Slack MCP Server

Instructions

Implementation Reference

• src/tools/users.ts:38-52 (handler)

  The main handler function for the 'invite_to_channel' tool. It validates input using inviteToChannelSchema, calls Slack's conversations.invite API with channel and comma-separated users, and returns the channel info.

  export async function inviteToChannel(client: SlackClientWrapper, args: unknown) {
    const params = inviteToChannelSchema.parse(args);
  
    return await client.safeCall(async () => {
      const result = await client.getClient().conversations.invite({
        channel: params.channel,
        users: params.users.join(','),
      });
  
      return {
        ok: true,
        channel: result.channel,
      };
    });
  }

• src/utils/validators.ts:41-44 (schema)

  Zod schema defining input validation for invite_to_channel: requires channel ID and non-empty array of user IDs.

  export const inviteToChannelSchema = z.object({
    channel: channelIdSchema,
    users: z.array(userIdSchema).min(1),
  });

• src/index.ts:151-171 (registration)

  Tool registration in the tools list for list_tools handler, including name, description, and MCP inputSchema.

  {
    name: 'invite_to_channel',
    description: 'Invite users to a channel',
    inputSchema: {
      type: 'object',
      properties: {
        channel: {
          type: 'string',
          description: 'Channel ID',
        },
        users: {
          type: 'array',
          items: {
            type: 'string',
          },
          description: 'Array of user IDs to invite',
        },
      },
      required: ['channel', 'users'],
    },
  },

• src/index.ts:423-423 (registration)

  Maps 'invite_to_channel' tool name to the userTools.inviteToChannel handler in the call_tool dispatcher.

  invite_to_channel: (args) => userTools.inviteToChannel(slackClient, args),