diff --git a/src/@shared/src/database/index.ts b/src/@shared/src/database/index.ts
index 1f6d237..38853d4 100644
--- a/src/@shared/src/database/index.ts
+++ b/src/@shared/src/database/index.ts
@@ -1,14 +1,16 @@
 import fp from 'fastify-plugin';
 import { FastifyInstance, FastifyPluginAsync } from 'fastify';
 
-import { Database as DbImpl } from './mixin/_base';
-import { UserImpl, IUserDb } from './mixin/user';
 import { isNullish } from '@shared/utils';
+import { Database as DbImpl } from './mixin/_base';
+import { IOauthDb, OauthImpl } from './mixin/oauth2';
+import { IUserDb, UserImpl } from './mixin/user';
 
 
 Object.assign(DbImpl.prototype, UserImpl);
+Object.assign(DbImpl.prototype, OauthImpl);
 
-export interface Database extends DbImpl, IUserDb { }
+export interface Database extends DbImpl, IUserDb, IOauthDb { }
 
 // When using .decorate you have to specify added properties for Typescript
 declare module 'fastify' {
diff --git a/src/@shared/src/database/init.dbml b/src/@shared/src/database/init.dbml
index 815cc23..c416aa7 100644
--- a/src/@shared/src/database/init.dbml
+++ b/src/@shared/src/database/init.dbml
@@ -17,9 +17,10 @@ Project Transcendance {
 
 Table user {
   id text [PK, not null]
-  name text [unique, not null]
+  name text [not null]
   password text [null, Note: "If password is NULL, this means that the user is created through OAUTH2"]
   otp text [null, Note: "If otp is NULL, then the user didn't configure 2FA"]
+  guest integer [not null, default: 0]
 
   Note: "Represent a user"
 }
@@ -27,7 +28,7 @@ Table user {
 Table auth {
   id integer [PK, not null, increment]
   provider text [not null]
-  user integer [ref: > user.id, not null]
+  user text [ref: > user.id, not null]
   oauth2_user text [not null, unique, Note: '''
     This makes sure that an oauth2 login is the always the same `user`
     Aka can't have two account bound to the same <OAUTH2> account
diff --git a/src/@shared/src/database/init.sql b/src/@shared/src/database/init.sql
index 5f2deb2..b6f6134 100644
--- a/src/@shared/src/database/init.sql
+++ b/src/@shared/src/database/init.sql
@@ -1,6 +1,6 @@
 CREATE TABLE IF NOT EXISTS user (
   id TEXT PRIMARY KEY NOT NULL,
-  name TEXT NOT NULL UNIQUE,
+  name TEXT NOT NULL,
   password TEXT,
   otp TEXT,
   guest INTEGER NOT NULL DEFAULT 0
diff --git a/src/@shared/src/database/mixin/oauth2.ts b/src/@shared/src/database/mixin/oauth2.ts
new file mode 100644
index 0000000..38c0861
--- /dev/null
+++ b/src/@shared/src/database/mixin/oauth2.ts
@@ -0,0 +1,88 @@
+// import type { Database } from './_base';
+import { isNullish } from '@shared/utils';
+import { UserId, IUserDb, userFromRow, User } from './user';
+
+// never use this directly
+
+export interface IOauthDb extends IUserDb {
+	getAllFromProvider(this: IOauthDb, provider: string): ProviderUser[],
+	getProviderUser(this: IOauthDb, provider: string, unique_id: string): ProviderUser | undefined,
+	getUserFromProviderUser(this: IOauthDb, provider: string, unique_id: string): User | undefined,
+	getUserFromProviderUserId(this: IOauthDb, id: ProviderUserId): User | undefined,
+	getProviderUserFromId(this: IOauthDb, id: ProviderUserId): ProviderUser | undefined,
+
+	createUserWithProvider(this: IOauthDb, provider: string, unique_id: string, username: string): Promise<User | undefined>,
+};
+
+export const OauthImpl: Omit<IOauthDb, keyof IUserDb> = {
+	getAllFromProvider(this: IOauthDb, provider: string): ProviderUser[] {
+		return this.prepare('SELECT * FROM auth WHERE provider = @provider')
+			.all({ provider })
+			.map(r => providerUserFromRow(r as Partial<ProviderUser> | undefined))
+			.filter(v => !isNullish(v)) ?? [];
+	},
+
+	getProviderUser(this: IOauthDb, provider: string, unique_id: string): ProviderUser | undefined {
+		unique_id = `provider:${unique_id}`;
+		return providerUserFromRow(this.prepare('SELECT * FROM auth WHERE provider = @provider AND oauth2_user = @unique_id')
+			.get({ provider, unique_id }) as Partial<ProviderUser> | undefined);
+	},
+
+	getProviderUserFromId(this: IOauthDb, id: ProviderUserId): ProviderUser | undefined {
+		return providerUserFromRow(this.prepare('SELECT * FROM auth WHERE id = @id')
+			.get({ id }) as Partial<ProviderUser> | undefined);
+	},
+
+	getUserFromProviderUser(this: IOauthDb, provider: string, unique_id: string): User | undefined {
+		unique_id = `provider:${unique_id}`;
+		return userFromRow(
+			this.prepare('SELECT user.* from auth INNER JOIN user ON user.id = auth.user WHERE auth.provider = @provider AND auth.oauth2_user = @unique_id')
+				.get({ provider, unique_id }) as Partial<User> | undefined,
+		);
+	},
+
+	getUserFromProviderUserId(this: IOauthDb, id: ProviderUserId): User | undefined {
+		return userFromRow(
+			this.prepare('SELECT user.* from auth INNER JOIN user ON user.id = auth.user WHERE auth.id = @id')
+				.get({ id }) as Partial<User> | undefined,
+		);
+	},
+
+	async createUserWithProvider(this: IOauthDb, provider: string, unique_id: string, username: string): Promise<User | undefined> {
+		unique_id = `provider:${unique_id}`;
+		const user = await this.createUser(username, undefined, false);
+		if (isNullish(user)) { return undefined; }
+		this.prepare('INSERT INTO auth (provider, user, oauth2_user) VALUES (@provider, @user_id, @unique_id)').run({ provider, user_id: user.id, unique_id });
+		return user;
+	},
+};
+
+export type ProviderUserId = number & { readonly __brand: unique symbol };
+
+export type ProviderUser = {
+	readonly id: ProviderUserId,
+	readonly provider: string,
+	readonly user: UserId,
+	readonly oauth2_user: string,
+};
+
+/**
+ * Get a user from a row
+ *
+ * @param row The data from sqlite
+ *
+ * @returns The user if it exists, undefined otherwise
+ */
+function providerUserFromRow(row?: Partial<ProviderUser>): ProviderUser | undefined {
+	if (isNullish(row)) return undefined;
+	if (isNullish(row.id)) return undefined;
+	if (isNullish(row.provider)) return undefined;
+	if (isNullish(row.user)) return undefined;
+	if (isNullish(row.oauth2_user)) return undefined;
+	return {
+		id: row.id,
+		provider: row.provider,
+		user: row.user,
+		oauth2_user: row.oauth2_user,
+	};
+}
diff --git a/src/@shared/src/database/mixin/user.ts b/src/@shared/src/database/mixin/user.ts
index 7cb3ef3..44d49f8 100644
--- a/src/@shared/src/database/mixin/user.ts
+++ b/src/@shared/src/database/mixin/user.ts
@@ -146,7 +146,7 @@ async function hashPassword(
  *
  * @returns The user if it exists, undefined otherwise
  */
-function userFromRow(row?: Partial<User>): User | undefined {
+export function userFromRow(row?: Partial<User>): User | undefined {
 	if (isNullish(row)) return undefined;
 	if (isNullish(row.id)) return undefined;
 	if (isNullish(row.name)) return undefined;