diff --git a/examples/program_deployment/src/bin/run_hello_world_with_authorization.rs b/examples/program_deployment/src/bin/run_hello_world_with_authorization.rs
index 39e1380f..a9750bce 100644
--- a/examples/program_deployment/src/bin/run_hello_world_with_authorization.rs
+++ b/examples/program_deployment/src/bin/run_hello_world_with_authorization.rs
@@ -4,7 +4,6 @@ use nssa::{
     program::Program,
     public_transaction::{Message, WitnessSet},
 };
-use nssa_core::account::Nonce;
 use sequencer_service_rpc::RpcClient as _;
 use wallet::WalletCore;
 
@@ -65,13 +64,7 @@ async fn main() {
         .await
         .expect("Node should be reachable to query account data");
     let signing_keys = [signing_key];
-    let message = Message::try_new(
-        program.id(),
-        vec![account_id],
-        nonces.iter().map(|x| Nonce(*x)).collect(),
-        greeting,
-    )
-    .unwrap();
+    let message = Message::try_new(program.id(), vec![account_id], nonces, greeting).unwrap();
     // Pass the signing key to sign the message. This will be used by the node
     // to flag the pre_state as `is_authorized` when executing the program
     let witness_set = WitnessSet::for_message(&message, &signing_keys);
diff --git a/indexer/core/src/block_store.rs b/indexer/core/src/block_store.rs
index 384217ff..bf3516e3 100644
--- a/indexer/core/src/block_store.rs
+++ b/indexer/core/src/block_store.rs
@@ -176,7 +176,7 @@ mod tests {
         )
         .unwrap();
 
-        let block = storage.get_block_at_id(1).unwrap();
+        let block = storage.get_block_at_id(1).unwrap().unwrap();
         let final_id = storage.get_last_block_id().unwrap();
 
         assert_eq!(block.header.hash, genesis_block().header.hash);
diff --git a/indexer/service/src/lib.rs b/indexer/service/src/lib.rs
index 47f9289e..10f1cade 100644
--- a/indexer/service/src/lib.rs
+++ b/indexer/service/src/lib.rs
@@ -40,10 +40,10 @@ impl IndexerHandle {
     }
 
     #[must_use]
-    pub fn is_stopped(&self) -> bool {
+    pub fn is_healthy(&self) -> bool {
         self.server_handle
             .as_ref()
-            .is_none_or(ServerHandle::is_stopped)
+            .is_some_and(|handle| !handle.is_stopped())
     }
 }
 
diff --git a/integration_tests/src/lib.rs b/integration_tests/src/lib.rs
index 2128a482..08e7cf9f 100644
--- a/integration_tests/src/lib.rs
+++ b/integration_tests/src/lib.rs
@@ -338,17 +338,17 @@ impl Drop for TestContext {
         let sequencer_handle = sequencer_handle
             .take()
             .expect("Sequencer handle should be present in TestContext drop");
-        if sequencer_handle.is_stopped() {
+        if !sequencer_handle.is_healthy() {
             let Err(err) = sequencer_handle
-                .stopped()
+                .failed()
                 .now_or_never()
-                .expect("Sequencer handle should be stopped");
+                .expect("Sequencer handle should not be running");
             error!(
                 "Sequencer handle has unexpectedly stopped before TestContext drop with error: {err:#}"
             );
         }
 
-        if indexer_handle.is_stopped() {
+        if !indexer_handle.is_healthy() {
             error!("Indexer handle has unexpectedly stopped before TestContext drop");
         }
 
diff --git a/key_protocol/src/key_protocol_core/mod.rs b/key_protocol/src/key_protocol_core/mod.rs
index cb21748c..8232d9f4 100644
--- a/key_protocol/src/key_protocol_core/mod.rs
+++ b/key_protocol/src/key_protocol_core/mod.rs
@@ -66,13 +66,13 @@ impl NSSAUserData {
     ) -> Result<Self> {
         if !Self::valid_public_key_transaction_pairing_check(&default_accounts_keys) {
             anyhow::bail!(
-                "Key transaction pairing check not satisfied, there are public account_ids, which is not derived from keys"
+                "Key transaction pairing check not satisfied, there are public account_ids, which are not derived from keys"
             );
         }
 
         if !Self::valid_private_key_transaction_pairing_check(&default_accounts_key_chains) {
             anyhow::bail!(
-                "Key transaction pairing check not satisfied, there are private account_ids, which is not derived from keys"
+                "Key transaction pairing check not satisfied, there are private account_ids, which are not derived from keys"
             );
         }
 
diff --git a/sequencer/service/src/lib.rs b/sequencer/service/src/lib.rs
index bc9a4ef5..5373b31f 100644
--- a/sequencer/service/src/lib.rs
+++ b/sequencer/service/src/lib.rs
@@ -50,12 +50,12 @@ impl SequencerHandle {
         }
     }
 
-    /// Wait for all Sequencer tasks to stop.
+    /// Wait for any of the sequencer tasks to fail and return the error.
     #[expect(
         clippy::integer_division_remainder_used,
         reason = "Generated by select! macro, can't be easily rewritten to avoid this lint"
     )]
-    pub async fn stopped(mut self) -> Result<Never> {
+    pub async fn failed(mut self) -> Result<Never> {
         let Self {
             addr: _,
             server_handle,
@@ -88,8 +88,12 @@ impl SequencerHandle {
         }
     }
 
+    /// Check if all Sequencer tasks are still running.
+    ///
+    /// Return `false` if any of the tasks has failed and `true` otherwise.
+    /// Error of the failed task can be retrieved by awaiting on [`Self::failed()`].
     #[must_use]
-    pub fn is_stopped(&self) -> bool {
+    pub fn is_healthy(&self) -> bool {
         let Self {
             addr: _,
             server_handle,
@@ -98,10 +102,11 @@ impl SequencerHandle {
             listen_for_bedrock_blocks_loop_handle,
         } = self;
 
-        server_handle.as_ref().is_none_or(ServerHandle::is_stopped)
+        let stopped = server_handle.as_ref().is_none_or(ServerHandle::is_stopped)
             || main_loop_handle.is_finished()
             || retry_pending_blocks_loop_handle.is_finished()
-            || listen_for_bedrock_blocks_loop_handle.is_finished()
+            || listen_for_bedrock_blocks_loop_handle.is_finished();
+        !stopped
     }
 
     #[must_use]
diff --git a/sequencer/service/src/main.rs b/sequencer/service/src/main.rs
index 326ded70..e78ad502 100644
--- a/sequencer/service/src/main.rs
+++ b/sequencer/service/src/main.rs
@@ -33,8 +33,8 @@ async fn main() -> Result<()> {
         () = cancellation_token.cancelled() => {
             info!("Shutting down sequencer...");
         }
-        Err(err) = sequencer_handle.stopped() => {
-            error!("Sequencer stopped unexpectedly: {err}");
+        Err(err) = sequencer_handle.failed() => {
+            error!("Sequencer failed unexpectedly: {err}");
         }
     }
 
diff --git a/wallet/src/lib.rs b/wallet/src/lib.rs
index 86e27784..bf82a1bd 100644
--- a/wallet/src/lib.rs
+++ b/wallet/src/lib.rs
@@ -22,7 +22,9 @@ use nssa::{
         circuit::ProgramWithDependencies, message::EncryptedAccountData,
     },
 };
-use nssa_core::{Commitment, MembershipProof, SharedSecretKey, program::InstructionData};
+use nssa_core::{
+    Commitment, MembershipProof, SharedSecretKey, account::Nonce, program::InstructionData,
+};
 pub use privacy_preserving_tx::PrivacyPreservingAccount;
 use sequencer_service_rpc::{RpcClient as _, SequencerClient, SequencerClientBuilder};
 use tokio::io::AsyncWriteExt as _;
@@ -253,7 +255,7 @@ impl WalletCore {
     }
 
     /// Get accounts nonces.
-    pub async fn get_accounts_nonces(&self, accs: Vec<AccountId>) -> Result<Vec<u128>> {
+    pub async fn get_accounts_nonces(&self, accs: Vec<AccountId>) -> Result<Vec<Nonce>> {
         Ok(self.sequencer_client.get_accounts_nonces(accs).await?)
     }
 
diff --git a/wallet/src/program_facades/amm.rs b/wallet/src/program_facades/amm.rs
index c430f29d..f1b94621 100644
--- a/wallet/src/program_facades/amm.rs
+++ b/wallet/src/program_facades/amm.rs
@@ -81,10 +81,7 @@ impl Amm<'_> {
         let message = nssa::public_transaction::Message::try_new(
             program.id(),
             account_ids,
-            nonces
-                .iter()
-                .map(|x| nssa_core::account::Nonce(*x))
-                .collect(),
+            nonces,
             instruction,
         )
         .unwrap();
@@ -195,10 +192,7 @@ impl Amm<'_> {
         let message = nssa::public_transaction::Message::try_new(
             program.id(),
             account_ids,
-            nonces
-                .iter()
-                .map(|x| nssa_core::account::Nonce(*x))
-                .collect(),
+            nonces,
             instruction,
         )
         .unwrap();
@@ -289,10 +283,7 @@ impl Amm<'_> {
         let message = nssa::public_transaction::Message::try_new(
             program.id(),
             account_ids,
-            nonces
-                .iter()
-                .map(|x| nssa_core::account::Nonce(*x))
-                .collect(),
+            nonces,
             instruction,
         )
         .unwrap();
@@ -378,10 +369,7 @@ impl Amm<'_> {
         let message = nssa::public_transaction::Message::try_new(
             program.id(),
             account_ids,
-            nonces
-                .iter()
-                .map(|x| nssa_core::account::Nonce(*x))
-                .collect(),
+            nonces,
             instruction,
         )
         .unwrap();
diff --git a/wallet/src/program_facades/native_token_transfer/public.rs b/wallet/src/program_facades/native_token_transfer/public.rs
index a54a215f..f91171db 100644
--- a/wallet/src/program_facades/native_token_transfer/public.rs
+++ b/wallet/src/program_facades/native_token_transfer/public.rs
@@ -31,16 +31,8 @@ impl NativeTokenTransfer<'_> {
 
             let account_ids = vec![from, to];
             let program_id = Program::authenticated_transfer_program().id();
-            let message = Message::try_new(
-                program_id,
-                account_ids,
-                nonces
-                    .iter()
-                    .map(|x| nssa_core::account::Nonce(*x))
-                    .collect(),
-                balance_to_move,
-            )
-            .unwrap();
+            let message =
+                Message::try_new(program_id, account_ids, nonces, balance_to_move).unwrap();
 
             let signing_key = self.0.storage.user_data.get_pub_account_signing_key(from);
 
@@ -75,16 +67,7 @@ impl NativeTokenTransfer<'_> {
         let instruction: u128 = 0;
         let account_ids = vec![from];
         let program_id = Program::authenticated_transfer_program().id();
-        let message = Message::try_new(
-            program_id,
-            account_ids,
-            nonces
-                .iter()
-                .map(|x| nssa_core::account::Nonce(*x))
-                .collect(),
-            instruction,
-        )
-        .unwrap();
+        let message = Message::try_new(program_id, account_ids, nonces, instruction).unwrap();
 
         let signing_key = self.0.storage.user_data.get_pub_account_signing_key(from);
 
diff --git a/wallet/src/program_facades/token.rs b/wallet/src/program_facades/token.rs
index ca36e723..3aa6891f 100644
--- a/wallet/src/program_facades/token.rs
+++ b/wallet/src/program_facades/token.rs
@@ -146,10 +146,7 @@ impl Token<'_> {
         let message = nssa::public_transaction::Message::try_new(
             program_id,
             account_ids,
-            nonces
-                .iter()
-                .map(|x| nssa_core::account::Nonce(*x))
-                .collect(),
+            nonces,
             instruction,
         )
         .unwrap();
@@ -354,10 +351,7 @@ impl Token<'_> {
         let message = nssa::public_transaction::Message::try_new(
             Program::token().id(),
             account_ids,
-            nonces
-                .iter()
-                .map(|x| nssa_core::account::Nonce(*x))
-                .collect(),
+            nonces,
             instruction,
         )
         .expect("Instruction should serialize");
@@ -491,10 +485,7 @@ impl Token<'_> {
         let message = nssa::public_transaction::Message::try_new(
             Program::token().id(),
             account_ids,
-            nonces
-                .iter()
-                .map(|x| nssa_core::account::Nonce(*x))
-                .collect(),
+            nonces,
             instruction,
         )
         .unwrap();