diff --git a/lazy-supplements-core/src/data/entity/mod.rs b/lazy-supplements-core/src/data/entity/mod.rs
index 5e38d96..c515558 100644
--- a/lazy-supplements-core/src/data/entity/mod.rs
+++ b/lazy-supplements-core/src/data/entity/mod.rs
@@ -1,11 +1,11 @@
-mod node;
+mod trusted_peer;
 mod record_deletion;
 
-pub use node::{
-    ActiveModel as NodeActiveModel,
-    Column as NodeColumn,
-    Entity as NodeEntity,
-    Model as NodeModel,
+pub use trusted_peer::{
+    ActiveModel as TrustedPeerActiveModel,
+    Column as TrustedPeerColumn,
+    Entity as TrustedPeerEntity,
+    Model as TrustedPeerModel,
 };
 
 pub use record_deletion::{
diff --git a/lazy-supplements-core/src/data/entity/node.rs b/lazy-supplements-core/src/data/entity/trusted_peer.rs
similarity index 85%
rename from lazy-supplements-core/src/data/entity/node.rs
rename to lazy-supplements-core/src/data/entity/trusted_peer.rs
index d932c8e..51647a6 100644
--- a/lazy-supplements-core/src/data/entity/node.rs
+++ b/lazy-supplements-core/src/data/entity/trusted_peer.rs
@@ -5,9 +5,11 @@ use sea_orm::entity::{
 };
 use serde::{Deserialize, Serialize};
 
+use crate::data::value::PeerIdValue;
+
 
 #[derive(Clone, Debug, PartialEq, DeriveEntityModel, Serialize, Deserialize)]
-#[sea_orm(table_name = "node")]
+#[sea_orm(table_name = "trusted_peer")]
 pub struct Model {
     #[sea_orm(primary_key, auto_increment = false)]
     pub id: Uuid,
@@ -18,9 +20,10 @@ pub struct Model {
     #[sea_orm(indexed)]
     pub synced_at: Option<DateTimeUtc>,
     #[sea_orm(indexed)]
-    pub peer_id: String,
+    pub peer_id: PeerIdValue,
     #[sea_orm(column_type = "Text")]
     pub note: String,
+    pub is_prefered: bool,
 }
 
 #[derive(Copy, Clone, Debug, DeriveRelation, EnumIter)]
@@ -46,14 +49,14 @@ mod tests {
 
     use super::*;
 
-    use libp2p::identity;
+    use libp2p::{identity, PeerId};
 
      #[tokio::test]
     async fn check_insert_node() {
         let db = get_or_init_test_data_database().await;
         
         ActiveModel{
-            peer_id: Set(identity::Keypair::generate_ed25519().public().to_peer_id().to_string()),
+            peer_id: Set(PeerIdValue::from(PeerId::random())),
             note: Set("test note".to_owned()),
             ..ActiveModel::new()
         }.insert(db).await.unwrap();
diff --git a/lazy-supplements-core/src/data/migration/m20220101_000001_create_main_tables.rs b/lazy-supplements-core/src/data/migration/m20220101_000001_create_main_tables.rs
index c69bfbe..9fa0be0 100644
--- a/lazy-supplements-core/src/data/migration/m20220101_000001_create_main_tables.rs
+++ b/lazy-supplements-core/src/data/migration/m20220101_000001_create_main_tables.rs
@@ -8,20 +8,20 @@ pub struct Migration;
 #[async_trait::async_trait]
 impl MigrationTrait for Migration {
     async fn up(&self, manager: &SchemaManager) -> Result<(), DbErr> {
-        Node::up(manager).await?;
+        TrustedPeer::up(manager).await?;
         RecordDeletion::up(manager).await?;
         Ok(())
     }
 
     async fn down(&self, manager: &SchemaManager) -> Result<(), DbErr> {
-        Node::down(manager).await?;
+        TrustedPeer::down(manager).await?;
         RecordDeletion::down(manager).await?;
         Ok(())
     }
 }
 
 #[derive(DeriveIden)]
-enum Node {
+enum TrustedPeer {
     Table,
     Id,
     CreatedAt,
@@ -29,10 +29,11 @@ enum Node {
     SyncedAt,
     PeerId,
     Note,
+    IsPrefered,
 }
 
 #[async_trait::async_trait]
-impl TableMigration for Node {
+impl TableMigration for TrustedPeer {
     async fn up<'a>(manager: &'a SchemaManager<'a>) -> Result<(), DbErr> {
         manager.create_table(
             Table::create()
@@ -44,6 +45,7 @@ impl TableMigration for Node {
                 .col(timestamp_null(Self::SyncedAt))
                 .col(string_len(Self::PeerId, 255))
                 .col(text(Self::Note))
+                .col(boolean(Self::IsPrefered))
                 .to_owned()
         ).await?;
         Ok(())
diff --git a/lazy-supplements-core/src/data/mod.rs b/lazy-supplements-core/src/data/mod.rs
index 25d0085..c1779c9 100644
--- a/lazy-supplements-core/src/data/mod.rs
+++ b/lazy-supplements-core/src/data/mod.rs
@@ -1,3 +1,4 @@
 pub mod entity;
 pub mod migration;
-pub mod value;
\ No newline at end of file
+pub mod syncable;
+pub mod value;
diff --git a/lazy-supplements-core/src/data/syncable.rs b/lazy-supplements-core/src/data/syncable.rs
new file mode 100644
index 0000000..2e0a784
--- /dev/null
+++ b/lazy-supplements-core/src/data/syncable.rs
@@ -0,0 +1,64 @@
+use sea_orm::{*, prelude::*, query::*};
+
+pub trait SyncableModel: ModelTrait<Entity = Self::SyncableEntity> {
+    type SyncableEntity: SyncableEntity<SyncableModel = Self>;
+    fn get_updated_at(&self) -> DateTimeUtc;
+    fn get_uuid(&self) -> Uuid;
+}
+
+pub trait SyncableEntity: EntityTrait<
+    Model = Self::SyncableModel,
+    ActiveModel = Self::SyncableActiveModel,
+    Column = Self::SyncableColumn,
+>{
+    type SyncableModel: SyncableModel<SyncableEntity = Self> + FromQueryResult;
+    type SyncableActiveModel: SyncableActiveModel<SyncableEntity= Self>;
+    type SyncableColumn: SyncableColumn;
+
+    async fn get_updated_after(date: DateTimeUtc, db: &DatabaseConnection) -> Result<Vec<<Self as EntityTrait>::Model>, SyncableError> {
+        let result: Vec<Self::SyncableModel> = <Self as EntityTrait>::find()
+            .filter(Self::SyncableColumn::updated_at().gte(date))
+            .all(db)
+            .await.unwrap();
+        Ok(result)
+    }
+    fn apply_updated(models: Vec<<Self as EntityTrait>::Model>, db: &DatabaseConnection) {
+        todo!()
+    }
+}
+
+pub trait SyncableActiveModel: ActiveModelTrait<Entity = Self::SyncableEntity> {
+    
+    type SyncableEntity: SyncableEntity<SyncableActiveModel = Self>;
+    fn get_uuid(&self) -> Option<Uuid>;
+    fn get_updated_at(&self) -> Option<DateTimeUtc>;
+    fn try_merge(&mut self, other: <Self::SyncableEntity as SyncableEntity>::SyncableModel) -> Result<(), SyncableError> {
+        if self.get_uuid().ok_or(SyncableError::MissingField("uuid"))? != other.get_uuid() {
+            return Err(SyncableError::MismatchUuid)
+        }
+        if self.get_updated_at().ok_or(SyncableError::MissingField("updated_at"))? < other.get_updated_at() {
+            for column in <<<Self as ActiveModelTrait>::Entity as EntityTrait>::Column as Iterable>::iter() {
+                self.take(column).set_if_not_equals(other.get(column));
+            }
+        }
+        Ok(())
+    }
+
+}
+
+pub trait SyncableColumn: ColumnTrait {
+    fn is_uuid(&self) -> bool;
+    fn is_updated_at(&self) -> bool;
+    fn updated_at() -> Self;
+    fn should_not_sync(&self);
+}
+
+
+#[derive(Debug, thiserror::Error)]
+pub enum SyncableError {
+    #[error("Invalid UUID")]
+    MismatchUuid,
+    #[error("mandatory field {0} is missing")]
+    MissingField(&'static str),
+    
+}
\ No newline at end of file
diff --git a/lazy-supplements-core/src/data/value/peer_id.rs b/lazy-supplements-core/src/data/value/peer_id.rs
index e28b5d4..b6558ca 100644
--- a/lazy-supplements-core/src/data/value/peer_id.rs
+++ b/lazy-supplements-core/src/data/value/peer_id.rs
@@ -4,9 +4,42 @@ use libp2p::PeerId;
 use sea_orm::{sea_query::ValueTypeErr, DbErr};
 use serde::{Deserialize, Serialize};
 
+use crate::error::Error;
+
 #[derive(Clone, Debug, PartialEq)]
 pub struct PeerIdValue(PeerId);
 
+impl<'de> Deserialize<'de> for PeerIdValue {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+        where
+            D: serde::Deserializer<'de> {
+        Self::from_str(&String::deserialize(deserializer)?).or(Err(<D::Error as serde::de::Error>::custom("fail to parse PeerId")))
+    
+    }
+}
+
+impl Serialize for PeerIdValue {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer {
+        serializer.serialize_str(&self.0.to_string())
+    }
+}
+
+impl FromStr for PeerIdValue{
+    type Err = libp2p::identity::ParseError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        Ok(Self(PeerId::from_str(s)?))
+    }
+}
+
+impl ToString for PeerIdValue {
+    fn to_string(&self) -> String {
+        self.0.to_string()
+    }
+}
+
 impl From<PeerId> for PeerIdValue {
     fn from(source: PeerId) -> Self {
         Self(source)
@@ -65,4 +98,23 @@ impl sea_orm::sea_query::Nullable for PeerIdValue {
     fn null() -> sea_orm::Value {
         <String as sea_orm::sea_query::Nullable>::null()
     }
-}
\ No newline at end of file
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::tests::{test_cbor_serialize_deserialize, test_toml_serialize_deserialize};
+
+    use super::*;
+
+    #[derive(Debug, Clone, Deserialize, Serialize, PartialEq)]
+    struct PeerIdValueWrapper {
+        content: PeerIdValue
+
+    }
+    #[test]
+    fn test_serialize_deserialize() {
+        let peer_id= PeerIdValueWrapper{content: PeerIdValue::from(PeerId::random())};
+        let x = toml::to_string(&peer_id).unwrap();
+        assert_eq!(peer_id.content, toml::from_str::<PeerIdValueWrapper>(&x).unwrap().content)
+    }
+}