WAHA MCP Server

Instructions

Implementation Reference

• src/index.ts:1270-1307 (handler)

  The main handler function for the 'waha_send_message' tool. Validates input parameters (chatId, text), calls WAHAClient.sendTextMessage, formats the success response using formatSendMessageSuccess, and returns the result.

   * Handle waha_send_message tool
   */
  private async handleSendMessage(args: any) {
    const chatId = args.chatId;
    const text = args.text;
    const replyTo = args.replyTo;
    const linkPreview = args.linkPreview !== false; // Default true
  
    if (!chatId) {
      throw new Error("chatId is required");
    }
  
    if (!text) {
      throw new Error("text is required");
    }
  
    const response = await this.wahaClient.sendTextMessage({
      chatId,
      text,
      reply_to: replyTo,
      linkPreview,
    });
  
    const formattedResponse = formatSendMessageSuccess(
      chatId,
      response.id,
      response.timestamp
    );
  
    return {
      content: [
        {
          type: "text",
          text: formattedResponse,
        },
      ],
    };
  }

• src/index.ts:115-141 (schema)

  Input schema definition for the 'waha_send_message' tool, including properties, descriptions, defaults, and required fields. This is part of the tool list returned by ListToolsRequestHandler.

  {
    name: "waha_send_message",
    description: "Send a text message to a WhatsApp chat. Returns message ID and delivery timestamp.",
    inputSchema: {
      type: "object",
      properties: {
        chatId: {
          type: "string",
          description: "Chat ID to send message to (format: number@c.us)",
        },
        text: {
          type: "string",
          description: "Message text to send",
        },
        replyTo: {
          type: "string",
          description: "Optional: Message ID to reply to",
        },
        linkPreview: {
          type: "boolean",
          description: "Enable link preview (default: true)",
          default: true,
        },
      },
      required: ["chatId", "text"],
    },
  },

• src/index.ts:1056-1057 (registration)

  Tool dispatch/registration in the CallToolRequestHandler switch statement, routing calls to 'waha_send_message' to the handleSendMessage function.

    return await this.handleSendMessage(args);
  case "waha_mark_chat_read":

• src/tools/formatters.ts:107-109 (helper)

  Helper function to format the success response for send message operations, used in the tool handler.

  export function formatSendMessageSuccess(chatId: string, messageId: string, timestamp: number): string {
    return `Message sent successfully!\nChat: ${chatId}\nMessage ID: ${messageId}\nTime: ${formatTimestamp(timestamp)}`;
  }

• src/client/waha-client.ts:193-219 (helper)

  Underlying WAHA API client method sendTextMessage that performs the actual HTTP POST to /api/sendText, called by the MCP tool handler.

  async sendTextMessage(
    params: SendTextMessageParams
  ): Promise<SendMessageResponse> {
    const { chatId, text, session, reply_to, linkPreview, linkPreviewHighQuality } = params;
  
    if (!chatId) {
      throw new WAHAError("chatId is required");
    }
  
    if (!text) {
      throw new WAHAError("text is required");
    }
  
    const body = {
      chatId,
      text,
      session: session || this.session,
      reply_to,
      linkPreview: linkPreview !== false, // Default true
      linkPreviewHighQuality: linkPreviewHighQuality || false,
    };
  
    return this.request<SendMessageResponse>("/api/sendText", {
      method: "POST",
      body: JSON.stringify(body),
    });
  }