diff --git a/backend/src/application.ts b/backend/src/application.ts
index dab8732..ab403bd 100644
--- a/backend/src/application.ts
+++ b/backend/src/application.ts
@@ -1,5 +1,5 @@
 import { BootMixin } from '@loopback/boot';
-import { Application, ApplicationConfig } from '@loopback/core';
+import { Application, ApplicationConfig, BindingScope } from '@loopback/core';
 import { RepositoryMixin } from '@loopback/repository';
 import { ServiceMixin } from '@loopback/service-proxy';
 import { AuthenticationBindings, AuthenticationComponent } from '@loopback/authentication';
@@ -9,9 +9,10 @@ import {
     TokenServiceBindings,
     UserServiceBindings
 } from '@loopback/authentication-jwt';
-import { SzakdolgozatUserService } from './services';
+import { AuthService, SzakdolgozatUserService } from './services';
 import { GraphQLBindings, GraphQLServer } from '@loopback/graphql';
 import { UserResolver } from './graphql-resolvers/user-resolver';
+import { SzakdolgozatBindings } from './bindings';
 
 export { ApplicationConfig };
 
@@ -36,14 +37,11 @@ export class SzakdolgozatBackendApplication extends BootMixin(
         this.get(TokenServiceBindings.TOKEN_SERVICE).then(tokenService => {
             this.bind(AuthenticationBindings.STRATEGY).to(new JWTAuthenticationStrategy(tokenService));
         });
-        this.bind(GraphQLBindings.GRAPHQL_AUTH_CHECKER).to(async (resolverData, roles) => {
-            const authenticate = await this.get(AuthenticationBindings.AUTH_ACTION);
-            const res = await authenticate((<any> resolverData.context).req);
-            console.log('Res: ', res);
-            return true;
-        });
 
         this.service(SzakdolgozatUserService, UserServiceBindings.USER_SERVICE);
+        this.service(AuthService, {defaultScope: BindingScope.REQUEST, key: SzakdolgozatBindings.AUTH_SERVICE});
+        this.get(SzakdolgozatBindings.AUTH_SERVICE).then(service => this.bind(GraphQLBindings.GRAPHQL_AUTH_CHECKER)
+            .to((resolverData, roles) => service.authUser(resolverData, roles)));
 
         this.projectRoot = __dirname;
         this.bootOptions = {
diff --git a/backend/src/bindings.ts b/backend/src/bindings.ts
new file mode 100644
index 0000000..c6087dc
--- /dev/null
+++ b/backend/src/bindings.ts
@@ -0,0 +1,7 @@
+import { BindingKey } from '@loopback/core';
+import { AuthService } from './services';
+
+export namespace SzakdolgozatBindings {
+    export const AUTH_SERVICE = BindingKey.create<AuthService>('szakdolgozat.auth');
+    //export const AUTH_TOKEN = BindingKey.create<string>('szakdolgozat.auth.token');
+}
diff --git a/backend/src/graphql-resolvers/user-resolver.ts b/backend/src/graphql-resolvers/user-resolver.ts
index 5adabb9..d56d5c5 100644
--- a/backend/src/graphql-resolvers/user-resolver.ts
+++ b/backend/src/graphql-resolvers/user-resolver.ts
@@ -3,7 +3,7 @@ import { User } from '../models';
 import { repository } from '@loopback/repository';
 import { UserRepository } from '../repositories';
 import { inject } from '@loopback/core';
-import { SzakdolgozatUserService } from '../services';
+import { AuthService, SzakdolgozatUserService } from '../services';
 import { TokenServiceBindings, UserServiceBindings } from '@loopback/authentication-jwt';
 import { TokenService } from '@loopback/authentication';
 import { SecurityBindings, UserProfile } from '@loopback/security';
@@ -12,6 +12,7 @@ import { UserRegisterInput } from '../graphql-types/input/user-register.input';
 import { validated } from '../helpers';
 import { LoginResult } from '../graphql-types/user';
 import { UserUpdateInput } from '../graphql-types/input/user-update.input';
+import { SzakdolgozatBindings } from '../bindings';
 
 @resolver(of => User)
 export class UserResolver {
@@ -20,8 +21,10 @@ export class UserResolver {
         @inject(UserServiceBindings.USER_SERVICE) private readonly userService: SzakdolgozatUserService,
         @inject(GraphQLBindings.RESOLVER_DATA) private readonly resolverData: ResolverData,
         @inject(TokenServiceBindings.TOKEN_SERVICE) public jwtService: TokenService,
-        @inject(SecurityBindings.USER, {optional: true}) public user: UserProfile
+        @inject(SecurityBindings.USER, {optional: true}) public user: UserProfile,
+        @inject(SzakdolgozatBindings.AUTH_SERVICE) private authService: AuthService
     ) {
+        console.log('Auth service', authService);
     }
 
     @mutation(returns => User)
@@ -55,16 +58,10 @@ export class UserResolver {
 
     @authorized()
     @mutation(returns => Boolean)
-    async logout(@inject(GraphQLBindings.RESOLVER_DATA) request: any): Promise<boolean> {
-        console.log('request:', request); //TODO
-        const split = request.headers.get('Authorization')?.split(' ');
-        if (split && split.length > 1) {
-            if (this.jwtService.revokeToken) {
-                await this.jwtService.revokeToken(split[1]);
-            } else {
-                console.error('Cannot revoke token');
-            }
-        }
+    async logout(): Promise<boolean> {
+        console.log('Logout service: ', this.authService);
+        console.log('token:', this.authService.receivedToken); //TODO
+        await this.jwtService.revokeToken?.(this.authService.receivedToken);
         return true;
     }
 
diff --git a/backend/src/services/auth.service.ts b/backend/src/services/auth.service.ts
new file mode 100644
index 0000000..b75dd53
--- /dev/null
+++ b/backend/src/services/auth.service.ts
@@ -0,0 +1,28 @@
+import { AuthenticateFn, AuthenticationBindings, AuthenticationStrategy } from '@loopback/authentication';
+import { ExpressContext, ResolverData } from '@loopback/graphql';
+import { Getter, inject } from '@loopback/core';
+import { JWTAuthenticationStrategy } from '@loopback/authentication-jwt';
+
+export class AuthService {
+    receivedToken: string;
+
+    constructor(@inject(AuthenticationBindings.AUTH_ACTION) private authenticate: AuthenticateFn,
+                @inject.getter(AuthenticationBindings.STRATEGY)
+                readonly getStrategies: Getter<AuthenticationStrategy | AuthenticationStrategy[] | undefined>) {
+        console.log('Created auth service', new Error().stack);
+    }
+
+    async authUser(resolverData: ResolverData, roles: string[]) {
+        const context = (<ExpressContext> resolverData.context);
+        const res = await this.authenticate(context.req);
+        const strat = <JWTAuthenticationStrategy> await this.getStrategies();
+        // Itt már biztosan van érvényes token
+        console.log('This: ', this);
+        this.receivedToken = strat.extractCredentials(context.req);
+        console.log('This: ', this);
+        console.log('Strat: ', strat);
+        console.log('Creds: ', strat.extractCredentials(context.req));
+        console.log('Res: ', (<any> res).id);
+        return true;
+    }
+}
diff --git a/backend/src/services/index.ts b/backend/src/services/index.ts
index e17ee5c..d99a6a5 100644
--- a/backend/src/services/index.ts
+++ b/backend/src/services/index.ts
@@ -1 +1,2 @@
 export * from './user.service';
+export * from './auth.service';