diff --git a/bbconf/bb_todo-datamodel.sql b/bbconf/bb_todo-datamodel.sql
index 14de577..d5f6796 100644
--- a/bbconf/bb_todo-datamodel.sql
+++ b/bbconf/bb_todo-datamodel.sql
@@ -1,3 +1,6 @@
+--
+-- Generated by basebox compiler (bbc) version 0.1.0-beta.23 at 2023-10-30 16:54:43+01:00
+--
 CREATE EXTENSION IF NOT EXISTS pgcrypto; 
 
 CREATE TABLE "List" (
@@ -32,3 +35,11 @@ ALTER TABLE "Task" ADD CONSTRAINT fk_task_2 FOREIGN KEY ("user_username") REFERE
 
 ALTER TABLE "Task" ADD CONSTRAINT fk_task_3 FOREIGN KEY ("list_id") REFERENCES "List" ("id");
 
+ALTER TABLE "User" ADD CONSTRAINT uq_user_4 UNIQUE (".ownerId");
+
+ALTER TABLE "List" ADD COLUMN ".ownerId" VARCHAR NOT NULL;
+
+ALTER TABLE "Task" ADD COLUMN ".ownerId" VARCHAR NOT NULL;
+
+ALTER TABLE "User" ADD COLUMN ".ownerId" VARCHAR NOT NULL;
+
diff --git a/bbconf/bb_todo-resolver.toml b/bbconf/bb_todo-resolver.toml
index 76288ff..7709456 100644
--- a/bbconf/bb_todo-resolver.toml
+++ b/bbconf/bb_todo-resolver.toml
@@ -1,40 +1,22 @@
-[resolvers.getUser]
-operation_name = "getUser"
+# 
+# Generated by bbc (basebox compiler) version 0.1.0-beta.23 at 2023-10-30 16:54:43+01:00
+#
+[resolvers.deleteTask]
+operation_name = "deleteTask"
 
-[resolvers.getUser.resolver]
+[resolvers.deleteTask.resolver.QueryBuilder]
+command_type = "SQLDelete"
+
+[resolvers.deleteTask.resolver.QueryBuilder.command]
+table = "Task"
 command_type = "SQLSelect"
-
-[resolvers.getUser.resolver.command]
-table = "User"
 columns = []
 modify_values = []
 nested_modify_tables = []
 aggregate_result = true
 
-[[resolvers.getUser.resolver.command.where_clauses]]
-table = "User"
-column = "username"
-condition_str = "= '$username'"
-index = ""
-
-[resolvers.updateList]
-operation_name = "updateList"
-
-[resolvers.updateList.resolver]
-command_type = "SQLUpdate"
-
-[resolvers.updateList.resolver.command]
-table = "List"
-columns = []
-nested_modify_tables = []
-aggregate_result = true
-
-[[resolvers.updateList.resolver.command.modify_values]]
-column = "title"
-value = "'$title'"
-
-[[resolvers.updateList.resolver.command.where_clauses]]
-table = "List"
+[[resolvers.deleteTask.resolver.QueryBuilder.command.where_clauses]]
+table = "Task"
 column = "id"
 condition_str = "= '$id'"
 index = ""
@@ -42,146 +24,200 @@ index = ""
 [resolvers.createList]
 operation_name = "createList"
 
-[resolvers.createList.resolver]
+[resolvers.createList.resolver.QueryBuilder]
 command_type = "SQLInsert"
 
-[resolvers.createList.resolver.command]
+[resolvers.createList.resolver.QueryBuilder.command]
 table = "List"
+command_type = "SQLSelect"
 columns = []
 nested_modify_tables = []
 where_clauses = []
 aggregate_result = true
 
-[[resolvers.createList.resolver.command.modify_values]]
+[[resolvers.createList.resolver.QueryBuilder.command.modify_values]]
 column = "title"
 value = "'$title'"
 
-[[resolvers.createList.resolver.command.modify_values]]
+[[resolvers.createList.resolver.QueryBuilder.command.modify_values]]
 column = "user_username"
 value = "'$user.$username'"
 
-[resolvers.createUser]
-operation_name = "createUser"
-
-[resolvers.createUser.resolver]
-command_type = "SQLInsert"
-
-[resolvers.createUser.resolver.command]
-table = "User"
-columns = []
-nested_modify_tables = []
-where_clauses = []
-aggregate_result = true
-
-[[resolvers.createUser.resolver.command.modify_values]]
-column = "username"
-value = "'$username'"
-
-[[resolvers.createUser.resolver.command.modify_values]]
-column = "name"
-value = "'$name'"
-
-[resolvers.deleteTask]
-operation_name = "deleteTask"
-
-[resolvers.deleteTask.resolver]
-command_type = "SQLDelete"
-
-[resolvers.deleteTask.resolver.command]
-table = "Task"
-columns = []
-modify_values = []
-nested_modify_tables = []
-aggregate_result = true
-
-[[resolvers.deleteTask.resolver.command.where_clauses]]
-table = "Task"
-column = "id"
-condition_str = "= '$id'"
-index = ""
-
 [resolvers.createTask]
 operation_name = "createTask"
 
-[resolvers.createTask.resolver]
+[resolvers.createTask.resolver.QueryBuilder]
 command_type = "SQLInsert"
 
-[resolvers.createTask.resolver.command]
+[resolvers.createTask.resolver.QueryBuilder.command]
 table = "Task"
+command_type = "SQLSelect"
 columns = []
 nested_modify_tables = []
 where_clauses = []
 aggregate_result = true
 
-[[resolvers.createTask.resolver.command.modify_values]]
+[[resolvers.createTask.resolver.QueryBuilder.command.modify_values]]
 column = "title"
 value = "'$title'"
 
-[[resolvers.createTask.resolver.command.modify_values]]
+[[resolvers.createTask.resolver.QueryBuilder.command.modify_values]]
 column = "description"
 value = "'$description'"
 
-[[resolvers.createTask.resolver.command.modify_values]]
+[[resolvers.createTask.resolver.QueryBuilder.command.modify_values]]
 column = "completed"
 value = "'$completed'"
 
-[[resolvers.createTask.resolver.command.modify_values]]
+[[resolvers.createTask.resolver.QueryBuilder.command.modify_values]]
 column = "list_id"
 value = "'$list.$id'"
 
-[[resolvers.createTask.resolver.command.modify_values]]
+[[resolvers.createTask.resolver.QueryBuilder.command.modify_values]]
 column = "user_username"
 value = "'$user.$username'"
 
 [resolvers.deleteList]
 operation_name = "deleteList"
 
-[resolvers.deleteList.resolver]
+[resolvers.deleteList.resolver.QueryBuilder]
 command_type = "SQLDelete"
 
-[resolvers.deleteList.resolver.command]
+[resolvers.deleteList.resolver.QueryBuilder.command]
 table = "List"
+command_type = "SQLSelect"
 columns = []
 modify_values = []
 nested_modify_tables = []
 aggregate_result = true
 
-[[resolvers.deleteList.resolver.command.where_clauses]]
+[[resolvers.deleteList.resolver.QueryBuilder.command.where_clauses]]
 table = "List"
 column = "id"
 condition_str = "= '$id'"
 index = ""
 
+[resolvers._bb_user_User]
+operation_name = "_bb_user_User"
+
+[resolvers._bb_user_User.resolver.InternalQueryBuilder]
+command_type = "SQLSelect"
+
+[resolvers._bb_user_User.resolver.InternalQueryBuilder.command]
+table = "User"
+command_type = "SQLSelect"
+modify_values = []
+nested_modify_tables = []
+aggregate_result = true
+
+[[resolvers._bb_user_User.resolver.InternalQueryBuilder.command.columns]]
+
+[resolvers._bb_user_User.resolver.InternalQueryBuilder.command.columns.Column]
+table = "User"
+column = "username"
+
+[[resolvers._bb_user_User.resolver.InternalQueryBuilder.command.where_clauses]]
+table = "User"
+column = ".ownerId"
+condition_str = "= $1"
+index = ""
+
+[resolvers.getUser]
+operation_name = "getUser"
+
+[resolvers.getUser.resolver.QueryBuilder]
+command_type = "SQLSelect"
+
+[resolvers.getUser.resolver.QueryBuilder.command]
+table = "User"
+command_type = "SQLSelect"
+columns = []
+modify_values = []
+nested_modify_tables = []
+aggregate_result = true
+
+[[resolvers.getUser.resolver.QueryBuilder.command.where_clauses]]
+table = "User"
+column = "username"
+condition_str = "= '$username'"
+index = ""
+
 [resolvers.updateTask]
 operation_name = "updateTask"
 
-[resolvers.updateTask.resolver]
+[resolvers.updateTask.resolver.QueryBuilder]
 command_type = "SQLUpdate"
 
-[resolvers.updateTask.resolver.command]
+[resolvers.updateTask.resolver.QueryBuilder.command]
 table = "Task"
+command_type = "SQLSelect"
 columns = []
 nested_modify_tables = []
 aggregate_result = true
 
-[[resolvers.updateTask.resolver.command.modify_values]]
+[[resolvers.updateTask.resolver.QueryBuilder.command.modify_values]]
 column = "title"
 value = "'$title'"
 
-[[resolvers.updateTask.resolver.command.modify_values]]
+[[resolvers.updateTask.resolver.QueryBuilder.command.modify_values]]
 column = "description"
 value = "'$description'"
 
-[[resolvers.updateTask.resolver.command.modify_values]]
+[[resolvers.updateTask.resolver.QueryBuilder.command.modify_values]]
 column = "completed"
 value = "'$completed'"
 
-[[resolvers.updateTask.resolver.command.modify_values]]
+[[resolvers.updateTask.resolver.QueryBuilder.command.modify_values]]
 column = "list_id"
 value = "'$list.$id'"
 
-[[resolvers.updateTask.resolver.command.where_clauses]]
+[[resolvers.updateTask.resolver.QueryBuilder.command.where_clauses]]
 table = "Task"
 column = "id"
 condition_str = "= '$id'"
 index = ""
+
+[resolvers.createUser]
+operation_name = "createUser"
+
+[resolvers.createUser.resolver.QueryBuilder]
+command_type = "SQLInsert"
+
+[resolvers.createUser.resolver.QueryBuilder.command]
+table = "User"
+command_type = "SQLSelect"
+columns = []
+nested_modify_tables = []
+where_clauses = []
+aggregate_result = true
+
+[[resolvers.createUser.resolver.QueryBuilder.command.modify_values]]
+column = "username"
+value = "'$username'"
+
+[[resolvers.createUser.resolver.QueryBuilder.command.modify_values]]
+column = "name"
+value = "'$name'"
+
+[resolvers.updateList]
+operation_name = "updateList"
+
+[resolvers.updateList.resolver.QueryBuilder]
+command_type = "SQLUpdate"
+
+[resolvers.updateList.resolver.QueryBuilder.command]
+table = "List"
+command_type = "SQLSelect"
+columns = []
+nested_modify_tables = []
+aggregate_result = true
+
+[[resolvers.updateList.resolver.QueryBuilder.command.modify_values]]
+column = "title"
+value = "'$title'"
+
+[[resolvers.updateList.resolver.QueryBuilder.command.where_clauses]]
+table = "List"
+column = "id"
+condition_str = "= '$id'"
+index = ""
diff --git a/bbconf/bb_todo-typemap.json b/bbconf/bb_todo-typemap.json
index 04bad23..532a667 100644
--- a/bbconf/bb_todo-typemap.json
+++ b/bbconf/bb_todo-typemap.json
@@ -88,7 +88,7 @@
         "gql_field": "user",
         "gql_type": "User",
         "sql_join_type": {
-          "OneToMany": {
+          "ManyToOne": {
             "sql_table_of_object": "List",
             "sql_table_of_field": "User",
             "sql_mapped_columns": [
@@ -107,7 +107,7 @@
         "gql_field": "lists",
         "gql_type": "List",
         "sql_join_type": {
-          "ManyToOne": {
+          "OneToMany": {
             "sql_table_of_object": "User",
             "sql_table_of_field": "List",
             "sql_mapped_columns": [
@@ -126,7 +126,7 @@
         "gql_field": "user",
         "gql_type": "User",
         "sql_join_type": {
-          "OneToMany": {
+          "ManyToOne": {
             "sql_table_of_object": "Task",
             "sql_table_of_field": "User",
             "sql_mapped_columns": [
@@ -145,7 +145,7 @@
         "gql_field": "tasks",
         "gql_type": "Task",
         "sql_join_type": {
-          "ManyToOne": {
+          "OneToMany": {
             "sql_table_of_object": "User",
             "sql_table_of_field": "Task",
             "sql_mapped_columns": [
@@ -164,7 +164,7 @@
         "gql_field": "list",
         "gql_type": "List",
         "sql_join_type": {
-          "OneToMany": {
+          "ManyToOne": {
             "sql_table_of_object": "Task",
             "sql_table_of_field": "List",
             "sql_mapped_columns": [
@@ -183,7 +183,7 @@
         "gql_field": "tasks",
         "gql_type": "Task",
         "sql_join_type": {
-          "ManyToOne": {
+          "OneToMany": {
             "sql_table_of_object": "List",
             "sql_table_of_field": "Task",
             "sql_mapped_columns": [
diff --git a/bbconf/todo_schema.graphql b/bbconf/todo_schema.graphql
index 71b7223..6de1263 100644
--- a/bbconf/todo_schema.graphql
+++ b/bbconf/todo_schema.graphql
@@ -1,17 +1,26 @@
 directive @bb_primaryKey on FIELD_DEFINITION
 directive @bb_resolver on FIELD_DEFINITION
+directive @bb_owned on OBJECT
+directive @bb_user on OBJECT
 
-type List {
+"""
+List of tasks or todo items.
+"""
+type List @bb_owned {
   id: ID!
   title: String!
   tasks: [Task]
   user: User!
 }
 
+input ListInput {
+  id: ID!
+}
+
 """
 Task or todo item.
 """
-type Task {
+type Task @bb_owned {
   id: ID!
   title: String!
   description: String,
@@ -23,13 +32,17 @@ type Task {
 """
 User type; owner of lists and tasks
 """
-type User {
+type User @bb_user {
   username: String! @bb_primaryKey
   name: String
   tasks: [Task]
   lists: [List]
 }
 
+input UserInput {
+  username: String!
+  name: String
+}
 
 type Query {
 
@@ -38,7 +51,11 @@ type Query {
   """
   getUser(
     username: String!
-  ): User @bb_resolver(_type: SELECT, _object: User, _filter: { username: { _eq: "$username" } })
+  ): User 
+    @bb_resolver(
+      _type: SELECT, 
+      _object: User, 
+      _filter: { username: { _eq: "$username" } })
 
 }
 
@@ -47,36 +64,76 @@ type Mutation {
   createUser(
     username: String!,
     name: String!
-  ): User  @bb_resolver(_type: INSERT, _object: User, _fields: { username: "$username", name: "$name" })
+  ): User  
+    @bb_resolver(
+      _type: INSERT, 
+      _object: User, 
+      _fields: { username: "$username", name: "$name" })
 
   createList(
     title: String!
-    user: User! # username needs to be specified as it's non-nullable
-  ): List @bb_resolver(_type: INSERT, _object: List, _fields: { title: "$title", user: "$user" })
+    user: UserInput! 
+  ): List 
+    @bb_resolver(
+      _type: INSERT, 
+      _object: List, 
+      _fields: { 
+        title: "$title", 
+        user: { username: "$user.$username" } 
+      })
 
   updateList(
     id: ID!,
     title: String!
-  ): List @bb_resolver(_type: UPDATE, _object: List, _filter: { id: { _eq: "$id" } },  _fields: { title: "$title" })
+  ): List 
+    @bb_resolver(
+      _type: UPDATE, 
+      _object: List, 
+      _filter: { id: { _eq: "$id" } },  
+      _fields: { title: "$title" })
 
-  deleteList(id: ID!): List @bb_resolver(_type: DELETE, _object: List, _filter: { id: { _eq: "$id" } })
+  deleteList(id: ID!): List 
+    @bb_resolver(_type: DELETE, _object: List, _filter: { id: { _eq: "$id" } })
 
   createTask(
     title: String!,
     description: String,
-    completed: Boolean!, # default not implemented yet, this needs to be added as it's non-nullable
-    list: List! # list needs to be specified as it's non-nullable
-    user: User! # username needs to be specified as it's non-nullable
-  ): Task @bb_resolver(_type: INSERT, _object: Task, _fields: { title: "$title", description: "$description", completed: "$completed", list: "$list", user: "$user" })
+    completed: Boolean!, 
+    list: ListInput! 
+    user: UserInput! 
+  ): Task 
+    @bb_resolver(
+      _type: INSERT, 
+      _object: Task, 
+      _fields: { 
+        title: "$title", 
+        description: "$description", 
+        completed: "$completed", 
+        list: { id: "$list.$id" }, 
+        user: { username: "$user.$username" } })
 
   updateTask(
     id: ID!,
     title: String,
     description: String,
     completed: Boolean,
-    list: List
-  ): Task @bb_resolver(_type: UPDATE, _object: Task, _filter: { id: { _eq: "$id" } }, _fields: { title: "$title", description: "$description", completed: "$completed", list: "$list" })
+    list: ListInput
+  ): Task 
+    @bb_resolver(
+      _type: UPDATE, 
+      _object: Task, 
+      _filter: { id: { _eq: "$id" } }, 
+      _fields: { 
+        title: "$title", 
+        description: "$description", 
+        completed: "$completed", 
+        list: { id: "$list.$id" }
+      })
 
-  deleteTask(id: ID!): Task @bb_resolver(_type: DELETE, _object: Task, _filter: { id: { _eq: "$id" } })
+  deleteTask(id: ID!): Task 
+    @bb_resolver(
+      _type: DELETE, 
+      _object: Task, 
+      _filter: { id: { _eq: "$id" }})
 
 }