diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2a43e1b0c..efaced221 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -46,6 +46,7 @@
 - Auto-reply: strip stray leading/trailing `HEARTBEAT_OK` from normal replies; drop short (≤ 30 chars) heartbeat acks.
 - Logging: trim provider prefix duplication in Discord/Signal/Telegram runtime log lines.
 - Discord: include recent guild context when replying to mentions and add `discord.historyLimit` to tune how many messages are captured.
+- Gateway: fix TypeScript build by aligning hook mapping `channel` types and removing a dead Group DM branch in Discord monitor.
 - Skills: switch imsg installer to brew tap formula.
 - Skills: gate macOS-only skills by OS and surface block reasons in the Skills UI.
 - Onboarding: show skill descriptions in the macOS setup flow and surface clearer Gateway/skills error messages.
diff --git a/src/discord/monitor.ts b/src/discord/monitor.ts
index e6159c8d9..a7ea34e56 100644
--- a/src/discord/monitor.ts
+++ b/src/discord/monitor.ts
@@ -81,7 +81,9 @@ export async function monitorDiscordProvider(opts: MonitorDiscordOpts = {}) {
   const allowFrom =
     opts.allowFrom ?? dmConfig?.allowFrom ?? cfg.discord?.allowFrom;
   const guildAllowFrom =
-    opts.guildAllowFrom ?? guildConfig?.allowFrom ?? cfg.discord?.guildAllowFrom;
+    opts.guildAllowFrom ??
+    guildConfig?.allowFrom ??
+    cfg.discord?.guildAllowFrom;
   const guildChannels = guildConfig?.channels;
   const requireMention =
     opts.requireMention ??
@@ -126,10 +128,8 @@ export async function monitorDiscordProvider(opts: MonitorDiscordOpts = {}) {
       if (!message.author) return;
 
       const channelType = message.channel.type;
-      const isGroupDm = channelType === ChannelType.GroupDM;
       const isDirectMessage = channelType === ChannelType.DM;
       const isGuildMessage = Boolean(message.guild);
-      if (isGroupDm) return;
       if (isDirectMessage && !dmEnabled) return;
       const botId = client.user?.id;
       const wasMentioned =
@@ -249,9 +249,7 @@ export async function monitorDiscordProvider(opts: MonitorDiscordOpts = {}) {
 
       const fromLabel = isDirectMessage
         ? buildDirectLabel(message)
-        : isGroupDm
-          ? buildGroupDmLabel(message)
-          : buildGuildLabel(message);
+        : buildGuildLabel(message);
       const groupSubject = (() => {
         if (isDirectMessage) return undefined;
         const channelName =
@@ -416,13 +414,6 @@ function buildDirectLabel(message: import("discord.js").Message) {
   return `${username} id:${message.author.id}`;
 }
 
-function buildGroupDmLabel(message: import("discord.js").Message) {
-  const channelName =
-    "name" in message.channel ? message.channel.name : undefined;
-  const name = channelName ? ` ${channelName}` : "";
-  return `Group DM${name} id:${message.channelId}`;
-}
-
 function buildGuildLabel(message: import("discord.js").Message) {
   const channelName =
     "name" in message.channel ? message.channel.name : message.channelId;
diff --git a/src/gateway/hooks-mapping.ts b/src/gateway/hooks-mapping.ts
index 1d29d786b..0b2ee8132 100644
--- a/src/gateway/hooks-mapping.ts
+++ b/src/gateway/hooks-mapping.ts
@@ -18,7 +18,13 @@ export type HookMappingResolved = {
   messageTemplate?: string;
   textTemplate?: string;
   deliver?: boolean;
-  channel?: "last" | "whatsapp" | "telegram" | "discord";
+  channel?:
+    | "last"
+    | "whatsapp"
+    | "telegram"
+    | "discord"
+    | "signal"
+    | "imessage";
   to?: string;
   thinking?: string;
   timeoutSeconds?: number;
@@ -50,7 +56,13 @@ export type HookAction =
       wakeMode: "now" | "next-heartbeat";
       sessionKey?: string;
       deliver?: boolean;
-      channel?: "last" | "whatsapp" | "telegram" | "discord";
+      channel?:
+        | "last"
+        | "whatsapp"
+        | "telegram"
+        | "discord"
+        | "signal"
+        | "imessage";
       to?: string;
       thinking?: string;
       timeoutSeconds?: number;
@@ -86,7 +98,7 @@ type HookTransformResult = Partial<{
   name: string;
   sessionKey: string;
   deliver: boolean;
-  channel: "last" | "whatsapp" | "telegram" | "discord";
+  channel: "last" | "whatsapp" | "telegram" | "discord" | "signal" | "imessage";
   to: string;
   thinking: string;
   timeoutSeconds: number;