Find Group by Invite

Instructions

Implementation Reference

• src/tools/find-group-by-invite.ts:37-84 (handler)

  The handler function `registerFindGroupByInvite` registers the tool named 'find_group_by_invite'. It makes a GET request to `/group/inviteInfo/{instance}?inviteCode=...`, fetches group info from the Evolution API, normalizes the response (id, subject, subjectOwner, subjectTime, size, desc, descId, creation, owner, admins), and optionally includes full participant list if `includeParticipants` is true.

  export function registerFindGroupByInvite(server: McpServer, client: EvolutionClient): void {
    server.registerTool(
      "find_group_by_invite",
      {
        title: "Find Group by Invite",
        description:
          "Get group information from an invite code without joining via the pinned instance. " +
          "Returns { id, subject, subjectOwner, subjectTime, size, desc, descId, creation, owner, admins } by default. " +
          "Set includeParticipants=true to also get the full participant list.",
        inputSchema: schema,
      },
      async (args) => {
        try {
          const data = await client.get(
            `/group/inviteInfo/${client.instanceName}?inviteCode=${encodeURIComponent(args.inviteCode)}`
          ) as RawGroupInfo;
  
          const participants: RawParticipant[] = Array.isArray(data.participants) ? data.participants : [];
  
          const admins = participants
            .filter((p) => p.admin != null && p.admin !== "")
            .map((p) => ({ jid: p.id ?? "", admin: p.admin }));
  
          const normalized: Record<string, unknown> = {
            id: data.id,
            subject: data.subject,
            subjectOwner: data.subjectOwner,
            subjectTime: data.subjectTime,
            size: participants.length,
            desc: data.desc,
            descId: data.descId,
            creation: data.creation,
            owner: data.owner,
            admins,
          };
  
          if (args.includeParticipants) {
            normalized["participants"] = participants.map((p) => ({ jid: p.id, admin: p.admin ?? null }));
          }
  
          return { content: [{ type: "text" as const, text: JSON.stringify(normalized, null, 2) }] };
        } catch (e) {
          if (e instanceof McpError) return { isError: true, content: [{ type: "text" as const, text: e.message }] };
          throw e;
        }
      }
    );
  }

• src/tools/find-group-by-invite.ts:25-35 (schema)

  Input schema using Zod: `inviteCode` (required string) and `includeParticipants` (optional boolean, defaults to false).

  const schema = {
    inviteCode: z.string().min(1).describe("Group invite code (the part after https://chat.whatsapp.com/)"),
    includeParticipants: z
      .boolean()
      .default(false)
      .optional()
      .describe(
        "When true, includes the full participant list in the response (may be large for big groups). " +
        "Default false returns only admins + size, which covers 95% of use cases."
      ),
  };

• src/tools/index.ts:128-128 (registration)

  The tool is registered in `registerAllTools` via `registerFindGroupByInvite(server, client)` at line 128. Import is at line 55.

  registerFindGroupByInvite(server, client);