diff --git a/projects/ucap-webmessenger-protocol-query/src/lib/services/query-protocol.service.ts b/projects/ucap-webmessenger-protocol-query/src/lib/services/query-protocol.service.ts
index 29ffd922..f2df4933 100644
--- a/projects/ucap-webmessenger-protocol-query/src/lib/services/query-protocol.service.ts
+++ b/projects/ucap-webmessenger-protocol-query/src/lib/services/query-protocol.service.ts
@@ -1,8 +1,30 @@
 import { Injectable } from '@angular/core';
+import { ProtocolService } from '@ucap-webmessenger/protocol';
+import { Observable } from 'rxjs';
+import { take, map } from 'rxjs/operators';
+import {
+  AuthRequest,
+  AuthResponse,
+  encodeAuth,
+  decodeAuth
+} from '../models/auth';
+import {
+  SVC_TYPE_QUERY_DATA,
+  SSVC_TYPE_QUERY_AUTH_REQ
+} from '../types/service';
 
 @Injectable({
   providedIn: 'root'
 })
 export class QueryProtocolService {
-  constructor() {}
+  constructor(private protocolService: ProtocolService) {}
+
+  public auth(req: AuthRequest): Observable<AuthResponse> {
+    return this.protocolService
+      .call(SVC_TYPE_QUERY_DATA, SSVC_TYPE_QUERY_AUTH_REQ, ...encodeAuth(req))
+      .pipe(
+        take(1),
+        map(res => decodeAuth(res))
+      );
+  }
 }