diff --git a/rust/src/trading.rs b/rust/src/trading.rs
index a87797c..20d5f12 100644
--- a/rust/src/trading.rs
+++ b/rust/src/trading.rs
@@ -30,7 +30,7 @@ use bullet_exchange_interface::types::{MarketId, OrderType, Side};
 
 use crate::generated::types::SubmitTxResponse;
 use crate::types::{CallMessage, UserAction};
-use crate::{Client, SDKError, SDKResult, Transaction};
+use crate::{Client, SDKError, SDKResult};
 
 // ── Order construction helpers ──────────────────────────────────────────────
 
@@ -127,8 +127,7 @@ impl Client {
             replace,
             sub_account_index,
         });
-        let signed = Transaction::builder().call_message(call_msg).client(self).build()?;
-        self.send_transaction(&signed).await
+        self.send_call_message(call_msg).await
     }
 
     /// Cancel specific orders on a market. Signs and submits the transaction.
@@ -157,8 +156,7 @@ impl Client {
     ) -> SDKResult<SubmitTxResponse> {
         let call_msg =
             CallMessage::User(UserAction::CancelOrders { market_id, orders, sub_account_index });
-        let signed = Transaction::builder().call_message(call_msg).client(self).build()?;
-        self.send_transaction(&signed).await
+        self.send_call_message(call_msg).await
     }
 
     /// Cancel all orders on a specific market. Signs and submits the transaction.
@@ -175,8 +173,7 @@ impl Client {
     ) -> SDKResult<SubmitTxResponse> {
         let call_msg =
             CallMessage::User(UserAction::CancelMarketOrders { market_id, sub_account_index });
-        let signed = Transaction::builder().call_message(call_msg).client(self).build()?;
-        self.send_transaction(&signed).await
+        self.send_call_message(call_msg).await
     }
 
     /// Cancel all orders across all markets. Signs and submits the transaction.
@@ -191,8 +188,7 @@ impl Client {
         sub_account_index: Option<u8>,
     ) -> SDKResult<SubmitTxResponse> {
         let call_msg = CallMessage::User(UserAction::CancelAllOrders { sub_account_index });
-        let signed = Transaction::builder().call_message(call_msg).client(self).build()?;
-        self.send_transaction(&signed).await
+        self.send_call_message(call_msg).await
     }
 
     // ── Account query convenience methods ─────────────────────────────────
@@ -292,8 +288,7 @@ impl Client {
     ) -> SDKResult<SubmitTxResponse> {
         let call_msg =
             CallMessage::User(UserAction::AmendOrders { market_id, orders, sub_account_index });
-        let signed = Transaction::builder().call_message(call_msg).client(self).build()?;
-        self.send_transaction(&signed).await
+        self.send_call_message(call_msg).await
     }
 }
 
diff --git a/rust/src/transaction_builder.rs b/rust/src/transaction_builder.rs
index b251f86..6172de1 100644
--- a/rust/src/transaction_builder.rs
+++ b/rust/src/transaction_builder.rs
@@ -355,6 +355,35 @@ impl Client {
         Err(self.submit_tx_api_error(error).await?)
     }
 
+    /// Build, sign, and submit a call message, retrying once if the chain hash
+    /// changed since startup (401 invalid signature → schema refresh → re-sign).
+    ///
+    /// Unlike calling `send_transaction` directly, this never returns
+    /// `TransactionOutdated` — the retry is handled internally, and if the
+    /// refreshed hash also fails the error is returned as `ApiError`.
+    pub async fn send_call_message(
+        &self,
+        call_message: CallMessage,
+    ) -> SDKResult<SubmitTxResponse> {
+        let signed =
+            Transaction::builder().call_message(call_message.clone()).client(self).build()?;
+        match self.send_transaction(&signed).await {
+            Err(SDKError::TransactionOutdated) => {
+                // chain hash was refreshed; re-sign with the new hash and retry once.
+                // submit directly so a second 401 comes back as ApiError, not TransactionOutdated
+                let signed =
+                    Transaction::builder().call_message(call_message).client(self).build()?;
+                let body = Transaction::to_base64(&signed)?;
+                match self.client().submit_tx(&SubmitTxRequest { body }).await {
+                    Ok(r) => Ok(r.into_inner()),
+                    Err(ErrorResponse(r)) => Err(SDKError::ApiError(r.into_inner())),
+                    Err(e) => Err(e.into()),
+                }
+            }
+            other => other,
+        }
+    }
+
     async fn submit_tx_api_error(&self, error: ApiErrorResponse) -> SDKResult<SDKError> {
         if error.status == 401 && error.message.contains("Invalid signature") {
             self.update_schema().await?;
diff --git a/wasm/src/transaction_builder.rs b/wasm/src/transaction_builder.rs
index f44d2f6..47b9fb2 100644
--- a/wasm/src/transaction_builder.rs
+++ b/wasm/src/transaction_builder.rs
@@ -480,9 +480,7 @@ impl WasmTradingApi {
         &self,
         msg: WasmCallMessage,
     ) -> WasmResult<crate::generated::WasmSubmitTxResponse> {
-        let signed =
-            RustTransaction::builder().call_message(msg.inner).client(&self.inner).build()?;
-        let resp = self.inner.send_transaction(&signed).await?;
+        let resp = self.inner.send_call_message(msg.inner).await?;
         Ok(crate::generated::WasmSubmitTxResponse(resp))
     }
 }