Zulip MCP Server

Instructions

Implementation Reference

• index.ts:420-435 (handler)

  Executes the zulip_post_message tool by validating input arguments (channel_name, topic, content), calling the ZulipClient's sendStreamMessage method, and returning the JSON-stringified response.

  case "zulip_post_message": {
    const args = request.params.arguments as unknown as PostMessageArgs;
    if (!args.channel_name || !args.topic || !args.content) {
      throw new Error(
        "Missing required arguments: channel_name, topic, and content"
      );
    }
    const response = await zulipClient.sendStreamMessage(
      args.channel_name,
      args.topic,
      args.content
    );
    return {
      content: [{ type: "text", text: JSON.stringify(response) }],
    };
  }

• index.ts:92-113 (schema)

  Defines the Tool metadata for zulip_post_message, including name, description, and input schema with required properties channel_name, topic, and content.

  const postMessageTool: Tool = {
    name: "zulip_post_message",
    description: "Post a new message to a Zulip channel (stream)",
    inputSchema: {
      type: "object",
      properties: {
        channel_name: {
          type: "string",
          description: "The name of the stream to post to",
        },
        topic: {
          type: "string",
          description: "The topic within the stream",
        },
        content: {
          type: "string",
          description: "The message content to post",
        },
      },
      required: ["channel_name", "topic", "content"],
    },
  };

• index.ts:539-547 (registration)

  Registers the zulip_post_message tool (as postMessageTool) in the list of tools returned by the ListToolsRequest handler.

    listChannelsTool,
    postMessageTool,
    sendDirectMessageTool,
    addReactionTool,
    getChannelHistoryTool,
    getTopicsTool,
    subscribeToChannelTool,
    getUsersTool,
  ],

• index.ts:263-277 (helper)

  ZulipClient helper method that constructs the message parameters and calls the Zulip JS client's messages.send to post the message to the specified stream and topic.

  async sendStreamMessage(streamName: string, topic: string, content: string) {
    try {
      const params = {
        to: streamName,
        type: "stream",
        topic: topic,
        content: content,
      };
      
      return await this.client.messages.send(params);
    } catch (error) {
      console.error("Error sending stream message:", error);
      throw error;
    }
  }