send_group_message

Instructions

Implementation Reference

• src/tools/groups.ts:132-150 (handler)

  The send_group_message tool handler: sends a text message to a WhatsApp group via POST to /sessions/{sessionId}/groups/{groupId}/messages.

  server.registerTool(
    "send_group_message",
    {
      description: "Send a text message directly to a WhatsApp group",
      inputSchema: {
        sessionId: z.string().describe("Session ID"),
        groupId: z.string().describe("Group ID"),
        text: z.string().describe("Message text content"),
      },
    },
    async ({ sessionId, groupId, text }) => {
      const data = await openwaClient({
        method: "POST",
        path: `/sessions/${sessionId}/groups/${groupId}/messages`,
        body: { text },
      });
      return { content: [{ type: "text" as const, text: JSON.stringify(data, null, 2) }] };
    }
  );

• src/tools/groups.ts:136-140 (schema)

  Input schema for send_group_message: requires sessionId (string), groupId (string), and text (string).

  inputSchema: {
    sessionId: z.string().describe("Session ID"),
    groupId: z.string().describe("Group ID"),
    text: z.string().describe("Message text content"),
  },

• src/tools/groups.ts:132-151 (registration)

  Registration of send_group_message tool on the MCP server, done inside registerGroupTools().

  server.registerTool(
    "send_group_message",
    {
      description: "Send a text message directly to a WhatsApp group",
      inputSchema: {
        sessionId: z.string().describe("Session ID"),
        groupId: z.string().describe("Group ID"),
        text: z.string().describe("Message text content"),
      },
    },
    async ({ sessionId, groupId, text }) => {
      const data = await openwaClient({
        method: "POST",
        path: `/sessions/${sessionId}/groups/${groupId}/messages`,
        body: { text },
      });
      return { content: [{ type: "text" as const, text: JSON.stringify(data, null, 2) }] };
    }
  );

• src/index.ts:18-18 (registration)

  Registration call: registerGroupTools is invoked from the main entry point, which adds send_group_message to the MCP server.

  registerGroupTools(server);

• src/client.ts:10-35 (helper)

  The openwaClient helper function used by send_group_message to make the POST request to the OpenWA backend API.

  export async function openwaClient<T = unknown>(opts: RequestOptions): Promise<T> {
    const url = `${BASE_URL}${opts.path}`;
  
    const headers: Record<string, string> = {
      "Content-Type": "application/json",
      "X-API-Key": API_KEY,
    };
  
    const res = await fetch(url, {
      method: opts.method,
      headers,
      body: opts.body ? JSON.stringify(opts.body) : undefined,
    });
  
    const text = await res.text();
  
    if (!res.ok) {
      throw new Error(`OpenWA API ${res.status}: ${text}`);
    }
  
    try {
      return JSON.parse(text) as T;
    } catch {
      return text as T;
    }
  }