diff --git a/src/runtime/core/core.ts b/src/runtime/core/core.ts
index 13a10b8..406a52b 100644
--- a/src/runtime/core/core.ts
+++ b/src/runtime/core/core.ts
@@ -2,7 +2,7 @@ import { generateRandomString, alphabet } from "oslo/crypto";
 import { checkDbAndTables, type tableNames } from "../database";
 import { getOAuthAccountsTableSchema, getSessionsTableSchema, getUsersTableSchema } from "../database/lib/schema";
 import { drizzle as drizzleIntegration } from "db0/integrations/drizzle/index";
-import type { checkDbAndTablesParameters, ICreateOrLoginParams, ISlipAuthCoreOptions, SchemasMockValue, SlipAuthSession } from "./types";
+import type { checkDbAndTablesParameters, DrizzleTransaction, ICreateOrLoginParams, ISlipAuthCoreOptions, SchemasMockValue, SlipAuthSession } from "./types";
 import { createSlipHooks } from "./hooks";
 import { UsersRepository } from "./repositories/UsersRepository";
 import { SessionsRepository } from "./repositories/SessionsRepository";
@@ -71,52 +71,56 @@ export class SlipAuthCore {
   public async registerUserIfMissingInDb(
     params: ICreateOrLoginParams,
   ): Promise<[ string, SlipAuthSession]> {
-    const existingUser = await this.#repos.users.findByEmail(params.email);
-
-    if (!existingUser) {
-      const userId = this.#createRandomUserId();
-
-      await this.#repos.users.insert(userId, params.email);
-
-      const _insertedOAuthAccount = await this.#repos.oAuthAccounts.insert(params.email, {
-        provider_id: params.providerId,
-        provider_user_id: params.providerUserId,
-        user_id: userId,
-      });
-
-      const sessionFromRegistrationId = this.#createRandomSessionId();
-      const sessionFromRegistration = await this.#repos.sessions.insert(sessionFromRegistrationId, {
-        userId,
-        expiresAt: Date.now() + this.#sessionMaxAge,
-        ip: params.ip,
-        ua: params.ua,
-      });
-
-      return [userId, sessionFromRegistration as SlipAuthSession];
-    }
-
-    const existingAccount = await this.#repos.oAuthAccounts.findByProviderData(
-      params.providerId, params.providerUserId,
-    );
-
-    if (existingUser && existingAccount?.provider_id !== params.providerId) {
-      throw new Error("user already have an account with another provider");
-    }
-
-    if (existingAccount) {
-      const sessionFromLoginId = this.#createRandomSessionId();
-      const sessionFromLogin = await this.#repos.sessions.insert(sessionFromLoginId, {
-        userId: existingUser.id,
-        expiresAt: Date.now() + this.#sessionMaxAge,
-        ua: params.ua,
-        ip: params.ip,
-      });
-      const { id, expires_at } = sessionFromLogin;
-
-      return [existingUser.id, { id, expires_at }];
-    }
-
-    throw new Error("could not find oauth user");
+    return await this.#orm.transaction(async (trx: DrizzleTransaction) => {
+      const existingUser = await this.#repos.users.findByEmail(params.email, trx);
+
+      if (!existingUser) {
+        const userId = this.#createRandomUserId();
+
+        await this.#repos.users.insert({ userId, email: params.email }, trx);
+
+        const _insertedOAuthAccount = await this.#repos.oAuthAccounts.insert(params.email, {
+          provider_id: params.providerId,
+          provider_user_id: params.providerUserId,
+          user_id: userId,
+        }, trx);
+
+        const sessionFromRegistrationId = this.#createRandomSessionId();
+        const sessionFromRegistration = await this.#repos.sessions.insert(sessionFromRegistrationId, {
+          userId,
+          expiresAt: Date.now() + this.#sessionMaxAge,
+          ip: params.ip,
+          ua: params.ua,
+        }, trx);
+
+        throw new Error("could not find oauth user");
+        return [userId, sessionFromRegistration as SlipAuthSession];
+      }
+
+      const existingAccount = await this.#repos.oAuthAccounts.findByProviderData(
+        params.providerId, params.providerUserId,
+      );
+
+      if (existingUser && existingAccount?.provider_id !== params.providerId) {
+        throw new Error("user already have an account with another provider");
+      }
+
+      if (existingAccount) {
+        const sessionFromLoginId = this.#createRandomSessionId();
+        const sessionFromLogin = await this.#repos.sessions.insert(sessionFromLoginId, {
+          userId: existingUser.id,
+          expiresAt: Date.now() + this.#sessionMaxAge,
+          ua: params.ua,
+          ip: params.ip,
+        }, trx);
+
+        const { id, expires_at } = sessionFromLogin;
+
+        return [existingUser.id, { id, expires_at }];
+      }
+
+      throw new Error("could not find oauth user");
+    });
   }
 
   public setCreateRandomUserId(fn: () => string) {
diff --git a/src/runtime/core/repositories/OAuthAccountsRepository.ts b/src/runtime/core/repositories/OAuthAccountsRepository.ts
index 8c7d67b..a3e042a 100644
--- a/src/runtime/core/repositories/OAuthAccountsRepository.ts
+++ b/src/runtime/core/repositories/OAuthAccountsRepository.ts
@@ -1,9 +1,11 @@
 import { eq, and } from "drizzle-orm";
 import { TableRepository } from "./_repo";
+import type { DrizzleTransaction } from "../types";
 
 export class OAuthAccountsRepository extends TableRepository<"oauthAccounts"> {
-  async insert(email: string, values: typeof this.table.$inferInsert): Promise<typeof this.table.$inferSelect> {
-    await this._orm
+  async insert(email: string, values: typeof this.table.$inferInsert, trx?: DrizzleTransaction): Promise<typeof this.table.$inferSelect> {
+    const orm = trx || this._orm;
+    await orm
       .insert(this.table)
       .values(values)
       .run();
diff --git a/src/runtime/core/repositories/SessionsRepository.ts b/src/runtime/core/repositories/SessionsRepository.ts
index 1e12e34..1f651b7 100644
--- a/src/runtime/core/repositories/SessionsRepository.ts
+++ b/src/runtime/core/repositories/SessionsRepository.ts
@@ -1,10 +1,11 @@
 import { eq, sql } from "drizzle-orm";
 import { TableRepository } from "./_repo";
-import type { ICreateSessionsParams } from "../types";
+import type { ICreateSessionsParams, DrizzleTransaction } from "../types";
 
 export class SessionsRepository extends TableRepository<"sessions"> {
-  async insert(sessionId: string, { userId, expiresAt, ip, ua }: ICreateSessionsParams): Promise<typeof this.table.$inferSelect> {
-    await this._orm
+  async insert(sessionId: string, { userId, expiresAt, ip, ua }: ICreateSessionsParams, trx?: DrizzleTransaction): Promise<typeof this.table.$inferSelect> {
+    const orm = trx || this._orm;
+    await orm
       .insert(this.table)
       .values({
         id: sessionId,
diff --git a/src/runtime/core/repositories/UsersRepository.ts b/src/runtime/core/repositories/UsersRepository.ts
index d9ed4d4..105aa1c 100644
--- a/src/runtime/core/repositories/UsersRepository.ts
+++ b/src/runtime/core/repositories/UsersRepository.ts
@@ -1,9 +1,11 @@
 import { eq } from "drizzle-orm";
 import { TableRepository } from "./_repo";
+import type { DrizzleTransaction } from "../types";
 
 export class UsersRepository extends TableRepository<"users"> {
-  async insert(userId: string, email: string): Promise<typeof this.table.$inferSelect> {
-    await this._orm
+  async insert({ userId, email }: { userId: string, email: string }, trx?: DrizzleTransaction): Promise<typeof this.table.$inferSelect> {
+    const orm = trx ?? this._orm;
+    await orm
       .insert(this.table)
       .values({
         id: userId,
diff --git a/src/runtime/core/types.ts b/src/runtime/core/types.ts
index 181061b..eec180e 100644
--- a/src/runtime/core/types.ts
+++ b/src/runtime/core/types.ts
@@ -1,3 +1,4 @@
+import type { drizzle as drizzleIntegration } from "db0/integrations/drizzle/index";
 import type { SQLiteTable } from "drizzle-orm/sqlite-core";
 import type { checkDbAndTables, tableNames } from "../database";
 import { getOAuthAccountsTableSchema, getSessionsTableSchema, getUsersTableSchema } from "../database/lib/schema";
@@ -5,6 +6,8 @@ import { getOAuthAccountsTableSchema, getSessionsTableSchema, getUsersTableSchem
 export type { tableNames };
 export type { supportedConnectors } from "../database";
 
+export type DrizzleTransaction = Parameters<Parameters<ReturnType<typeof drizzleIntegration>["transaction"]>["0"]>[0];
+
 export type checkDbAndTablesParameters = Parameters<typeof checkDbAndTables>;
 
 export interface ICreateOrLoginParams {