Mattermost MCP Server

Instructions

Implementation Reference

• src/index.ts:555-592 (handler)

  Main handler for the 'get_channel_messages' tool within the CallToolRequestSchema switch statement. Extracts parameters, fetches messages from Mattermost API via client, enriches with user details, formats output, and returns JSON response.

  case "get_channel_messages": {
    const channelId = args.channel_id as string;
    const page = (args.page as number) || 0;
    const perPage = (args.per_page as number) || 60;
    
    const messages = await client.getChannelMessages(channelId, page, perPage);
  
    // 고유한 user_id 추출 및 사용자 정보 조회
    const uniqueUserIds = [...new Set(messages.order?.map((postId: string) => messages.posts[postId].user_id) || [])];
    const userMap = await client.getUsersInfo(uniqueUserIds);
  
    const posts = messages.order?.map((postId: string) => {
      const post = messages.posts[postId];
      const createTime = formatTimestamp(post.create_at);
      const userInfo = userMap.get(post.user_id);
      
      return {
        id: post.id,
        message: post.message,
        user_id: post.user_id,
        username: userInfo?.username || "unknown",
        user_name: userInfo?.name || "Unknown User",
        create_at: createTime,
      };
    }) || [];
  
    return {
      content: [
        {
          type: "text",
          text: JSON.stringify({
            channel_id: channelId,
            posts: posts,
          }, null, 2),
        },
      ],
    };
  }

• src/index.ts:279-302 (registration)

  Tool registration in the ListToolsRequestSchema handler's tools array, defining name, description, and input schema for 'get_channel_messages'.

  {
    name: "get_channel_messages",
    description: "특정 채널의 최근 메시지들을 가져옵니다. 결과에는 자동으로 작성자의 이름(user_name)과 username이 포함됩니다.",
    inputSchema: {
      type: "object",
      properties: {
        channel_id: {
          type: "string",
          description: "채널 ID",
        },
        page: {
          type: "number",
          description: "페이지 번호 (기본값: 0)",
          default: 0,
        },
        per_page: {
          type: "number",
          description: "페이지당 메시지 수 (기본값: 60)",
          default: 60,
        },
      },
      required: ["channel_id"],
    },
  },

• src/index.ts:159-161 (helper)

  MattermostClient helper method that makes the API request to fetch channel messages, used by the main tool handler.

  async getChannelMessages(channelId: string, page: number = 0, perPage: number = 60): Promise<MattermostPostsResult> {
    return await this.request(`/channels/${channelId}/posts?page=${page}&per_page=${perPage}`) as MattermostPostsResult;
  }