diff --git a/src/main/kotlin/dev/usbharu/hideout/core/domain/model/notification/Notification.kt b/src/main/kotlin/dev/usbharu/hideout/core/domain/model/notification/Notification.kt
new file mode 100644
index 00000000..e1b48e5d
--- /dev/null
+++ b/src/main/kotlin/dev/usbharu/hideout/core/domain/model/notification/Notification.kt
@@ -0,0 +1,12 @@
+package dev.usbharu.hideout.core.domain.model.notification
+
+import java.time.Instant
+
+data class Notification(
+    val userId: Long,
+    val sourceActorId: Long?,
+    val postId: Long?,
+    val text: String?,
+    val reactionId: Long?,
+    val createdAt: Instant
+)
diff --git a/src/main/kotlin/dev/usbharu/hideout/core/service/notification/NotificationManagimentService.kt b/src/main/kotlin/dev/usbharu/hideout/core/service/notification/NotificationManagimentService.kt
new file mode 100644
index 00000000..3281087d
--- /dev/null
+++ b/src/main/kotlin/dev/usbharu/hideout/core/service/notification/NotificationManagimentService.kt
@@ -0,0 +1,7 @@
+package dev.usbharu.hideout.core.service.notification
+
+import dev.usbharu.hideout.core.domain.model.relationship.Relationship
+
+interface NotificationManagimentService {
+    fun sendNotification(relationship: Relationship, notificationRequest: NotificationRequest): Boolean
+}
diff --git a/src/main/kotlin/dev/usbharu/hideout/core/service/notification/NotificationRequest.kt b/src/main/kotlin/dev/usbharu/hideout/core/service/notification/NotificationRequest.kt
new file mode 100644
index 00000000..3080c32e
--- /dev/null
+++ b/src/main/kotlin/dev/usbharu/hideout/core/service/notification/NotificationRequest.kt
@@ -0,0 +1,36 @@
+package dev.usbharu.hideout.core.service.notification
+
+sealed class NotificationRequest(open val userId: Long, open val sourceActorId: Long)
+
+interface PostId {
+    val postId: Long
+}
+
+data class MentionNotificationRequest(
+    override val userId: Long, override val sourceActorId: Long, override val postId: Long
+) : NotificationRequest(
+    userId, sourceActorId
+), PostId
+
+data class PostNotificationRequest(
+    override val userId: Long, override val sourceActorId: Long, override val postId: Long
+
+) : NotificationRequest(userId, sourceActorId), PostId
+
+data class RepostNotificationRequest(
+    override val userId: Long, override val sourceActorId: Long, override val postId: Long
+) : NotificationRequest(userId, sourceActorId), PostId
+
+data class FollowNotificationRequest(
+    override val userId: Long, override val sourceActorId: Long, override val postId: Long
+
+) : NotificationRequest(userId, sourceActorId), PostId
+
+data class FollowRequestNotificationRequest(
+    override val userId: Long, override val sourceActorId: Long, override val postId: Long
+) : NotificationRequest(userId, sourceActorId), PostId
+
+data class ReactionNotificationRequest(
+    override val userId: Long, override val sourceActorId: Long, override val postId: Long, val reactionId: Long
+
+) : NotificationRequest(userId, sourceActorId), PostId
diff --git a/src/main/kotlin/dev/usbharu/hideout/core/service/notification/NotificationService.kt b/src/main/kotlin/dev/usbharu/hideout/core/service/notification/NotificationService.kt
new file mode 100644
index 00000000..9c453e49
--- /dev/null
+++ b/src/main/kotlin/dev/usbharu/hideout/core/service/notification/NotificationService.kt
@@ -0,0 +1,8 @@
+package dev.usbharu.hideout.core.service.notification
+
+import dev.usbharu.hideout.core.domain.model.notification.Notification
+
+interface NotificationService {
+    suspend fun publishNotify(notificationRequest: NotificationRequest): Notification
+    suspend fun unpublishNotify(notificationId: Long)
+}