fix: implement sequence number caching support

cosmpy/aerial/client/__init__.py

@@ -190,6 +190,7 @@ def __init__(
         cfg.validate()
         self._network_config = cfg
         self._gas_strategy: GasStrategy = SimulationGasStrategy(self)
+        self._last_sequence_numbers: Dict[str, Tuple[datetime, int]] = {}
 
         parsed_url = parse_url(cfg.url)
 
@@ -270,6 +271,23 @@ def query_account(self, address: Address) -> Account:
             sequence=account.sequence,
         )
 
+    def get_last_sequence_number(self, address: Address) -> Optional[int]:
+        raw_address = str(address)
+
+        if raw_address not in self._last_sequence_numbers:
+            return  None
+
+        expiry, seq = self._last_sequence_numbers.get(raw_address)
+        if datetime.utcnow() > expiry:
+            del self._last_sequence_numbers[raw_address]
+            return None
+
+        return seq
+
+    def set_last_sequence_number(self, address: Address, sequence: int):
+        expiry = datetime.utcnow() + timedelta(seconds=120)
+        self._last_sequence_numbers[str(address)] = (expiry, sequence)
+
     def query_params(self, subspace: str, key: str) -> Any:
         """Query Prams.
 

cosmpy/aerial/client/utils.py

@@ -48,6 +48,13 @@ def prepare_and_broadcast_basic_transaction(
     if account is None:
         account = client.query_account(sender.address())
 
+        # in cases where the RPC node is slow to update the statement above can return out of date information.
+        cached_seq = client.get_last_sequence_number(sender.address())
+        if cached_seq is not None:
+            if account.sequence < cached_seq:
+                print(f'RPC Endpoint appears out of sync {account.sequence} vs {cached_seq}')
+                account.sequence = cached_seq
+
     if gas_limit is not None:
         # simply build the fee from the provided gas limit
         fee = client.estimate_fee_from_gas(gas_limit)
@@ -76,7 +83,12 @@ def prepare_and_broadcast_basic_transaction(
     tx.sign(sender.signer(), client.network_config.chain_id, account.number)
     tx.complete()
 
-    return client.broadcast_tx(tx)
+    resp =  client.broadcast_tx(tx)
+
+    # store the next sequence number
+    client.set_last_sequence_number(sender.address(), account.sequence + 1)
+
+    return resp
 
 
 def ensure_timedelta(interval: Union[int, float, timedelta]) -> timedelta: