diff --git a/frontend/src/App.vue b/frontend/src/App.vue
index 60c8577..924349a 100644
--- a/frontend/src/App.vue
+++ b/frontend/src/App.vue
@@ -1,11 +1,11 @@
 <script setup async lang="ts">
 import { provide, ref } from 'vue';
 import { useRouter } from 'vue-router';
-import { Auth, TokenInjectType, isErrorResponse } from '@/api';
+import { TokenInjectType } from '@/api';
 
 const router = useRouter();
 
-const jwt = ref<string | null>(null);
+const jwt = ref<string | null>(localStorage.getItem('token'));
 
 function setToken(token: string) {
 	jwt.value = token;
@@ -18,14 +18,6 @@ function logout() {
 	router.push({ name: 'login' });
 }
 
-jwt.value = localStorage.getItem('token');
-if (jwt.value == null) await router.push({ name: 'login' });
-else {
-	const new_token = await Auth.refresh_token(jwt.value ?? '');
-	if (isErrorResponse(new_token)) logout();
-	else setToken(new_token.jwt);
-}
-
 provide<TokenInjectType>('jwt', {
 	jwt,
 	setToken,
diff --git a/frontend/src/router/index.ts b/frontend/src/router/index.ts
index 30c6a3e..12066ff 100644
--- a/frontend/src/router/index.ts
+++ b/frontend/src/router/index.ts
@@ -4,10 +4,12 @@ import SignupView from '@/views/SignupView.vue';
 import HomeView from '@/views/HomeView.vue';
 import AboutView from '@/views/AboutView.vue';
 import FSView from '@/views/FSView.vue';
+import SetTokenView from '@/views/SetTokenView.vue';
 
 const routes: Array<RouteRecordRaw> = [
 	{
 		path: '/',
+		name: 'home',
 		component: HomeView
 	},
 	{
@@ -25,6 +27,10 @@ const routes: Array<RouteRecordRaw> = [
 		name: 'signup',
 		component: SignupView
 	},
+	{
+		path: '/set_token',
+		component: SetTokenView
+	},
 	{
 		path: '/fs/:node_id',
 		name: 'fs',
diff --git a/frontend/src/views/LoginView.vue b/frontend/src/views/LoginView.vue
index 50338d3..22c0eec 100644
--- a/frontend/src/views/LoginView.vue
+++ b/frontend/src/views/LoginView.vue
@@ -54,6 +54,7 @@ async function login() {
 		<input type="text" placeholder="Code" v-model="otp" />
 	</template>
 	<button @click="login()">Login</button>
+	<a href="/api/auth/gitlab">Login with gitlab</a>
 	<router-link to="signup">Signup instead?</router-link>
 </template>
 
diff --git a/frontend/src/views/SetTokenView.vue b/frontend/src/views/SetTokenView.vue
new file mode 100644
index 0000000..e737e33
--- /dev/null
+++ b/frontend/src/views/SetTokenView.vue
@@ -0,0 +1,19 @@
+<script setup lang="ts">
+import { inject } from 'vue';
+import { TokenInjectType } from '@/api';
+import { useRoute, useRouter } from 'vue-router';
+
+const router = useRouter();
+const route = useRoute();
+
+const jwt = inject<TokenInjectType>('jwt') as TokenInjectType;
+
+if ('token' in route.query) jwt.setToken(route.query['token'] as string);
+router.replace({ path: '/' });
+</script>
+
+<template>
+	<router-link to="home">Click here to go home</router-link>
+</template>
+
+<style scoped></style>
diff --git a/package.json b/package.json
index 15f402a..6c29f73 100644
--- a/package.json
+++ b/package.json
@@ -31,6 +31,7 @@
 		"@nestjs/serve-static": "^3.0.0",
 		"@nestjs/typeorm": "^9.0.0",
 		"argon2": "^0.28.7",
+		"axios": "^0.27.2",
 		"jsonwebtoken": "^8.5.1",
 		"nodemailer": "^6.7.8",
 		"notp": "^2.0.3",
diff --git a/src/controller/auth.ts b/src/controller/auth.ts
index 438b2b8..30c7be4 100644
--- a/src/controller/auth.ts
+++ b/src/controller/auth.ts
@@ -6,6 +6,8 @@ import {
 	HttpCode,
 	ParseBoolPipe,
 	Post,
+	Query,
+	Redirect,
 	Request,
 	UnauthorizedException,
 	UseGuards
@@ -45,7 +47,7 @@ export default class AuthController {
 		}
 		return {
 			statusCode: 200,
-			jwt: await this.authService.login(req.user)
+			jwt: await this.authService.login(req, req.user)
 		};
 	}
 
@@ -110,7 +112,7 @@ export default class AuthController {
 		@Body('username') username,
 		@Body('password') password
 	): Promise<Responses.Auth.SignupResponse> {
-		if ((await this.authService.findUser(username)) != null)
+		if ((await this.authService.findUser(username, false)) != null)
 			throw new BadRequestException('Username already taken');
 		await this.authService.signup(username, password);
 		return {
@@ -120,11 +122,31 @@ export default class AuthController {
 
 	@Post('refresh')
 	async refresh(@Request() req): Promise<Responses.Auth.RefreshResponse> {
-		const token = await this.authService.login(req.user);
+		const token = await this.authService.login(req, req.user);
 		await this.authService.revoke(req.token);
 		return {
 			statusCode: 200,
 			jwt: token
 		};
 	}
+
+	@Public()
+	@Redirect()
+	@Get('gitlab')
+	async gitlab(@Request() req) {
+		return {
+			url: this.authService.getGitlabAuthUrl(req)
+		};
+	}
+
+	@Public()
+	@Redirect()
+	@Get('gitlab_callback')
+	async gitlabCallback(@Request() req, @Query('code') code) {
+		const user = await this.authService.getGitlabUserFromCode(req, code);
+		const token = await this.authService.login(req, user);
+		return {
+			url: `/set_token?token=${token}`
+		};
+	}
 }
diff --git a/src/entities/index.ts b/src/entities/index.ts
index affa0f7..7c3f631 100644
--- a/src/entities/index.ts
+++ b/src/entities/index.ts
@@ -47,6 +47,8 @@ export class INode {
 export class User {
 	@PrimaryGeneratedColumn()
 	id: number;
+	@Column({ default: false })
+	isGitlabUser: boolean;
 	@Column()
 	name: string;
 	@Column()
@@ -78,6 +80,11 @@ export class User {
 
 	@Column({ nullable: true })
 	tfaSecret: string;
+
+	@Column({ nullable: true })
+	gitlabAT: string;
+	@Column({ nullable: true })
+	gitlabRT: string;
 }
 
 @Entity()
diff --git a/src/services/auth.ts b/src/services/auth.ts
index db06bfb..b06b44e 100644
--- a/src/services/auth.ts
+++ b/src/services/auth.ts
@@ -15,6 +15,15 @@ import * as jwt from 'jsonwebtoken';
 import { createTransport } from 'nodemailer';
 import * as notp from 'notp';
 import { randomBytes } from 'crypto';
+import { FastifyRequest } from 'fastify';
+import axios from 'axios';
+
+const GITLAB_ID =
+	'98bcbad78cb1f880d1d1de62291d70a791251a7bea077bfe7df111ef3c115760';
+const GITLAB_SECRET =
+	'7ee01d2b204aff3a05f9d028f004d169b6d381ec873e195f314b3935fa150959';
+const GITLAB_URL = 'https://gitlab.mattv.de';
+const GITLAB_API_URL = 'https://ssh.gitlab.mattv.de';
 
 const jwtSecret = 'CUM';
 
@@ -35,6 +44,19 @@ interface jwtPayload {
 	iat?: number;
 }
 
+interface GitlabTokenResponse {
+	access_token: string;
+	token_type: string;
+	expires_in: number;
+	refresh_token: string;
+	created_at: number;
+}
+
+interface GitlabUserResponse {
+	username: string;
+	is_admin?: boolean;
+}
+
 @Injectable()
 export class AuthService {
 	constructor(
@@ -61,9 +83,10 @@ export class AuthService {
 		});
 	}
 
-	async findUser(username: string): Promise<User | null> {
+	async findUser(username: string, gitlab: boolean): Promise<User | null> {
 		return this.userRepo.findOneBy({
-			name: username
+			name: username,
+			isGitlabUser: gitlab
 		});
 	}
 
@@ -74,7 +97,7 @@ export class AuthService {
 	}
 
 	async validateUser(username: string, pass: string): Promise<User | null> {
-		const user = await this.findUser(username);
+		const user = await this.findUser(username, false);
 		if (!user)
 			throw new UnauthorizedException('Invalid username or password');
 		if (!(await argon2.verify(user.password, pass)))
@@ -136,7 +159,11 @@ export class AuthService {
 		await this.userRepo.save(user);
 	}
 
-	async login(user: User) {
+	async login(req: Request, user: User) {
+		if (user.isGitlabUser && !(await this.verifyGitlabUser(req, user))) {
+			await this.revokeAll(user);
+			throw new UnauthorizedException('Invalid gitlab token');
+		}
 		const token = new JWTToken();
 		token.ownerId = user.id;
 		const db_token = await this.tokenRepo.save(token);
@@ -153,16 +180,31 @@ export class AuthService {
 		return jwtToken;
 	}
 
+	async singupInternal(user: User): Promise<User> {
+		const root = await this.fsService.generateRoot(user);
+		user.rootId = root.id;
+		return this.userRepo.save(user);
+	}
+
+	async singupGitlab(
+		info: GitlabUserResponse,
+		data: GitlabTokenResponse
+	): Promise<User> {
+		const user = new User();
+		user.name = info.username;
+		user.password = '';
+		user.isGitlabUser = true;
+		user.role = info.is_admin ? UserRole.ADMIN : UserRole.DISABLED;
+		return this.singupInternal(await this.setGitlabTokens(user, data));
+	}
+
 	async signup(username: string, password: string) {
-		if (await this.findUser(username))
+		if (await this.findUser(username, false))
 			throw new BadRequestException('User already exists');
 		const user = new User();
 		user.name = username;
 		user.password = await argon2.hash(password);
-		const dbUser = await this.userRepo.save(user);
-		const root = await this.fsService.generateRoot(dbUser);
-		dbUser.rootId = root.id;
-		await this.userRepo.save(dbUser);
+		await this.singupInternal(await this.userRepo.save(user));
 	}
 
 	async revoke(token: JWTToken) {
@@ -176,6 +218,87 @@ export class AuthService {
 			ownerId: user.id
 		});
 	}
+
+	async setGitlabTokens(
+		user: User,
+		data: GitlabTokenResponse
+	): Promise<User> {
+		user.gitlabAT = data.access_token;
+		user.gitlabRT = data.refresh_token;
+		return this.userRepo.save(user);
+	}
+
+	getGitlabRedirectUrl(req: Request): string {
+		const _req = req as unknown as FastifyRequest;
+		return `${_req.protocol}://${_req.hostname}/api/auth/gitlab_callback`;
+	}
+
+	getGitlabAuthUrl(req: Request): string {
+		const params = new URLSearchParams();
+		params.append('redirect_uri', this.getGitlabRedirectUrl(req));
+		params.append('response_type', 'code');
+		params.append('scope', 'read_user');
+		params.append('client_id', GITLAB_ID);
+		return `${GITLAB_URL}/oauth/authorize?${params.toString()}`;
+	}
+
+	async getGitlabUserFromCode(req: Request, code: string): Promise<User> {
+		const params = new URLSearchParams();
+		params.append('redirect_uri', this.getGitlabRedirectUrl(req));
+		params.append('client_id', GITLAB_ID);
+		params.append('client_secret', GITLAB_SECRET);
+		params.append('code', code);
+		params.append('grant_type', 'authorization_code');
+		const resp = await axios.post(
+			`${GITLAB_API_URL}/oauth/token?${params.toString()}`,
+			{}
+		);
+		const data: GitlabTokenResponse = resp.data;
+		const userInfoResp = await axios.get(`${GITLAB_API_URL}/api/v4/user`, {
+			headers: { Authorization: `Bearer ${data.access_token}` }
+		});
+		const userInfo: GitlabUserResponse = userInfoResp.data;
+		let user = await this.findUser(userInfo.username, true);
+		if (!user) user = await this.singupGitlab(userInfo, data);
+		else user = await this.setGitlabTokens(user, data);
+		return user;
+	}
+
+	async isGitlabATValid(user: User): Promise<boolean> {
+		try {
+			await axios.get(`${GITLAB_API_URL}/oauth/token/info`, {
+				headers: { Authorization: `Bearer ${user.gitlabAT}` }
+			});
+			return true;
+		} catch (e) {
+			return false;
+		}
+	}
+
+	async tryRefreshGitlabTokens(req: Request, user: User): Promise<boolean> {
+		const params = new URLSearchParams();
+		params.append('redirect_uri', this.getGitlabRedirectUrl(req));
+		params.append('client_id', GITLAB_ID);
+		params.append('client_secret', GITLAB_SECRET);
+		params.append('refresh_token', user.gitlabRT);
+		params.append('grant_type', 'refresh_token');
+		try {
+			const resp = await axios.post(
+				`${GITLAB_API_URL}/oauth/token?${params.toString()}`,
+				{}
+			);
+			const data: GitlabTokenResponse = resp.data;
+			await this.setGitlabTokens(user, data);
+			return true;
+		} catch (e) {
+			return false;
+		}
+	}
+
+	async verifyGitlabUser(req: Request, user: User): Promise<boolean> {
+		if (await this.isGitlabATValid(user)) return true;
+		return await this.tryRefreshGitlabTokens(req, user);
+	}
 }
 
 @Injectable()
@@ -218,6 +341,13 @@ export class AuthJwtService extends PassportStrategy(JWTStrategy) {
 			throw new UnauthorizedException(
 				'Invalid token, please log in again'
 			);
+		if (
+			user.isGitlabUser &&
+			!(await this.authService.verifyGitlabUser(req, user))
+		) {
+			await this.authService.revokeAll(user);
+			throw new UnauthorizedException('Invalid gitlab token');
+		}
 		// eslint-disable-next-line @typescript-eslint/ban-ts-comment
 		// @ts-ignore
 		req.token = token;
diff --git a/yarn.lock b/yarn.lock
index 66858f8..7ff7215 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1699,6 +1699,14 @@ avvio@^8.1.3:
     debug "^4.0.0"
     fastq "^1.6.1"
 
+axios@^0.27.2:
+  version "0.27.2"
+  resolved "https://registry.yarnpkg.com/axios/-/axios-0.27.2.tgz#207658cc8621606e586c85db4b41a750e756d972"
+  integrity sha512-t+yRIyySRTp/wua5xEr+z1q60QmLq8ABsS5O9Me1AsE5dfKqgnCFzwiCZZ/cGNd1lq4/7akDWMxdhVlucjmnOQ==
+  dependencies:
+    follow-redirects "^1.14.9"
+    form-data "^4.0.0"
+
 babel-jest@^28.1.3:
   version "28.1.3"
   resolved "https://registry.yarnpkg.com/babel-jest/-/babel-jest-28.1.3.tgz#c1187258197c099072156a0a121c11ee1e3917d5"
@@ -2800,6 +2808,11 @@ flatted@^3.1.0:
   resolved "https://registry.yarnpkg.com/flatted/-/flatted-3.2.7.tgz#609f39207cb614b89d0765b477cb2d437fbf9787"
   integrity sha512-5nqDSxl8nn5BSNxyR3n4I6eDmbolI6WT+QqR547RwxQapgjQBmtktdP+HTBb/a/zLsbzERTONyUB5pefh5TtjQ==
 
+follow-redirects@^1.14.9:
+  version "1.15.1"
+  resolved "https://registry.yarnpkg.com/follow-redirects/-/follow-redirects-1.15.1.tgz#0ca6a452306c9b276e4d3127483e29575e207ad5"
+  integrity sha512-yLAMQs+k0b2m7cVxpS1VKJVvoz7SS9Td1zss3XRwXj+ZDH00RJgnuLx7E44wx02kQLrdM3aOOy+FpzS7+8OizA==
+
 fork-ts-checker-webpack-plugin@7.2.11:
   version "7.2.11"
   resolved "https://registry.yarnpkg.com/fork-ts-checker-webpack-plugin/-/fork-ts-checker-webpack-plugin-7.2.11.tgz#aff3febbc11544ba3ad0ae4d5aa4055bd15cd26d"