diff --git a/backend/src/application.ts b/backend/src/application.ts
index c0b1678..bd62260 100644
--- a/backend/src/application.ts
+++ b/backend/src/application.ts
@@ -9,10 +9,9 @@ import {
     TokenServiceBindings,
     UserServiceBindings
 } from '@loopback/authentication-jwt';
-import { AuthService, SzakdolgozatUserService } from './services';
+import { SzakdolgozatUserService } from './services';
 import { GraphQLBindings, GraphQLServer } from '@loopback/graphql';
 import { UserResolver } from './graphql-resolvers/user-resolver';
-import { SzakdolgozatBindings } from './bindings';
 import { SzakdolgozatAuthChecker } from './szakdolgozat-auth-checker';
 
 export { ApplicationConfig };
@@ -38,10 +37,9 @@ 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).toProvider(SzakdolgozatAuthChecker);
+        this.bind(GraphQLBindings.GRAPHQL_AUTH_CHECKER).toDynamicValue(SzakdolgozatAuthChecker);
 
         this.service(SzakdolgozatUserService, UserServiceBindings.USER_SERVICE);
-        this.service(AuthService, SzakdolgozatBindings.AUTH_SERVICE);
 
         this.projectRoot = __dirname;
         this.bootOptions = {
diff --git a/backend/src/bindings.ts b/backend/src/bindings.ts
index ff9af01..1944520 100644
--- a/backend/src/bindings.ts
+++ b/backend/src/bindings.ts
@@ -1,7 +1,5 @@
 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 dbbd167..9d77a3e 100644
--- a/backend/src/graphql-resolvers/user-resolver.ts
+++ b/backend/src/graphql-resolvers/user-resolver.ts
@@ -57,11 +57,13 @@ export class UserResolver {
 
     @authorized()
     @mutation(returns => Boolean)
-    async logout(@inject(SzakdolgozatBindings.AUTH_TOKEN) token: string): Promise<boolean> {
-        console.log('Logout service: ', token);
-        console.log('Context: ', this.context?.name);
-        //console.log('token:', this.authService.receivedToken); //TODO
-        //await this.jwtService.revokeToken?.(this.authService.receivedToken);
+    async logout(): Promise<boolean> {
+        const token = await this.context.get(SzakdolgozatBindings.AUTH_TOKEN);
+        if (this.jwtService.revokeToken) {
+            await this.jwtService.revokeToken(token);
+        } else {
+            console.error('Cannot revoke token');
+        }
         return true;
     }
 
diff --git a/backend/src/services/auth.service.ts b/backend/src/services/auth.service.ts
deleted file mode 100644
index 2bd99fb..0000000
--- a/backend/src/services/auth.service.ts
+++ /dev/null
@@ -1,7 +0,0 @@
-export class AuthService {
-    receivedToken: string;
-
-    constructor() {
-        console.log('new auth service');
-    }
-}
diff --git a/backend/src/services/index.ts b/backend/src/services/index.ts
index d99a6a5..e17ee5c 100644
--- a/backend/src/services/index.ts
+++ b/backend/src/services/index.ts
@@ -1,2 +1 @@
 export * from './user.service';
-export * from './auth.service';
diff --git a/backend/src/szakdolgozat-auth-checker.ts b/backend/src/szakdolgozat-auth-checker.ts
index cdf642b..3276df4 100644
--- a/backend/src/szakdolgozat-auth-checker.ts
+++ b/backend/src/szakdolgozat-auth-checker.ts
@@ -1,32 +1,25 @@
 import { AuthenticateFn, AuthenticationBindings, AuthenticationStrategy } from '@loopback/authentication';
-import { AuthChecker, ExpressContext, ResolverData } from '@loopback/graphql';
-import { Context, Getter, inject, Provider, ValueOrPromise } from '@loopback/core';
+import { AuthChecker, ExpressContext } from '@loopback/graphql';
+import { Context, Getter, inject, ValueOrPromise } from '@loopback/core';
 import { JWTAuthenticationStrategy } from '@loopback/authentication-jwt';
 import { SzakdolgozatBindings } from './bindings';
-import { AuthService } from './services';
 
-export class SzakdolgozatAuthChecker implements Provider<AuthChecker> {
-    constructor(@inject(AuthenticationBindings.AUTH_ACTION) private authenticate: AuthenticateFn,
-                @inject.getter(AuthenticationBindings.STRATEGY)
-                readonly getStrategies: Getter<AuthenticationStrategy | AuthenticationStrategy[] | undefined>,
-                @inject(SzakdolgozatBindings.AUTH_SERVICE) private authService: AuthService,
-                @inject.context() private context: Context) {
-        console.log('new auth checker');
+export class SzakdolgozatAuthChecker {
+    constructor() {
+        console.log('New auth checker');
     }
 
-    value(): ValueOrPromise<AuthChecker> {
-        return this.authUser.bind(this);
-    }
-
-    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('Context: ', this.context.name);
-        this.context.bind(SzakdolgozatBindings.AUTH_TOKEN).to(strat.extractCredentials(context.req));
-        console.log('This: ', this.authService);
-        console.log('Res: ', (<any> res).id);
-        return true;
+    static value(@inject(AuthenticationBindings.AUTH_ACTION) authenticate: AuthenticateFn,
+                 @inject.getter(AuthenticationBindings.STRATEGY)
+                     getStrategies: Getter<AuthenticationStrategy | AuthenticationStrategy[] | undefined>,
+                 @inject.context() context: Context): ValueOrPromise<AuthChecker> {
+        return async (resolverData, roles) => {
+            const econtext = (<ExpressContext> resolverData.context);
+            const res = await authenticate(econtext.req);
+            const strat = <JWTAuthenticationStrategy> await getStrategies();
+            // Itt már biztosan van érvényes token
+            context.bind(SzakdolgozatBindings.AUTH_TOKEN).to(strat.extractCredentials(econtext.req));
+            return true;
+        };
     }
 }