diff --git a/src/main/kotlin/logic/repositories/AuditRepository.kt b/src/main/kotlin/logic/repositories/AuditRepository.kt
new file mode 100644
index 0000000..db0bcde
--- /dev/null
+++ b/src/main/kotlin/logic/repositories/AuditRepository.kt
@@ -0,0 +1,10 @@
+package com.berlin.logic.repositories
+
+import com.berlin.model.AuditLog
+
+interface AuditRepository {
+    fun addAuditLog(auditLog: AuditLog):Boolean
+    fun getAuditLogsByProjectId(projectId:String):List<AuditLog>
+    fun getAuditLogsByTaskId(taskId:String):List<AuditLog>
+    fun getAuditLogsByUserId(userId:String):List<AuditLog>
+}
\ No newline at end of file
diff --git a/src/main/kotlin/logic/repositories/AuthenticationRepository.kt b/src/main/kotlin/logic/repositories/AuthenticationRepository.kt
new file mode 100644
index 0000000..5f56b95
--- /dev/null
+++ b/src/main/kotlin/logic/repositories/AuthenticationRepository.kt
@@ -0,0 +1,9 @@
+package com.berlin.logic.repositories
+
+import com.berlin.model.User
+
+interface AuthenticationRepository {
+    fun createUser(user:User):Boolean
+    fun getUserById(userId:String):User?
+    fun getAllUsers():List<User>
+}
\ No newline at end of file
diff --git a/src/main/kotlin/logic/repositories/ProjectRepository.kt b/src/main/kotlin/logic/repositories/ProjectRepository.kt
new file mode 100644
index 0000000..17fbc66
--- /dev/null
+++ b/src/main/kotlin/logic/repositories/ProjectRepository.kt
@@ -0,0 +1,11 @@
+package com.berlin.logic.repositories
+
+import com.berlin.model.Project
+
+interface ProjectRepository {
+    fun createProject(project:Project):Boolean
+    fun getProjectById(projectId:String):Project?
+    fun getAllProjects():List<Project>
+    fun updateProject(project: Project):Boolean
+    fun deleteProject(projectId: String):Boolean
+}
\ No newline at end of file
diff --git a/src/main/kotlin/logic/repositories/StateRepository.kt b/src/main/kotlin/logic/repositories/StateRepository.kt
new file mode 100644
index 0000000..e0589d3
--- /dev/null
+++ b/src/main/kotlin/logic/repositories/StateRepository.kt
@@ -0,0 +1,11 @@
+package com.berlin.logic.repositories
+
+import com.berlin.model.State
+
+interface StateRepository {
+    fun createState(state: State):Boolean
+    fun getStatesByProjectId(projectId:String):List<State>
+    fun deleteState(stateId:String):Boolean
+    fun updateState(state: State):Boolean
+    fun getStateByTaskId(taskId:String):State?
+}
\ No newline at end of file
diff --git a/src/main/kotlin/logic/repositories/TaskRepository.kt b/src/main/kotlin/logic/repositories/TaskRepository.kt
new file mode 100644
index 0000000..5dbbae8
--- /dev/null
+++ b/src/main/kotlin/logic/repositories/TaskRepository.kt
@@ -0,0 +1,13 @@
+package com.berlin.logic.repositories
+
+import com.berlin.model.Task
+import com.berlin.model.User
+
+interface TaskRepository {
+    fun createTask(task:Task):Boolean
+    fun getTaskById(taskId:String):Task?
+    fun getTasksByProjectId(projectId:String):List<Task>
+    fun updateTask(task: Task):Boolean
+    fun deleteTaskById(taskId: String):Boolean
+    fun getAssignedUserByTaskId(taskId: String):User?
+}
\ No newline at end of file
diff --git a/src/main/kotlin/model/AuditAction.kt b/src/main/kotlin/model/AuditAction.kt
new file mode 100644
index 0000000..8e09f80
--- /dev/null
+++ b/src/main/kotlin/model/AuditAction.kt
@@ -0,0 +1,5 @@
+package com.berlin.model
+
+enum class AuditAction {
+   CREATE, UPDATE, DELETE
+}
\ No newline at end of file
diff --git a/src/main/kotlin/model/AuditLog.kt b/src/main/kotlin/model/AuditLog.kt
new file mode 100644
index 0000000..1cc246d
--- /dev/null
+++ b/src/main/kotlin/model/AuditLog.kt
@@ -0,0 +1,12 @@
+package com.berlin.model
+
+
+data class AuditLog(
+    val id:String,
+    val timestamp: Long,
+    val createdBy:User,
+    val auditAction:AuditAction,
+    val changesDescription:String?,
+    val entityType:EntityType,
+    val entityId:String
+)
diff --git a/src/main/kotlin/model/EntityType.kt b/src/main/kotlin/model/EntityType.kt
new file mode 100644
index 0000000..f3b4354
--- /dev/null
+++ b/src/main/kotlin/model/EntityType.kt
@@ -0,0 +1,5 @@
+package com.berlin.model
+
+enum class EntityType {
+    PROJECT,TASK
+}
\ No newline at end of file
diff --git a/src/main/kotlin/model/Project.kt b/src/main/kotlin/model/Project.kt
new file mode 100644
index 0000000..8b77e24
--- /dev/null
+++ b/src/main/kotlin/model/Project.kt
@@ -0,0 +1,9 @@
+package com.berlin.model
+
+data class Project(
+    val id:String,
+    val name:String,
+    val description:String?,
+    val statesId:List<String>,
+    val tasksId:List<String>
+)
diff --git a/src/main/kotlin/model/State.kt b/src/main/kotlin/model/State.kt
new file mode 100644
index 0000000..a0a3580
--- /dev/null
+++ b/src/main/kotlin/model/State.kt
@@ -0,0 +1,7 @@
+package com.berlin.model
+
+data class State(
+    val id:String,
+    val name:String,
+    val projectId:String,
+)
diff --git a/src/main/kotlin/model/Task.kt b/src/main/kotlin/model/Task.kt
new file mode 100644
index 0000000..1c576a3
--- /dev/null
+++ b/src/main/kotlin/model/Task.kt
@@ -0,0 +1,13 @@
+package com.berlin.model
+
+
+data class Task(
+    val id:String,
+    val projectId:String,
+    val title:String,
+    val description:String?,
+    val stateId:String,
+    val assignedTo:User,
+    val createBy:User,
+    val auditLogs:List<AuditLog>
+    )
diff --git a/src/main/kotlin/model/User.kt b/src/main/kotlin/model/User.kt
new file mode 100644
index 0000000..df2e76f
--- /dev/null
+++ b/src/main/kotlin/model/User.kt
@@ -0,0 +1,9 @@
+package com.berlin.model
+
+
+data class User(
+    val id:String,
+    val userName:String,
+    val password:String,
+    val role:UserRole
+)
diff --git a/src/main/kotlin/model/UserRole.kt b/src/main/kotlin/model/UserRole.kt
new file mode 100644
index 0000000..e5ce06e
--- /dev/null
+++ b/src/main/kotlin/model/UserRole.kt
@@ -0,0 +1,5 @@
+package com.berlin.model
+
+enum class UserRole {
+    ADMIN,MATE
+}
\ No newline at end of file