema-version: 1\nsleep-count-policy: include\nfuture-root: keep\nplayers:\n  " + playerId + ":\n    accumulated-millis: 25\n    unlocked: false\n    prepared-login: true\n    concealed: false\n    qualifying-since: '2026-08-14T10:00:00Z'\n    last-known-name: Alex\n    future-player: keep-too\n");
         YamlStealthStateRepository repository = new YamlStealthStateRepository(stateFile);
 
         PersistentStealthState loaded = repository.load();
         PlayerStealthState player = loaded.player(playerId);
+        assertEquals(SleepCountPolicy.INCLUDE, loaded.sleepCountPolicy());
         assertEquals(25L, player.accumulatedMillis());
         assertTrue(player.preparedLogin());
         assertEquals(Instant.parse("2026-08-14T10:00:00Z"), player.qualifyingSince());
@@ -31,6 +44,7 @@ class YamlStealthStateRepositoryTest {
         repository.save(loaded.withPlayer(player.withAccumulatedMillis(50L)));
         String saved = Files.readString(stateFile);
         assertTrue(saved.contains("future-root: keep"));
+        assertTrue(saved.contains("sleep-count-policy: include"));
         assertTrue(saved.contains("future-player: keep-too"));
         assertEquals(50L, repository.load().player(playerId).accumulatedMillis());
     }