Slack

Instructions

Implementation Reference

• index.ts:248-264 (registration)

  Registration of the slack_post_message MCP tool, including title, description, input schema, and handler function that delegates to SlackClient.postMessage.

  server.registerTool(
    "slack_post_message",
    {
      title: "Post Slack Message",
      description: "Post a new message to a Slack channel or direct message to user",
      inputSchema: {
        channel_id: z.string().describe("The ID of the channel or user to post to"),
        text: z.string().describe("The message text to post"),
      },
    },
    async ({ channel_id, text }) => {
      const response = await slackClient.postMessage(channel_id, text);
      return {
        content: [{ type: "text", text: JSON.stringify(response) }],
      };
    }
  );

• index.ts:111-122 (handler)

  The core handler function in SlackClient that executes the Slack API call to post a message using chat.postMessage endpoint.

  async postMessage(channel_id: string, text: string): Promise<any> {
    const response = await fetch("https://slack.com/api/chat.postMessage", {
      method: "POST",
      headers: this.botHeaders,
      body: JSON.stringify({
        channel: channel_id,
        text: text,
      }),
    });
  
    return response.json();
  }

• index.ts:253-256 (schema)

  Zod input schema definition for the tool parameters: channel_id and text.

  inputSchema: {
    channel_id: z.string().describe("The ID of the channel or user to post to"),
    text: z.string().describe("The message text to post"),
  },