diff --git a/LightlessSyncAPI/Dto/Chat/ChatDtos.cs b/LightlessSyncAPI/Dto/Chat/ChatDtos.cs
new file mode 100644
index 0000000..ae9adca
--- /dev/null
+++ b/LightlessSyncAPI/Dto/Chat/ChatDtos.cs
@@ -0,0 +1,85 @@
+using System;
+using System.Collections.Generic;
+using LightlessSync.API.Data;
+using LightlessSync.API.Dto.User;
+using MessagePack;
+
+namespace LightlessSync.API.Dto.Chat;
+
+public enum ChatChannelType : byte
+{
+    Zone = 0,
+    Group = 1
+}
+
+public enum ChatSenderKind : byte
+{
+    Anonymous = 0,
+    IdentifiedUser = 1
+}
+
+[MessagePackObject]
+public readonly record struct ChatChannelDescriptor
+{
+    [Key(0)] public ChatChannelType Type { get; init; }
+    [Key(1)] public ushort WorldId { get; init; }
+    [Key(2)] public ushort ZoneId { get; init; }
+    [Key(3)] public string? CustomKey { get; init; }
+
+    public ChatChannelDescriptor WithNormalizedCustomKey() =>
+        this with { CustomKey = string.IsNullOrWhiteSpace(CustomKey) ? string.Empty : CustomKey };
+}
+
+[MessagePackObject(keyAsPropertyName: true)]
+public readonly record struct ChatPresenceUpdateDto(ChatChannelDescriptor Channel, ushort TerritoryId, bool IsActive);
+
+[MessagePackObject(keyAsPropertyName: true)]
+public readonly record struct ChatSendRequestDto(ChatChannelDescriptor Channel, string Message);
+
+[MessagePackObject(keyAsPropertyName: true)]
+public readonly record struct ChatSenderDescriptor(
+    ChatSenderKind Kind,
+    string Token,
+    string? DisplayName,
+    string? HashedCid,
+    UserData? User,
+    bool CanResolveProfile);
+
+[MessagePackObject(keyAsPropertyName: true)]
+public readonly record struct ChatMessageDto(
+    ChatChannelDescriptor Channel,
+    ChatSenderDescriptor Sender,
+    string Message,
+    DateTime SentAtUtc,
+    string MessageId);
+
+[MessagePackObject(keyAsPropertyName: true)]
+public readonly record struct ChatReportSubmitDto(
+    ChatChannelDescriptor Channel,
+    string MessageId,
+    string Reason,
+    string? AdditionalContext);
+
+[MessagePackObject(keyAsPropertyName: true)]
+public readonly record struct ChatParticipantResolveRequestDto(
+    ChatChannelDescriptor Channel,
+    string Token);
+
+[MessagePackObject(keyAsPropertyName: true)]
+public readonly record struct ChatParticipantResolveResultDto(
+    ChatChannelDescriptor Channel,
+    ChatSenderDescriptor Sender,
+    UserProfileDto? Profile);
+
+[MessagePackObject(keyAsPropertyName: true)]
+public readonly record struct ZoneChatChannelInfoDto(
+    ChatChannelDescriptor Channel,
+    string DisplayName,
+    IReadOnlyList<string> Territories);
+
+[MessagePackObject(keyAsPropertyName: true)]
+public readonly record struct GroupChatChannelInfoDto(
+    ChatChannelDescriptor Channel,
+    string DisplayName,
+    string GroupId,
+    bool IsOwner);
diff --git a/LightlessSyncAPI/SignalR/ILightlessHub.cs b/LightlessSyncAPI/SignalR/ILightlessHub.cs
index 663df4c..f2679fd 100644
--- a/LightlessSyncAPI/SignalR/ILightlessHub.cs
+++ b/LightlessSyncAPI/SignalR/ILightlessHub.cs
@@ -1,15 +1,16 @@
 using LightlessSync.API.Data;
 using LightlessSync.API.Data.Enum;
 using LightlessSync.API.Dto;
+using LightlessSync.API.Dto.Chat;
 using LightlessSync.API.Dto.CharaData;
 using LightlessSync.API.Dto.Group;
 using LightlessSync.API.Dto.User;
 
 namespace LightlessSync.API.SignalR;
 
-public interface ILightlessHub
-{
-    const int ApiVersion = 34;
+public interface ILightlessHub
+{
+    const int ApiVersion = 37;
     const string Path = "/lightless";
 
     Task<bool> CheckClientHealth();
@@ -21,7 +22,7 @@ public interface ILightlessHub
     Task Client_GroupPairJoined(GroupPairFullInfoDto groupPairInfoDto);
     Task Client_GroupPairLeft(GroupPairDto groupPairDto);
     Task Client_GroupSendFullInfo(GroupFullInfoDto groupInfo);
-    Task Client_GroupSendProfile (GroupProfileDto groupInfo);
+    Task Client_GroupSendProfile(GroupProfileDto groupInfo);
     Task Client_GroupSendInfo(GroupInfoDto groupInfo);
     Task Client_ReceiveServerMessage(MessageSeverity messageSeverity, string message);
     Task Client_ReceiveBroadcastPairRequest(UserPairNotificationDto dto);
@@ -43,8 +44,11 @@ public interface ILightlessHub
     Task Client_GposeLobbyPushCharacterData(CharaDataDownloadDto charaDownloadDto);
     Task Client_GposeLobbyPushPoseData(UserData userData, PoseData poseData);
     Task Client_GposeLobbyPushWorldData(UserData userData, WorldData worldData);
+    Task Client_ChatReceive(ChatMessageDto message);
 
-    Task<ConnectionDto> GetConnectionDto();
+    Task<ConnectionDto> GetConnectionDto();
+    Task<IReadOnlyList<ZoneChatChannelInfoDto>> GetZoneChatChannels();
+    Task<IReadOnlyList<GroupChatChannelInfoDto>> GetGroupChatChannels();
 
     Task GroupBanUser(GroupPairDto dto, string reason);
     Task GroupChangeGroupPermissionState(GroupPermissionDto dto);
@@ -105,4 +109,8 @@ public interface ILightlessHub
     Task GposeLobbyPushCharacterData(CharaDataDownloadDto charaDownloadDto);
     Task GposeLobbyPushPoseData(PoseData poseData);
     Task GposeLobbyPushWorldData(WorldData worldData);
-}
+    Task UpdateChatPresence(ChatPresenceUpdateDto presence);
+    Task SendChatMessage(ChatSendRequestDto request);
+    Task ReportChatMessage(ChatReportSubmitDto request);
+    Task<ChatParticipantResolveResultDto?> ResolveChatParticipant(ChatParticipantResolveRequestDto request);
+}