diff --git a/build.gradle.kts b/build.gradle.kts
index 18d7d23..0adabc9 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -32,7 +32,7 @@ dependencies {
 
     implementation(libs.spring.boot.starter.web)
     implementation(libs.spring.boot.starter.actuator)
-//    implementation(libs.spring.boot.starter.security)
+    implementation(libs.spring.boot.starter.security)
     implementation(libs.spring.boot.starter.cache)
     implementation(libs.spring.boot.starter.data.jdbc)
     implementation(libs.spring.boot.starter.validation)
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 2e91484..e43dfa6 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -11,6 +11,7 @@ spring-grpc = "1.0.1"
 protoc = "3.25.1"
 grpc-java = "1.60.0"
 springdoc = "2.8.6"
+mockk = "1.13.13"
 
 [libraries]
 spring-boot-starter-web = { module = "org.springframework.boot:spring-boot-starter-web" }
@@ -33,6 +34,7 @@ flyway-database-postgresql = { module = "org.flywaydb:flyway-database-postgresql
 kotlin-reflect = { module = "org.jetbrains.kotlin:kotlin-reflect" }
 kotlin-test-junit5 = { module = "org.jetbrains.kotlin:kotlin-test-junit5" }
 junit-platform-launcher = { module = "org.junit.platform:junit-platform-launcher" }
+mockk = { module = "io.mockk:mockk", version.ref = "mockk" }
 
 sentry-bom = { module = "io.sentry:sentry-bom", version.ref = "sentry" }
 sentry-spring-boot-starter = { module = "io.sentry:sentry-spring-boot-starter-jakarta" }
diff --git a/src/main/resources/db/migration/V2__add_oauth2_fields.sql b/src/main/resources/db/migration/V2__add_oauth2_fields.sql
new file mode 100644
index 0000000..0db4084
--- /dev/null
+++ b/src/main/resources/db/migration/V2__add_oauth2_fields.sql
@@ -0,0 +1,9 @@
+ALTER TABLE public.users ADD COLUMN provider VARCHAR(20);
+ALTER TABLE public.users ADD COLUMN provider_id VARCHAR(255);
+ALTER TABLE public.users ADD COLUMN created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP NOT NULL;
+
+CREATE UNIQUE INDEX idx_users_provider_provider_id
+    ON public.users(provider, provider_id);
+
+CREATE INDEX idx_users_email ON public.users(email);
+