feat: add discord_list_forum_threads tool

Add new tool to list all threads (posts) in a Discord forum channel,
including both active and archived threads. This addresses the limitation
where discord_search_messages only returns 25 message results and doesn't
provide a complete thread listing.

- Fetch active threads via channel.threads.fetchActive()
- Optionally fetch archived threads via channel.threads.fetchArchived()
- Deduplicate and sort threads by creation date (newest first)
- Return thread metadata including id, name, creator, dates, message count

src/schemas.ts

@@ -25,6 +25,12 @@ export const GetForumPostSchema = z.object({
     threadId: z.string()
 });
 
+export const ListForumThreadsSchema = z.object({
+    forumChannelId: z.string(),
+    includeArchived: z.boolean().optional().default(true),
+    limit: z.number().min(1).max(100).optional().default(100)
+});
+
 export const ReplyToForumSchema = z.object({
     threadId: z.string(),
     message: z.string()

src/server.ts

@@ -13,6 +13,7 @@ import {
   getForumChannelsHandler,
   createForumPostHandler,
   getForumPostHandler,
+  listForumThreadsHandler,
   replyToForumHandler,
   deleteForumPostHandler,
   createTextChannelHandler,
@@ -110,6 +111,11 @@ export class DiscordMCPServer {
             toolResponse = await getForumPostHandler(args, this.toolContext);
             return toolResponse;
 
+          case "discord_list_forum_threads":
+            this.logClientState("before discord_list_forum_threads handler");
+            toolResponse = await listForumThreadsHandler(args, this.toolContext);
+            return toolResponse;
+
           case "discord_reply_to_forum":
             this.logClientState("before discord_reply_to_forum handler");
             toolResponse = await replyToForumHandler(args, this.toolContext);

src/toolList.ts

@@ -102,6 +102,19 @@ export const toolList = [
       required: ["threadId"]
     }
   },
+  {
+    name: "discord_list_forum_threads",
+    description: "Lists all threads (posts) in a Discord forum channel, including both active and archived threads",
+    inputSchema: {
+      type: "object",
+      properties: {
+        forumChannelId: { type: "string", description: "The ID of the forum channel to list threads from" },
+        includeArchived: { type: "boolean", description: "Whether to include archived threads (default: true)", default: true },
+        limit: { type: "number", description: "Maximum number of archived threads to fetch (default: 100, max: 100)", minimum: 1, maximum: 100, default: 100 }
+      },
+      required: ["forumChannelId"]
+    }
+  },
   {
     name: "discord_reply_to_forum",
     description: "Adds a reply to an existing forum post or thread",

src/tools/forum.ts

@@ -1,5 +1,5 @@
 import { ChannelType, ForumChannel } from 'discord.js';
-import { GetForumChannelsSchema, CreateForumPostSchema, GetForumPostSchema, ReplyToForumSchema, DeleteForumPostSchema } from '../schemas.js';
+import { GetForumChannelsSchema, CreateForumPostSchema, GetForumPostSchema, ListForumThreadsSchema, ReplyToForumSchema, DeleteForumPostSchema } from '../schemas.js';
 import { ToolHandler } from './types.js';
 import { handleDiscordError } from "../errorHandler.js";
 
@@ -145,6 +145,99 @@ export const getForumPostHandler: ToolHandler = async (args, { client }) => {
   }
 };
 
+export const listForumThreadsHandler: ToolHandler = async (args, { client }) => {
+  const { forumChannelId, includeArchived, limit } = ListForumThreadsSchema.parse(args);
+
+  try {
+    if (!client.isReady()) {
+      return {
+        content: [{ type: "text", text: "Discord client not logged in." }],
+        isError: true
+      };
+    }
+
+    const channel = await client.channels.fetch(forumChannelId);
+    if (!channel || channel.type !== ChannelType.GuildForum) {
+      return {
+        content: [{ type: "text", text: `Channel ID ${forumChannelId} is not a forum channel.` }],
+        isError: true
+      };
+    }
+
+    const forumChannel = channel as ForumChannel;
+
+    // Fetch active threads
+    const activeThreads = await forumChannel.threads.fetchActive();
+
+    // Fetch archived threads if requested
+    let archivedThreads: typeof activeThreads | null = null;
+    if (includeArchived) {
+      archivedThreads = await forumChannel.threads.fetchArchived({ limit: limit });
+    }
+
+    // Combine and format thread information
+    const threads: Array<{
+      id: string;
+      name: string;
+      createdAt: Date | null;
+      archived: boolean;
+      locked: boolean;
+      messageCount: number | null;
+      ownerId: string | null;
+    }> = [];
+
+    // Add active threads
+    activeThreads.threads.forEach(thread => {
+      threads.push({
+        id: thread.id,
+        name: thread.name,
+        createdAt: thread.createdAt,
+        archived: thread.archived || false,
+        locked: thread.locked || false,
+        messageCount: thread.messageCount,
+        ownerId: thread.ownerId
+      });
+    });
+
+    // Add archived threads if fetched
+    if (archivedThreads) {
+      archivedThreads.threads.forEach(thread => {
+        // Avoid duplicates
+        if (!threads.find(t => t.id === thread.id)) {
+          threads.push({
+            id: thread.id,
+            name: thread.name,
+            createdAt: thread.createdAt,
+            archived: thread.archived || false,
+            locked: thread.locked || false,
+            messageCount: thread.messageCount,
+            ownerId: thread.ownerId
+          });
+        }
+      });
+    }
+
+    // Sort by creation date (newest first)
+    threads.sort((a, b) => {
+      if (!a.createdAt || !b.createdAt) return 0;
+      return b.createdAt.getTime() - a.createdAt.getTime();
+    });
+
+    return {
+      content: [{
+        type: "text",
+        text: JSON.stringify({
+          forumChannelId,
+          totalThreads: threads.length,
+          threads
+        }, null, 2)
+      }]
+    };
+  } catch (error) {
+    return handleDiscordError(error);
+  }
+};
+
 export const replyToForumHandler: ToolHandler = async (args, { client }) => {
   const { threadId, message } = ReplyToForumSchema.parse(args);
   

src/tools/tools.ts

@@ -7,6 +7,7 @@ import {
   getForumChannelsHandler,
   createForumPostHandler,
   getForumPostHandler,
+  listForumThreadsHandler,
   replyToForumHandler,
   deleteForumPostHandler
 } from './forum.js';
@@ -43,6 +44,7 @@ export {
   getForumChannelsHandler,
   createForumPostHandler,
   getForumPostHandler,
+  listForumThreadsHandler,
   replyToForumHandler,
   deleteForumPostHandler,
   createTextChannelHandler,