diff --git a/extensions/zalouser/src/channel.directory.test.ts b/extensions/zalouser/src/channel.directory.test.ts
new file mode 100644
index 00000000000..70b18e0c1fe
--- /dev/null
+++ b/extensions/zalouser/src/channel.directory.test.ts
@@ -0,0 +1,52 @@
+import { describe, expect, it, vi } from "vitest";
+
+const listZaloGroupMembersMock = vi.hoisted(() => vi.fn(async () => []));
+
+vi.mock("./zalo-js.js", async (importOriginal) => {
+  const actual = (await importOriginal()) as Record<string, unknown>;
+  return {
+    ...actual,
+    listZaloGroupMembers: listZaloGroupMembersMock,
+  };
+});
+
+vi.mock("./accounts.js", async (importOriginal) => {
+  const actual = (await importOriginal()) as Record<string, unknown>;
+  return {
+    ...actual,
+    resolveZalouserAccountSync: () => ({
+      accountId: "default",
+      profile: "default",
+      name: "test",
+      enabled: true,
+      authenticated: true,
+      config: {},
+    }),
+  };
+});
+
+import { zalouserPlugin } from "./channel.js";
+
+describe("zalouser directory group members", () => {
+  it("accepts prefixed group ids from directory groups list output", async () => {
+    await zalouserPlugin.directory!.listGroupMembers!({
+      cfg: {},
+      accountId: "default",
+      groupId: "group:1471383327500481391",
+      runtime: undefined,
+    });
+
+    expect(listZaloGroupMembersMock).toHaveBeenCalledWith("default", "1471383327500481391");
+  });
+
+  it("keeps backward compatibility for raw group ids", async () => {
+    await zalouserPlugin.directory!.listGroupMembers!({
+      cfg: {},
+      accountId: "default",
+      groupId: "1471383327500481391",
+      runtime: undefined,
+    });
+
+    expect(listZaloGroupMembersMock).toHaveBeenCalledWith("default", "1471383327500481391");
+  });
+});
diff --git a/extensions/zalouser/src/channel.ts b/extensions/zalouser/src/channel.ts
index a0414b7b245..24ecb2367e3 100644
--- a/extensions/zalouser/src/channel.ts
+++ b/extensions/zalouser/src/channel.ts
@@ -117,6 +117,25 @@ function parseZalouserOutboundTarget(raw: string): {
   return { threadId: normalized, isGroup: false };
 }
 
+function parseZalouserDirectoryGroupId(raw: string): string {
+  const normalized = normalizePrefixedTarget(raw);
+  if (!normalized) {
+    throw new Error("Zalouser group target is required");
+  }
+  const lowered = normalized.toLowerCase();
+  if (lowered.startsWith("group:")) {
+    const groupId = normalized.slice("group:".length).trim();
+    if (!groupId) {
+      throw new Error("Zalouser group target is missing group id");
+    }
+    return groupId;
+  }
+  if (lowered.startsWith("user:")) {
+    throw new Error("Zalouser group members lookup requires a group target (group:<id>)");
+  }
+  return normalized;
+}
+
 function resolveZalouserQrProfile(accountId?: string | null): string {
   const normalized = normalizeAccountId(accountId);
   if (!normalized || normalized === DEFAULT_ACCOUNT_ID) {
@@ -501,7 +520,8 @@ export const zalouserPlugin: ChannelPlugin<ResolvedZalouserAccount> = {
     },
     listGroupMembers: async ({ cfg, accountId, groupId, limit }) => {
       const account = resolveZalouserAccountSync({ cfg: cfg, accountId });
-      const members = await listZaloGroupMembers(account.profile, groupId);
+      const normalizedGroupId = parseZalouserDirectoryGroupId(groupId);
+      const members = await listZaloGroupMembers(account.profile, normalizedGroupId);
       const rows = members.map((member) =>
         mapUser({
           id: member.userId,