diff --git a/src/storage/garage.rs b/src/storage/garage.rs
index b883623..965953e 100644
--- a/src/storage/garage.rs
+++ b/src/storage/garage.rs
@@ -5,27 +5,19 @@ pub struct GrgStore {}
 pub struct GrgRef {}
 pub struct GrgValue {}
 
-pub struct GrgTypes {}
-impl Sto for GrgTypes {
-    type Builder=GrgCreds;
-    type Store=GrgStore;
-    type Ref=GrgRef;
-    type Value=GrgValue;
-}
-
-impl RowBuilder<GrgTypes> for GrgCreds {
+impl IRowBuilder for GrgCreds {
     fn row_store(&self) -> GrgStore {
         unimplemented!();
     }
 }
 
-impl RowStore<GrgTypes> for GrgStore {
+impl IRowStore for GrgStore {
     fn new_row(&self, partition: &str, sort: &str) -> GrgRef {
         unimplemented!();
     }
 }
 
-impl RowRef<GrgTypes> for GrgRef {
+impl IRowRef for GrgRef {
     fn set_value(&self, content: Vec<u8>) -> GrgValue {
         unimplemented!();
     }
@@ -40,7 +32,7 @@ impl RowRef<GrgTypes> for GrgRef {
     }
 }
 
-impl RowValue<GrgTypes> for GrgValue {
+impl IRowValue for GrgValue {
     fn to_ref(&self) -> GrgRef {
         unimplemented!();
     }
diff --git a/src/storage/in_memory.rs b/src/storage/in_memory.rs
index 56df266..dc3d1e1 100644
--- a/src/storage/in_memory.rs
+++ b/src/storage/in_memory.rs
@@ -5,27 +5,19 @@ pub struct MemStore {}
 pub struct MemRef {}
 pub struct MemValue {}
 
-pub struct MemTypes {}
-impl Sto for MemTypes {
-    type Builder=MemCreds;
-    type Store=MemStore;
-    type Ref=MemRef;
-    type Value=MemValue;
-}
-
-impl RowBuilder<MemTypes> for MemCreds {
+impl IRowBuilder for MemCreds {
     fn row_store(&self) -> MemStore {
         unimplemented!();
     }
 }
 
-impl RowStore<MemTypes> for MemStore {
+impl IRowStore for MemStore {
     fn new_row(&self, partition: &str, sort: &str) -> MemRef {
         unimplemented!();
     }
 }
 
-impl RowRef<MemTypes> for MemRef {
+impl IRowRef for MemRef {
     fn set_value(&self, content: Vec<u8>) -> MemValue {
         unimplemented!();
     }
@@ -40,7 +32,7 @@ impl RowRef<MemTypes> for MemRef {
     }
 }
 
-impl RowValue<MemTypes> for MemValue {
+impl IRowValue for MemValue {
     fn to_ref(&self) -> MemRef {
         unimplemented!();
     }
diff --git a/src/storage/mod.rs b/src/storage/mod.rs
index ee475ee..82f7c6a 100644
--- a/src/storage/mod.rs
+++ b/src/storage/mod.rs
@@ -28,55 +28,39 @@ pub enum Error {
     Internal,
 }
 
-pub trait Sto: Sized {
-    type Builder: RowBuilder<Self>;
-    type Store: RowStore<Self>;
-    type Ref: RowRef<Self>;
-    type Value: RowValue<Self>;
-}
-
-pub struct Engine<T: Sto> {
+pub struct Engine {
     pub bucket: String,
-    pub row: T::Builder,
-}
-
-pub enum AnyEngine {
-    InMemory(Engine<in_memory::MemTypes>),
-    Garage(Engine<garage::GrgTypes>),
-}
-impl AnyEngine {
-    pub fn engine<X: Sto>(&self) -> &Engine<X> {
-        match self {
-            Self::InMemory(x) => x,
-            Self::Garage(x) => x,
-        }
-    }
+    pub row: RowBuilder,
 }
 
 // ------ Row Builder
-pub trait RowBuilder<R: Sto> 
+pub trait IRowBuilder
 {
-    fn row_store(&self) -> R::Store;
+    fn row_store(&self) -> RowStore;
 }
+pub type RowBuilder = Box<dyn IRowBuilder>;
 
 // ------ Row Store
-pub trait RowStore<R: Sto> 
+pub trait IRowStore
 {
-    fn new_row(&self, partition: &str, sort: &str) -> R::Ref;
+    fn new_row(&self, partition: &str, sort: &str) -> RowRef;
 }
+type RowStore = Box<dyn IRowStore>;
 
 // ------- Row Item
-pub trait RowRef<R: Sto> 
+pub trait IRowRef 
 {
-    fn set_value(&self, content: Vec<u8>) -> R::Value;
-    async fn fetch(&self) -> Result<R::Value, Error>;
+    fn set_value(&self, content: Vec<u8>) -> RowValue;
+    async fn fetch(&self) -> Result<RowValue, Error>;
     async fn rm(&self) -> Result<(), Error>;
-    async fn poll(&self) -> Result<Option<R::Value>, Error>;
+    async fn poll(&self) -> Result<Option<RowValue>, Error>;
 }
+type RowRef = Box<dyn IRowRef>;
 
-pub trait RowValue<R: Sto> 
+pub trait IRowValue
 {
-    fn to_ref(&self) -> R::Ref;
+    fn to_ref(&self) -> RowRef;
     fn content(&self) -> ConcurrentValues;
     async fn push(&self) -> Result<(), Error>;
 }
+type RowValue = Box<dyn IRowValue>;