MCP-Discord

Instructions

Implementation Reference

• src/tools/send-message.ts:5-50 (handler)

  The sendMessageHandler function that executes the 'discord_send' tool: validates input, checks client readiness, fetches the channel, and sends the message.

  export const sendMessageHandler: ToolHandler = async (args, { client }) => {
    const { channelId, message } = SendMessageSchema.parse(args);
  
    try {
      if (!client.isReady()) {
        return {
          content: [{ type: 'text', text: 'Discord client not logged in.' }],
          isError: true,
        };
      }
  
      const channel = await client.channels.fetch(channelId);
      if (!channel?.isTextBased()) {
        return {
          content: [
            { type: 'text', text: `Cannot find text channel ID: ${channelId}` },
          ],
          isError: true,
        };
      }
  
      // Ensure channel is text-based and can send messages
      if ('send' in channel) {
        await channel.send(message);
        return {
          content: [
            {
              type: 'text',
              text: `Message successfully sent to channel ID: ${channelId}`,
            },
          ],
        };
      }
      return {
        content: [
          {
            type: 'text',
            text: 'This channel type does not support sending messages',
          },
        ],
        isError: true,
      };
    } catch (error) {
      return handleDiscordError(error);
    }
  };

• src/tool-list.ts:53-64 (schema)

  Input schema for 'discord_send' exposed in the tool list for MCP listTools request.

  {
    name: 'discord_send',
    description: 'Sends a message to a specified Discord text channel',
    inputSchema: {
      type: 'object',
      properties: {
        channelId: { type: 'string' },
        message: { type: 'string' },
      },
      required: ['channelId', 'message'],
    },
  },

• src/server.ts:105-108 (registration)

  Registration and dispatching of 'discord_send' to sendMessageHandler in the MCP server's CallToolRequest handler.

  case 'discord_send':
    this.logClientState('before discord_send handler');
    toolResponse = await sendMessageHandler(args, this.toolContext);
    return toolResponse;

• src/schemas.ts:7-10 (schema)

  Zod schema for input validation used within the sendMessageHandler.

  export const SendMessageSchema = z.object({
    channelId: z.string(),
    message: z.string(),
  });

• src/tools/tools.ts:24-24 (registration)

  Re-export of sendMessageHandler for convenient import in server.ts.

  export { sendMessageHandler } from './send-message.js';