diff --git a/src/interface.cairo b/src/interface.cairo
index bbaf205..aa895f8 100644
--- a/src/interface.cairo
+++ b/src/interface.cairo
@@ -33,4 +33,5 @@ pub trait IPushComm<TContractState> {
     fn unsubscribe(ref self: TContractState, channel: ContractAddress);
     fn batch_subscribe(ref self: TContractState, channels: Array<ContractAddress>);
     fn batch_unsubscribe(ref self: TContractState, channels: Array<ContractAddress>);
+    fn chain_id(self: @TContractState) -> felt252;
 }
diff --git a/src/lib.cairo b/src/lib.cairo
index 4353415..6b3d06b 100644
--- a/src/lib.cairo
+++ b/src/lib.cairo
@@ -65,10 +65,9 @@ pub mod PushComm {
 
     #[starknet::storage_node]
     pub struct User {
-        is_activated: bool,
-        // TODO: optimized packing
-        start_block: u64,
         subscribed_count: u256,
+        start_block: u64,
+        is_activated: bool,
         is_subscribed: Map<ContractAddress, bool>,
         subscribed: Map<ContractAddress, u256>,
         map_address_subscribed: Map<u256, ContractAddress>,
@@ -313,7 +312,9 @@ pub mod PushComm {
             notif_settings: ByteArray
         ) {
             let caller_address = get_caller_address();
-            assert!(self._is_user_subscribed(channel, caller_address), "User not subscribed to channel");
+            assert!(
+                self._is_user_subscribed(channel, caller_address), "User not subscribed to channel"
+            );
 
             let modified_notif_settings = format!("@{}+@{}", notif_id, notif_settings);
             self
@@ -350,7 +351,6 @@ pub mod PushComm {
                     ChannelAlias {
                         chain_name: self.chain_name.read(),
                         chain_id: self.chain_id.read(),
-                        // chain_id: 1, //self.chain_id.read(),
                         channel_owner_address: get_caller_address(),
                         ethereum_channel_address: channel_address
                     }
@@ -399,5 +399,9 @@ pub mod PushComm {
         fn get_push_token_address(self: @ContractState) -> ContractAddress {
             self.push_token_address.read()
         }
+
+        fn chain_id(self: @ContractState) -> felt252 {
+            self.chain_id.read()
+        }
     }
 }
diff --git a/tests/test_channel_alias.cairo b/tests/test_channel_alias.cairo
index 1824f5d..06d1873 100644
--- a/tests/test_channel_alias.cairo
+++ b/tests/test_channel_alias.cairo
@@ -14,6 +14,7 @@ fn test_verify_channel_alias() {
     let contract_address = deploy_contract();
     let push_comm = IPushCommDispatcher { contract_address };
     let channel_address: EthAddress = 'some address'.try_into().unwrap();
+    let chain_id: felt252 = 'SN_SEPOLIA'.try_into().unwrap();
 
     let mut spy = spy_events();
 
@@ -29,7 +30,7 @@ fn test_verify_channel_alias() {
                     PushComm::Event::ChannelAlias(
                         PushComm::ChannelAlias {
                             chain_name: CHAIN_NAME(),
-                            chain_id: 1,
+                            chain_id: chain_id,
                             channel_owner_address: USER_1(),
                             ethereum_channel_address: channel_address
                         }
diff --git a/tests/test_channel_settings.cairo b/tests/test_channel_settings.cairo
index 38564ea..fdda0d6 100644
--- a/tests/test_channel_settings.cairo
+++ b/tests/test_channel_settings.cairo
@@ -41,7 +41,7 @@ fn test_channel_channel_user_settings() {
 }
 
 #[test]
-#[should_panic(expected:"User not subscribed to channel")]
+#[should_panic(expected: "User not subscribed to channel")]
 fn test_channel_channel_unsubscribed_user_settings() {
     let contract_address = deploy_contract();
     let push_comm = IPushCommDispatcher { contract_address };
@@ -52,4 +52,4 @@ fn test_channel_channel_unsubscribed_user_settings() {
     let notif_id = 1;
     let notif_settings: ByteArray = "notif_settings";
     push_comm.change_user_channel_settings(CHANNEL_ADDRESS, notif_id, notif_settings.clone());
-}
\ No newline at end of file
+}